Lowering front end of 85
11-02-2007, 08:11 PM
#1
Pro
Thread Starter
Lowering front end of 85
I am trying to figure out how to lower the front end of my 85 autocross car. I have removed everything from the car that isn't necessary. I installed an 8 point cage and a 96 355 Vortec carbureted engine. In the process of building this car, it seems like the front end raised up about 2 inches. I would like to drop the front end about 3 to 3.5 inches.
I am still running the stock 85 suspension, but would like suggestions on suspension mods, particularly on the front end. Is coil overs an option top consider for a C4?
Dave
I am still running the stock 85 suspension, but would like suggestions on suspension mods, particularly on the front end. Is coil overs an option top consider for a C4?
Dave
11-03-2007, 12:01 AM
#3
Race Director
you can remove the rubber shims on top of the middle of the spring, and at the end perches, but you'll be lucky if that give you 1". I don't know who make coil-overs off-hand, but I'm sure they are available.
Vette-brakes may may springs that will lower your car also.
Vette-brakes may may springs that will lower your car also.
11-03-2007, 08:24 AM
#4
Melting Slicks
you can remove the rubber shims on top of the middle of the spring, and at the end perches, but you'll be lucky if that give you 1". I don't know who make coil-overs off-hand, but I'm sure they are available.
Vette-brakes may may springs that will lower your car also.
Vette-brakes may may springs that will lower your car also.
Good call David! You can also take both front lower control arms off and cut out the aluminum triangle pocket where the spring perch end sits. Get a VERY GOOD aluminum welder to drop it 1" and reweld.
Mallett Cars used to do this years ago on C4's and works great. So with David's mod and this one I believe you can gain a 1 & 3/4 more drop.
Then use the rear lowering bolt kit from Mid America and lower the rear and corner balance & align.
Aaron Quine
11-03-2007, 08:52 AM
#5
Pro
Thread Starter
lower c4
Thanks for the advice guys. At this time I am running in BP class. I am way outclassed, but my son and I want to continue to "work" the car until we are at least competitive. I will contact vettebrakes to see what they have to offer for the front spring and also consider the front spring perch modification.
Any others that have any thoughts on coil overs for a C4
Thanks again.
Dave
Any others that have any thoughts on coil overs for a C4
Thanks again.
Dave
11-03-2007, 08:56 AM
#6
Melting Slicks
A word of caution here....
Removing the rubber shims will lower the car, but you want to make sure that the spring isn't hitting the top of the cross memeber between the mounting points. That would significantly change the spring rate.
If it is contacting the cross member it is going to lower the car a lot more too, since you will be flattening the spring.
Also make sure you put something between the frame and the spring that has some rubber on it so that the spring isn't sitting directly on a narrow piece of metal. That can cause a stress riser in the fiberglass spring and cause it to crack...
Removing the rubber shims will lower the car, but you want to make sure that the spring isn't hitting the top of the cross memeber between the mounting points. That would significantly change the spring rate.
If it is contacting the cross member it is going to lower the car a lot more too, since you will be flattening the spring.
Also make sure you put something between the frame and the spring that has some rubber on it so that the spring isn't sitting directly on a narrow piece of metal. That can cause a stress riser in the fiberglass spring and cause it to crack...
11-03-2007, 10:37 AM
#7
Team Owner
IIRC, Vette Brakes has a lowering kit that will drop the car about an inch in the front. It includes new shims that replace the stock rubber ones.
Do a search in C4 Tech on "front spring" or similar keywords. There have been some issues with some lowering kits where the replacement shims were glued in place and the adhesive wasn't strong enough.
Do a search in C4 Tech on "front spring" or similar keywords. There have been some issues with some lowering kits where the replacement shims were glued in place and the adhesive wasn't strong enough.
11-04-2007, 08:22 AM
#8
Pro
Thread Starter
Is there such a thing as dropped spindles for a C4? If so, would that work?
Dave
Dave
11-04-2007, 11:29 AM
#10
Pro
Thread Starter
[QUOTE I have a VB&P adjustable front spring on mine. It did a nice job to lower the car and the spring works great for autox.
Do you remember the part # of the spring that you used? What year C4? and about how much did the front of the car drop?
Thanks for your help.
Dave
Do you remember the part # of the spring that you used? What year C4? and about how much did the front of the car drop?
Thanks for your help.
Dave
11-04-2007, 12:27 PM
#11
Team Owner
I looked thru my Vette Brakes catalog and there is no adjustable spring setup for the 84-87 cars. The 88 and later cars can use the V-B "Extreme" front spring (it's $500 by itself
).
IIRC, V-B (forum supporting vendor) posted something a few months ago about their spring setups and they didn't have any plans to make the adjustable spring for early C4's.
That's too bad as their "Extreme Touring System" was designed as an autocross package and they got technical help from SCCA winners like Danny Popp and Guy Ankey. That system is supposed to be very close to the suspension system on the 88-90 Corvette Challenge cars that GM built for SCCA racing.
). IIRC, V-B (forum supporting vendor) posted something a few months ago about their spring setups and they didn't have any plans to make the adjustable spring for early C4's.
That's too bad as their "Extreme Touring System" was designed as an autocross package and they got technical help from SCCA winners like Danny Popp and Guy Ankey. That system is supposed to be very close to the suspension system on the 88-90 Corvette Challenge cars that GM built for SCCA racing.
