Corvette Forum : DigitalCorvettes.com Corvette Forums banner
1 - 20 of 22 Posts

·
Registered
Joined
·
1,477 Posts
Discussion Starter · #1 ·
Some of you may have followed my Conversion thread and know that I now have a C3 with a heads and cam LSx, 6-spd that puts an honest to god 380 HP to the ground (on an Eddy Current dyno less).

While I was planning to do some extravagant things with the suspension tires and brakes in the next couple years, I realazied . . . . given my occasional tendency towards excessive rambunctiousness, I'm kinda driving a death trap. So I've come up with most of a package that will cost about a third of my original plan and hopefully achieve about 90% of my original goal . . . a worthwhile trade to stay alive :)

The good news is that this won't take nearly as long as the previous phase and I'll structure it so that I can move up with over time with nominal extra costs.

WHEELS/TIRES
I have a buddy who is building his own naughty C3 (old school) and had a set of Torque Thrust II 17x8" rims with correct C3 offsets that he let go at a reasonable price. After much to-and-fro I settled on a set of Nitto NT450s 255/50x17. Total cost mounted and balanced was near as much makes no difference, $1,500 (rims and tires). I'll eventually burn up the Nittos and can resell the TT IIs for not much less than I paid. I went with 255/50x17s because they had they same diameter as stock (255/60x15) and were a reasonably priced A temp, 150mph speed rated tire with good tread wear. . . we'll see.

This is kind of a side note and may be more appropriate for the tires forum, but it seems to me that the difference between smoking tires and acceleration is in many cases attention to the accelerator, which is almost always telling you what the vehicle is willing to do. (Note: I don't have any electronic nannies: no traction/stability control, no abs, no fly-by-wire, . . . nothing). Of course fat sticky drive wheels make it easier to put the hammer down, but you can do a lot with less-than-perfect tires if you're paying attention. (I live in SoCal, where the average road temp is probably fairly high and surely this makes a difference.)

REAR SUSPENSION
It was my dream to go to a Guldstrand 5-link with his race style coil over, which I'm sure is utterly brilliant. But at nearly $5k installed . . . it's a little bit ouch. So I thought, okay, what are the biggest problems with my 82' rear suspension. Answer, it's fairly softly sprung so squat and dive is a bit of an issue. It also seems the the bushings in the rear are a bit tired and deflect. The solution was to go with all poly busings, a Vette Brakes and Parts Dual Mount mono spring for the rear and new heim jointed strut rods, and while I'm at it, 550lbs front coils. This should go a LONG way to eliminating squat, dive and deflection. I still have a bit of concern about toe change under heavy braking but we'll see. Total cost installed will be closer to $1,500 as opposed to $5k.

BRAKES
This is the doozy. I'm deciding amongst many options and slightly leaning towards building a C5 or C6 ZO6 kit for C3s, especially if I can sell it at a competitive price. Otherwise, prices range from $1k for VBP stock-like calipers, rotors, and pads to $4k+ for a full-tilt direct fit Wilwood kit.
 

·
Premium Member
Joined
·
532 Posts
BRAKES....A friend of mine is helping me engineer a bracket for my front C6 calipers on 14in rotors for my 69. Hopefully I should have it for Saturday????? He may want to keep it secret but I'll see if I can sneak a picture! I think its a great idea! I'm sure there are plenty of guys who want C5/6 brakes on there C3! I was lucky, I bought a pair of new C6 front brakes,rotors on ebay for $500! and then bought a pair of 14in slotted rotors for $315 and my friend is makin the bracket for free! $800 for great brakes...not bad!
 

·
Registered
Joined
·
512 Posts
Brakes: I think Baer is ready to ship their C3 setup. Probably 3K+ though. I am working on a Brembo GT conversion for my car but it requires some pretty serious machine/fabrication work (that is not close to complete).

Do you have a picture or the specs for the C5/6 Z06 calipers?
 

·
Registered
Joined
·
119 Posts
Brakes: I think Baer is ready to ship their C3 setup. Probably 3K+ though. I am working on a Brembo GT conversion for my car but it requires some pretty serious machine/fabrication work (that is not close to complete).

Do you have a picture or the specs for the C5/6 Z06 calipers?

C5, C5 Z06 and C6 calipers
Front - PBR 2 piston floating 1 9/16" pistons
Rear - PBR 1 piston floating 1 3/4" piston

C6 Z06
Front - 6 piston fixed Don't know piston size - 6 pads per front caliper
Rear - 4 piston fixed Don't know piston size - 4 pads per rear caliper
Thats 20 brake pads for the car!!


One thing that needs to be mentioned for all those C5/C6 brake wannabe's. The caliper pistons are considerably smaller than the stock C3 setup. That means your pedal effort will go up or your clamping power will go down.

With a smaller sized master cylinder, you can compensate for the smaller caliper pistons. If you run power, you would need a 1" master and for manual a 7/8" should be fine. Pedal feel can also be adjusted with pedal ratio. You also need an adjustable proportioning valve.

