Written by Mike Kojima
Last updated: 04/13/00
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Please Submit your tips! The editors of SE-R.net would like to make our set-up database as large as possible. If you have chassis set up data or reviews of parts that work well for you please submit them to me.
Send your contributions to: Mike Kojima. They will be reviewed by se-r.net editors and posted within one or two weeks.
Welcome to the suspension set up page! We at SE-R.net wish to supply you, the enthusiasts who drive the SE-R, all the correct current information on vehicle set-up to enhance your driving pleasure. Below will be listed some mods and suggestions so you can do your own suspension tuning to adjust your car to your personal driving tastes. Before we go further, lets get the "failure to warn" clause done with. Please read the stuff below in bold carefully. Dont touch your car one bit until you read, agree with and understand this?
Warning: Fast driving on public highways is illegal, dangerous to yourself, innocent bystanders and irresponsible. The recommendations listed below will change the way your vehicle handles from what was the manufactures design intent was. It is possible to change your handling in a way that could be construed as dangerous by some shysters. Please do all of your testing off the highway on a racetrack or sanctioned solo event under controlled circumstances. The editors of SE-R.net are not responsible for anything that could happen to you when modifying your car or even under any circumstances so dont even think of suing us if you f---- up! If you are the suing type and cannot accept responsibility for your own actions, do not ever touch anything on your car and please do not ever come back to se-r.net again.
Oh well, enough of that legal nonsense. We put it there because of Ralph Nader et. al. Well forget him and lets get down to business.
Even though the SE-R is nothing more than a hopped up econo box handicapped with an econo FWD drive train doesnt mean it cannot get down! Nissan has done a pretty good job in making it a well balanced car from the factory. With sticky tires and a few tweeks it can corner with the best of them.
Believe it or not the SE-R can be set up to be nearly neutral in high speed turns and close to neutral in tight turns, even though it is handicapped by FWD and a front heavy weight bias.
In racing SE-Rs in SCCA Showroom Stock , Improved Touring and IMSA Firehawk, I know first hand that these incredible cars can, if properly set up, can out turn almost anything in their class and even things way out of their class. I have a memorable in-car camera video from an SCCA enduro race in which I battled an ex-factory Porsche 935 DP GTX car for many laps. Before I get flamed to another dimension, many list members that have been over to my place have even seen this video. Granted the driver of the car sucked big time, doing almost every wrong trick in the book, (probably some rich doctor in his very first race or something) and he eventually got away from me (on the straights) but this 600+ hp monster never lapped me during my entire 1 hour driving stint. If Hans Stuck was driving that car it would have been over faster that a Bill Clinton sex session but with the poor driver, it was a very fun battle.
Can you imagine the possible conversations that this guy might have had: "How was your first race honey?", "We'll it was really hairy, this Nissan was all over me but my superior piece of German engineering allowed me to blow it off the track after a while". "WOW honey did you race against Steve Millens GT S-1 car at a local event?" "uh no it was a Sentra I think". "What I cant hear you " . I had better quit now. Porsche guys are now preparing their nuclear, flat six cruise missile launchers, targeting my coordinates and the rest of you are going "Yeah right".
Anyway lets forget the bench racing, take off the hip boots, spray some lysol to clear the air, grab some tools and get dirty.
|Understanding Vehicle Dynamics|
Before we start we gotta have an explanation of common vehicle dynamics terms. We had better understand the common ways to describe the different aspects of vehicle dynamics before we even turn a wrench, so here we go: [Diagrams of Oversteer and Understeer]
Because our cars are front heavy, front tire overloaded, front wheel drive cars, does that mean that we are condemned to econobox hell for driving fun? Heck no! By design we can not change the basic layout of our cars to significantly change the PMI or weight distribution (unless Searl comes out with a mid engine, 4wd 200SX soon) but we can sure tweek the slip angles of the tires to achieve world class handling out of our killer econo transportation units.
