Zach/90\irocZ

iTrader: (6)

i have eibach sportlines that are way to soft and really disliking them and car pushes alot unless i stomp on gas or do some crazy braking
i also have lcrb and control arms sway bar end link poly and im running 10" wide wheels all around

as for what i want is a neutral feeling car with a bit of oversteer. to better control car with trottle then doing crazy hard braking to get car to turn in

im going to be getting konis with the new springs

so im woundering from guys who use moog springs and autocross what would be a good choice i want to cut them to get the same stance i have now from ground to fender is 25" front and rear is around 26" so prop need to cut a coil or more and i was reading that when you cut springs it increase the spring rate
new konis all around with new springs also was thinking around 800 front 200 rear
thank you

Roostmeyer

iTrader: (3)

I think global west has a spring in the 800lb range. Of course the stiffer IROC springs should be able to get to 800lb/in with a little trimming.

If you want to experiment, I think a 900lbx5.5x12" spring will drop in and be close on ride height, may need a little trimming, or a 1200x5.5x11. I know a 900x5.5x11 is way too short. In the back 150x5x12 is a perfect fit w/o isolators, I have a pair if you want to try them. 200x5x11 should be just about right as well. Just depends on what front/rear bars you're running.

In the back its easy to ditch or add the isolators if you need to raise or lower the car some. Up front its not as easy of course, but you can cut the springs too. Right now I've had to put the stock front spring isolators on the driver side to try to get the ride height equal in the front. Honestly the weight jacks may be worth it if you value your time...

WARNING: Something is not right with the front spring length calcs and this spreadsheet is messy. Still has fourth gen front ARB dims, so balance may be off. Use at your own risk.
https://docs.google.com/spreadsheet/...G9hMlM4R21KMGc

Zach/90\irocZ

iTrader: (6)

Yea i was planning to get weight jacks but I don't see myself constantly adjusting ride height I like where it sits now so I was just thinking about getting coil springs would be better and more bang for the buck and be done wow I need to read a lot more because I'm kinda of lost when it comes to the spring calculations
I'm running sportlines all around with no isolater in the rear front sits at 25inch and rear is 26 inches and sportlines are way to soft performance wise and being that low its to soft
But weight jacks seem easier and convenient

Zach/90\irocZ

iTrader: (6)

In running stock sway bars there the biggest ones that came from factory I think rear is like 24 and front r 36 I'm not sure but if that's correct but I check awhile back and verified the equip code and it was largest from factory

BlackenedBird

iTrader: (5)

Going too stiff in the rear, like 200s, can contribute to preventing the rear suspension from doing its job & not allowing the rear to "drop" & tghe chassis weight to transfer. And don't forget about shocks as well. They contribute to controlling the suspension move as well.

Then there is tire choices to think about like hard rubber vs soft rubber/compound, etc. Then there is the Control Arms/Panhard Bar (stock/boxed/tubular) & their connection points (rubber/poly/heim).

Zach/90\irocZ

iTrader: (6)

yes im going to up grade the front bushings the rear is all poly fronts will be to shocks are going to be koni and add a adjustable panhard bar everything else stock nothing to hardcore
oh ok so a 150 prob be a better choice i never drove a iroc with stock springs sportlines came with car so cant compared to stock vs sportlines with the different spring rates

hellz_wings

iTrader: (2)

I have stock IROCs and they're very stiff. I trimmed the rear, and it's a bit stiffer but still rides alright. I'm at about 27" in the front and 27.5" in the rear. The fronts are 706lbs and the rears were 107lbs, but I trimmed 3/4 of a coil so it's slightly stiffer now, although not that much. I will eventually get weight jacks in the rear and run 150lbs AFCO springs because my panhard bar is lowered by 3.5".

For the rear, don't get full poly PHB and LCA. Get atleast a heim/poly combo if street or all out heim joint for all out racing. Poly will bind and cause snap oversteer which can be dangerous. Also, the angle of the LCA makes the car more neutral and safer as well, it is supposed to be slightly lower on the axle side than on the body side (max 1" lower on the axle side.. In between 0.5" and 1" lower on the axle side is good for a neutral steering car.)

