FostersPerformance

Getting there on my project. Its been on its own feet for a few weeks now, so im starting to adjust things. Car is so low in front my camber is visibly off.

I have the VBP front extreme spring, and the VBP sport in rear. I also have the GM manual that gives ride height dimensions. But in the book, dosent say if measurement is to the frame, or the pinch weld area. I assume its the frame (im only getting an idea of how high it was stock).

Also, out of the top of the spring where the height adjustment bolt is, i have maybe another 3/4 of an inch left. I know i need to get the car up more as it seems way too low. But even taking the weight mostly off the spring, the 'puck' is still touching the lower a-arm, and i feel like tightening it more will break something. I installed this spring long time ago, and i know its correct (believe i still have a thread on here somewhere about it).

Anyone with this spring? The car was built to do some amateur auto cross, but its mostly for street, so cant have it too low.

Thanks!!

blackozvet

I imagine that adjusting the c4 front spring would be just like adjusting the c5 front spring.
I adjusted my c5 spring recently and you have to put a block of wood or rubber on the jack (so as to not damage the spring) and jack the spring up till it just starts to come off the A arm. If there is any reasonable amount of touching between the adjuster and the a arm its tough to get the bolt turning.

rjacobs

its not at all like the C5/C6.

The C4 has no bolts on the front spring.

blackozvet

the c4 spring does not, but the VBP extreme C4 spring does !

MatthewMiller

Agreed. I have a VBP Xtreme front spring as well, and even with the front all the way off the ground and the wheels at full droop, the adjuster bolt pads still touch the control arms.

FostersPerformance

Mine is the same way. Spring has some preload even with wheels off ground. So jack up the spring?
How much tread is on the top of the spring after you got the height you wanted? Also, may I ask what your ride height is?
Thanks everyone!

FostersPerformance

Ok so still messing with this. Now that the front air dam is installed i have about 2.75" ground clearance between air dam and ground. This is with the bolt heads being flush to spring (almost). This is way too low.

Ive been looking at hockey pucks and also hard rubber block 1" thick to use as a spacer between 'puck' and a-arm. But to be honest i dont like the idea too much.

At this point im debating going to coil-overs. I hate to do it as the car has 2 miles on it (still no plates due to shut down). The car has all VBP stuff (extreme front spring, sport rear, full Bilstein shocks, 1.25" front sway bar, 1" rear, and all heimed rods out back except the 4 dog bones.).
It pains me to spent 2500 on coil overs, but shes way too low in front to street this car. When i started this project in 2002 i loved the idea of go kart stiff suspension. Now i like the idea of being able to set the shocks softer for when the wife wants to ride with me.

Penny for your thoughts?

Thanks

FostersPerformance

Aardwolf

I would have to go and measure to be sure but that looks close to the same as mine. I haven't found it to be a problem. If you need to adjust ride quality then yes do coil overs. Drive it around and see just don't try to straddle large dead raccoons etc.

MatthewMiller

Thoughts:

• Aren't there some deeper air dams out there, maybe for Z51 packages? I wonder if your air dam is lower than mine was. It's hard to tell from the pics, but it kind of looks like it is. That would mean that even if your car is at the same ride height as mine was, the air dam would be lower.
• I'm sorry I missed out on your question in post #6. I must have somehow not seen it. Unfortunately, I sold my C4 in February so I can't measure anything now. Going from memory and jack clearance. I doubt I had more than 3" under the front air dam. I did have some threads still showing on the top of the front spring adjuster bolts.
• Make sure the pads at the bottom of the adjusters are still in good shape. You could definitely add some shims or pucks under there to raise the ride height a bit.
• Also, make sure you don't have the spring shimmed up in its mounts. Remove as much thickness of pads/shims on the underside of the spring in its mounts as possible, and move as much thickness of pads/shims to the top side as possible. Doing so effectively raises the frame up on the spring.

That's $0.04 worth of thoughts! I hope at least one of them is helpful.

FostersPerformance

Thanks for the input. The idea of changing things this close to being able to drive it irks me.

The air dam is from Corvette America. I believe its the only set they have for an 88. I can measure it today.

The spring shouldnt have anything on its mounts to the K member. I still have the directions, but i remember it saying to make sure no shims or anything are there. I know there isnt....But i was wondering if that was a possibility also to raise the height up.

I guess i could try to get the long adjusting bolts out and get longer ones. I think (?) the 'puck' is threaded into the bolt (another thing i dont like -when you turn bolt the puck is trying to spin on the a-arm). Even with the car off the ground the puck still touches the a-arm. If i throw an 1" whatever in there seems like the spring would be really stressed out.

MatthewMiller

Take a look at it. If there is sufficient threads on the bolts for those clamps, and if I'm thinking about this correctly, then you could probably add additional spacers above the spring, and the car would lift by the same amount as the spacer thickness.

You won't stress the spring out - it's made to always carry the front weight of the car, and once you have the car sitting on the ground it won't be any different with shims between the pads and the control arm seats. The spring will still have the same load and arch, only the front ride height will be higher. For that matter, there's no reason you couldn't swap to longer adjuster bolts. You'd just need to match the thread with a longer bolt that's threaded all the way to the head.

FostersPerformance

Thanks for the input...ill see if i can get longer bolts in there on the ends. I dont see that being a problem. Hell if i could get the front up another 1" that should be enough. I like that idea alot better then putting a hokey puck in there lol....ill update this. Thanks again!

Kevova

How high is it at rockers? Are center spring pads as stock or are they cut down? If you remove top shock nut. Then slide a adequate length of tubing over stud so as to guide it when control arm is raised.You should be able to drop control arm away from spring make adjustment easier. There was longer adjusting bolts, IDK remember where I saw them. It seems early Z51 had a taller deflector.

FostersPerformance

I was trying to get a measurement from k member to ground instead of air dam. Reason is the front bumper i installed isnt adjusted fully so that can throw things off....but you cannot get 2 fingers between tire and hood. But same thing-hood isn't adjusted fully yet either. The FSM gives a ride height but dosent say if spec is to frame or pinch weld. So i figured k member to ground would be more a accurate, but way more difficult to measure.
and there are no shims or anything between spring and k member per VBP instructions.

Kevova

In the first part of section 3 should have something about trim height. There should be a measurement from rocker to the ground, ar both ends of door. It probably in mm around 200mm converted to 8" +/-. Pinch weld might be 5/8" if you measured to it.

FostersPerformance

Yeah i have the book. Its just unclear what they are measuring to. My car dosent have the lower rocker piece as it had the Greenwood kit since it was new. So i couldnt tell if the distance is to the frame or what. Ill get a pic before i guess what the distance was. Either way its low. Ive got the rear pretty much where i think is good. Trying to backyard align everything too has been fun. Once i can get the front height good i can have it aligned (if i can ever get plates for it). Im debating getting an alignment kit so i can do it myself as i trust anyone with it.

FostersPerformance

Kevova

J & K are from rocker to ground. IDK how Greenwood kit fits, but usually jacking points are still accessible. Remember pinch weld is lower.than rocker. You probably want atleast 6 ground clearance for the side skirts.

FostersPerformance

Thanks....ill get some pics after work