SE-R Suspension Tuning Tips

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.

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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. Don’t 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 don’t 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 doesn’t 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-R’s 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 Millen’s GT S-1 car at a local event?" "uh no it was a Sentra I think".  "What I can’t 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.

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]

• Friction circle: This is basically a vehicles performance envelope. It's expressed in lateral G’s, accelerating and braking G’s. When graphed, the friction circle looks like an egg with the X axis lateral G’s and the Y access braking and accelerating G’s.
• Understeer: This is when, at the limit of vehicle traction, the front of the car slides first before the rear. Race car drivers call this "push". This is the way that many cars come set up to behave from the factory as it is the most predictable for average drivers. The crash mode for understeer is that when the limit of adhesion is exceeded, the car will plow strait ahead off the road nose first. This is not the fast way to have your car set up but if you are a dork mode driver. When the car understeers you should regain control if you let off the gas, unless of course you run out of road first. That is what air bags are for. Even my uncoordinated evil twin sister could get that right, maybe. It is not efficient for extracting maximum lateral G’s because the car will dynamically use the front tires excessively for turning, overloading them while the rear tires basically just hold the back of the car up. Front wheel drive cars like ours tend to exhibit understeer as the final terminal mode of balance.
• Oversteer: This is when, at the limit of vehicle traction, the rear of the car slides first before the front. Race car drivers call this "loose". The rest of us call this "spinning out", "spinning a shitty", "doing a brodie" or even crashing. The final crash mode of oversteer is backwards, tail first into the woods or in the worst case spinning round and round with the driver as a helpless passenger. Since the infamous days of Ralph Nader and the Corvair, most auto manufactures avoid oversteer like the plague. Oversteer is difficult for a dork to handle because recovery requires judicious use of countersteering and throttle feathering to control; fine motor skills that only some of us can deal with. Although oversteer looks neat and macho it is really a slow way to drive except in pro-rally on the dirt which I don’t know too much about. Oversteer is slow on the pavement because hanging the tail out bleeds off a great deal of speed going through a corner. Conserving the momentum is the fast way around as turn.
• Neutral: This is the fast way around a turn where all four wheels slide evenly. Since the total friction circle traction of each tire is being used, all the available grip that the tires have is being put to the ground. Racers call this "drifting". This not to be mistaken for the idiotic Japanese Option Magazine video stuff which makes a mockery of proper driving technique. Neutral is the fast way around a corner most of the time. Neutral is also the hardest handling mode to achieve for the suspension tuner.
• Polar Moment of Inertia: Or PMI as we will refer to it, is a description of how a cars mass is distributed along the length of the vehicle. A car with a high PMI is like a rear engine, rear drive car like a Porsche 911 or a front engine, front wheel drive car like our beloved SE-R, same thing only the poles are different, so to speak. A car with a low PMI would be a mid engine car like a Boxster. Low PMI cars have most of their mass about the middle, high PMI cars have the mass at one end or another. Low PMI cars are the easiest to get a neutral balance out of due to the balanced, centralized mass. High PMI cars like to oversteer, in the case of the 911 or understeer like our cars. To get a feel for this phenomena, hold a bowling ball in one hand and rotate it back and forth by twisting your wrist. Now get a set of dumbbells of the same weight, grab the middle of the bar and do the same thing. Bet the bowling ball wants to rotate easier right? Guess what type of car will be easier to get neutral!
• Slip Angle: This is the wonderful thing that allows us to tune our cars suspensions despite the design limitations caused by the PMI. Proper manipulation of slip angle is the great equalizer and is what suspension tuning is all about. Slip angle is the difference in which a cars wheels are pointed vs the angle that the tires contact patch is placed on the road. The main thing that affects slip angle is the manipulation of the individual load placed on each wheel while cornering. This is the key for suspension tuning. A front wheel drive car has most of the weight on the front wheels. So the front wheels run at higher slip angles and develop understeer. Conversly the same for a rear wheel drive, rear engine car developing oversteer. That is also a reason why a mid engine car with equally loaded tires will be more or less neutral. Slip angles, weight distribution and PMI are the main factors in how a vehicle will handle.

