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FWD Handling Improvements

This article has been put together from various sources while I was researching on how to improve the handling of my Panda, it was not written by me except for some Fiat specific data that was added. Since i saved the data as text I'm not sure on what the sources are so i'll add them on when I find out. Thanks.

These are the things that most effect the handling of a vehicle.

1. Weight of the vehicle and distribution of that weight.
2. Engine placement/motor mount stiffness
3. Frame stiffness, and where the frame is stiffest (front/rear).
4. Spring rates.
5. Shock stiffness and ability to dampen the movement of the springs.
6. Center of gravity of the car, effected by height/length/track width/motor placement/suspension setup
7. Wheel base and track width.
8. Tire width, sidewall height/stiffness, tread compound and wheel size.
9. Alignment, front and rear.  This includes camber, positive or negative, and toe in/out.
10. Suspension design/geometry and swaybars
     

Definitions of a few terms:

Oversteer:  Oversteer is a term referring to the tendency of the rear wheels of the car to "rotate" or "come out" in a corner.  A car that likes to oversteer is often referred to as "tail happy".  RWD cars, and especially rear engine RWD cars, are famous for this.

Lift Throttle Oversteer: Same as the above, but only happens when you let off the gas.  Usually an issue with RWD cars, especially rear engine RWD cars.

Understeer:  The tendency of the front of a car to "push" or "plow".  Basically understeer is when the car won't turn in, due to either inadequate traction, bad alignment, or excessive speed.  If you're going 100mph and try to take a 90 degree corner, and the car slides straight, then your car is understeering.

Four Wheel Drift:  When a car, in a corner, slides all 4 tires equally or nearly so, essentially "drifting" on all 4 tires.

Bumpsteer:  Slight changes in the cars direction as a result of the rebound from hitting a bump at high speed. This is usually caused by the a-arm and the tie rod not being in the proper orientation as the suspension compresses, which actually causes the wheel to turn a little, just like turning the steering wheel, when the suspension moves upward. As the wheel moves up, the a-arm gets effectively shorter, and the tie rod gets effectively longer. You can see how that would cause the wheel to toe-in. You usually don't have this problem unless you start lowering ride height.

Camber: The vertical position of the wheels in the wheel wells in relation to the body.  "Negative camber" means the "top" of the tire is tilted in more toward the body, and the contact patch further away from the body.  Negative camber looks like this, if you're looking at the car from the front:  /-----\
Positive camber looks like this: \-----/
Keep in mind that these are rather extreme examples.  Camber is usually measured in degrees.

Toe: Toe is the relation of the wheel to the body, from front to back, referenced to as toe "in" or "out".  If looking down on the car from the top of the car, toe in would look like this:  /-----\
and toe out would look like this: \-----/
Again these are extreme examples.  This much toe and your tires would be smoking as you drove down the road.  Toe is usually measured in fractions of an inch, though occasionally it is measured in degrees.
 

Swaybars/Anti-roll bars: Bars that work with the suspension to reduce body roll

Damping: The ability of a shock/strut to slow and control the oscillation of the springs as they move to absorb road irregularities.
 

Jounce damping: The ability of a strut/shock to damp compression movements of the suspension.
 

Rebound damping: The ability of a strut/shock to damp the release of the energy stored in the springs after they've absorbed a bump.
 

Fundamental Concepts

    First, some fundamental concepts for you.  The first, and most important, is this:  If you stiffen up the front of the car, the car will tend to understeer more.  The stiffer the rear, the more it will oversteer.  Every modification you do to these cars after you have it balanced to your liking requires something to even it out.  If you add frame bracing in the hatch or trunk area of a car it will want to oversteer more.  So you might add a strut tower bar and urethane swaybar bushings to make it understeer more to even it out.

Another concept is "stiffer is good", within reason.  You want some suspension travel, and you want the springs to be soft enough to take bumps without making the car bumpsteer, while being stiff enough to control the wheels and reduce body roll.  Balance balance balance.  Hammer that into your head, because you won't be happy if the car isn't balanced to your liking.  A poorly balanced car is scary to drive, a precisely balanced car is a joy to take into a corner while scaring the pants off of your passengers.

With that done we'll now look at the top ten items listed above.
 

1.) Weight of the Vehicle

Why does weight matter in cornering?  Simple, the heavier the car is, the more the tires have to fight to keep it from sliding and the more the suspension will tend to let the body roll, affecting control.  A 2400 pound car (with everything else equal) will out handle a 3000 pound car.  This is simple to understand.  The placement of this weight, often effected most by engine placement due to the engine weight and its tendency to shift (discussed more in #2) depends on what part of the car will be the hardest to hold to the road.    You can't do much about this except perhaps to lighten the car a bit, which is always good for cornering  as well as straight line performance.  Weight that is higher up in the car will affect handling more than weight lower in the car.
 

2.) Engine Placement and Motor Mount Stiffness

Engine placement we can do little about, as we're all front engine people.  But, placement of the engine can change how a car handles dramatically due to the weight involved.  In front engine cars the weight tends to be mostly up front, causing the front to be more likely to lose traction first.  Mid-engine cars will grip better overall due to a more even distribution of weight.  Rear engine cars can be tail happy beasts, depending on suspension design and overall weight balance.  A good example are the older Porsche RWD cars, who are famous for lift-throttle oversteer, though in newer cars this has been dialed out somewhat with suspension and alignment changes.

Motor mounts effect us some, since the engine is suspended on rubber to dampen vibration.  The softer the rubber or the more worn the mounts the more the engine can shift in acceleration and cornering.  Stiffen up the mounts and the car will handle and likely launch from a standstill better due to less engine movement.  How much is hard to say.  Motor mounts have a lot more effect on FWD cars for launching than on RWD or AWD cars.  Bad motor mounts are a good way to end up with wheel hop and broken CV joints.
 
 

3.)  Frame Stiffness

Frame stiffness is a big player in handling.  The stiffer the frame, the less the wheels "fold under" from cornering forces, and thus you need less negative camber to start with.  (See #9, Alignment.)  Also, it can play a role in ride quality and controllability.  Unfortunately most frame stiffening measures add weight.  Still, they can be very advantageous, especially on hatchback cars like the Daytona and Shadow.