The C5 uses the same power pedal ratio as ours, same brake booster, and a 1" master cylinder. Brake proportioning is a function of the ABS/Traction Control system and is electronically controlled based on demand.

The big advantages I found with the C5 setup are looks and the floating calipers so you don't have the hassle of shimming for rotor runout.
 

·
Registered
Joined
·
4,607 Posts
Im taking notes. Id love to see some simple conversion options hit the market.

:cheers:

edit: I read your website 70 LS1. Great write up. Its my understanding that the stock 1" MC in a PB system will give me pseudo correct pedal feel.
 

·
Registered
Joined
·
119 Posts
Im taking notes. Id love to see some simple conversion options hit the market.

:cheers:

edit: I read your website 70 LS1. Great write up. Its my understanding that the stock 1" MC in a PB system will give me pseudo correct pedal feel.
You can use the stock manual 1" master with an early power booster and you should be fine.
 

·
DC Crew
Joined
·
4,751 Posts
I think you have a good plan.

Rumor has it that VB&P will be out with a complete C5 brake bolt on kit that uses the 13" C5 calipers.

Should hear more on that soon.

Also...since you have the LS in there, your front axle weight is much reduced. You will want to go coil over or VB&P front dual mount spring so you can adjust your ride height.

I just put an LS2 in a 85 Vette with a de-arched VBP front spring - and still have the nose of the car riding way too high.

The wheel choice is nice. There are more and more great ones out there. I went with Intro Pentia on my car. Intro has more styles available now as well that suit a later model better.
 

·
Registered
Joined
·
119 Posts
Is changing to C5 brakes even an upgrade?

Depends on you definition of upgrade. Most people relate pedal effort to good brakes. I think good brakes are ones that can stop you without the worry of fade. The pedal should feel firm with little travel, good feedback and easy to modulate. I also prefer the feel of manual brakes. Its all opinion.

Its an upgrade in the fact that they are much lighter, more resistant to fade, less prone to leaking and pumping air into the system and the aluminum calipers will dissipate heat better

The C5 brake install is all or nothing. You have to match all the components of your braking system to get it to work properly. True: pairing stock C5 fronts to stock C3 rears will result in a dangerously rear biased car that would require more pedal effort to stop.

Set up properly, they will have the same if not more clamping power than stock. But lets be realistic, if you can lock the stock brakes, you can lock the brakes and you don't need more clamping power.
 

·
Registered
Joined
·
1,343 Posts
Great thread. I have the stock C3 manual brakes on mine and have always felt that they were adequate brakes, but always felt like they could be better. I would like to see some of the adaptions that you guys have done to make C5/C6 brakes work. It would be nice to have more stopping power available when needed.

I am especially interested since I am going to be doing the LS conversion this winter and may need a little more stopping power.
 

·
Registered
Joined
·
1,477 Posts
Discussion Starter · #12 ·
Wilwoods on all 4 wheels under $1K:

www.corvettengineering.com
I keep coming back to this one. About the only thing that holds me off is that I'd like to go to a larger than stock rotor. While we're tossing around rumors, a little bird told me Van Steel is developing a direct fit 13" package for C3s that will use the SSBC Force 10 Calipers and a custom two piece rotor.
 

·
Registered
Joined
·
1,477 Posts
Discussion Starter · #13 ·
Depends on you definition of upgrade. . . .
Set up properly, they will have the same if not more clamping power than stock. But lets be realistic, if you can lock the stock brakes, you can lock the brakes and you don't need more clamping power.
Exactly. I'm basically looking for the things you mentioned, but numero uno is pedal feel. I don't have any serious leaks and shouldn't have any air in my line, but the pedal feel ain't so hot. It's soft . . . light, then begins to bite towards the end. Probably the calipers have just a little air in them that's compressing. I'm not loosing any fluid. I know people rave about the hydroboost, but I have one major thing against those setups and that is if the engine dies for whatever reason, puff you sorta ain't got no brakes no more. :nuts:
 

·
Registered
Joined
·
1,477 Posts
Discussion Starter · #14 ·
New Wheels and Tires

Well, the old wisdom of there is probably no single better handling upgrade you can make than to step up your wheels and tires sure was true in my case. I went from the stock 255/60x15 with Good Year GTII, to 255/50x17 Nitto NT450s. Wow, it's like a different car. I have manual steering and the biggest surprise was the reduction of steering effort even at lower speeds. The other things I was hoping for like a a reduction in wobbliness met or exceeded expectations, which is always nice. For those of you running around on similar stock setups and want to tighten up your ride, I can really recommend this upgrade. Also, I'm not a big fan of super low profile tires. In going with the 50 series I kept the total diameter identical so it looks right on the car, and the ride didn't suffer at all, maybe even improved overall because of the reduction in bounciness. :thumbsup:
 

·
Registered
Joined
·
855 Posts
Check out the Dragvette 6-Link Kit if you are interested in something to sure up the rearend geometry. I just installed it on my car....still have a tad of fine tuning to do but it really locks everything down in the rear making it all very rock solid. Everything use to feel snug before...now it feels rock solid as I can' budge anything at all. Real test will be next weekend to see how well it does.