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-R’s 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.

Here are some general basic rules if you want to improve your cars handling:

• If you race in sanctioned competition, read your rule book before performing any modifications at all to your vehicle. It would be a pity to buy a fortune in trick parts only to have them declared illegal by an official. Beware of SCCA’s Street Prepared rules as many hot and popular street car mods would put you out of this class.

• Do not lower your car too much! This perhaps is the number one no no. It is a symbol of a true rice-boy (not a racial slur, means all show no go, typical car that has $5000 bucks of wheels and tires, a big 5 inch tip, aero kit, a thumping stereo, vinyl graphics, no springs and not much else). Lowering looks really cool and can make a significant improvement to a cars cornering capability but going too low is detrimental to both handling and even safety. Going too low can cause bumpsteer, where the tie rods and control arms are traveling different arcs resulting in the wheels steering themselves with no steering wheel input. When a car is so low that the suspension bottoms under cornering loads, the end of the car that bottoms first will violently slide out. Super low guys are convinced that they are driving super touring cars but if you take them out on the track they will suck incredibly. Our SE-Rs are cursed with short travel suspension as it is and cannot take being lowered more than 1.5-2 inches at the most. So install some good springs such as Eibach, H&R or Ground Control and DO NOT CUT THEM MORE TO MAKE YOUR CAR LOWER. If you have the Ground Control springs do not adjust them to lower your car more than two inches except if you are going to compete in car shows where the car will be a stationary display. You want to maintain at least 1-3/4" of travel.

• Buy and install matched components from a single manufacture. For instance do not put H&R front springs in with Eibach rear or a Suspension Techniques front bar with a TMC rear. Suspension manufactures usually offer these parts as a tuned set with rates, etc. made to match each other. So unless you really know what you are doing don’t mix and match. Good stuff for our cars is made by Eibach, H&R, Suspension Techniques, Ground Control and Stillen.

• If you are using high performance springs, try to wait until you can afford the shocks also. Performance springs store more potential energy when they are compressed. They need a shock with more rebound damping to keep the car from bouncing all over the place after you hit a bump. Really good shocks like Koni or GAB’s are adjustable so you can tune your shocks to the springs. Performance springs with stock shocks usually feel floaty on high speed undulations. I find that that feels a little spooky. Performance spring’s quicker rebound characteristics also seems to wear out stock shocks quickly making them get super floaty. I prefer GAB’s because of their easy adjustably (Koni’s require removal from the car to adjust them) and durability. In IMSA racing other brands of shocks would be shot after one race. GAB’s would last a whole season. Tokico’s are inexpensive but don’t last as long. They also seem to have too much compression damping and not enough rebound in my opinion so they are harsh but floaty.

• Limiting body roll is good. Our SE-R’s sit high, and have fairly soft springs from the factory. They roll almost as bad as French cars. Install stiff springs and swaybars with matching shocks, and lower the car to a reasonable level. Limiting roll keeps the weight from transferring excessively, allowing the inside tires to work more in a turn. Limiting roll also helps keep the car from bottoming in a turn and keeps the car out of the bumpsteer zone. McPherson strut cars like ours do not gain negative camber under roll either so limiting roll helps keep the tires from folding over.

• Having adjustably is good. Having the ability to adjust shocks, camber and toe is very useful when trying to extract G’s from your car. On a showroom stock racer I was working on, optimizing the alignment and tire pressures alone made the car go from 0.79 to 0.86 g’s on the skidpad and 3 seconds a lap faster at Willow Springs. As front camber is not adjustable on our cars it is important to make it so. Stillen and Ground Control make high quality camber plates. These will slightly harshen your ride but will sharpen turn in due to the elimination of squishy rubber with metal bearings. Rear camber adjustably is not critical on most FWD cars. To make poor boy adjustable camber, you can drill out one of the two strut to spindle bolt holes on the strut housing by about 1/16" This will get you a couple of degrees of camber adjustment. If you are racing Solo II stock class or Showroom stock and don’t want to cheat, you can get about ½ degree more negative camber by loosening all of the suspension bolts and having someone hold the wheel in the negative position while you retighten everything. No one currently makes an adjustable set of antisway bars for our cars but Ground Control can make you some custom ones if you are willing to send them your car for a few weeks. In fact, it would be no problem for just about any decent race shop to whip some up.

