burn0ut305

I need advice on what would help my suspension/handling 4 autocross… I’ve read post after post over this subject, and to tell you the truth I’m totally lost… I think the best place to start would be to purchase a sfc from spohn… followed by a front end rebuild kit, wonder bar, and strut tower brace, along with koni yellows. There are a few things I’m not sure if I should keep stock or not, like my sway bars, lca’s (should I get a relocation bracket?) and last my springs. Keep in mind if I stayed with my stock sway bars and lca’s I would get new bushings. I read a few post about binding in the rear (not really comprehending what is meant by that) but this is why I was wondering about the sway bar’s and lca’s… well I hope I’m heading in the right direction, but if I’m not please help me out…

BMmonteSS

The theory behind the SCCA auto-x series is that any Joe Smoe can take his bone stock car and be placed in a class and be some what competitive. In a nutshell the lowest level stock class basically lets you use any DOT legal tire and only replace wear items on the car with equivalent parts. In a wierd twist of the rules you are allowed to use ANY shock and ANY front sway bar. Everything else has to be stock, you can't even use polyurathane bushings.

If you want to have fun, just crank your tire presures up to 40 psi and go have fun.

Souseless

Do you want to be competitive or simply the fastest you can go? I will assume that you are using SCCA rules and FS is the best place for our cars. The next best place is ESP.
For FS 36/24 sway bars and the stiffest stock spring option for your car, Koni yellows, new stock type posi diff , and R comp tires. This can be a very fast car.
For ESP 315 r comp tires and a T2R diff with above will kick ***. The other small items you can do are different levels of unimportant except for the wonder bar.
If you have a worn out chasis that needs subframe connectors then you really need to go all the way to CP if you want to be competitive. Now on a local level things can be different when I say competitive I mean on a national level. In my region SM and CP are unable to beat the raw times of the ESP class.

burn0ut305

Souseless im not gonna lie I have no clue what classes ur talking about. The different classes in my local scca club are Stock, Street prepared, street Modified, Prepared, STS, and last STX… I plan on running in either Street Prepared or street Modified… I honestly don’t care if the car is competitive on a national level; I just want it to be the best it can be. My plan is to do all the work, and then go and get my car inspected and see what class I falls into.

burn0ut305

I did a little looking around and the only company that I could find that sales 36mm front sway bars is Hotchkis. They want almost $280 4 one, is there anyone else that sales them 4 cheaper? For that price I could get a 1 5/16” front and 1” back sway bar from Spohn(would that b another good option?).

Tidbit

The very best things you can buy for you car in this order (Trust me) These will yeild you the best bang for the buck and the best times in autox for each addition.


First of all, do not yet waste your money on a STB(strut tower brace) of SFC's (sub frame connectors) YET (yes I said YET) Why? Because the STB will not work yet without another more crucial part and the SFC's will make you illegal right of the bat in autox.


Here is my suggest order of importance,p>

1) Tires- you need these to be safe and have any kind of resonable competitve grip- spend good money here and a decent agressive street alignment with about 4* caster, -.5* camber , and about 3/32 toe for a stock suspension car daily driven.


2) GOOD shocks and struts Why? Good quality struts will control the weight transfer of the chassis and movement roll- Buy Koni Yellows. They are the only over the counter performance oriented shock that is quality valved for performance with very good rebound damper rates and percision comp-to-rebound damper quality (They have minimal slop, you get what you pay for- buy Koni's)
3) and often neglected or overlooked- I can not stress the importance of good quality solid bushing strut mounts. Get rid of those crappy factory rubber dounut mounts that allow slop in strut damper and steering responsiveness. Only until you change these does a STB become effective. Putting an STB on a car with stock strut mounts is POINTLESS.


4) For now, just put urethane replacement bushings on your current swaybars and leave them be. They are balanced. Until you later swap your spring rates and dsee how the car then handles, you may not need the bars you bought prior to this change and will have to buy one or two new bars again to fine tune the lateral spring balance of the new suspension. Just use your current bars with new bushings acquired for palces like autozone- new uretahne end links also.