The easy way to tweek the slip angles are with anti-sway bars and springs. Shock absorbers, going against what people think that they do, are not really for changing the handling balance. Shocks mostly act as spring dampers and affect understeer/oversteer balance mostly only in transient (which is big word for a change from straight line travel to turning) maneuvers like initial turn-in and zig zaging around slalom cones.
Changing to heavier springs changes the slip angle differential by resisting the cars tendency to roll on the end of the car that they are installed on. The resistance of the heavier spring to compression causes more weight to be transferred to the outside wheel of the end of the car that they are installed on as the car tries to lean over in a corner. This causes that wheel to proportionally run at a higher slip angle than it normally would. If you put heavier than stock springs in the rear of your SE-R while not changing the spring rate of the front, the car would tend to understeer less.
Antisway bars work in much the same way. Antisway bars are torsion bars attached to the cars chassis and are linked to the right and left control arms. Antisway bars offer resistance to independent side to side wheel movement. This is how these bars limit sway in the turns and hence their name. While limiting sway, the antisway bars also cause weight transfer to the outside wheels. By altering the diameter of the antisway bars or installing them where there were none before adds yet another chassis tuning element. If you were to increase the size of the rear antisway bar on an SE-R you would be increasing the amount of weight transfer to the outside rear wheel, thus causing it to run a bigger slip angle. This would give you more oversteer.
Tire pressure also can affect the slip angle. Higher pressures reduce the slip angle and lower pressures increase it. A great deal of suspension tuning can be done for free by adjusting the tires pressure.
Alignment also has a great deal of effect on a vehicles handling balance. Caster and camber affect how a tires contact patch is positioned on the ground by compensating for a tires tendency to flex and lift the inside tread while cornering, By helping keep the tread flat, these settings can increase or decrease the available friction circle traction on an end of a car thus affecting balance. Toe in or out can affect balance also by changing how a vehicle turns in.
Here is a rough and general matrix on how different parts and adjustments of the suspension and how the adjustments can affect your cars balance. SE-Rs do not have all of these factors adjustable but an SE-R can be modified to have most of these items adjustable.
You might want to print this table out and put it in your toolbox.
Affect on vehicle balance, extreme useable adjustment limit
Symptom of TOO MUCH adjustment
|Front spring rate increase||More understeer||Terminal understeer, front of car hops in corners, excess wheelspin in FWD car|
|Front spring rate decrease||Less understeer||Too much oversteer, oversteer then understeer if spring is so soft that the car bottoms under lean, car bottom excessively with a jolting ride|
|Rear spring rate increase.||More oversteer||Too much oversteer, hop in corners, twitchy|
|Rear spring rate decrease||Less oversteer||Car understeers, if way to soft car understeers then oversteers as car bottoms out under lean, car bottoms out excessively with a jolting ride|
|Front antisway bar stiffer||More understeer||Terminal understeer, Lifts inside front tire off the ground which can cause massive wheelspin, also not good for most effective tire usage as inside wheel is now doing nothing|
|Front antisway bar softer||Less understeer||Oversteer|
|Rear antisway bar stiffer||More oversteer||Big time oversteer, Can cause the inside rear tie to lift off the ground which is not two bad on a FWD car. On Classics, if this happens while trail braking into a turn, the abs can shut the brakes down which can be a bit scary|
|Rear antisway bar softer||Less oversteer||understeer|
|Front tire pressure higher||Less understeer
Except with BFG R-1 tires. They will grip less and understeer more if the pressures are increased within a reasonable amount.
|No traction as tire is crowned so more understeer, bad wheel spin, jarring ride, center of tires wears out|
|Front tire pressure lower||More understeer
Except with BFG R-1 tires. They will grip more and understeer less if the pressures are decreased within a reasonable amount.
|Edges of tires wear quickly because tire is folding over, feels mushy, tires chunk because low pressure means more heat build up|
|Rear tire pressures higher||Less oversteer
Except with BFG R-1 tires. They will grip less and oversteer more if the pressures are increased within a reasonable amount.
|No traction as tire is crowned so more oversteer, bad wheel spin on RWD cars, jarring ride, center of tire wears out|
|Rear tire pressures lower||More oversteer
Except with BFG R-1 tires.
