BUILD THREAD 86 GP 2+2~Blown 6.0

[81cutlass]

My 15x8.5 vectors have had 275/50 drag radials for 8 years and the tires were used and I got them so they are 10 year old tires, hard and wore out.

The new 275/60's are about 2" taller and they were a bit worrysome that they would clear the fender lip with the new taller tires since they only have like 3.5" of BS

The eventual plan is to get some 15x10 Pontiac ralleys on the car but I'm money spending fatigued for now so I'm going to swap the new tires on these wheels and deal with the correct wheels later.

10% never looked so big!

They should clear on a hard launch but just barely.

 

[81cutlass]

Random ramblings on wheel fitment.

The vectors I have are 8.5 wide with 3.625" BS. I actually traded an aluminum cutlass hood to Blake442 for them like 10 years ago! I have probably 1.5" of clearance to the frame, 4.25-4.5" of BS would be perfect to be centered. The wheel could take 5.125" with minimal (zero) clearance to the wheel but I don't know how safe it would be tire sidewall wise.

The wheel vintiques 15x10 ralleys I want are 5" BS, Good news! But, when you put a drag radial on a wider wheel it stretches the sidewall out and gets close to the frame.

The 17x9 year one ralleys I have now are 5" BS and barely clear also. They fit with the 274/40/17's since the sidewall tucks in really well but only have 1/4" to the frame.

The 15x10 puts all extra of the 1.5" wheel width in backspace compared to the 15x8.5 which is fine, the frame can totally accept it. And with no really extra frontspace, the outside of the tire shouldn't get into the fender lip.

This guy has a 29.5/10.5W with a frame notch on his 15X10's with a rolled fender lip.

I might be able to squeeze a 275/60 onto the 15x10 into the chassis unmodified, but I feel like it's going to stretch the inner tire wall close enough to the frame that i will need a mild, like 1/2" notch and not have to do anything to the fender well.

Basically I am chickening out buying the new wheels and mounting the DR's until winter since there is like a 50% chance I need to do moderate frame surgery to make them fit. At first I thought I could just get a 1/4" spacer and solve any frame fitment issues by moving the wheel out, but I'm going to end up putting the wheel into the fender with any more frontspace on the wheel, so where it is with the existing 8.5" wheel is where the 10" wheel needs to sit.

But that meaty 10" wheel on the rear is what I am going for, and if cutting the frame is what it takes it's what I'll do!

 

[81cutlass]

Went home to see some family for the weekend. Used dad's tire machine and swapped my drag radials.

It's a bit rough on aluminum wheels especially wider ones and it kinda dinged up one wheel on the lip but worse things have happened. It's would be nice to have a rim clamp machine but the $100 or so he paid for it it's definitely paid itself off.

 

[565bbchevy]

I think for a 15 x 10 rim to fit the way you want you are going to be doing a frame notch.

 

[64nailhead]

We have tried 8", 9" 9.5" and 10" rears. 8" make all issues go away. And we can put the same 275/60 on the 8-10" wide rim without any issue.

Jinkies, haven't kept up with this thread. Just seen your flex sensor wiring issue repair. Resistance checks on wire, highly prescribed by OEM's and most everywhere you look, but that means of wiring checks sucks. Been burnt by that, at work, for thousands of lost dollars of labor. Load testing with a halogen head light bulb - true test that works every time. Bigger PITA than resistance checking, but will confirm if the wires are good or bad.

Really glad you found it. Get to the track and see what it does!!!

 

[64nailhead]

Random ramblings on wheel fitment.



But that meaty 10" wheel on the rear is what I am going for, and if cutting the frame is what it takes it's what I'll do!
View attachment 155997

Someone should tell this guy that 35lbs is a , ahh, too much lol. If they don't look flat, then ..................smh. And I love the drag tire look as well.



Kidding aside, Hoosier has 2 275/60R15 - which one did you get? Really interested to see how they work. They're $40 less than the Mickey's.

 

[81cutlass]

Splashed some e30 in the car and took it on an an hour round trip to the supercharger pulley guy and picked up my party pulley. Flex content seems to work so I am going to splash some e85 in and see where it ends up.

Stock gt500 is 3", I had him make a 2.75 2 years ago and I had him make a 2.55 now which is as small as I can go. I need to buy a shorter belt.

And I mounted my drag setup. They stick out on the rear more than I would like but I jacked the passenger side up as far as I could and it didn't rub yet, the rear bar is kinda stiff so that helps.

I have a few things to wrap up before Saturday, going to try to make a few 1/8 mile runs to test the new setup.

 

[81cutlass]

I think for a 15 x 10 rim to fit the way you want you are going to be doing a frame notch.

Yeah, I did the quick measurements and with the new tires mounted, I think a frame notch is in my future. I'm totally OK with that, just not a project I want to undertake right now.

We have tried 8", 9" 9.5" and 10" rears. 8" make all issues go away. And we can put the same 275/60 on the 8-10" wide rim without any issue.

Jinkies, haven't kept up with this thread. Just seen your flex sensor wiring issue repair. Resistance checks on wire, highly prescribed by OEM's and most everywhere you look, but that means of wiring checks sucks. Been burnt by that, at work, for thousands of lost dollars of labor. Load testing with a halogen head light bulb - true test that works every time. Bigger PITA than resistance checking, but will confirm if the wires are good or bad.

Really glad you found it. Get to the track and see what it does!!!

Someone should tell this guy that 35lbs is a , ahh, too much lol. If they don't look flat, then ..................smh. And I love the drag tire look as well.



Kidding aside, Hoosier has 2 275/60R15 - which one did you get? Really interested to see how they work. They're $40 less than the Mickey's.

Yeah, I can see a 15x8 working well. These 15x8.5's fit pretty well. My 15x10 fantasy is just to stretch the tire out a bit partially for the look and tread width but I don't think it's going to gain much of anything in the traction department.

It was a huge relief to solve the flex wiring issue. I've never heard of the halogen light test, but just thinking about it makes sense. Actually loads the circuit vs. just checking continuity which as it turns out didn't do much in my case.

I got the HOO-17317 tires. They are not the DR2 style. The previous set of 295/50/16 I had are the DR2. They might be a different compound? But the only thing I noticed different is the tread pattern.

This is my 3rd set of hoosiers, I have never actually had MT's. The 275/50's i had were hard and old (like 10 years) and due for replacement. I bought them used from a local guy affordable but I had good luck with them.

My 295/50/16's were the only DR available in that size back when I had 4th gen wheels on this car

These 275/60's I bought since MT's were out of stock at summit,

Like I say I don't have experience with MT's but the hoosiers have been good to me. They seem softer than a MT tire, but I have never had an A to B test on them.

 

[81cutlass]

More prep work getting the car ready to race.

Drained the antifreeze and filled with straight water

Welded the exhaust bracket that cracked and broke where it attached to the rear frame rail.

Built some brackets to fasten the ecm and two step box instead of just gravity and zip ties

Test fit the DR's in the back seat. I ran a tool box and the tires on a cargo rack last year but I am trying to get away from that this year and run every thing inside the car.

And I replaced the bulb in the trunk and it never shut off. Turns out the shutoff switch isn't anywhere close to being in the right spot. Anyone with a stock 2+2 know how this switch is supposed to be mounted?

 

[Blake442]

I would imagine you could whip up a collar that fits over the end of the strut with a little tab so that as it closes it pushes the switch closed...
A hose clamp would probably work... depending on how nice you want it lol