5) Go have fun like that. If you never deside to autox again, these improvements will at least be benefcial to your every day driving and safety.


6) would be some good brake pads- I recommend Stillen Metal Matrix pads (Again Trust me)
Dean


ps- My car has about 40X the modifications I just mentioned. It is extremely built for daily street use and here is an autox run I did in it on worn street tires (25,000 miles on them and the same agressive street alignment that render them still an amazing 25,000 hard miles before they were replaced the next day after this event.)- the GTA you see just before me ran a 71.3 best. I ran a 63.3 best.

http://www.zippyvideos.com/8464669705208156/d3/

Zepher

iTrader: (1)

I am running pretty much stock suspension,
36/24 sway bars (stock WS6 parts)
KYB GR2 Struts and KYB Gas-A-Just Shocks (ok replacement parts but not the best)
Eibach Sportline Springs (mainly for asthetics since I like the look, the Pro Kit would probably be a better choice)
Lakewood LCA's with rubber on the body side and poly on the axle

The best mod for the money would be R-Compound tires. you can have the best suspsension in the world but if the tires can't grip, then you will just spin and slide everywhere.

I ran my street tires last sunday and drove the way I would normally drive on my R tires and just lost it on the first run, so I had to tone it down a lot to keep the car going straight.

I have the Nitto 555RII tires which are a little bit of a harder R compound and will be trying a set of softer Kumho V710's at the next event (these are popular auto-x tires).
here is my post of the vids from last sunday,
https://www.thirdgen.org/forums/posts/organized-drag-racing-autocross/424113-my-auto-x-runs/3347157-post1.html

burn0ut305

Just thought I show u guys a lil video of my first time autocrossing… given its not in a camaro, but it was worth it 4 me to go out and practice…
http://s89.photobucket.com/albums/k2...soloschool.flv
Haven’t been able to get the camaro out yet, because I blew the tranny this last fall. I called dana up at probuilt and am getting his road racing rebuild kit… so at this currant time both the engine and tranny are pulled…. Cant wait to go autocrossing in the cammaro…

burn0ut305

http://www.spohn.net/product.cfm?productid=1366

i assume that these bushings would work well???

blyth18md

beyond endlinks, motor, tranny and torque arm mount theyre arent too many bushings I would replace with poly...even then im not sure how many of those changes are legal.

burn0ut305

Like I said b4 ill make the changes now and fall into a class after everything is done…. So it doesn’t really matter if it’s legal 4 the stock class or not… anyway I just wanna know if it’s a complete and good kit...

//<86TA>\\

iTrader: (14)

i think you are looking at this all wrong, you should figure out what class you want to be in, then get the rules regarding what you can and cannot do, then start sourcing parts. if you just buy a bunch of stuff and build up the car, there is a possibility you will be illegal in all classes that you would want to be in, and you just wasted a whole lot of time and money. do all your homework of the class of choice first, then build the car.
my

burn0ut305

Well for the most part I know what a can and can’t do 4 every class… what I’m hung up on is if I want SFC or not…. Everyone on this board praises them, but if I add them it jumps me up to street modified(well as long as I don’t have cross bracing on them)… other then that with all the mods I have planed ill be in street prepared, or at lest I think ill be… there are a few other parts like spohn’s front end rebuild kit, and there Fabricated Spherical Upper Strut Mounts, that I’m not sure if they will change what class I’m in so if anyone knows tell me…

So idk…. I know what I’m doing a little bit, and I’m not going to do anything to make my car illegal. For me I however I just want my car to be the best it can be… if I’m not competitive I don’t care much, I just wanna have a little fun…

burn0ut305

Oh well just thought of another question I was meaning to ask. My car sits low already with my stock springs, and I also have hooker 2055’s headers… so what springs should I go with, that wont let my car bottom out all the time…?

Axoid

Sorry I'm late to this thread.