For example, on my old Laser in its stock form, you could jack up the car on both front corners and one rear corner with the hatch open, and the hatch would be so far out of alignment that you couldn't shut it.  It was so bad that the edges  of the hatch just bounced off the body!  Adding a shock tower brace improved this immensely; it allowed the hatch to close easily when the car is jacked up.  Also it added a good amount of oversteer tendencies due to the increased stiffness and improved the ride as well, since the springs absorb the impact, not the frame flexing.  This was extremely noticeable in my friend's T-top Daytona.  It also stopped most of the creaking from the rear interior panels when going over speed bumps and ramps into driveways.  On the other hand, in my Neon I noticed no real difference at all when I fabricated a rear strut-tower brace, but the Neon is a much stiffer platform than any of the K-car derivatives.

Strut tower bars can also help lessen front frame flex.  On my friend's Spirit R/T, we welded 1/4" steel plate on to the rear axle to improve stiffness.  Rollcages are another way to add frame stiffness (as well as safety) at the cost of functionality of the interior and extra weight.
 
 

4.) Springs

The kind of springs you use on your car has a profound effect on the handling of your car.  Performance springs can also slightly lower the car, giving it a lower center of gravity.  A lot of people take this too far; slamming the car so it rides 1" off the ground and has no suspension travel is a bad idea.  A slight drop helps looks and performance, but lowering is not the only thing that performance springs do.  They also increase spring rates, making the car ride harsher but making the car roll less in the corners.  Don't clamp or cut springs, especially with a torch, if handling is a primary concern for you!  Both of these change the spring rates, usually to slightly different values on each corner of the car, especially with cutting with a torch since the heat tempers the metal, making it harder.  This makes for a funky, bouncy ride that the shocks and struts can't control, destroyed bumpstops, destroyed shock/strut seals from bottoming them out, rattling your teeth from the suspension bottoming out, unpredictable handling, and worst of all, extreme bumpsteer.  A friend's Daytona had spring clamps on it when he bought it and the car would nearly change lanes while going moderately fast on less than perfect roads.  We took them off, and it did much better but the springs were less than perfect from being clamped for so long, and the shocks, well, were terminal.  The bumpstops had been pounded to nonexistence, and the car would go "CLANG!" every time it hit more than a mild dip in the road from the top of the strut impacting the strut mount as the suspension bottomed out.

The 1-1.5" drop of a good set of performance springs, either the MP Road race or autocross springs, or the Eibach spring sets that are available for the non-L-body cars. Eibach springs are available for the Lbodies if you have Ground-Control convert your Koni's to coil-overs.  I personally like Eibach springs for the older cars but avoid them like the plague for newer cars like the Neon, as they're more "drop" springs than performance springs for these models, and the Neon Eibach springs are known to drop the Neon too much for good handling.  Note that while the suspension parts are interchangeable between the P (Shadow/Sundance) and G (Daytona/Laser) bodies, the Eibachs are different.  The Shadow ones lower the rear of the car 1", the Daytona, only .7". I've heard some people say the Shadow/Sundance springs are the ones to get, due to higher spring rates.  A while back I picked up a set of P-body Eibach springs for my '88 Shadow and compared them to my friend's Eibach G-body springs he had just purchased as well.  There are differences; the Daytona springs have one less coil than the Shadow ones do, but  note that this extra coil is in the "progressive" section of the spring.  This seems to make the ride a bit nicer considering the higher spring rates of the non-progressive part of the coil on the Shadow vs. the Daytona springs.  Since my Shadow project had stalled out, I sold these springs to my friend who has a '91 Spirit R/T.  The car rides firm with KYB GR-2 struts in the front and Gas-A-Just shocks in the rear with well-controlled body motions.  His 1986 Daytona CS has the G-body springs with GR-2's all around, and it rides in a very bouncy fashion with, in my opinion at least, poor damping.  I suspect that either the Shadow springs are softer, contrary to what I've heard, or they've revised the GR-2 struts in recent years to have firmer rebound damping.  The Gas-A-Justs are much better than the GR-2 equivalents for shocks, however. 

Mopar also makes springs for both the older turbo cars as well as for Neons.  The springs for the turbo cars aren't very common, and I believe they're no longer available.  For the 1995-1999 Neon, Mopar makes linear performance springs that lower a Neon 1" or so, in both  "High Rate" (225lb/in front, 185lb/in rear) or an "Extra High Rate" (310lb/in front, 230lb/in rear) variations.  Compare this to the stock 150lb/in front and 120lb/in rear, and you can see how much stiffer these are than stock.  Again, the Eibach springs for the Neon are not much more than lowering springs, and lower the Neon too much to maintain good suspension travel.  You spend more time on the bumpstops than anything, don't get these unless you only want the looks of a lowered car.   If that is the case, I don't know why you're reading this!  Note that aftermarket coil-overs are available for the Neon, which have spring rates as high as the 600-700in/lb range, which can be needed on the track to keep a Neon off it's bumpstops.
 
 

5.) Shocks and Struts

Shocks and struts, adjustable or not, vary widely from manufacturer to manufacturer.  Koni, KYB, and Monroe are the three major suppliers that people talk about on our cars.  Gabriel I've heard is to be avoided at all costs.  Bilstein last I heard made a good front strut for the 2.2/2.5L cars, but are nearly as expensive as the Konis, and there are no rear shocks available. 

KYB for a while made "Gas-A-Justs" which were nice and stiff and performance oriented.  Unfortunately, they've discontinued the struts for our cars.  If you want some nice oversteer and don't want to spend a lot of money, purchase some KYB Gas-a-justs for the rear and use plain KYB GR-2's on the front.  The extra stiffness of the rear shocks helps with handling a good margin over the GR-2.  A side note, however, is that some people have claimed that the GR-2 can't control the Eibachs properly.  This is due to the fact that the GR-2 is a "normal" shock not intended for performance, and doesn't have enough rebound damping to properly control them.  As I said above, my friend's Spirit R/T does fine with the GR-2 up front with the Shadow Eibachs, but the G-body springs with GR-2's all around have poor damping.  I'm hoping, since the Spirit R/T's GR-2's are newer than the ones on the Daytona, that KYB has re-valved the struts for better rebound damping in newer GR-2 struts.