BlackenedBird

iTrader: (5)

I'm running GCWJ 9.25"/600lbs up front & 10"/180lbs out back on my daily driver & am quite happy with it. I have a set of 10"/225lbs for the rear but they are way too stiff. The 180" has been a good compromise for street driving without the stiffness but stiff enough to avoid road irregularities unless I do something stupid like hitting an old cattle guard crossing to fast that is actually a couple inches below street level. I shoulda slowed down more & a rear tire suffered. Lesson learned! My front adjusters are almost bottomed out so in reality? A shorter spring might be a better choice to allow the adjuster to be higher & could get my car even lower if I wanted it to be, but my center fender lip height is at 25.5"(rear is at 26.5") now & that puts the nose just above the curb height which is perfect for parking at stores/parking curbs & having the nose clear without having to worry about damaging the nose.

For the fronts I would go up a little higher if I was doing AutoX still, like 800lb springs, maybe just 750lbs.

Zach/90\irocZ

iTrader: (6)

On the relocating bracket I install lca on lowest sitting when I didn't have the relocating bracket with stock lca it oversteer pretty easy but relocating bracket calm the oversteer down that's the first thing I notice when hitting the gas in hairpen turns But I should experiment with heim poly combo

Zach/90\irocZ

iTrader: (6)

My iroc is same ride height as yours and I clear parking curbs etc and I like that I don't think I want my car any lower than it is a inch lower maybe I don't mind the stiffness most my cars I owned had stiff suspension I was thinking 750 -800 up front rears 150-200 how is your car with the 600 / 180 ? Is it more neutral or more oversteer or slight push 600 seems to be pretty soft I think my eibach Sportlines up front are 700 range maybe I wrong that's what I've search on this forum

BlackenedBird

iTrader: (5)

600 is soft for track use, which is why I suggested 750 or 800. Your thinking is exactly what I suggested above. Closest my car sees to track use is spirited 2-lane back roads. Obviously I won't push it near as far as I would in a parking lot with lots of paved runoff space.

Only a slight oversteer, no push, but I do have 275s front/315s rear so that equates to a bit more traction everywhere than if I was running stock 245s all around. I think if I upped the front rates higher, that might make it a little more Neutral, but if it fine for what I do.

I do have Heim joints on both the LCAs & APHB, but stock rubber fronts, and I like that it gives a quicker/more solid feel to what my tires are doing vs stock rubber or poly (or a heim/poly combo). The road noise is completely tolerable to me & (female) passengers, who have never complained or said anything about it being bad.

Zach/90\irocZ

iTrader: (6)

Lol 2 lane back roads sounds fun Yea I'm going to be running 285 all around maybe lil wider in the rear 10" wide wheel all around I like a bit of oversteer more of a fun car you have 315 on rear and still have a bit of oversteer ? Is your engine stock ?

BlackenedBird

iTrader: (5)

Oversteer only if I PUSH it on hard corners but I've had a 3rd gen since the mid 90s so I've definitely practiced a "bit" & am used to what these cars can & can't do after trying too many combinations.

As for the engine...Just the typical bolt-ons really. No internal engine work yet. I have a much bigger project (not a 3rd gen) getting all the heavy work.

83 Crossfire TA

iTrader: (2)

Cutting 1 coil off the stiffest stock springs will put you in the high 7xx range and will probably lower the car more than you want, that combination + one of the thicker rear spring isolator put my '83 about as low as it would go without bottoming on the bump stops.

Zach/90\irocZ

iTrader: (6)

oh ok ill try to get some iroc springs then and see how that works out how the handling with that setup i removed my rear isolater to lower it a bit more i stll have them tho

Zach/90\irocZ

iTrader: (6)

yea this is my 2nd thirdgen but havent really gotten in auto-x till i got station here in san diego i live down the street from the stadium where scca solo events are held !! im use to how it drives just want to tune it to my driving style

hellz_wings

iTrader: (2)

83crossfire: how many inches is your front from fender to ground?

Zach/90\irocZ

iTrader: (6)

25inchs front
26inchs rear
I like this ride height and it works with the wheel setup up I'm going to run 10in wide all around

BlackenedBird

iTrader: (5)

I just found this chart of spring rates.
http://www.austinthirdgen.org/index.php?pid=43

Zach/90\irocZ

iTrader: (6)

I've been reading that today lol couple mins ago

Zach/90\irocZ

iTrader: (6)

think im going to just try 5662front and 5665 rear cut them to get the same drop i have and should be 800ish front and 150ish rear just a guess
i have 24mm rear swaybar so i have to see what direction to head after that this is a budget build and rather spend money to get koni shocks/struts all around than weight jacks

hellz_wings

iTrader: (2)

if you go that low and stiff you'll need good shocks like Koni to deal with that stiffness.

