im looking for a composite spring for my 68 to compliment the Bilstein HD shocks and 460 front springs. This is strictly for street use, no racing, no autocross. I've gathered that I need 330-340 spring rate correct? Searching online I've been the prices range from $330-$450 for a composite spring, is that based on VBP, TRW and Hyperco brand names?

Id like to get VBP since I dont want the rear to be raised up, is there a way to determine what brand the spring is? a lot of the websites just have prices and specs but dont state the brand name.

 

I have the same setup in both my small block 66 and 68 coupes. Don't waste your time with Vette Brakes and Products, they are out of business. Try calling Danny at Van Steel in Florida. They will be able to steer you in the right direction. Jerry

 

I second calling Dan at Van Steel. Great help and you'll find what you need.

 

460 front springs use a 300 lbs composite in the rear with Bilstein HDs

550 front springs use a 360lbs composite in the rear with Bilstein Sports

 

though I haven't tried all of the combinations.

VB&P composite springs may still be available on eBay, or even on this Forum. That's where I got my 385 lb NOS unit (360 lb shortened one inch at the factory for a higher spring rate). With Bilstein Sports, it is not harsh at all, and kinda wish I had found a 420 lb spring instead. I just completed a rear-end rebuild with rebuilt trailing arms and heim-jointed strut rods. I have no idea what's in the front, but I need new shocks, and everything else up there.

 

Yes, the 360 lbs spring in my 78 OEM gymkhana suspended car with Bilstein Sports Rear only is very comfortable......firm but not harsh at all.

You cannot equate a composite spring rate to a steel spring rate..they are not equivalent. The OEM 78 Sport steel spring rate was 292lbs and was MUCH stiffer and harsh.

Like you ^^^^, one day when I need a new composite (the one now is from 1986), I will probs go to a 420 composite since the rear is still a hair too soft by modern sports cars' standards...my 10 C6Z06, 12 Lexus IS350 F Sport, and 08 Chrysler 300 with a slightly modified Suspension including Bilsteins/Strut tower brace, and ultra High performance AS ZR tires are all MUCH stiffer than my 78 C3.....

 

Call Van Steel.
They supplied all my suspension parts, are very knowledgeable and will give you good advise based on how you plan to use your car.
I still call them and ask for advice and they give it freely and haven't steered me wrong yet.
As a matter of fact just ordered a set of their tubular lower control arms for my 73.

 

Thanks for all the help guys! I will contact van steel. Most probably will go with a 330 or 360

 

why would installing a composite rear spring raise the rear of the vehicle ? Can you order a lowered composite spring ? Thanks

 

I bought a set of extra-long bolts, thinking I'd need them. The VB&P spring is fairly flat. I was able to lower the car an inch using the original length bolts, switching from a steel spring.

The Van Steel spring, I've heard, is more curved. I'd call them and ask if I were in the market for another spring.

 

 

Hey guys. My '80 steered and handled like a dream, until things started to break as I played with it. Rear shock fell apart in 2 pieces as I removed it, the power steering went bad and stopped working. Steeroids are waiting for time to put it on, and i just bought the HD Bilstein package...however, I wanted to upgrade my rear spring to a mono(mainly because the bastages at Speed Direct don't make the Sharkbite for us Batwing folks yet) and I'm at a loss for which way to go. I love the way my vette handled before, stiff but not break my spine(Like my 77), hugged the street as I took corners at speeds I never even thought of going before, and almost no body roll. The 77 rides so harsh I can drive over a postage stamp and tell you how much it's worth.

I've read through threads here and want to maintain the razor sharp handling. Everything I have read says the monospring makes it ride smoother, handle better and just makes it more fun. I want to play with it, maybe drag it, some autocross if I can ever get the time, but 99% of the time it will be a daily toy to make getting up in the morning a pleasure, and going home with a smile on my face because I get to drive my dream car again.