If you want to build to E-Street Prepared rules and want to firm up the chassis, there is currently only one option, installing 6 point roll bars. I had a custom set made by a local race car builder, he kept the front down bars low so it didn't really effect getting in and out of the car. It made a serious difference to the car. But if you interested in SFCs you may want to hold off until next year. There is a proposal for allowing SFCs in street prepared next year, but no decision has been made yet.

As for springs, my advice is the get weight jacks and race springs. That way you can adjust the ride height, you just have to be careful not to through off the corner weighting too much. But there is a cheap way of testing that with out the need for corner scales. Sam Strano Jr. at Stranoparts.com is really great source. He's also a two time ESP national champion, so he knows what he's taking about.

The fabricated spherical upper strut mounts are legal in ESP, it's covered by allowance for camber plates for cars with struts. The front end rebuild kit should be ok if you use the stock adjustment sleeves and don't go for Spohn's adjusters. I did and I have been warned that I can get protested for them, but no one at the local level cares.

If you haven't already, you can download a PDF copy of the rules from the SCCA's web site.

burn0ut305

Haha so wow I’ve been doing some research on my own and I gotta say, I had no clue springs were gonna b this complicated… anyway axoid u cleared a lot up for me, but now I’m lost on weight jacks, and springs… the weight jacks look like something I would like to do.. I just can’t find any place that sells them… I also don’t have a clue on what type of spring to use with them… I’m way lost, the more research I do the more complicated everything is getting… I sure hope crazyhawaiian chimes in, he seems to have a great knowledge about weight jacks…

Tidbit

1st off, Do you have access to scales? You'll need to scale the car with weight jackers to get the corner weights correct.


Basic feature of weight jackers is changing spring rate and being able to them scale the car and set the cross weights and the ride height no matter what spring choices you make- Without scales, this feature is useless.


Any questions on cornerweights, wedge, cross (static and /or dynamic), roll centers, antidive, roll oversteer/understeer, bumpsteer, shock damper, off corner bite, pinion angle, stagger, bumpsteer, camber gain, caster trail, roll movement, etc - you name it I can answer it for you in laymans terms. What you need to know getting into advanced setups constitutes a multitude of marraiged setup specs and moving just one thing can affect 3 others, etc.What I am getting at is using weightjackers is mostly a one time thing finding someone with scales and then never ever touching it again. this could also be done using shims and extended balljoint with conventional springs if the car is scaled and then shims added to get the corners weighted diagonally even AND- with conventional springs you gain the feature of better spring frequency and rate consistency rather than having to utilize shorter free coil springs with limited height of weightjackers- basically how they got to coil bind quicker and lose free coils- rate goes up more quickly. If you are never ever going to change spring rates for different tracks, then you do not need the versatility of weightjackers, the same pricipal can be done cheaper and more effective with conventional springs on a one time street or autox setup.

ps- yes I do this semi professionally and will take a picture of my grid and scales I get to play with on a semi weekly basis. I am currently milling a new lighterweight aluminum grid so the assembly will be easier to transport and assemble. I will be milling some more of that on Monday.


Do yourself a favor, go back and read my first post where I offered solid advice and I even took the time to give an explination to each numbered suggestion. Don't worry about corner weights yet, you are not even close with any modifications to worry about that level of performance. Sped your money on a few basic 101 very valueable performance upgrades or else anything else you do will be pointless unless you have these mods done first. Don't ever put springs in a car first without good dampers- there is a maniditory oder in purchases otherwise you are going to bounce down the road with no chassis control or grip

CrazyHawaiian

If you don't care about classes and you just want to have fun then you can do any mods you want. If that is the case then I would go out stock first and get some seat time so you can get a feel for the car. If you're just doing it for fun then you don't need alot of mods to have a good time. And when you're done you can identify where the car is lacking and mod accordingly. Just make sure the cooling system is running tops and the brakes and suspension are in good shape. If you want to compete then it's harder to mod the car because alot of mods that are common for a street car these days might put you in higher classes with guys that might have some serious mods. I found that alot of my projects are bumped into higher classes because of motor/drivetrain work I've done, didnt even get into the suspension part yet. In those higher classes the range of allowed mods is beyond what I'm building (basically just a street car) and people can be really serious with alot of money invested. Eventually I realized that I'm better off using a bone stock car with an OEM drivetrain and some minimal suspension mods. So for me that would mean going backwards on alot of mods I already did, so I lost interest in autocross for now. Who wants to give up their T56 or replace all the bushings again? Not me!! hahahah Maybe some day if I do another 3rd gen project ... but probably not.

