Bud2

I called Vette Brakes and Products a while back to ask them what size backspace I would be able to use with their shortened mono spring and off-set TA? They said 5.5 inches. Being trusting, I went and pushed the issue to the max and bought the 8’ rims and Mickey Thompson street radials, 275/50R/15 that have a tread width of 10”and stand 26 inches tall (same height as my street tires). I figured I was going to be in trouble right away when I measured the backspace of the new rims at 5 5/8”. But VBP were wrong too. It took me a while to get things organized but at least they are on. I had to use my .25” spacers and grind a bit more (maybe 3mm) off the corner of the spring, then they will fit. This leaves me with about 3mm clearance from spring to rim and 3mm clearance from frame to tire at the top. Not much room to spare but at least I’m not auto crossing.

Because I’ve had to move the tire out the .25”, I now have a problem with the fender lip. Even with the lip trimmed a little, I’m only about .5’’ from cracking the fibreglass if I were to hard launch or to hit a bump in the road. As such I’m going to have to use about an inch of high impact rubber ‘shims’ placed between the trailing arms and override bumpers. So in race trim, my suspension is going to consist of the 16 pounds of air in the tires. It’ll be a bouncy ride out to the strip!



Clearance at the top.


Spring Clearance.


View from the back.


View from the front

toddalin

They stick out a bit much for my taste. You may gain some spring and fender lip clearance by adding a bit more negative camber.

Bud2

They do stick out too much. But understand it is only for the strip that they get used. The MT tires get put on and the shims get put in, go racin' and reverse the proceedure to drive to church. While the negative camber would give me a bit of room, I don't think its the answer. It just gonna be this way or by new rims and tires. Beside the cost of exchanging, I think I'm gonna need the 10 inches with the new motor being 500hp at the crank.

Bud.

54greg

Those are REALLY tight. It sure looks like they will rub

Kerrmudgeon

Looks like the 70's to me....all you need are a set of air shocks now!

66since71

The spring end and hardware is way too close to the tire sidewall. Expect to cut the tire during cornering. Or in your case hard launches. First hand experience.......

If you can recover any money on the deal, now is the time. Otherwise your next expense will be for body work...

Harry

OldKarz

Pilot Dan

I understand you are only using these on the strip, but are you really gaining any measurable performance advantage over a slightly smaller tire/rim combo??? Pilot Dan

66jack

You remember the 70's?

63Corvette

Rear negative camber is the right answer for autocross or track. However, since the car squats on launch, with attendent negative camber, the right answer for drag strip is for some POSITIVE camber, which then changes to a FLAT race tire/road surface interface on launch. It DOES look like your tire will hit the fender (maybe crack it) on launch....especially if you dial in positive camber. I would solicit the opinion of Donny Brass here on the forum, as he is the C2 Drag Strip expert.

nassau66427

It looks as though your spring end bolt hangs down below the rim.

I don't know about Aussie rules (do you even have any? ) but here a lot of places won't let you run if you have suspension bits hanging below the rim.

A flat tire could have you singing a Faron Young song.

highschool67

Don't we all?
I have a set of Monroe Air Shocks on my 67 camaro that I installed in the mid 70's.... They are still holding pressure!

63 Roadster

Do you feel that if you had used a 5" BS it would have been better? What about 4.75" ?

427Hotrod

That looks a little tight back there. You might want to consider dropping down a size with different wheels. You'd be amazed at how well a Vette will hook on small sticky tires. You don't want it riding on the snubbers either. You want a good stiff spring and shocks with the snubbers just being protection.

JIM

oldsarge

Me too, but it is the 60's I have trouble with..........

magicv8

Before I swapped the 9 leaf for a 7 leaf, air shocks were necessary to keep the headlamps out of the trees when I load the car to go mountain hiking.

Adjusting headlamps 6 or 8 times a year is a PITA compared to putting in air and letting it out. The 7 leaf is too stiff on an empty cabin unless the tank is full. If I change the spring again, air shocks will be baaaack.

firstgear

one good hookup and the back end squatting down....UGH.....not sure I would trust the rubber bumpers to protect me.....I know this won't help you now, but knowing the backspace of the wheels that were on previously coupled with the tire dimensions, you could have calculated how close the tire would end up to the various part. It isn't hard to do. Need a piece of paper, computer to get tire specs and about 15 minutes, if you had calculated that the tire would be within 1/4" - 3/8" of contacting something, that would be way too close.....would have saved you a bunch of grief and messing around.....