For Neons, the KYB GR-2 is a good inexpensive upgrade from the stock struts.  It works well with the Mopar "High Rate" springs, though don't have the damping to handle the Extra-High Rate ones.  They don't, however, have the adjustable camber that the Konis have.

Monroe only really makes the "Sensa-Tracks" for our cars.  These are rather pitiful and soft.  They're good if you want the car to float like a boat, bad if you want performance.  I've seen them on a Daytona; talk about bloopy, though with some miles on them they seem to get somewhat better.

Koni is my personal favorite.  Expensive ($135+ each for struts, $85+ each for shocks, more for L-body cars, about $165 each for Neons) but are high performance, adjustable and rebuildable.  These are the shock/struts to get for one of the older turbo cars if you can afford it and don't mind it being a stiff ride.  For the Neon they were used in the first-generation ACR cars with good success, though you can get some pretty nice coilover kits for them now that will go well beyond aftermarket springs and Konis.  Konis are also known to last longer than conventional units and have a lifetime defects warranty, all of which helps offset the initial cost.  Also note that there are places that will rebuild Konis to have dual adjustability for both jounce and rebound.  Stock Konis are only rebound-adjustable.  They can also custom-valve them for your spring rates and suspension setup, but this can be very pricey.  Many people do this if they're using a "sleeve conversion" kit from a company like Ground Control, where you slide a threaded sleeve over the body of the strut to gain coilover adjustability and a wider selection of spring rates.

Once again, you want stiffer in the back than the front.  Don't go for softer rear shocks than struts.  This will be a nightmare for handling, and it's very difficult to impossible to balance the handling back out; it's better to avoid it in the first place.  I've seen people get Konis struts then use KYB GR-2's in the rears for some reason; I don't know how they can live with the handling.  The Konis are much stiffer than the GR-2s are, even on full soft.

If you like a soft ride you're going to have a hard time finding good handling while keeping that cushy ride.  Konis with stiff springs are not the way to go if you value your luxury car-like ride.  A very good performing car in the corners is next to impossible to keep cushy to the point that Grandma won't complain when you give her a ride to the store.

 
 

6.) Center of Gravity, Ride Height, and Top Heaviness

In general, the lower the center of gravity, the better a car will handle.  A low, flat car  like a Daytona will have an advantage over something like an Omni in this area, which has a relatively tall body, though the L-body has more of it's weight within the wheelbase and a stiffer frame than a G-body, which helps to offset the extra height.  Lowering a car will also effect the center of gravity.  You don't want to do this too much, however, since reduced wheel travel also hurts handling.  1.25" is the most any after market spring I know of lowers a one of the older turbo cars.  Aftermarket Neon springs can drop it up to 2", but at that point you're riding the bumpstops over every dip in the road.  Keep in mind that lowering the car also throws off the alignment of the panhard bar, the diagonal crossbrace on the rear axle on the 2.2/2.5L cars with the solid rear axle.  This can cause some weird wheel well rub by the tires in extreme cornering.  While racing a Mustang with a friend driving my car, we took a long sweeper at about 85-90mph, and the rear passenger side tire rubbed the wheel well loudly. If this was constant and prolonged (like in a road race) you'd run risk of destroying the sidewall.  A stiffer axle can also help counter this, as well as stiffer bushings.  Neons don't have this problem due to the independent rear suspension design they have.  See section #10 for more details on this.

 

7.) Wheel Base and Track Width

It should make sense that the wider and longer the car is, the more stable it is in a corner.  Body roll is less so there is less risk of tipping over.  A long wheelbase also plays a role in drag racing.  A car like a Daytona or Shadow has a wider track width than an Omni, as well as a lower center of gravity due to not being as top heavy.  The Omni however does have an advantage in a longer wheelbase, less weight than most of the K-car derivatives, and a stiffer frame than any of the 2.2/2.5L turbo cars, with the Neon being stiffer than even the Omni.  Obviously there is very little you can do to modify a car's wheelbase or track width, at least without changing wheel offsets and adding wheel spacers, which is tricky since it tends to throw off the suspension geometry, leading to odd handling.  Note that while the body of a car may be wide, the track width can be much narrower!  Most K-car derivatives like the Daytona and Shadow have the same track width.  The minivans, Omni/Charger and Neon have a very different track widths.  The Omni is funny in the way that it feels like it's going to tip over in more extreme cornering, when it actually isn't going to.  "Seat of the pants," as always, isn't the most accurate way to tell how well a car handles.  The Daytona/Laser can lean quite a bit, and you won't feel it nearly as much as in the taller Omni due to the difference in seating position.  The Neon and K-car derivatives have similar track widths, though the wheelbase varies from model to model.  The G and P-body have a 97" wheelbase, the H-body (Lancer) 103", Omni 99", Charger 96.5", AA body (Spirit, Acclaim) 103.5", and Neon, 104", giving it the longest wheelbase of the group, though only marginally over the AA-body.  A car with a long wheelbase will also be easier to control in oversteer situations.  Cars with short wheelbases tend to come around faster than those with long wheelbases, making the rear end harder to catch.  My Laser was vicious that way, especially on gravel, which isn't surprising considering the short 97" wheelbase.
 
 

8.) Wheel Width, Tire Width, Sidewall Height/Stiffness and Tread Compounds

Tires can make a huge difference in the handling of any vehicle.  Cheap, hard, flimsy and easily overheated all season radials will make a car that corners at 1.05g on nice Z-rated rubber handle like your great grandma Bertha on ice skates.  My first set of tires were 195/70R15 "Dayton Daytona" radials.  The sidewalls were weak, the tread hard, and it was an overall crappy tire.  I had these on my Laser for a while even with the Konis and Eibachs on.  The car still handled very well, but there were issues with the sidewalls folding under and lack of grip.  You had to get the car settled on the sidewalls, then set your line through the corner.  When I replaced them, I was putting more wear on the sidewalls than on the tread blocks!

