camaro1185

iTrader: (2)

I have been recently getting big into the pro touring scene with my 1988 Iroc-z camaro. Last winter, I went through every bit of suspension on the car to make the car handle like its on rails. I have achieved that, and my mind is blown everytime I drive it at how well it handles, BUT the ride is extremely rough when just cruising around town (im 27, so thats saying a lot) and on the highway. My goal now is to have a car that i can drive everyday without getting beat up. Also, this car is driven A LOT. Its not just a weekend car, so loosing a little bit of handling for more comfort is ok with me.

My setup:
32psi Falken 912 tires
34mm front/24mm rear sway bars with poly bushings and end links front and rear
stock lower control arm with global west del a lum bushings
Eibach pro kit springs: 714 lb/in linear front 1 inch lower/109/177 lb/in progressive rear 1 inch lower (stock isolators front and back)
Tokico Illumina 5-way adjustable shocks (Set on 1)
UMI subframe connectors (weld in)
UMI tubular rear control arms with poly bushings
UMI rear re location brackets
UMI adjustable panhard bar with poly bushings


Any help at all would be appreciated

99Bluz28

iTrader: (35)

Hotchkis 1" lowering springs(pt#1903) have lower spring rates, front(600 lbs./in) and rear(100/140 lbs./in.) . BTW you can buy just the front or rear Hotchkis springs. There's also Vogtland lowering springs #959212 that lower 1.2", but I can't find any spring rate specs for them. I've came away with a better impression of Vogtland lowering springs than any Eibach springs I've ever had over the yrs..
So I see that your Tokico Illumina struts/shocks adjust both rebound and compression dampening at the same time, I believe that a set Koni SA sport struts/shocks(rebound adjustment only) will work better for you. IMO, you don't need much compression dampening at all, you mostly need rebound control, which the Koni's offer.

camaro1185

iTrader: (2)

Thanks for the reply. I might have to try the hotchkiss springs. My buddy has them in his TA and the ride is quite a bit better. Although, IIRC his springs are rated at 7xx in/lbs???

99Bluz28

iTrader: (35)

That's odd, the hotchkis website list exactly what I posted.

So where did you get this spring rate info...?

camaro1185

iTrader: (2)

Thats what he told me, I never got that number from any site. Ill have to double check

SuperSport01

Does it hit the bumpstops? I don't remember any Eibach's being too harsh unless you were contacting the stops. UMI has caster/camber plates that allow more compression travel in front.

transwiz

iTrader: (26)

Get the koni's to start. I don't like the eibach springs. Like 98Bluz28 says the hotchkis or the vogtland.

z28bryan

iTrader: (7)

I tried doing a google, and I seem to find a lot of answers on 600 linear... but you know what they say about what you hear over the internet. That's obviously only the front.. no idea on the rear.

Stupid Hotchkis website I couldn't find the rates... they just say it will stiffen up the ride. Why is it so hard to post the damn springrates for a lot of companies?

camaro1185

iTrader: (2)

Maybe should have specified, this setup is on my 3rd gen camaro, not 4th gen.
http://www.hotchkis.net/8292_gm_fbod...l_springs.html

It looks like
600 linear front
100-140 progressive rear



Here is for a 4th gen.
http://www.hotchkis.net/982002_gm_fb...l_springs.html

How the hell is a 4th gen spring rate so much less than my 3rd gen and the 4th gens weigh more.

z28bryan

iTrader: (7)

What about stock springs for a 3rd gen? Those probably ride the best maybe? I'd probably pair them up with some Konis

camaro1185

iTrader: (2)

I was thinking of that. The stock replacement springs are 706 in/lb where factory was 550.

Would a taller spring with a 7xx spring rate, be a nicer feel on the road than a 7xx spring rate lowering spring?

How does spring height play into road feel?

99Bluz28

iTrader: (35)

Does you car already have after-market caster/camber plates and shorter front bumpstops? If not I'd do these first.
As already stated the caster/camber plates will allow more compression travel in front struts, an the shorter Bumpstops a little more spring/strut compression.

leadfoot4

iTrader: (1)

Shortly after I bought my 3rd gen (1985 F'bird), I first installed a set of Koni (yes, Koni) lowering springs. They were a bit harsh, but did lower the car about an inch over the OE springs. Over time, I had them teamed with both Monroe and Gabriel struts. A couple of years before I sold the car in '95, I switched to a set of Suspension Techniques springs, because I wanted the rear a little lower than the Koni springs had it sitting. I'm pretty sure the ST springs were a bit softer, because the car rode better.

With respect to the OP's set-up, depending on how smooth the roads are where you live, I would say the del-a-lum LCA bushings are big contributors to your harsh ride. Those bushings have next to zero deflection. I think a better description would be bearings, rather than bushings.

Sam Strano

iTrader: (41)

Ahhhhh, I'd turn the shocks UP some. They can't handle those springs on 1, and that rides worse than more appropriate damping. Illumina's ain't great, and lowering springs aren't the way to get the best ride. But what you are doing is the equal to running trashed shocks on stock springs, the one can't control the other.

camaro1185

iTrader: (2)

Yes, aftermarket camber caster plates, and none of the bumpstops are cut, although I really dont think i am hitting the stops

What do you recommend? Lets assume i was going to do the over again and build a car that can handle amazing but keeping in mind it spends 95% of its time on the street corner carving and 5% on the track/auto x. Im pretty much ok with anything except for the ground control weight jacks. Id rather just a spring/shock kit.

Sam Strano

iTrader: (41)

I'd run stock springs, Koni's, LCA's that are not poly, probably skip brackets too. I'd run a 35 solid or 36 hollow front bar a 22mm rear. If it's a street car the camber plates weren't needed anyway.

A number of the things you have, and that I would have skipped, have a detrimental effect on ride.

camaro1185

iTrader: (2)

Thanks. What should I get rid of?

The spring rate of stock replacement iroc springs are 706 which is close to what I have on the pro kit springs now. Will that extra length of spring even though its at 700's spring rate and konis make the car handle decent and be close to stock feel when on the street?

Sam Strano

iTrader: (41)

The springs aren't helping the ride. The all poly LCA's aren't helping the ride. the 24mm bar isn't helping the ride (but less than the other things). The Tokico's set so soft with those springs isn't helping the ride.

Lowering springs are stiffer, period.. stiffer means stiffer. The only way you can make stiffer springs "ride" better is the best shock you can run.

Coppertone

FWIW, I have stock springs with Koni's (all else is stock other than a PHB) and the ride is very harsh on bumps, highway seams, etc. I'm looking at other options as we speak.

z28bryan

iTrader: (7)

I think the OP is on a 3rd gen though, not a 4th gen.