For the weight jacks, they sit above the spring (fronts) or below (rears) and allow you to adjust the ride height of the car. For the serious racer this allows adjustment of the corner weights. For me I just use them to set ride height, I'm not a serious racer. When you run weight jacks you need to run shorter springs than normal because the weight jack itself takes up at minimum around 2 inches of space, even more when adjusted. If used with a stock height spring it would actually raise the car up and any adjustments would make it go even higher. So running springs that are at least 2 inches (or shorter) than stock is the way to go. You can buy them through stock car racing / circle track / dirt track racing types of places. The other place people go is Ground Control (its not listed on the website, gotta call em up) but from my experience Ground Control is pretty expensive. For the springs I would go through Suspension Spring Specialists (www.bluecoilspring.com) or Eibach. For most of my cars I'm running Eibach in the front and SSS in the rear, but the manufacturer dosn't matter as much as the specs. When ordering these springs you'll want a specific height and you can also specify the spring rate. Most of us are doing it trial and error, I've found a good combo to be around 700# front springs and #125-150 rears. But other people also have their own preferances, there is no single one correct answer to these things.

One thing to keep in mind when trying to find the correct spring is the concept of the suspension combination. The spring works in conjunction with the strut/shock and swaybar, they work as a combo. Changes to any of the three can change the handling characteristics, so changing alot of things at once can make tuning harder. This is why most of us (amature enthusiasts) have to go by trial and error to find the setup that best compliments our driving styles. If you are serious about suspension tuning be prepared to swap alot of parts and try alot of different combinations.

91_5.7_TPI

iTrader: (2)

I did the buy parts and go see thing...not a good idea. My car is a fun street car, but I think it's in ESP (street prepared). In that class, I am way over my head. I'd do what TidBit said and go from there. Get out there and drive before you start changing things too much. Experience is better than mods.

Axoid

I agree that scales are the best way of doing it, but a trick that I do to get it set close is to put the front tires on dollies and then place a jack under the rear axles pumpkin and jack the car up until both tires are just off the ground. Which ever rear tire is further off the the ground is under weighted or the opposing front corner is under weighted. It is not a perfect method, but it works in a pinch.

When install weight jacks for the first time. Change the fronts and the weight the car with the stock rear spings still in place, then change the rear springs and weight the car again.

Tidbit

Axoid, hat is not even a close method at all- I'll explain what you are doing and whay it is actually hurting you and not helping you.


What that does is puts 'wedge' into the car and does nothing to set the cross weights. 1st of all, ou need to scale the car with the driver in it (helmet, gear etc- race weight with average fuel load). Doing this would really weight the left side of the car more to tip to that side even greater with your method. So, now as you decrease the front right weight jacker to get the LR tire even height with the RR tire, you are simply not changing cross weight but merely tilting the attitude of the chassis onto the LF with preload or hence the term 'wedge' ( you are wedging up the left rear).


You absolutely need scales to set both your diagonal weights even WITH the driver in the seat.


With your method, your right rear tire will always be higher off the ground, so when you then extend the height of the left front to diagonally drop the right rear to be even height with the left rear you have just put more diagonal weight onto those two tires and less cross percentage on the other two. You will definately be sitting way more towards 45% cross which is major bad. The car will be really loose to the left on corner entrace and tight out/ and kindof visa versa for the right- tight in and maybe good to tight out. That method give a bad reading in the opposite of what you would think you need.