• Align your suspension and optimize your tire pressures. In the previous paragraph, I said that alignment and tire pressures can make a huge difference. IT IS TRUE! If you are poor, you can still make big improvements in your cars grip by just playing with tires pressures and the car’s alignment. Try the poor boy technique and dial in some front negative camber, increase the front tire pressure, decrease the rear and set your toe. Boy will you see a difference. Try to find a place that does racing alignments near your house as alignment is where people really get ripped off as it is almost never done correctly. Most hacks just throw a car on the rack and if it falls somewhere within in the wide factory specs, don’t touch a thing. What you need is a blueprint type alignment where the suspension is adjusted exactly to spec. Most repair shop dorks don’t understand this and will argue and tell you that that is not necessary. A race prep shop will understand. When your car is aligned, it should be done with your weight in the drivers seat and with the technician bouncing the car after every adjustment to settle the suspension. Set your tire pressure before you take the car in. Remember that you must realign the car if you lower it!

• In my opinion, the Ground Control Spring kit works wonders. This is the biggest single difference of any bit of aftermarket parts out. One of the design problems that the SE-R has is that the struts really lack very much wheel travel. When lowered our poor cars typically have less than an inch of travel. This lack of travel can result in bottoming in a turn. When the car bottoms in a turn the wheels spring rate essentially becomes infinitely stiff causing a massive slip angle at the end of the car that bottoms resulting in instantaneous, massive under or oversteer. This condition can cause a reduction in one’s life expectancy and soiling of one’s clothes. Even street oriented aftermarket springs are not stiff enough to insure that this won’t happen under all conditions. Furthermore, the aftermarket street springs are mostly meant for street use and are only about 20-30 percent stiffer than stock which is not stiff enough to prevent bottoming if the car is lowered in the 2 inch range. The Ground Control springs are available all the way up to 600 inch pounds which is way stiff. I recommend the 300 in/lb front with a 200 in/lb rear spring. This works pretty well even on the street as it is about 100% stiffer than stock. The ride is even better that regular street type high performance springs in some cases. The car takes big bumps like railroad tracks and chuck holes better as the suspension does not bottom out as hard or at all. The suspension is stiffer on little things like ripple bumps, botts dots and tar strips but is still not bad. Body roll is just about eliminated and the handling is very predictable. The ride height is also adjustable with these shocks. You can be true Mr. performance one day and a low riding rice boy the next. Remember, when you change the ride height your alignment will change and you have to at least reset the toe when you raise or lower the car as it will get thrown off by the change. Some list members have complained of clunking noises made by GC springs. Remember that this is a full race type item that can be run on the street so it is devoid of all the rubber isolators and stuff that your stock springs have, thus some noise like clunks and squeaks is to be expected. If you are a squeak and rattle freak than these springs are not for you as they are definitely more noisy than stock. The noise can be mostly eliminated by proper installation also. It is very important for the threaded collar to sit square on the shock so the spring will not get cocked sideways and rub on the collar making noise. I have had good luck by running four o-rings to hold the collar on instead of the recommended two. It is important for the o-rings to be equally spaced so the collar won’t cock under load either. Spray silicon lube on the o-rings and the shock body when installing. Slide the collar on to the shock body with a twisting action and the o-rings should go on straight. Then get a real little screwdriver and push the o-ring down ensuring even spacing. After a day or so the silicon will dissipate and things will be super solid. If you are running Stillen or GC camber plates you need to get a special upper spring seat from GC that has a torrington bearing in it. If you run the regular upper seat it will rattle and clunk like crazy with a camber plate. With the adjustable GC springs, corner weights can be set. This is done by raising and lowering the cars individual corners to alter the static weight on each wheel. The object is to run an equal cross weight percentage. If this is done the car’s balance will be the same in right and left turns despite differences in side to side weight distribution caused by drive weight, etc. You need corner weight scales which individually measure the static weight on each wheel to properly adjust your corner weights. Any race prep shop can help you do this. [Editoral note: here's two links of interest: 1) Mike's SCC article on suspension 2) Larry Weeks pictures of his Ground Control setup.]