They will grip more and oversteer less if the pressures are decreased within a reasonable amount.
|Edges of tires wear quickly because tire is folding over and cupping upward, feels loose in back, tires chunk because low pressure means more heat build up|
|More negative camber on front wheels||Less understeer/ -3 degrees||Poor braking, car is road crown sensitive, twitchy, tires wear out on the inside edge|
|Positive camber on front wheels||More understeer, a little can make the tires last a little longer||Poor braking, car is road crown sensitive, twitchy, tires wear out on the outside edge You almost never want to have positive camber unless you are a dweeb|
|More negative camber on rear wheels||Less oversteer, more rear grip, less breakaway warning when limit is exceeded/-3 degrees||More oversteer, car feels twitchy in back, tires wear out on inside edge|
|More positive camber at rear||More oversteer, more forgiving at limit||Car feels twichy in the back, tires wear out on outside edge|
|Ride height to low, rice boy style||Car twitchy with unpredictable dynamics, dont race on when you see it because they will crash, taking you out||Everything that could possibly be wrong, sudden over or understeer, twichy due to bumpsteer|
|Toe-in front||Car is stable while going straight. Turn in is average/1/8 inch total toe-in||Car has slow twichyness under braking, feels odd, kills the outside edge of tires|
|Toe-in rear||car is less likely to suddenly oversteer when throttle is lifted/1/8 inch total toe-in||Weird slow rocking movement in back, feels slow but still unstable, wears the outside edge of tires|
|Toe-out front||Car turns in well, works pretty good in FWD cars as they tend to toe-in under load/1/4 inch total toe out||Car is real twitchy under braking, car is very road crown sensitive, car wanders on straight road, kills inside edge of tires.|
|Toe-out rear||Helps the car rotate, useful on tight low speed courses and slalom events/1/8 inch total toe out||Not to good for street driving, causes lift throttle oversteer, car makes violent side to side rocking motions in rear, tires wear more on insides|
|Positive front caster||Helps both stability, steady state cornering and turn in because the suspension will get more negative camber when the wheel is turned/ 6-7 degrees positive, negative caster is not useable||Can increase understeer, especially in cars with wide, low profile tires due to a non linear increase in corner weight. Increases steering effort, SE-Rs are not easily modified to make this adjustable, FWD cars can see an increase of torque steer with excessive positive caster|
Here are some general basic rules if you want to improve your cars handling:
|Some Suggested Setups|
Below are some suggestions for different sorts of set ups. These are parts combinations and settings that I have had some success with. Beware of my SCCA Street Prepared set -up as I havent looked at the GCR for some years. If I have recommended something Illegal please submit a correction. Also the suspension adjustments are the settings that I would use and what you can use as a baseline. You might need to change these to suite your personal preference. Also some of the alignment specs for SCCA Showroom Stock and Stock Solo II can be fudged if you are willing to take the risk of getting caught. See the poor boy method of adjusting camber. Before anyone flames me for possibly running a big front bar in stock class in a car that understeers, the reason for doing so is that sometimes a big bar alone can reduce understeer! It can do it by reducing roll which reduces negative camber loss under roll, which in turn will keep the wheels flatter on the road giving the tires more grip. This trick has the best chance of working on McPherson strut cars that lean a lot under cornering, just like our cars! The additional understeer caused by the bars weight transfer can be eliminated by adding toe-out in the front and rear. This will handle really crappy on the street with all the toe out, but I have set up a winning FWD D stock cars like that and it worked very well. I guess youll have to do some testing as I am not to interested in Solo II and have not done direct tuning for that on our cars. The stuff I did before was a job assignment! The tire pressures that I have listed are the hot pressure settings. Hot pressure is the pressure once the tire have come up to full operating temperature. Cold pressure is the pressure that the tires will start out at after cold soaking for a few hours or overnight.