Any cross weight outside the boundries of 49-51% (50 is perfect) on a road race type setup (symetrical cornering such as street driving, autox or roadrace) is terible and will not weight the rear drive wheel evenly causing all sorts of handling problems at steady state and exit, and weight transfer under braking loads the different direction unevenly also with one loose and the other pushing.

Axoid

As I understand it, wedge and cross-weight are the same thing.
http://grassrootsmotorsports.com/new...er-weights.php

The way that I have done it is not perfect, but it does work, because the pumpkin is in the center of the rear axle and when the car is jacked up there it becomes a pivit point. Which ever corner has less preload will set lower.

When I first installed the weight jacks one front spring was slightly shorter than the other and with the jacks set at the same height, this caused one corner to be under-loaded. I drove it a couple times in autocross before knowing better and I didn't notice a serious handling problem, but what it did do was have premature lock up on the under-loaded side's front brake. That quickly flat spotted a tire down to the cords.

After adjusting it the way I did it solved the brake lock up issue and it handles evenly, even though solid axles car always have a harder time going right than left. I still put it on scales, but since I don't own a set, it is not the first thing I run out to do every time I tweek the setup.

Tidbit

Cross and wedge are not the same thing- This is a common misnomer. They are related because they use the same adjusments settings but it has two different affects. You can increase cross without increasing wedge, and you can increase wedge without increasing cross. Or you can do both together turning the same scew jacks front and rear together in scaled sequences.


When you try and adjust your cross with only front weightjackers, you are also affecting wdge also. You can not turn up or down the rear diagonal coresponding weightjacker to keep the wedge in chack but gain or lose cross.


I will give examples how wedge can be changed but cross left the same. Takle a car with these scaled readings and ride height-


LF 975 lbs/ ride height 4 inches- RF 875lbs/ 4 inchesLR 710lbs/ 4 inches- RR 610 lbs/ 4&quot;


Now with those same cross weights set on all four corners at 50% cross and 4&quot; ride height all around, We now take a few rounds out of the RF and put those same rounds into the LR maling those ride hights go to RF 3 inches and LR 5 inches- but keeping the cross identical on scales.


Ex 2:Wedge is also refered to turns put into he left rear in the heat of a pitstop to increase the original cross setup- Via it be 54% cross to begin with, they may put 4-5 turns of wedge into it and and wedge it up 1% from the baseline 54%. I have seen it used both ways to explain terminology. this example DOES change cross though. This is the one people here and think that wedge and cross is the same and basically is if used this way other than cross is baseline and wedge is alterations to the baseline cross.


True wedge is my first example

Axoid

I see what your getting at, but I never said to only adjust the front jacks.

If you install only the front jacks and leave the stock rear springs which have equal preload (with in factory variance) and then adjust the front jacks, the front will have equal preload. Then install the rear jacks and ONLY adjusting there rear jacks (since the front already have equal preload) level the car. This would have the car with equal diagonal weights and even side to side ride height (relative to stock).

LilJayV10

iTrader: (5)

I thought I did enough research when I did my suspension build last year. Wrong. I finally found a suspension guy, kinda like Dana at ProBuilt knows about trannys, this guy knows suspension. Now I am changing my springs and probably struts/springs.

1st thing I'd change is the shocks/struts, stock isn't very good at all. Koni's are suppose to be the best followed by revalved bistiens.

adjustable panhard bar is good if you lower the car any

stay away from poly control arms. it binds the rear suspension up, spherical/poly combo is suppose to be much better.

Alignment

Sway bars

Oh, don't buy sportlines for handling. They suck. The pro kit's rates are better.

Stephen

iTrader: (12)

Learn to drive, and practice, practice, practice! When I first started out running autox years ago, I had one of the local gurus run my car, and show me the ropes.

I tell ya...all the best parts in the worl, won't make you a great driver. He had never been in my car, yet he STOMPED my track times, and I had been driving that car for almost 2 years, and I *thought* I could drive it pretty good. Boy was I wrong!