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Hi again guys.
hoping to get some info so as to cut down on down time and "trial and error ".
my car is a 77 L82, factory gymkhana suspension.
Resent engine rebuild with alloy heads and previous alloy intake has resulted in a lighter engine and a bit higher ride height. Front end is currently sitting at 29 inches from floor to inside top edge of fender. A bit high. Around 27 and a half inches would be great for my needs. Due to my extreme budget, cutting the springs seems the only answer at this time. Read all about the 1inch off the coil is about 2 inches of ride height. But thats 1inch at compressed installed height. Very hard for me to get an accurate measurement with springs installed and weight on the car.
looking to drop the car 1 and a half inches. With the original gymkhana springs. Anyone have any experience with this??
1/2 a coil? Full coil?? Hoping not to pull it apart several times.
Next question, I've been looking at also adjusting the rear suspension. I see Zip sells a 8 inch bolt they say will help with ride height adjustment. But how long are the factory rear spring outer bolts? Mine are as long as you can get and still get the cotter pin in. But not certain about the length. I am certain they are factory if that helps.
Thanks for the help guy's.
Last edited by 4-vettes; Jul 12, 2020 at 03:43 AM.
Hi, if you're really on a tight budget and don't want to buy anything, the quickest way to lower the ride height and see what you're going to get right away is to use an acetylene torch to heat up a small section until the spring starts to drop. I've done this before on cars that I didn't want to take apart to cut the coils, but needed to drop it down a bit. I'd do each side of each spring, going back and forth from driver's side to passenger side until you get it where you want it.
Baby steps, cut 1/2 coil and see where it gets you. It's dependent on how much weight you've taken out of the front end as to how much it drops. Cut too much and you'll be buying new springs.
Thanks guys. I guess I was thinking before I posted this that yes, baby steps would be the way I'd have to go. Was kinda hoping someone out there had done this to stock gymkhana springs before and could save me a step or 2.
yes I have a coil spring compressor tool and everything needed to do the job. But working in a tiny one car garage I was hoping to get close the first time.
as per heating perfectly good springs with a torch. Ahhh, not at all a good idea. Sorry but I really am a professional mechanic.
as per the rear adjustment, is there a formula for how long the bolt needs to be to get the desired height adjustment?
See, this is what I'm up against. Looks like a bloody 4wheel drive. Factory original springs. Pretty sure there not shot. Lightening up the engine made a huge difference. Those are 255-60 /15's . Should fill in that fender better than that!
Hi 4-Vettes,From across the Tassie ..I cut a whole coil (not gymkhana)and the front end dropped 40mm which gave me better wheel clearance (was rubbing) and the coil sits in the pockets correctly...Drives and handles away better
In the rear end I got C4 bolts 10" and cut them down to 8 1/2" drilled them and used castle nuts(dropped 45mm)...they look stock and I didn't trust the nylon ones!!
Thanks for that. Not sure how high you were before the cut. But here in the land of speed bumps. I'm thinking that looks a bit too low for me. I do remember when I rebuilt my ft end a few years back that the coils never did fit properly top and bottom. Quess I'll need to pull them and make a judgment call.
Well, I got this far today.
1/2 coil cut off the bottom of each spring.
Crawling around on the floor isn't much fun for an old fart like me. So another day I'll get it back together and see how she sits.
I'm very lucky however as my employer gives me a whole day off once a week!
Well, I'll get to see how she sits when I get her back together. Another question guy's, how much bolt in the rear to lower? Is it one more inch of bolt will lower 1 inch?
They say 2 inches of bolt gets 1 inch of height. Still 15 inch tires. End of bolt needs to not be below the rim. Once you get ride height cut the excess off.
Thanks for that Derek, but not sure that really s sounds right. I'm at 29 inches to wheel arch now with stock bolts and nurathane bushings. Was sitting pretty good with the rubber bushings on the end of my composite spring. But the rubber bushes went to **** in just a couple of years. So I put in the nurathane bushings. They don't squash so now the rear is high. Not finding long 9/16th's bolts here in Australia. Anyone else have experience with this lowering of a rear? Do I really need 8 and a half inch bolts just to get one inch of drop at the rear? And if so no one has bolts that clear the rims with 15 inch tires.
Anyone??
WOW! Thursday night, finally got the car down off the jack stands. Was a bloody bugger of a job. One ball joint just didn't want to play the game. You guys know the drill.
cut half a coil off each spring. Set it down tonight after everything is torqued down. Roll the car back and forth in the garage, bounce it best we can.
measure it. Dropped 9/16th's of an inch!
Bloody hell! Exactly what I was hoping to avoid.
Will take it for a drive when I get time. But not thinking it'll settle another inch.
All back apart again! I'm not getting any younger and my back is killing me. Sooo, now what? Another 1/2 a coil will get things seated in the sockets better, will that be another 9/16th's of an inch? Or more because it's in the upper and lower sockets better?
and the rear spring bolts???. Still only one answer.
not going to attempt the rear until I can get the front sitting properly.
Any help guys???
Finally got the car out for a spin today. Bounced it down the road for a few miles. It is definitely better than before I started, but measuring it when I got her back in the garage showed that I got a total of 3/4's of an inch drop with half a coil cut.
car back up in air. Pulled the springs out again. Second time around things went much better. Cut another 1/2 coil off the springs.
My old body is killing me. Perhaps get it back together tomorrow. Was looking for 1 and a half inches from the start to get it to factory ride height.
Thinking I should be close now.
Then on to the rear early next week.
From: SUFFIELD CT USA 2023 C8 CORVETTE UN-MODIFIED FINALIST
2023 C8 of the Year Finalist - Unmodified
Be careful. When you do the rear it will shift your CG and slightly effect your front ! 8 inch bolts should be plenty for you and you can play with the adjustment easily. Quantity of gas will effect the rear also if you are fussy !
O.K. , so a second half a coil cut. (One full coil all up) Took it for a 30 mile drive. Too low! 26 and 3/4's. Putting my spoiler a bit to low to the ground.
seems I cant win on this one. Going to put a 10mm. Spacer under each spring in the days to come. Hoping that pulls me up closer to my target of 27 and a half. Front wheels are also noticeably tipped in at the top with this much lower ride height.
not going to play with the alignment until I can get front and rear dialed in.
Well today my 10mm spacers (approximately 3/8th's of an inch). Showed up in the post. Pulled it all apart again. Put the 10mm spacers in the pockets of the lower A arms. All back together and took it for a spin to settle it in. Now measuring at 27 and a quarter. Rear measurement is at 29 and a 1/8th. Slightly up from the start of all of this. Waiting on 8 inch spring bolts. Couldn't find any anywhere near my home, went to 5 bolt shops the other day and no luck. Thinking when I drop the rear the front may lift a tad more. My goal when all this started was 27 and a half front and 28 rear. Thinking if I trim these nolathane bushings in the rear a tad, as they don't compress like rubber. I should get this close. I started this thread as I was hoping to get the front ride height done in one go. 3 times I've had it apart.
perhaps I'll be able to help the next guy.
77 suspension questions- Ride height.