There are many, many different tires out there from different manufacturers.  All have different features, tread patterns, and compounds.  If you're going for handling, of course you want a nice sticky, high performance tire.  A few things to look for in a high performance tire:

• Speed Rating
• Heat/Temperature rating
• Traction Rating

The speed rating defines the "maximum sustained speed" the tire can maintain without failure.  Here's a chart for your reference:


 

 

 
 
Note that most all season tires come in the M through S ratings.  "Performance tires" usually start in the H range and go up to the ZR (W-Y) range.

Traction rating is based off of, oddly enough, not cornering performance, or even dry performance!  Traction ratings are based off of federal tests of straight-line braking performance on wet asphalt and concrete.  The ratings are AA, A, B, or C.  AA is the best, C is the worst.  Keep this in mind when comparing tires; if you live in a wet climate, you want to avoid a C rated tire at all costs!   

Temperature rating is based off of the tires ability to dissipate and resist the generation of heat.  Note that these are only correct when the tire is correctly inflated and not overly worn or under excessive load.  These fall under A, B, and C, A being the best, C being the worst.  Note that people doing dry-hop burnouts on cheap all-season radials with low heat ratings have experienced tire failures even on tires that didn't have many miles on them.  This rating is something you want to pay close attention to, especially if you often drag race on street tires.  Personally I don't like the idea of a tire delaminating on me when I cross the 1/4th mile mark at over 100mph!

Treadwear ratings define how long you can expect the tire to last.  A treadwear rating of 500-700 is relatively high, found in tires with long-life (40,000+ mile) warrantees.  A tire with a 150 rating, for example, will wear 1.5 times as well as a tire with a 100 rating.  The performance tires I've seen range between 180-250 in treadwear ratings, though in recent years I've seen some good high performance tires in the 280-300 range.  This is important since this defines how hard the tread compound is.  The higher the rating, the longer the tire lasts, but the less "sticky" it is.  A tire in the 400+ range can feel a whole lot like plastic, and stick to the road about as well.

Sidewall stiffness is key in handling.  Flimsy sidewalls make the tire feel "bloopy" or "wobbly" in the corners, and hurt rapid turn-in.  The stiffer the sidewall, the crisper the handling, and the quicker the steering response.  A stiff sidewall, however, hurts ride quality, since it lessens the tires ability to dampen bumps.  Many "touring" tires have flimsy sidewalls for this reason.  A tall sidewall is the natural enemy of a stiff sidewall, which is why so many racecars use low profile tires on huge rims.  A stiff sidewall won't help if you put the tire on a rim that's too narrow for it.  Ideally you want a 6-6.5" wide tire for a 205/50R15 for example, though for a 225/50R15 you want 6.5" minimum and preferably more like 7-7.5".  If you put a tire on a rim that's too narrow for it, the tire will tend to "wallow" and fold under.

There are a wide selection of tires out there to choose from.  Personally I avoid all-season radials, preferring to purchase winter tires instead.  Here are comments on some tires myself and friends have tried.

Dunlop SP Sport 8000 (225/50R15 ZR)
A good, solid, well-wearing tire.  Decent in the rain, extremely solid in the corners, good braking, moderate to good acceleration traction.  I killed a pair of these in two weeks with a goofed up toe setting (about 1/2" per wheel).  After fixing this, I rotated them to the front.  They wore well until I had steering rack problems and the alignment went off.  Lasted perhaps 15,000 hard miles, would have lasted at least 30k with a good alignment.  Remember that excessive toe kills tires!

Upside:  Great steering response, okay wet traction, well-wearing for a ZR tire.
Downside: Expensive ($100/tire through www.tirerack.com, though I paid $90/tire).  Traction gets poor as the tread gets down and the tire hardens with age.

Yokohama AVS Intermediates (225/50R15 ZR) (Now Discontinued)
Sticky comes to mind immediately.  These are better in a straight line than the Dunlops.  The tread wear rating, however, is lower at 180.  These tires make "slurping" noises on hot pavement going over seams in the roadway.
Initially, they felt extremely loose and poor-responding.  After 1,000 miles, steering response was almost as good as the Dunlops.  These tires need heat cycles to be at their best!  These tires to wear quickly (as most Yoko performance tires seem to in my limited experience) but are great while they last.  They don't seem to stick as well as far as lateral G's compared to the Dunlops.

Upside: Cheap ($65 from www.tirerack.com) and sticky, great for both straight line and corners.
Downside: Wears quickly (Probably gone in 15,000-20,000 miles tops), not much good in the corners until they've been heat-cycled a few times.  I've heard you can't get these in 225/50R15 sizes any longer as well.

Pirelli P-700-Z (205/50R15 VR) (Now Discontinued)
These tires have been used on my friend's 1985 Omni GLH-T for some time now.  They're quite sticky, wear well, and are very solidly built.  They seem to be somewhat heavy compared to many tires, but they have pretty solid construction, a friend of mine mangled one and kept driving it despite being able to slide a finger under the treadblocks.  The tire never delaminated even at freeway speeds until it was replaced.  The tire has solid steering response, good straight line traction, and was inexpensive.

Upside: Cheap, dependable tire that doesn't come apart easily while offering excellent dry traction.
Downside: Not available in a wide selection of tires (no 225/50R15 or even 205/60R15) so this selection is limited to L-bodies and select S-cars.  These may be heavier than average.
 
Kumho ECSTA Supra 712 (205/50R15 WR)
These are a good, cheap W-rated tire.  They have good treadwear (280) while still being sticky, though not as much as, for example, the old AVS-Intermediate with the 180 treadwear rating.  I had them on my Neon for three summers, they do well on the wet and have firm sidewalls.  They do get noisy as the tread gets lower, and I'd not recommend driving with them in temperatures less than 50 degrees, but that goes for most of the performance tires out there.  These are about to be replaced with a new tire, the Kumho ECSTA SPT KU31, which I've yet to have any experience with.