• Cut your snubbers. It is important to cut the rubber strut shaft snubbers on our shock shafts to get a little more wheel travel out of our lowered struts. Cut an inch or one segment out of the front and rear ones. Classics have a super soft microceller urethane front snubber which can be left uncut. 200SX’s have almost no travel in the rear when lowered and must have the rear snubbers cut for any kind of handling and ride quality what so ever. Do not go crazy and remove the snubbers or cut off more than half of them away. That can cause the struts piston to bottom on the foot valve, breaking it. If the car suddenly gets real bouncy, that is what probably happened. The only solution is to get new shocks.

• If you are racing, run R compound tires on the widest wheels that will fit. These tires can get more that 2 seconds for every 30 seconds on a slalom course or 3 seconds for every minute on a road course. These tires usually have a vestigial tread and a really short tread life so you don’t want to run these as a daily driver tire. Also R type tires only have about 10 good heat cycles in them so their stickiness will decline quickly in daily use, leaving you with a fast wearing, not so sticky tire.

• Don’t over tire or wheel your car. Our cars will go the fastest and handle best with the widest, lightest 15 inch wheel that will fit. 16, 17 and 18 inch wheels which look radical, really slow the car down because they are heavy and the bigger diameter screws up the gear ratio (yes, I know that I run 17 inch wheels on my car but I love the look and don’t mind being a rice boy sometimes). There are no R type tires out yet in these big plus sizes to my knowledge yet either. The widest tire that you should run unless you have a turbo or some other ungodly power is a 205. Wider tires will result in more drag that our relatively low power engines can accelerate. A 205/50-15 works well in most cases and a wide variety of R compound tires are available in this size. The maximum rim width that the 200SX can run is 7.5 inches with a 35-40 mm offset. A Classic (correct me if I am wrong classic owners) can run a 7 inch rim with a 30-35 mm offset as their is less wheel clearance in the rear. Since this always comes up, the bolt circle measurement on our wheels is 4x100 mm. The competition wheel that impresses me the most is the SSR type X. This wheel is forged so it can be much thinner than a cast type wheel. It weighs like 11 lbs which is twice as light as a regular wheel. The other good light wheel is the Enkei RPO-1 it weighs about 13 lbs which is still very light. Remember that 1 lb on the wheel is worth about 10 on the car due to the wheels rotational Inertia. Searl has the SSR’s on his car and can get quite a holeshot on mine even though I have at least 20 hp on him. I can’t begin to catch him until 3^rd gear! The difference is all in the wheel weight and tire diameter. The stupid 17 inch wheels are probably keeps my car at the high 14 second quarter mile point even though I have really good power. I just love that look so much. I guess I need to build my motor more…

• Tire pressures rise considerably during a run/race. Take notes of your tire pressures before and after every run so you can start with a cold pressure that will increase to your desired hot pressure during a run. Bleed your tire pressure down after every run to keep it constant.

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 haven’t 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 spec’s 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 you’ll 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.