If you cut the front 5662 and rear 5665 you will get a pretty stiff ride. The rear will oversteer a ton with the springs cut that much in the rear, unless you lower the roll center or go smaller sway bar like 22mm in the rear.

My car has 5662 stock (749lbs) with 0.75" extended ball joints and it sits at 27" from the ground to the center of fender. The rear sits at about 27.5" from ground to center of fender. I have 4th gen insulators so it raises the back a bit so I trimmed 3/4 of a coil to get it where it sits now. This made the rear a tad stiffer but nothing too noticeable. The rear roll center is lowered by 3.5" so for me a stiffer 150lbs spring would be a good choice, I'm not so sure it would be good for you, might wanna go only a 125lbs spring with a 24mm bar, or try 150lbs with a 22mm bar.

My advice, try 125lbs with the 24mm bar first, and if it doesn't suit your driving style, then cut more to get as stiff as you can without dropping it too much and replace the 24mm bar with a 22mm bar.

Zach/90\irocZ

iTrader: (6)

i will be running koni ..

my rear sits at 26in thats with out the stock insulator

it shouldnt be to bad since fronts re increasing in rate also ompared to rears ?

Zach/90\irocZ

iTrader: (6)

how about using 5664 moog spring with the 5665 rear that probably be better combo with the 5665 ive been messing around with the calculator for spring rate but not sure if i have the right specs on the spring
i can only find this http://www.austinthirdgen.org/index.php?pid=43

hellz_wings

iTrader: (2)

You could add a 4th gen isolator to raise the rear and then trim the rear springs, which would increase rate, and lower it back to 26" (plus with the isolator in there it protects the car from metal to metal contact from the spring on the body). I would cut 1/4 coil at a time and do it properly (not overheat, go slow, etc.)

Zach/90\irocZ

iTrader: (6)

whats the difference i assume isolator is taller ?
well been searching all day and found couple members running
home made weight jacks that you weld in and adjust on the car
kinda like these using a couple other parts and you can adjust like gcwj
just cheaper and you can adjust easier and solve the issue for running different length springs instead of using isolator for rear and adjust to ride height for my liking and weight blance of car
http://www.southwestspeed.com/?sec=v...5.5\"%20Spring

hellz_wings

iTrader: (2)

Yes weight jacks are the ideal solution. Buy spring with the rate you want, and use jacks to adjust height.

Zach/90\irocZ

iTrader: (6)

thanks for all the info im clueless when it comes to spring rates
search read search search read post read search read lol

finishing up on mocking up 18x10 all around just running in trouble with the front hub want to move 1/2inch more in but centerbore of wheel face and hub are not allowing that

suspension upgrades are next and just waiting to click buy lol
growing to hate sportlines and kyb more and more cant wait

//<86TA>\\

iTrader: (15)

yes, sportlines suck, i hated them, especially the rears

take the wheels to a machinist or good wheel repair shop and you can have the centers bored to the proper 70.3mm to allow them to sit flush in the hub and be snug to the hub as well for added strength. Depending on the ID of your wheels hub opening, you may still need a hubcentric ring to make them fit snugly. IDK what those wheels have for a bore ID

what the offset/backspacing of those wheels? how close to the strut are you? they should fit and work nicely if you can get them inboard enough. You may have to lengthen the steering stops on the a-arm to keep them front rubbing the back of the control arm. address that before driving with them so you dont scrape them all up.

Look up some of deans old posts, he has some good suggestions for starting springs rates. Also poke around FRAXX, you will find a lot more useful info there from people who actually race their cars.

I answered your pm too

-Phil

Zach/90\irocZ

iTrader: (6)

Ok I check out fraxx that probably better place to start

I check wheel lock to lock I didnt have no issues with control arm I double check that

Thanks again I'm going to read it now

Offset is -25 mm Backspacing is 6.26in and I'm about a 1 inch from strut body

87350IROC

iTrader: (2)

Make sure to triple check once you have the wheels sitting all the way on the hub. My aren't even close to clearing the a-arm at full lock (6.375" BS). But that is with the Spohn a-arm, perhaps the stockers have better clearance.