Upside: Cheap, good wet traction, good dry traction, though you slide around in temperatures below 55 degrees.
Downside: The more the tire wears, the louder it gets, and the more it wants to follow ruts.  Not as sticky as some tires in this list, but better than many.

Cooper Cobra (185/60R14 M+S Rated)
440 treadwear rating.  Good turn-in for a M+S tire, poor traction on acceleration and cornering.  Stiff sidewalls for a tire of this type, but hard as a rock.

Upside: Cheap and good tread wear, stiff sidewalls for this class of tire.
Downside: Poor traction in all situations, M+S rated so no good for high speeds.

Fuzion ZRi (225/50R16 WR)
A good treadwear rating (300) Z-rated tire.  Craig's Spirit R/T has them on it, with no complaints so far.  They're quiet, track well, have excellent turn-in, and have excellent straight-line traction. 

Upside: Good traction, good treadwear, quiet.
Downside: A little more expensive than some, and funky name meant to appeal to rice-boys. (a spinoff of Bridgestone)

Bridgestone Blizzack WS-50 (185/70R14)
Don't touch this tire for anything other than snow/ice driving.  Period.  Poor rain traction, flimsy sidewalls, squirmy treadblocks makes this a put on when you have to, take off as soon as possible winter tire.

Upside: Excellent Snow/Ice traction
Downside: Flimsy sidewalls, poor rainy weather traction, squirmy tread, poor steering response.

Pirelli Winter 210 SnowSport (195/50R15 or 205/50R15 HR)
This is an excellent winter tire for performance driving.  The sidewalls are stiff, the steering response is crisp, and they have a good amount of traction, especially for a snow tire.  They also do well on snow and ice, and are intended for a winter-only tire, not an all-season tire.  These tires easily outdo any of the "all season" tires I've ever seen, both in the dry and in snow and ice.

Upside: Good snow tire and a good performance tire in one.
Downside: Expensive ($92/tire) and come in limited profiles (no 205/60R15 or 225/50R15, only 195/50R15 and 205/50R15)

If you have a tire you'd like a review of here, send me a few lines at teseract@(nospam)arias.net.

 

 (insert pic here)

9.) Alignment

Alignment is very critical in cornering ability.  Most FWD cars come from the factory with positive camber in the front and negative camber in the back.  This is horrible for handling.  Worse, the guys at the alignment shops have been taught that modifying the alignment from factory specs will "wear tires out in a month" or worse.  This is only true if you align it wrong, or you go to too much of an extreme for your driving style.  Be forewarned: They will tell you it'll ruin the tires.  They'll tell you it'll make the car pull left or right, or make the car handle funny.  You'll hear no end of lines of B.S. when you walk into your average shop that does alignments and you ask them to go out of spec.  Keep this in mind, and don't budge from what you want.  If they won't give you what you want, go elsewhere, and make a big huff about it to the manager if at all possible.  If they treat you like crap in this, they'll treat you like crap for other things as well.

That said, let's continue.  Why is the factory alignment in most cars so horrible?  First, let's understand the technical reason of why it is so bad for handling.  The major problem is camber.  Car frames and suspension flex.  In a corner, even a mild one, the wheels will tend to "fold under" on the side of the car facing the outside of the corner due to the side-load being placed on the suspension.  If you have positive camber you have less traction to begin with, since the tire patch is already lessened by the slant inward of the tire, leaving part of the tire off the ground or with less forceful contact.  You go into a corner, the wheels fold under more.  For example (hypothetically) if a car has +.2 degrees of camber in the front going into the corner, depending on the frame stiffness, it might be pushed more positive to the point you might have +.8 degrees or more of positive camber.  This decreases the actual amount of tire contact patch even further.  You end up taking the corner on the outer edge of the tire, not on the tread.  The faster you go or the weaker the frame and/or suspension components, the more they push under, and the less traction the tire has on the pavement. 

The rear tires, having more negative camber, tend to grip more while in a corner.  Why?  Again, the force on the contact patch of the tire is pushing the wheels positive in camber again.  -1 degrees negative camber is the factory limit on most of the 2.2/2.5L turbo FWD Mopars for the rear wheels.  In hard cornering, they fold under, and more rather than less tire patch is in contact with the road.  This makes the rear stick and the front slide, causing the dreaded understeer effect.  With the alignment as bad as the factory ones tend to be, you get a lot of tire squealing and screeching as a warning before the car starts losing a significant amount of grip.  Plus, this bad alignment lowers the ability of the car to take corners quickly.  So instead of 16 year old Johnny taking a corner too fast and nailing the median at 80mph when the tires break loose, the car is handling so bad he's only pushing it at 40mph when he hits.  This has an obvious effect on survivability of accidents when people screw up.

Also, people don't know how to handle oversteer.  Take your average, stereotypical minivan driving Mom.  She's in a rush to pick up Susie from ballet practice since she was busy watching Jerry Springer and lost track of time, so she takes a corner fast to beat a yellow light.  If the car is set up to have the tires scream loudly long before there is any terminal danger, she'll take corners slower for fear of sliding nose-first into something.

Now, set up that minivan's alignment to have a bit of oversteer and grip better.  She's taking the corners 15mph faster, and whoops, the tail end steps out on her.  What does she do?  Panics and nails the brakes!  Sccrrreeeeccch, BANG!  360's across the intersection, wraps her minivan around a light pole, leaving her kids to walk home in the dark.  Does she accept it as her fault?  Hell no!  The minivan did it, not her.  "I was just taking the corner and the car just spun all of a sudden!" she'll sob to her lawyers, and next thing you know, Ma Mopar is in for a 10 million dollar lawsuit and is on 60 minutes for having "uncontrollable cars"! 

Think it wouldn't happen?  The State of California sued Porsche for it's 1980 911 Turbo, because people complained so much that it was "uncontrollable" since they didn't know how to deal with lift throttle oversteer that most rear drive, rear engine cars tend to have. SUVs, Trucks, and Vans tend to use bad alignments a lot as well.  Otherwise, these top heavy vehicles would have a greater tendancy to roll over in the corners instead of sliding.