Some of you will be disgusted that I even mention this, but do you think its fair that the Neons ACRs can have adjustable camber when regular Neons do not? In my opinion ACRs should be regulated to street prepared where they will get whooped on. By selling out to a factory special interest group the SCCA is allowing legalized cheating by the Mopar camp. Well off the soap box.
You can use the poor boy method to get up to 2 degrees of negative camber. Do it on both the front and rear wheels so it wont be too obvious. Suspension Techniques can re-heat treat your stock springs for a lower ride height. Look at your stock springs before you send them and take note of the color code marks and write them down. Then send your springs off to Suspension Tech. Dont lower the car more than 1.5 inches with the stock spring rate. When you get them back paint the spring the proper shade of semi-gloss and re-apply the color code marks using model paint or paint pens. Then laugh at the tech inspectors and kick some Neon butt. You might not be able to get away with this stuff at the Runoffs in Kansas but for nationals and local races you should have no problem snowing the techs. "Honest sir the car came with these" hahahaha!
Tires that behave differently than typical radial R
Here are some more notes on the Comp TA R-1 tire. As many of you have reminded me much to my disbelief which was caused by my ignorance (thanks list), the comp TA R-1 does not behave like any prior radial tire yet produced. It is an autocross specific tire with negative camber passively built into its construction. It features a super stiff inner sidewall combined with a compliant outer sidewall. The tire is also molded with built in conicity which means that it is kinda like a cone lying on its side. This is like getting molded-in negative camber. These features should make these tires killer in stock class competition and other negative camber challenged applications. The way in which these tires behave differently is that to increase the grip at one end of the car or another when balancing the chassis, is that you decrease the pressure. This is the opposite of what you do to a regular tire to decrease slip angle. The amount of traction gained by decreasing the pressure more than offsets the slip angle increase due to the tires unique construction. These tires seem to like being set in the low 30 psi range. These tires do not like as much static negative camber as conventional radials either usually requiring at least one degree less negative camber. Other than that, these tires will respond like other tires to the other common tuning tweeks.
My set up suggestions for camber and tire pressures will most likely not work on these tires and unfortunately I do not have any hands-on experience with them so I cannot make any good suggestions on what settings works well with them. Maybe other list members can suggest some or, failing that, here is the link to BFGs information page for some qualified tips! [BFG R-1 information]
My ignorance to the BFGs relates to some bad experiences that I had with them, most of which were due to my misapplication of them. I ran them on my SSB Classic to see if autocross tire could work for road racing and had them rapidly chunk in testing, which they were admittedly not designed for. I was pretty unimpressed and never bothered to use them again even though BFG obviously has made strides to improve them since. Oh well, its a good thing that fellow list members spotted my omission and set me right.
The other tire that requires a different setup is the Hoosier Autocrosser. The Hoosiers are unique in that they feature a bias-ply instead of radial construction. Bias-Ply is a tire construction method in which the plies or layers of fabric that make up the tires carcass are laid out in a diagonal cross fashion. This type of construction was popular up to the early 70s for tires until they were replaced with the current radial design. In radial tires the plies run straight across the carcass with circumvential belts on top of them. Radial tires superseded bias plies because they typically have more traction as the stiff belts hold the tread flatter on the ground when cornering. Radials also have less rolling resistance because the opposing plies of the bias -ply tire tend to rub on each other, heating up and causing internal friction.
Well enough of this history lesson. The main difference in the Hoosiers is that they run at large slip angles compared to radials. This means that you will have to turn the steering wheel about ¼ turn more to turn as much as you would with radials. This is a peculiarity of bias ply tires. This will feel very strange at first. Hoosier are very sensitive to overpressuring as the bias ply construction allows the tread to balloon up so you end up running only on the crown of the tire, loosing traction. It helps to have really adjustable suspension to get the most out of these tires because you cannot do as much with pressures as you can with radials.