Cost was about $900 so its much cheaper than the other kit you were considering.

Cheers....
 

·
Registered
Joined
·
1,477 Posts
Discussion Starter · #16 ·
Check out the Dragvette 6-Link Kit if you are interested in something to sure up the rearend geometry. I just installed it on my car....still have a tad of fine tuning to do but it really locks everything down in the rear making it all very rock solid. Everything use to feel snug before...now it feels rock solid as I can' budge anything at all. Real test will be next weekend to see how well it does.

Cost was about $900 so its much cheaper than the other kit you were considering.

Cheers....
Thanks for the tip, I'll check it out. I'm actually going to pick up bushings, dual mount monospring, and new strut rods tomorrow. I want to lock it down, but not like a solid axle/drag lock down, but more like a very tight controlled modern independent suspension that has proper compliance. . . well, reasonably close to it any way. :cheers:

Even just the wheels tires made a profound improvement in overall feel.
 

·
Registered
Joined
·
855 Posts
unless you just love R&R your rear suspension...you can save a ton of time if you get the dragvette kit as you have to R&R 99% of the same components on the dragvette kit as the dual mount rear spring. We just did both last weekend. Unfortunately I screwed up a camber bolt on my passenger side so I have to wait to get a new one before I can play around with it. If you like...send me a PM or email and I will try to upload and send you the drag kit installation dvd. It will give you a great idea of what it does. Basically it will keep your rear wheel camber firmly planted creating the best contact patch between the road & your tire at all styles of driving and also takes pressure off the half shaft as a supporting member so if you snap a half shaft the rear will be still supported.

Send me a PM or email and I will try to zip and upload the file to you later tonight or this weekend.

btw...I hope to have my LS2 swap by this time next year as that is truely the last mood in my resto-mod project that I need to complete. I got a ROD6 already along with a ton of other goodies....last thing now will be the engine which I am saving up for.
 

·
Registered
Joined
·
1,477 Posts
Discussion Starter · #18 ·
unless you just love R&R your rear suspension...you can save a ton of time if you get the dragvette kit as you have to R&R 99% of the same components on the dragvette kit as the dual mount rear spring. We just did both last weekend. Unfortunately I screwed up a camber bolt on my passenger side so I have to wait to get a new one before I can play around with it. If you like...send me a PM or email and I will try to upload and send you the drag kit installation dvd. It will give you a great idea of what it does. Basically it will keep your rear wheel camber firmly planted creating the best contact patch between the road & your tire at all styles of driving and also takes pressure off the half shaft as a supporting member so if you snap a half shaft the rear will be still supported.

Send me a PM or email and I will try to zip and upload the file to you later tonight or this weekend.

btw...I hope to have my LS2 swap by this time next year as that is truely the last mood in my resto-mod project that I need to complete. I got a ROD6 already along with a ton of other goodies....last thing now will be the engine which I am saving up for.
I'll PM later. I went to pick up my parts today and VBP failed to send the complete dual mount spring setup, so I got the bushings and heim-jointed camber rods. Out of curiousity, could I mix the the lower camber rods with the rest of the dragvette kit? Does the kit include a new (adjustable) spring?
 

·
Registered
Joined
·
1,477 Posts
Discussion Starter · #19 ·
SUSPENSION:
My usual installer finished the rear-end bushings, dual mount VBP monospring, and heim jointed camber rods for the rear, but suffered a shoulder injury and I had to take over for the front coil springs. I can do it, but I'm slow and don't have so much time, but I will finish installing the lowering 550lb front coil springs this Thursday. I look forward to seeing how much things tighten up and track. From just the little bit I got to drive (on old high profile tires while one of my new ones was being replaced) it's going to be quite a difference.

BRAKES:
I've made some decisions recently that substantially reduced my original budget and timeline for suspension and tires/wheels. However, I think I'm going to stick to my original idea of a pretty Gucci brake setup. So far, and I've pretty much settled on it, Hot Rod USA has the best engineered Wilwood based setup I can find for the C3.

I'll go for the 6 Piston Superlite on a 13" rotor for the fornt and a 4 Piston Superlite on 12" with integral parking brake for the rear. Both come with custom hubs for zero offset, maintaining stock turning radius etc. Additionally, I'll get the appropriate Master and new proportioning vale, etc., basically a complete brake system. Since it requires removing the rear trailing arms to install the new hub, I think I'll put on some offset trailing arms, but this raises the cost and pushes out the time line a bit.

In the meantime, my brakes aren't so hot and it seems the driver rear caliper is just not clamping much at all. So, for now I'm just going to replace with reman units available from Autozone, $60/pc after core, so no big deal.
You can learn more about the Corvette Kits by going here:
https://www.hotrodsusa.com/store/brakescorvette.html
 

·
Registered
Joined
·
1,477 Posts
Discussion Starter · #20 ·
In Action

Here's a little of the vehicle in action at the track. Nothing so special, but maybe interesting.
 
1 - 20 of 22 Posts
Top