So, you're not the average driver, I'm hoping, if you're here.  Are you ready to step outside the factory limits and improve the alignment of your car?  OK then.  First of all, chuck the factory alignment.  If you're going to do a bunch of modifications to the cars suspension, do that before you get the alignment, for obvious reasons.  Every modification to the car changes how it handles a bit, making it more or less controllable, making it understeer or oversteer more, and decreases or increases body roll.  If you align it first then add bigger sway bars, urethane bushings, etc., you'll likely be less happy with how it handles.  Changing a car from the factory suspension requires balance.  The alignment is the final touch to a well set up car, meant to balance it to perfection.  How you want a car to handle depends on your driving style.  I prefer a tad bit of oversteer in hard cornering, leaning toward neutral.  If you autocross a lot, you might want a lot of oversteer.  If you're uncertain of your reflexes, or don't know how to counter oversteer, you'll want a neutral to slightly understeering car.  A lot of people are most comfortable with a car set up for a bit of understeer or four wheel drift tendencies, since that's what they're used to.  If you give up your oversteer, the car loses it's ability to a degree to take tight corners quickly.  If you don't know how to control oversteer, you'll lose it and spin out.  If you do a bit of understeer, in high speeds the car will push, and you'll lose a bit of control (if you're lucky) to all of your control if you really screw up, then slide into a guardrail or worse.  This is why I like a bit of oversteer, if nothing else, you can countersteer out of it if you're quick and precise and don't panic.  I don't claim to be fantastic at it, I'm perhaps an average driver, but that's how I like the car to handle.  For this reason, I'll give a few general good alignment tips.  What you pick depends on you, your car, your driving style, and of course, tire wear.  I'd always plan for a car that oversteers some at 0 camber on all 4 wheels.  This gives you room to play with, it's a lot easier to get a car to understeer with alignment changes than oversteer.  In my experience it's pretty easy to achieve this in a FWD Mopar if you know what to do.

Any 2.2/2.5L Turbo Mopar should have adjustable front camber.  With most Neons and many other cars, the camber may or may no be "frozen".  If you're stuck with this, you can do a couple different things.  On my Neon I've used "Crash bolts" (Mopar P/N 4762135 for the fronts, I'd not touch the rears since it's so hard to get them even).  These are little more than slightly skinnier bolts than stock, which gives you some play in the holes to allow about 1 degree positive or negative camber.  I did this on my Neon with good success, though I'd like a bit more to counter the stock -1 degrees of camber.  This isn't good for if you like hitting curbs though, since they have a slightly higher tendancy to "slip" than stock bolts under impacts.  Autocrossers put some paint on the strut before tightening the bolt down to "glue" it down and give it more hold.  This is also handy since it shows you if it's slipped.  Another method is using a die grinder to grind the hole in the strut into a slot.  Or, better yet, get Konis which come with adjustable camber (unless they're OEM ACR struts, which are black-painted Konis without the adjustable camber).  Or you can go all-out and get camber plates, which allow the greatest range of available settings.  If you do get camber plates on a Neon, don't bother with the rears unless you like cutting sheet metal.  Most of the aftermarket ones require modification in the rear to make them fit, and the -1 in the rear is a good amount for most handling setups short of an all-out race car.  If you're going for camber plates, though, you might as well go with a full coilover suspension for a Neon in my opinion, since you'll have more adjustability that way.
 

Most older Mopar turbo cars have a solid rear axle and use shims behind the spindles to adjust the camber/toe.  Alignment guys hate these, so be forewarned, and make sure they understand exactly what you want so they don't have to do it twice.  Usually they don't complain about negative in the rear since up to -1 is in spec for our cars generally.  Make sure they're accurate though, one guy I took my car to had one at -.6 and the other at -1, and said, "Well, it's in spec!" even though the car pulled right.  The Neon uses adjusters built into the rear control arms which are easier to adjust than taking the whole brake assembly off like on the turbo cars. 
 

First, my favorite, neutral with a bit of oversteer.  For this, you need a car that has a bit of a tendency to oversteer already by following the tips above.  It's simple, really.  If you corner hard a lot, like I do, you'll want some greater than average amount of negative camber.  If you drive more mildly, and are worried about wearing the inside of the tire, go for less, say 30-40% less on all 4 wheels for this particular type of alignment.  On my '85 Laser, even with only a few mods, this worked well:

Front: -1.4 degrees, 1/16" toe in (you can go 1/16" toe out, but you'll hurt straight line stability)
Rear: -1 degree, zero toe

A more "mild" alignment, in this case, might be -.9 in front with -.5 in the rear.

Note: I can only vouch for the alignment specs I've tried on my car, the rest I'm "guesstimating".  Again, use your judgment for your own car!

Next, the "Extreme oversteer" solution.  Use this only if you autocross or drive lots of tight, sharp twisties a lot and _know_ how to manage that ass end coming out!

Front: As much as you can get (-1.6 is as much as you can get out of Konis/Eibachs from what I've seen), 0 toe
Rear: -.5 or approximately 65% less than the fronts.  If you really like oversteer, go for 0 in the back.  I know some autocross guys actually remove their front sway bars to get more oversteer.  Adjustable shocks, mentioned above, really come in handy for tuning this kind of thing.  -1.5 in front should be plenty for street driving, I've found -1.4 to be about perfect for balancing tire wear and handling on my car.  -1.6 wore the inside of the tire a bit.

Then we have the "4 wheel drift" solution.  This one will likely take an alignment or two of fine tuning to get exactly right for your car:

Front: -1.1 , 1/16" toe in
Rear: -1, zero toe.

For "Slight Understeer".  Again, fine tune:

Front: -.7, 1/16" toe out
Rear: -1, zero toe.