Hoosiers also do not care for as much negative camber as radials usually liking 1-1/2 degree less negative camber than a radial. The redeeming feature of the Hoosier is its super soft tread compound. These are some of the softest DOT approved tires that I have ever seen!
Personally, I do not like the Hoosiers as they make the car feel unresponsive but that is my opinion. Some people have gone real fast on them.
Stock Class Solo II
Street Prepared Class Solo II, SCCA ITB, Hot Street Car
Normal High Performance Streetcar
|How to adjust your suspension|
The stuff listed above are my baseline settings. These work pretty well for my driving style (as well as most of the good drivers that I have worked with) and preferences. Your preference could be different. To find the optimal settings for your personnel suspension set-up there are a few tricks that you can do to make the process less painful and quicker.
To adjust your suspension you need a just a few simple things.
When at the track, first note your initial settings including the air pressure. Write it all down. Paint a stripe of white out on your tires sidewalls going down to the tread. It helps if you have someone do all these things for you as it gets pretty hectic when you are trying to get ready to run. Go out and drive the car, making mental notes on how it handles, what you like and what you dislike. When you pit or when your run is over, immediately measure your tire temperatures. You only have a few seconds to do this as the temperatures drop quickly. If the course is clockwise, measure the left side of the car first starting with the left front. If it is counterclockwise, measure the right side first starting on the right front. You want to measure the treads temperature in three places, the outside, the middle and the inside. Push the wire of the bead probe slightly into the rubber for the most accurate measurement. Measure all the tires quickly and be sure to write it all down. Next measure and record the tires pressure quickly before the tires have a chance to cool much. Look at the white out stripe that you made. It is there to indicate if your tires are rolling onto the sidewalls. The stripe should not be worn past the rounded corner of the tread- sidewall junction.
Now review your notes and the recorded data. How did you like the way the car handled? Did it push? Was it loose? Was it perfect? Look at your temperature distributions across the tread. Ideally it should be about 10 degrees hotter on the inside than the outside with an even gradient across the tread. This is usually only attainable on a race car with optimized suspension geometry. On a street, production based car that is totally modified for adjustably, even temperatures across the tread may be possible and on a FWD car usually the outside will always be a bit higher. On a stock car you cannot usually get better than a 20 degree gradient. Anyway, the camber and pressures might need some adjustment to get an optimal temperature gradients out of the tires. If the temps are fairly even, it means you are using the whole tread of the tire to its fullest. You also want to get the average temps on the front and rear tires the same. That is not possible with a FWD production based car. A spread of 30-40 degrees is about the best that can be expected with the front tires running hotter than the rears.
Modern R compound tires work the best at temperatures above 180-190 degrees. At temperatures much above 220 degrees, most tires will start to chunk. To know the exact temp that your tire works best, call your tire manufactures tech line for advice. Watch for chunking on the outside edge of the tire, where it is most likely to be a problem with a FWD car. Like I said, play with your air pressures and camber to get the temps right and an even distribution to avoid chunking. Raising the tire pressure will reduce flexing and the tire will run cooler, lowering it will cause the tire to run hotter. Raising the pressure will cause the inside of the tread to run hotter and the edges cooler, lowering will make the outside edges hotter and the inside cooler.
Once you are using all of your tires tread properly, you can play with the balance. Look at the previously displayed chart to see all of the variables. Usually you want to play with swaybar and spring rates to balance the car. Toe settings are useful to get the car to turn in and rotate. Keep on monitoring the tire temps and pressures and note how changes affect the car. (BE SURE TO WRITE ALL CHANGES DOWN AND MAKE ONLY ONE CHANGE AT A TIME) In a few sessions you will be able to have a good grip on how to set your car up (bad pun).
