domdaaxe58

Im looking to lower my 82 vette around 2'' to 2.5'' in the rear and 1'' to 1.5'' in the front. trouble is I cant seem to find a lowering kit that can lower a c3 corvette. If anyone knows of any decent kits let me know.

Thanks, Dominic

MotorHead

Cut the springs in the front and use longer bolts in the rear and don't go over any bumps larger than 1/4"

TheSkunkWorks

To elaborate a mite on MotorHead's post...

A carbide blade works nicely on the front coils, and you needn't bother re-closing the end you cut off (don't cut off the closed end if there's only one). Best to "waste" time on a couple of mock ups than to cut too much at once. When re-installing them, make sure the remaining closed end is properly seated in the upper pocket in the frame. Out back, just install 2" longer, quality spring bolts and run the nuts up to suit.

Don't know where your ride heights currently are, but I'd suggest not to ending up with the nose higher than the rear when measured at the fender wells to avoid the potential adverse effects of negative rake at speed. For the best reference points from which to work, use the "Z" and "D" specs (see pic below), before and after, making sure your suspension is fully settled between measurements, including when adjusting the rear spring bolt nuts. Good idea to have a full load of fuel and approx. drivers weight aboard for this, too. IMHO, if you're going to the trouble of lowering below original OEM heights, why not set up as near to factory recommended road race prep Z & D specs as is practical[?]

I'd caution against going so low that your half-shafts end up pointing down from the outer stubs to the inner yokes, as from level on any bump or squat will result in rear toe moving towards out, which isn't desirable when cornering hard. Note that, with a bit more work, the diff can be raised in the chassis as a counter to this issue.

Finally, running very low may require stiffer springs to avoid excessive bottoming, but that's not necessarily a bad thing...


TSW



edit - There is a lot of potential energy stored in the springs so use caution, and a proper compressor on the coils.

terry82

i dont know where you live but.up here in the north with some of the pot holes and bad roads.i would never lower my car .

domdaaxe58

Im in IL, I do my best at avoiding pot holes speed bumps ect.. But I would like to get rid of the wheel gap and at the same time give it a lower center of gravity. I just realized the passenger side is a 1/2'' higher then the driver side in the rear and about 1/4'' higher in the front. will I need to replace all the suspension on the car? Also if I wanted to lower the rear 2'' on an oem suspension what size bolts would I need? Thanks

heres a pic of my car...

doctorgene

Hello Mr. Dominic, I've been learning some of the ups and downs on suspension in the last two days. It sounds like I need to learn a lot more before I proceed down the path of self destruction. Talk to a lot of people before you learn by trial and error. Nice Car. Doctorgene

TheSkunkWorks

Oh, that's your car. Didn't make the connection with your wheel adapter thread (you need a catchy avatar), where I complimented your new wheels.

As for dropping the rear ~2", 8" spring bolts ought to do the trick out back. Tho it's not a common practice on the street, I subscribe to putting the driver's approx. weight on board for ride height setup. However, if you tend to have a passenger with you more often than not and don't press the limits when alone, I wouldn't worry about your weight.

That said, since your driver's side is already lower w/o your weight on board, it is somewhat important to deduce whether your side to side height variations are in the suspension geometry, frame or body, so I suggest taking those Z & D measurements before making any asymmetric spring adjustments for dialing them out. Make certain the car isn't sitting with the suspension in a bind from turning into it's parking place, and that this place is very close to level side to side and fairly lever front to rear. Let us know what you find.

domdaaxe58

I measured the length of the bolts and they are 6.5'' so if I got an 8'' long bolt that would lower it 1.5''? Also what diameter of bolt would I need? Its hard getting the diameter without taking it out. Thanks

doctorgene

Yes Sir: hey guy, you need to talk to the king of suspension who gave you a comment about the wheels today. TheSkunkworks Mr. Charlie He might talk you in to doing what you need instead of what you want, LOL. But the suppliers sell bolt kits to lower your car, buy one of them, these have grade 5 or 8 bolts with special nuts with them. Ask Willcox about them on this forum. It appears there is something else wrong the way you describe how the sides set so different. Do some more research, We at the Forum want to keep you around. Doctorgene

domdaaxe58

I put the car on more level ground and found out its only 1/4'' off not the 1/2'' I thought before. I will talk some more with them. And thank you for the kind words

gr8vet

If your still thinking about this, here is my 82. Cut one coil and added 2 inches to rear.






PM if I can help.

tt

Jughead

Cut the front springs 1/2 coil and 10" bolts out back. I wouldn't go any lower than 26.5" fender lip height. Watch your oil pan clearance.

bluegtp

i have some vb&p springs upfront and ended up cutting a little more than a coil off i believe. 10" bolts outback.... mines pretty low, but that how i like it!

have fun and your wheels look good on the white C3.....

MotorHead

Mine was lower at one time. It was a pain in a the azz, you will find out, my chin spoiler would hit on smooth higher speed roads where there was a small dip it. I had to plan my routes, going into and unknown parking lots was an adventure I won't miss.

domdaaxe58

Thanks for the help guys. Put the new 8'' bolt in and lowered it about 3/4'' for now. I'll have to get pics in the morning. But first things first, I need to change the oil tomorrow. But I cant find the right kind. The shop manual says SF SF/CC SF/CD oil only. But everywhere I go I cant seem to find anyone who carries it. Is there another oil I can use for the crossfire 350? Thanks

doctorgene

Just get some Valvoline Conventional SAE 10W-30 motor oil, It will work fine.
Questions?? 1-800-TEAM VAL Gene

domdaaxe58

It says do not use oils labeled only SA, SB, SC, SD, CA, CB, CC or CD. Just wondering what the difference is between SA and SAE oils. sorry, im kinda a noob. Thanks

MN-Brent

Usually to get a rear suspension that high, people go with a new TRW type of spring, not realizing how far out they are from the OEM arch character. If you have this TRW composite mono spring, this is adding to your problem out back.

Can you show us a picture of your rear end?

You may need 10 inch bolts to get where you need to be.

I just put in 10 inch bolts, cut to 9 inch and pretty much maxed out on the thread adjustment to get a new steel 9 leaf 80-82 spring to sit at 28.0 inch on a 27 inch tire (255-60-R15s)

My front, with 3/4 turn cut out of the coil, sits at 27 5/8 fender height on a 27 inch tire.

Brent.

Bee Jay

A 2.5" longer bolt only lowered the rear 3/4"? Wow. I guess you do need the 10" bolt.
Damn that car looks good with C5 Z06 wheels on it.
Bee Jay

MN-Brent

Also about the oil, you can find many discussions about ZDDP additives and levels at ~1200ppm.

I started running Mobil1 15W50 full synthetic this year as it meets the requirements of SL oil which has enough protection for your flat tappet cam.

Check it out:http://www.mobiloil.com/USA-English/...1_15W-50_.aspx