I'm pretty sure no one wants extreme understeer.  At this point, I'm sure you can guess the logic of picking alignment specs.  More rear negative camber than the front, more understeer.  Less negative camber in the back, the more it will oversteer.  Having the same camber on all 4 wheels generally doesn't work, the frame stiffness isn't the same front to back, plus most FWD front engine cars have more weight in the front than the rear.  Thus it takes more to make the front end "stick".  If you want a less extreme amount of camber, you can go for less, as long as you do it _equally_ all the way around the car.  Just don't go positive if you can avoid it!  Even -.8 on my Laser in the front resulted in tire wear on the outside of the tire more than the inside, and corner harder than most people as well.  On my Neon, -1 was a bit too much for winter driving on my Blizzack tires, and there was slightly more wear on the inside than the outside.  In an ideal world you could tailor your alignment to the seasons, but oh well.
 
By following these general guidelines, you can set up your car to handle the way you want it to, even if it means a few trips to the alignment shop and some stubborn behavior on your part when it comes to dealing with the alignment techs.

 

10.) Suspension Design, Geometry, and Swaybars
 

There are many different kind of suspension setups on both FWD and RWD vehicles.  We will of course focus on the FWD vehicles in this article.  First, the different types of suspension for the different cars we'll be speaking of:

K-Car Derivatives (Daytona, Shadow, Spirit/Acclaim, etc.):
MacPherson strut front suspension with either stamped control arms with a "stub strut" rear bushing (1984-1989)  or cast aluminum or steel arms with a "hinged" rear bushing (1990-1994).  Note that the cars with the 11" front brakes have revised spindles to change the roll center of the car, improving handling.  Rear suspension is standard solid-beam semi-independent setup with springs mounted inboard of shocks with a locating panhard bar.  There is no stock rear swaybar on any of these cars, instead it uses a "stiffener" bar built into the "U" shape of the rear axle.  Front swaybars vary in size from 7/8" all the way up to 1-1/4" diameter.  The "Sportier" cars like the Daytona CS, Daytona Shelby, Spirit R/T, and Lebaron GTC cars generally had the larger bar.  Most came with the 1-1/8" bar.  Rear bars are available in the aftermarket, in both 1-1/8" sizes and 1-/14" sizes, from Polybushings.com,

L-body cars (Omni, Charger, etc.):
Similar MacPherson strut front suspension, only available with stamped steel front arms with the stub-strut style rear bushing.  The rear suspension is still solid beam axle, with the GLH and GLHS cars getting stiffer versions.  The rears ride on struts instead of the separate spring/shock combination the K-car derivatives use.  The rear axle is still located by panhard bar.  Front swaybars also varied in diameter, the GLH versions getting the thicker swaybars.  Rear aftermarket bars are available, in 1" and 1-1/8" sizes from Polybushings.com.

Neon:
Front MacPherson strut design.  Cast aluminum front control arms in the first generation neons and steel for the rear, stamped steel all around for second generation.  Uses a stub strut bushing for the front controll arms rear mount, though it differs from the style used on the earlier suspensions of the above cars.  The bushing mounts so the bolt goes through it vertically, instead of horizontally at an angle like the earlier cars.  While not as good as a hinged design, it does take less space and offers advantages over the earlier stub strut bushings.  The rear suspension is a complete departure from the earlier cars, with a multi-link fully independent rear suspension design riding on struts at all four corners.  Depending on trim level, there may or may not be a rear swaybar.  Stock diameter for the 1995-1999 Neon if you have one is 16mm, though there are many aftermarket replacements and adding a bar is as simple as adding a little hardware if you don't have one.  Mopar Performance actually offered the hardware as a kit, under Part Number P5007279.  They also offered other front and rear sized bars for purchase, the largest being a 22mm front and rear bar.  Early 22mm rear bars were adjustable, the newer ones aren't.  Most of these stemmed from the Neon's successes in SCCA racing, both road race and autocross. 
The second generation Neon has fewer options from Ma Mopar, though if you have a rear bar, the stock rear bar is still 16mm unless you find one of the (rare) ACR versions with the 19mm rear bar.  I've heard rumors that some of the second gens don't have the mounting points for the rear bar like all first gen Neons did, but this is unconfirmed.  The second generation Neon does have an advantage in compression/jounce travel, resulting in less need for stiff springs to keep it off the bump stops.  The SRT-4 is a different animal, and one I have little experience with, but still shares the standard MacPherson strut front/multilink strut rear that all other Neons have and has many things in common with the standard second generation Neon suspension.

Front Suspension: MacPherson Strut Vs. Double A-arm, Vs. Double Wishbone Suspension

The MacPherson strut is a compact, cost effective method of designing a front suspension.  It consists of a strut with the spring mounted over it, which bolts to a steering knuckle that bolts to the control arm with a single balljoint.  The strut itself is the load-bearing part of the suspension, which twists with the wheel when turning.  It has good strength, camber and toe control while being relatively inexpensive.  The double A-arm suspension is quite different.  Two control arms, an upper and a lower, are the load bearing members in the system, both shaped like an "A".  There are two ball joints which allows the wheel to swivel around the A-arms.  A coilover shock generally bolts to the lower A-arm then to the body.  This design has better camber control than the MacPherson strut design, while being more complex and thus more expensive.  The Double-Wishbone suspension is even more complex, offering better camber/toe control than either of the above, and taking up less space under the car.  All of the cars dealt with in this article have a MacPherson strut front design. 

Rear Suspension: Independent Vs. Semi-independent Beam Suspension

Solid Beam Axle:

All of the 1983-1994 K-Car based cars as well as L-body based cars come with a beam-style solid rear axle.  This is mounted to the body with two trailing arms, and the the wheels mount on the ends of the beam.  A panhard beam bolts from the axle diagonally up to the body, keeping the axle centered while cornering. 

Advantages: This is a relatively inexpensive rear suspension that also takes up less space than an independent rear suspension, and allows a lower, more flat loading area for cars like hatchbacks and minivans.  This is why the PT Cruiser, while being based on the Neon chassis, has a beam rear axle instead of the independent setup the Neon has. 