On a stock car, about the only variables you can play with are tire pressures and toe. Adjust your pressures so the temp gradient is as even as possible across the tread. Since your adjustably is limited this will not be possible. Do not add so much pressure that the outside and middle of the tire are at the same temperature. At this point the tire is crowning with a bulge in the middle. This is not using the tire well. Tire pressures can be used to tune the balance. Try 2 psi increments as most good drivers can feel a difference in that. Remember to only adjust one thing at a time! Toe adjustments are very useful on the stock car also. A little front toe-out can help reduce push and get the car to turn in and set quicker. A little rear toe out can get the rear of a pushing car to rotate in tight turns.
If you dont have a pyrometer, then use the white out sidewall stripe method to determine if the tire is rolling over excessively. If you adjust the tire pressure so it is only rolling just to the end of the rounded tread to sidewall juncture, then you are very close to the proper set up. Dont be afraid of adding to much air as I have run up to 55 psi hot on the front tires of heavily understeering Showroom Stock cars with no ill side effects. In fact this is probably safer than allowing the tire to overheat and chunk. Just having the ability to play with the tire pressures at the track can give you a good edge over the typical slalom weekend warrior, at least in the beginners type classes. As you get better, you will have to master the art of suspension setup to remain competitive.
Dont be afraid to ask fast guys for help and advice but take it with a grain of salt. Most of these people are helpful and friendly but every once and a while one of them will see you as a potential threat and will feed you misinformation so you will mess your set up all to hell. If someones advice seems the exact opposite of what I outlined here, be extra careful as this person could be snowing you.
My outline here is not the last word in suspension tuning. It is just meant to help explain things and to be a guide The final element is you. You need to be able to make the car do what you want it to do. Dont be afraid to experiment as long as it is under safe and controlled circumstances. Please experiment to get an idea what different settings do. Set your car wrong and know how that feels. Write everything down. Compare notes. Soon you will become a tweek master! Hopefully these hints will give you the winning edge and help guide your learning process.
So in closing I wish you happy hunting! Please stay safe.
Jay Stewart writes:
After reading the excellent new Suspension Tuning Tips by Mike Kojima, I didn't find any references to camber bolts for tweaking a extra degree or so of negative camber without going to camber plates. I imagine they fall into the "cheat" catagory. Are these considered a "shoemaker" approach, or are they an accepted bit? I got the Specialty Products catalog (800-525-6505), and they have listed an EZ CAM? kit (part # 83450) that allows ± 1°
I've had these F & R now on my XE and now on my NX for over a year now. I have absolutely nothing but good things to say about them. My alignment guy loves them (I see him pretty often, but that's another story). Right now I have been setting the camber at the negative end of the factory specs, and the car handles awesome. I've had the car aligned mebbe 15 times with the bolts, and had the struts on/off/apart probably twice that, and they're built very sturdy, and work well.
I'd say they're one of the best bang for the buck mods I have done so far....
Anthony Harrington writes:
Mike, first I would like to commend you and SCC on doing a GREAT job. Your car is an excellent example of a "Honda Fighter", and SCC has come a LONG way from the hydraulics and crazy paint jobs. I'm writing this letter in regards to your rim size specs. on first generation SR20DE's in the "Suspension Tuning" section. I currently have two NX2K's, of which I run 16x7.5's on both, with 205-45/16. The wheels have a 35mm offset. For springs I am running Intrax 1.75's on one and Eibach's 1.25 on the other with GAB's.I have run this settup for about 3 yrs now and have never had a problem with clearance. Thanks and keep up the excellent work.
Bob Liu writes:
If anyone's interested, there are quite a few good books on suspension handling:
- Fundamentals of Vehicle Dynamics - by Tom Gillespie
- Race Car Vehicle Dynamics - by Milliken & Milliken
- Tune to Win, Race to Win, etc. - by Carroll Smith
- How to Make Your Car Handle - by Fred Puhn (haven't read this book, just heard about it. I THINK I got the name and author correct)
I know there are others such as, How to Make Your Car Handle, Puhn?, Tires, Wheels, and Suspensions, author?.