Cheating
Some of you will be disgusted that I even mention this, but do you think it’s fair that the Neons ACR’s can have adjustable camber when regular Neons do not? In my opinion ACR’s 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 won’t 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. Don’t 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 compound tires.
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 it’s 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 BFG’s information page for some qualified tips! [BFG R-1 information]

My ignorance to the BFG’s 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, it’s 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 Hoosier’s 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 tire’s carcass are laid out in a diagonal cross fashion. This type of construction was popular up to the early 70’s 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 Hoosier’s 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 it’s 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

• Use GAB or Koni Shocks. Set shocks on 3 front and 4 rear.
• Maybe use a Front Antisway bar (definitely have to test)
• Set front and rear camber to maximum negative by the loosen, push and retighten method.
• Set front toe out to 1/8 inch, Set rear toe to Zero or 1/8 out to help car rotate, be careful not to overdo.
• Start with 40 psi front, 35 rear for tire pressures.
• 200SX’s cannot adjust anything in the back.
• These settings will feel yucky on the street and will promote lift throttle oversteer as well as chew up your tires alive.

SCCA SSC

• Set front and rear camber to maximum negative by the loosen, push and retighten method.
• Set front toe out to 1/8 inch to Zero, Set rear toe to Zero or 1/16 in.
• Start with 40 psi front, 35 rear for tire pressures.
• 200SX’s cannot adjust anything in the back.
• These setting will feel good on the street but the car may wander more.

Street Prepared Class Solo II, SCCA ITB, Hot Street Car

• Use GAB or Koni Shocks, set shocks at 3-4 front and 4-6 rear
• Run Ground Control springs 300-500in/lb front 200-400in/lb rear, set ride height so you have at least one inch of laden travel all the way around. Set corner weights for equal cross weight percentage. The lower spring rates listed are very streetable, the higher, ouch.
• Run GC or Stillen camber plates.
• Run Suspension Techniques Bars or Custom Adjustable. If custom try a 1.125 front diameter bar with a 1.00 rear.
• Front and rear STB bars (Strut Tower Brace) Stillen makes the best one. I think classic owners have to make their own rear STB.
• Energy Polyurethane Bushings when they become available.
• Set camber for 2-2.5 degrees negative front, 1-1.5 degrees rear. 200SX, have a good chassis shop bend the beam axle for 0.50 degrees negative. Set Front toe for 1/8" out for Solo, Zero for Road Race or Street. Set rear toe to Zero to 1/8 out for Solo, 1/16 inch in to Zero for road race or street. Leave toe alone for 200SX.
• Set front tire pressure to 37-8 psi and rear tires at 34-5 psi

Normal High Performance Streetcar

• Eibach Pro-Kit springs
• GAB, Koni or Tokiko shocks set on softest setting.
• Suspension Techniques swaybars.
• Front and rear STB’s
• Use poorboy alignment technique to set camber at 1 degree negative for front and rear. 200SX leave rear alone.
• Set toe at Zero for front 1/8 in for rear. 200SX do not adjust toe in rear.
• Set tire pressure to 37-8 psi front, rear at 34-5 psi.

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.

• First you need a good, accurate tire pressure gauge. A gauge with a bleeder valve is very useful. Gauges like this can be gotten at just about any racers supply house for about 20 bucks. Don’t waste your money on those expensive electronic gauges. Those are slow to use and never come with bleeder valves.
• The next bit of stuff to have is a compressed air tank for adjusting tire pressures. Tracks almost never have a handy air tank. I got my tank from Sears for about 50 bucks. Fill it at a gas station or use your home air compressor before heading out. Make sure the tank you buy has a safety relief valve so you don’t blow the crap out of your self if you leave the tank in your hot car during lunch or something.
• A digital pyrometer is very important. Get one with a wire bead probe. These are used for measuring tire temperature differentials across the tread which is a good tool for judging whether your tires pressures and alignment settings are right. You can get one of these at any racers supply house for 50 to 200 bucks. If you don’t want to shell out the bucks for this, bring a bottle of white out with you.
• A notepad and pen are critical also. With so many adjustment parameters it is important to try to write everything down as you will never remember it all.

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 tire’s 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 it’s 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 don’t 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. Don’t 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.

Don’t 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 someone’s 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. Don’t 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.