TXCatfish

Looking to possible change from a 28x10 to 29x10.5w. Just trying to see what all it takes to make it fit. From what i've read it's pretty much a little beating inside the fenderwells.

Also what kind of changes should I expect? I'm making decent mph in the 1/8th and crossing around 63-6400rpm. Every once in a while it spins off the line or down track but mainly because of track conditions. Hoping this will help with that as well.

Thanks!

a05c

in Ray's car, its a full tub, narrowed rear etc etc etc.

Get with Eric and he can step you in the right direction.

TXCatfish

Thanks! I like those wheels!!! I was hoping to find a little info with the stock length rear.

JL ws-6

iTrader: (50)

Stock length rear likely won't work.

I put a 18192 hoosier on my car which is a 30.6 inch tire with a 13.4 inch carcass width, on a 15x12 double beadlock wheel.

If you are going to a 29.5W I would highly suggest a 12 inch wide wheel, to help spread the tire properly.

Now, 15x12 inch wheel, if you want to get one inside the car with a stock width rear it would have to have a 9.5 back spacing, which no one that I am aware of makes. So now you're narrowing the rear.

You will, have to minitub at a minimum, and the front lip if you don't pull the tire in far enough will have to get trimmed along with the rear bumper cover a bit.

I would suggest also shifting the lca inwards, build a boxed in mount so that it can be put inside of the inner lower mounting point so that the mount on the rear can also be moved inwards, allowing the tire to go inwards, which will allow you to not have to trim the 1/4 as much if at all.

I narrowed the rear 6 inches per side, and went with a 15x12 4.5 inch backspace wheel. this pulled the entire 12 inch rim inwards about 1.5 inches giving me lots of room around the outer fender lip, etc. the minitub we did cut WAY into the frame, think about the stock shock mounting point, we cut in past the bolt hole in the frame.

Cage structure is tieing all of the rear end up, and you will be moving the shocks inside the frame rails as well to do this.

You can get them in with less work than this, but if you want it to look right and sit right this is what you can expect to have to deal with, fwiw.

TXCatfish

Thanks JL! Lot of good info.

I was hoping just to make a tire swap and run my current 15x10 5.5 backspace wheels. I just read a few other treads some member were able to make it work by beating inside the wheelwells and some others said they had to trim the rear bumper.

I can deal with the wheelwells but any trimming on the bumper or minitubs I may look into a different size. Still I'm not 100% certain i'm going in the right direction or if this will improve my e/t and consistency in the 1/8. Just kicking the idea around.

Thanks!

Coach 02 A3 Z/28

iTrader: (10)

Jamie,

Call Madman at the shop. 281-432-0393

He did my car when I went to 29.5x10.5x15. You have to trim both the front & rear of the wheel well.

TXCatfish

Thanks!

JL ws-6

iTrader: (50)

Of pull the tires in like I did, a lot.


What issues are you having/what are you trying to get out of going to the bigger tire?

TXCatfish

Trying to get a little more consistency off the line. Every couple runs or few runs it spins off the line. If i'm one of the 1st few cars to do down may spin down track as well. But i'm also wondering if my e/t is down for my mph?? It varies on the weather but it's anywhere from 98mph to 101mph and goes 6.96 to 7.00's.

Reason i'm questioning the e/t is I see some cars go 6.50's - 6.70's at 100-102mph. What do you think? Is it just they make way more power or my setup a little off? Still 1/8 e/t it runs pretty deadly but if I can improve my tire size I'm going to look into it.

JL ws-6

iTrader: (50)

Tire size may help, what you need to do from the sounds of it, is get the car less "track dependant"

There's a few things I can tell you that will help with this, one being the biggest tire you can fit in the car.

Another, and this is not going to make it go any faster, it's actually going to slow the car... is put a transmission in with a longer first gear. If you're running a Th400 or a Th350 a glide would do wonders with the longer first gear towards making the car more consistent, and repeat a lot better.

As for comparing your MPH to others and ET, I'm going to guess that if you see people going a lot faster ET with no more MPH they're most likely lighter than you are. You can't beat physics.

Blown06

iTrader: (32)

I run a 29.5x10.5 on a 12" wheel and it looks pretty good. If I were ever to decide that I wanted to move to the 29.5x10.5W.......I'd probably put it on a 14" wheel.

TXCatfish

Thanks! I'm thinking without any major mods a 29x10.5 may be the biggest I can go. I'm running a th350 with a 275 low. It's been a nightmare and cost me most of the season last year to get this to work. But this year it's dialed in an working out pretty good so far.

I didn't even think about weight and others running a quicker e/t. That makes perfect sense. And I can almost guarantee the cars I'm talking about are lighter then mine. Thanks for the info, it helps alot!!!

I'm on a 28x10 5.5 and was told a 29x10.5w will fit. What modification did you do to make it fit under the car???

Thanks

JL ws-6

iTrader: (50)

a 28x10.5W will fit with more BFH to the front of the fender well or a standard minitub as long as your control arms are offset inwards as much as possible in the stock mounts, outer fender lip will need rolling as well.

I would, if it was me, try a 28x10.5W first and see if that helps, and if it does, maybe start looking for a 1.8 first gear glide to put in the car.

That longer first gear will do more for consistency than going from a 28 to a 29.5 will do trust me on that.

TXCatfish

Sounds good. Thanks! Still got a couple more races left but I'll be make the changes this winter.

JL ws-6

iTrader: (50)

I should mention that at your power level with the converter right the car will probably go a tenth or 2 slower with the 1.8 glide, but I bet it will mph a mph or 2 higher.

Back 1/2 of the run will be a good bit stronger. And if you're not on a 4.56 gear you probably will be able to go to it and make the car pull better in high than you are right now... if you're already on a 4.56 nevermind that lol.

TXCatfish

More then likely I will stick with the th350. Like I said it was a nightmare at first with this trans and now I finally got it working. So far this year it has been flawless.

I'm running a newly installed 12bolt strange with a 4.88. I don't remember exactly how much power I make but I think it's 430hp. I just got it re-tuned earlier this year.

a05c

Starting line ratio plays into part of how its going to work also. First gear ratio, rear gear ratio etc.

If you plan on stepping up at some point and going faster, I'd suggest a TH400 or a Glide. They're much more widely supported and don't have to do crazy stuff to them to make them live for a long time.

Like for instance, an SFI case and bell are much easier to find for a 400 than a 350.

JL ws-6

iTrader: (50)

A 2.75 first with a 4.88 rear you're going to fight the starting line all the time.

Start thinking about a Trans swap, your power level you do not need a super expensive glide, you can buy a brand new one in a Sfi case for about 3000 new with adequate parts, a used one would likely be a good option.

Be the best thing you can do for consists cry if that's what you're truly after

Blown06

iTrader: (32)

It's' under a 2006 silverado that is tubbed. So I don't have tire size fitment issues. Sorry.

JL ws-6

iTrader: (50)

18192 Hoosier, about the biggest 29.5 tire made, no 1-5 trim just a touch of the rear bumper cover. Pull it in enough and you won't have to touch the exterior. And my **** sits pretty low