Unfortunately, the general consensus seems to be Bilstein Sport shocks for any monospring, and anything less than a 360lb spring sounds like mashed potatoes. One of the most recurring sentiments in this topic seems to be "I wish I had gotten the 420lb or stiffer spring." Corvette Central(my go-to) sells a full kit, but only go to 355. After reading on the forums the HD's were the best way to go for stock, I bought the set of those. I suppose I can send them back if I had to, but since I have the car on stands anyway, now is the time to get all this crap done.

Should I go with the 420(sourced from Corvette Mods) send the HD's back, swap for Sports, or keep the HD's and go with a 360? I live 5 miles back on a dirt road in the southwest, and i don't want to bottom out and hammer the bumpstops. It's a substantial investment, and I just don't want to have to buy everything twice because i didn't listen to the voices of experience.

 

You had me until "I live 5 miles back on a dirt road..." Yikes!

I choose my routes, and can avoid bad roads for the most part. 385 lbs is too soft for the way I drive my 4-speed, and I have zero interest in drag racing (My engine mounts are bad, winter project, so I can't even launch the car if I wanted to). With the swaybar in the back, it will probably be okay, but I want to make sure the front is balanced and stiffened first (again, winter project), lest I end up looking like a Mustang leaving Cars and Coffee.

I'd suggest starting a new thread, as your application is very different than titanle's.

 

You need to know what you have now before picking a composite Spring rate for the rear since you need to match the spring rate to the front coil rate. Otherwise, you will have an imbalance that could adversely effect the handling.

Do you have a rear 7/16 inch sway bar? If you do, then you have the gymkhana sport suspension with a 292lbs rear transverse rear spring. I doubt you do since you said the car rides soft now. The base suspension rear spring is 172 LBS which by sports cars standards is VERY SOFT, bordering on cadillac ride soft from the 70/80's.

If you do have a base suspension 80 C3 which 75% of the 80's were and not a gymkhana suspension C3 then you would want a 300lbs rear composite spring. If you have the sport suspension then the 360 spring.

The Bilstein HD's are fine with the 300 lbs spring but I use Sports in the rear only (360lbs Composite spring) of my 78 OEM equipped Gymkhana car with HD's in front with the sport front coil springs.

I would not advocate someone going to a 420 lbs rear spring without desiring serious sports car like handling for their C3..sounds like your car is more for cruising if you have the base suspension....The 77 and 80 suspensions are the same so if your 77 rode hard (gymkhana suspension) and your 80 is soft, then the 80 with the 172lbs rear spring is the reason although I must admit you say the 80 has "razor sharp" handling which is near impossible with the base suspension.....

So what do you have now?

 

VBP is out of business, call Dan at VanSteel he's a great guy. That's where I bought mine and they'll give you some good advice on what your set up should be.

 

Well, the rear sway bar is a puny little 3/8 bar, so I imagine it's just the base version. As for spring matching, I'm fine upgrading springs up front to match the rear. I'm new to suspension tuning, normally for my 4x4 projects I add or remove a leaf if it rides like crap, make sure it fits and change the shocks.

Thanks for the replies!

 

No the rear sway bar being present means you have a gymkhana suspension car..GREAT NEWS! Base cars have NO REAR sway bar. It is a 7/16 inch rear bar if it is an OEM GM bar. The front swaybar should be 1 1/8 inch which is pretty big even today and giant back in 1980. Assuming you have OEM front coil springs, they should be 550 lbs spings. If you go with a 360 rear composite to match your front sport coils, use Bilstein HD's in front and Bilstien Sports in the rear with the 460 composite. I think you will be very happy with the ride and handling.

 

Hollon, I'm confus. So the Gymkata suspension has 550lb coils in the front, so you say go 360 monospring in the rear, Bilstein HD's up front and Sports in the rear....then you mention a 460?! I had a long week, I can't parse that.

 

Sorry typo,,,meant 360 not 460 ...Bilstein Sports in the rear with 360 composite