Here are a few quotes about tire pressures:
Gillespie - "Since inflation pressure increases carcass stiffness but reduces contact length, the net influence on cornering stiffness cannot be generalized across all types of tires. It is generally accepted that increasing inflation pressure results in increasing cornering stiffness for passenger-car tires"
Milliken&Milliken - "grip is not very well understood but, in general, lowering the contact pressure between the rubber tread and the road raises the effective friction coefficient"
Jared Holstein writes:
These are my suspension setup tips, based on the experience I've had setting up the car for street and autox/road course use.
The first time I went autocrossing, the SE-R had its stock suspension. Though I came away with shaved door handles (lots of stock body roll ;) I also came away with a profound respect for the car, as well as its propensity for oversteer! When I moved to C-Street Prepared, I purchased the classic budget-limited combo: Eibach Pro-kits, Tokico HPs, and Suspension Techniques anti-sway bars (as well as a not so budget conscious Stillen upper STB.) This setup was wonderful, not too stiff, and only improved all facets of handling, even oversteering like a Nova :) Alignment specs were set to more or less what Mike suggests, which seems the optimal setup and works great. The only thing that was changed was 1/16" total front toe out rather than 1/8" in the interest of street tire life and road course use. This setup provided nothing but grins, though the slightly lower rear was somewhat aesthetically annoying. While the Tokicos are a great deal at around $85 a piece and are sufficient for street use, I wish I had invested in the GABs. After about 8 mos., the car started to "porpoise" under hard breaking (with race tires) on the track. After this short amount of time, the Tokicos lost their edge, with rebound dampening simply not firm enough.
About two months ago the move was made to the GC coil over setup. Apart from the install hassle, the benefits like ride height adjustability, the variety of available spring rates, and being able to have the car corner weighted were very attractive. I also purchased Custco camber plates (Beautiful!) to give more adjustability up front (I have camber bolts in the rear). My first test drive with the new setup yielded big grins, with unbelievable turn-in due to the camber plates (it feels like you're on race tires.) The new setup, with 300lb/fr and 200lb/rr springs, definately quite a bit stiffer. The prematurely worn Tokicos made themselves apparent with more porpoising under hard braking, and Honda-like bouncing on the freeway :( My advice: Unless your car is only for street use, invest in the GABs, which are better to begin with (and adjustable) and last longer. The main temptation given the adjustability of the GCs is to dump the car, which may look cool, but will adversely effect handling. Our cars do not have much suspension travel to begin with, and lowering the car makes the situation worse. I have found a happy medium close to the 1.25" Eibach Pro-Kit drop, with the car raked slightly forward. Those more adventurous may want to try cutting off and relocating the perch on the strut for more travel.
Tires: Air pressures for racing completely depends on what kind of tire you are running; R1's like fairly low tire pressures (below 30 psi) but Kumhos, for example, need about 42/38 psi fr/rr. R1's are great for camber limited cars like ours (they have a fair amount built in), but if you want to get decent tire wear on Kumhos, quite a bit of negative camber is necessary, for which you need Mike's poor-boy technique or camber plates (better). All these techniques and setups yield great turn-in, great transitioning, and little body roll, but when it comes to absolute grip, nothing makes the difference in steady-state turning like fat, sticky rubber. I had the opportunity to drive an SE-R with stock 130K!! suspension with 205/55-14 R1's back to back with a 200SX SE-R with the full GC setup, bars, etc. with rather sticky 205/50-15 P700Zs on the track. The SE-R with the worn-as-your-Moma's-Crown-Vic suspension still yielded better lap times. Moral: No matter what setup you have, good tires will make a huge difference, and while it might look a bit ghetto to run 14X8" wheels on the street with 225/50-14 R1's, it will allow you to kick (Porsche :) arse on the track.