Disadvantages:  Lowering the car makes the panhard bar too long, pushing the suspension out of alignment, leading to tire rub while cornering.  Often times the panhard bar and/or the mounting point of it to the body isn't strong enough to handle the increased cornering stresses, which can lead to tire rub as well due to the axle shifting out of alignment due to the side-load forces.  The trailing arms (rather weak in themselves on our cars) mount to the body with bushings, which also deflect and lead to miss-alignment of the rear axle under cornering stresses.  Exhaust routing room is also reduced, since you have to wiggle a big pipe between the body and the rear suspension, especially around the panhard bar, at least the 2.2/2.5L cars.  Also, since the wheels are mounted to a solid beam, any impact that one wheel takes is transferred into the other wheel to a greater or lesser degree.  This can lead to bumpsteer, making the rear end "hop" over mid-corner bumps, and an overall more choppy ride than an independent suspension offers in most cases.  Also, you can't do custom suspension like you can with coilovers since the spring and shock are separate.  The L-body is an exception since it uses struts in the rear instead of a separate spring and shock, though to my knowledge nothing off the shelf exists for the L-body for this application, though supposedly Ground Control can convert them.

You can help solve these problems by stiffening the panhard bar and making it adjustable to locate the rear suspension properly when lowering the ride height, and making it stiffer.  You can also stiffen the panhard bar mount on the body to reduce deflection.  You can replace the bushings with stiffer ones (Polybushings.com makes replacements for many of our cars).  You can add an aftermarket swaybar which mounts to the body as well as to the axle, which will help keep it located as well as offering better body roll control.

Independent Rear:

All Neons come with an independent rear suspension.  This consists of four steel links (stamped steel in 2000+ models) that bolt to the body in the center of the car, which then bolt to the struts and spindles on each side of the car.  There's a front link that bolts to the spindle as well to better control front to back movement of the suspension.  Click Here for a picture showing this (from the Sport Compact Car Magazine web site).  Each wheel has a full range of independent motion.

Advantages:
Less unsprung weight compared to beam-axle style suspensions.  There are no problems with side-to-side flexing as with a beam-style rear axle, as the control arms mount rigidly to the frame, the only flex coming from the bushings. This, in my opinion at least, is the biggest advantage over a solid rear axle.  If one wheel hits a bump or other road imperfection the other wheel isn't affected.  The ride tends to be smoother as well, since a jolt doesn't travel through the entire rear suspension.  Roadholding is increased in this manner as well, as the jolt from one wheel hitting a bump doesn't cause the other wheel to react as well, avoiding the possibly of the opposite tire breaking traction due to an upset on the other side of the car.  This is especially true when driving at the limits of tire adhesion.  Note that in most cases the average driver will never notice the difference, though an enthusiast may.  Driving down a rough road near my home in my old Laser would make the rear end hop around more, especially on mid corner bumps.  Though by no means enough to cause me a big problem, driving the same road in my Neon makes the rear end feel more "planted" over bumps.  Also, as there is no panhard bar, you can lower the car without worrying about disrupting the side to side geometry of the rear suspension.  Exhaust routing is simpler since there's fewer bars going this way and that in the path of the exhaust.  Plus there are many options for full coilover suspension systems for the Neon, giving you full control over ride height and a much wider selection of spring rates and damper adjustability.

Disadvantages:
Cost.  There are more pieces involved, not to mention about four times as many bushings as used in most solid axle suspension systems.  This is a major downside for manufacturers.  Also, it takes up more space under the floor of the car, reducing available trunk space and sometimes passenger space as well.  On the first generation Neon in particular there isn't as much jounce travel, making the car more likely to bottom out on harsh bumps.  Lowering a first generation Neon more than an inch without coilovers can reduce your jounce travel to next to nothing.  The second generation Neon has more jounce travel, but also gains 200-250lbs depending on trim level, and uses cast instead of solid steel control arms like the first generation Neon.  Many cars including the Neon have very soft suspension bushings to reduce noise.  This results in a lot of flexing in the many bushings that make up an independent suspension, more so than the lesser number of bushings in a beam-style rear suspension.  This requires replacing many more bushings than the ones in a solid rear axle.  This is bad enough in the SRT-4 to make the rear end "hop" under heavy braking, as the bushings store up energy then rebound like a spring.  So, for either type of suspension, you're going to be replacing bushings, both in the front end and in the rear.

If you wish to see more about the many types of suspension layouts, you might want to visit The Suspension Bible, it goes into much more detail than is within the scope of this article and also includes illustrations of the different types.

Swaybars: What They Are And What They Do

Swaybars, or anti-roll bars, are simply a bar usually made out of spring steel that bolts to both the body and to each wheel in the suspension on the front and back of a vehicle.  Without swaybars, especially on cars with fully independent suspension systems, a car would heave over like a sailboat caught in a strong wind every time you took a corner unless you had monstrous spring rates.

Simply put, swaybars link the wheels on each side of the car to one another to counter roll.  This works by mounting the bar to the suspension so that when the car starts to roll it pushes against the spring steel bar that is linking that wheel to the wheel on the opposite side of the car.  This transfers some of the load to the opposite wheel of the car and to the body, fighting the tendancy of the car to want to roll in the direction of the outside of the corner.  This reduces the independent action of the wheels as well as adding to the effective spring rate making ride quality harsher.  This means most cars come with rather skinny swaybars, and many come with no rear swaybar at all in the interest of comfort and cost savings.  Solid beam rear axle equipped cars generally come with no swaybar at all on the rear, relying on the stiffness of the axle that links the two wheels to act like one big swaybar.  The lower trim level Neons have no rear bar in the interest of cost as well as ride quality.  Here's a picture of a typical set of aftermarket swaybars for a Neon:

 

The top bar is the rear bar, the lower is the front bar.  Bars can be hollow or solid.  Usually there is little difference in stiffness between the solid and hollow bars, the main difference being weight.  Bars can also be adjustable, with softer and stiffer settings that let you tune the amount of body roll you want on the front or rear.  They also use many different types of mounting hardware, though the most common is end links, similar to the below picture:

 

Copyright Nelson 2004-2009, no part of this page can be used without the author's permission.
Last revised: 2009-11-15.