Backspacing w/ 15x8

[TWISTER]

I plan on ordering new wheels and running 15x8 on the rear w/ 275 50 15 M/T drags and 15x6 195 / 15 out front but what should I order for backspace? The wheels are the warrior Centerlines. I saw they listed 3 3/8s and stock is 3 1/2 so will this work with a wheel 1" wider on the rear and keep it the same for the front? Thanks I just want to double check.

 

[Slow91z]

On a 8" wheel you want as close to 4" of BS as possible, I have welds with 3.5" BS and I had to roll the fender with 275/60's.

With a 4" it should fit just right and I thought they made warriors in a 4" BS but I was looking before I replied and didn't see em.

 

[norbs]

not sue if this will help you this is 3.5"b.s on a 28 x 10.5 slick

http://www3.sympatico.ca/norbz/megaslic.JPG

 

[2QUIK6]

I've got 15/8.5 rims on the rear with 3.75" BS and fitment is perfect for 275/50/15, 275/60/15 and MT ET streets 28x11.5. So anywhere in the 3.75" - 4" BS will be fine.

 

[TWISTER]

From what Ive seen listed 3 3/8" and 5" is what is pffered I guess I'll have to call Summit and see but Im sure I've seen them on GNs before.

 

[2QUIK6]

From what Ive seen listed 3 3/8" and 5" is what is pffered I guess I'll have to call Summit and see but Im sure I've seen them on GNs before.

5" BS is too much for a 8" rim. Stock is 4" and thats about as close as you can get without rubbing the frame rails witha 275 tire. The added width will help some to put the 275 out a bit further, but not enough for a 5" BS.

 

[QUIP'6']

5" BS is too much for a 8" rim. Stock is 4" and thats about as close as you can get without rubbing the frame rails witha 275 tire. The added width will help some to put the 275 out a bit further, but not enough for a 5" BS.

STOCK IS 3.5 NOT 4" SO I THINK 3 3/8 WILL BE FINE ITS ONLY 1/8 DIFFERENCE FROM STOCK

 

[QUIP'6']

5" BS is too much for a 8" rim. Stock is 4" and thats about as close as you can get without rubbing the frame rails witha 275 tire. The added width will help some to put the 275 out a bit further, but not enough for a 5" BS.

NOT TO HIJACK THREAD BUT HOW IS THE 6131 THINKING OF GETTING IT I HAVE A RESTALLED D-5 WILL THAT BE SUFFICIENT ALSO HOW IS IT AT 18# COMPARED TO A STOCK TURBO WILL BE GETTING RAZORS ALKY IN SPRING GOT MY MOTOR TORN DOWN PORTING HEADS AND INTAKE RUNNING STOCK CAM RERING AND BEARINGS

 

[2QUIK6]

NOT TO HIJACK THREAD BUT HOW IS THE 6131 THINKING OF GETTING IT I HAVE A RESTALLED D-5 WILL THAT BE SUFFICIENT ALSO HOW IS IT AT 18# COMPARED TO A STOCK TURBO WILL BE GETTING RAZORS ALKY IN SPRING GOT MY MOTOR TORN DOWN PORTING HEADS AND INTAKE RUNNING STOCK CAM RERING AND BEARINGS

Here's a current discussion about the GT6131E
http://www.turbobuick.com/forums/showthread.php?t=174009
The turbo really wakes up at 20+ psi. Can run 20# with no knock on pump gas. I've razors kits also so its usually set at 24# which is where it works best with stock untouched heads.

About the Backspacing, gnttype.org is down right now, but the Stock steel chrome wheels on 86/87 GNs are 4" BS and the TType aluminum rims are 3.75", I just went thru this getting new rims over the summer.

 

[QUIP'6']

Here's a current discussion about the GT6131E
http://www.turbobuick.com/forums/showthread.php?t=174009
The turbo really wakes up at 20+ psi. Can run 20# with no knock on pump gas. I've razors kits also so its usually set at 24# which is where it works best with stock untouched heads.

About the Backspacing, gnttype.org is down right now, but the Stock steel chrome wheels on 86/87 GNs are 4" BS and the TType aluminum rims are 3.75", I just went thru this getting new rims over the summer.

on g body parts it says 3.5

 

[UNGN]

on g body parts it says 3.5

3.5 is too much for a wide tire unless you roll the fender lip.

Given a choice between 3.5" and 3.75", I would pick 3.75".

Given a choice between 3.5" and 4", I would pick 4" because you can always add a small space to the 4" wheel to keep it off the frame.

The backspacing on T wheels is 3.75"

The backspacing on GN wheels is 3.9"

 

[turbobose13]

I have 15/7 with 275/60 with 4" back space and have too use a spacer, on my GN my buddy has a ttype with the same set up and it fits fine, all car's are different.

 

[2QUIK6]

I have 15/7 with 275/60 with 4" back space and have too use a spacer, on my GN my buddy has a ttype with the same set up and it fits fine, all car's are different.

The rearends are not centered on our cars, each one is different, some rub on driver side, others on pass side, or none at all or both sides since manufacturing specs weren't all that tight. Also, the Ttypes have aluminum brake drums that are thicker than the GN iron ones which makes the wheel stick out a bit further and clear the frame rails easier.

 

[TWISTER]

My choice is a 3 3/8" and 5" and that is all that I can see listed so unless somebody has a cure all for my problem I think I may have to go with another wheel. I dont dare call Summit for their opinion because then Im paying shipping till I find the right combo. Thanks again

 

[norbs]

Well i posted pics with measurements, it can't get much clearer. A 4" offset wont fit a big tire, 3.75 will fit a 28 x 9" tire on a type rim, you will need a 3.5" offset on a et street or simlar with a slick sidewall you might be abble to fot a 3.75 with a radial since it has a square shoulder.


P.s my lips are NOt roller, but i must use air bags for the slick or it will rub on launch!

 

[2QUIK6]

The 3 3/8" BS will work as long as you don't go wider than a 275 tire or 28x11.5 ET Street which I think is the same with as a 28x10 ET Drag.
I have 3.75 BS witha 8.5 inch rim which would put my outer edge 1/8" closer to the lip than your 8" rims with 3 3/8" BS and I don't have the lip rolled, but I do have a PS air bag....but again, remember that each car is a little different.
Also, check with your local Discount Tire, I've had luck with them being able to work with manufactures to get customer wheel sizes that were not advertised before.

 

[TWISTER]

Thanks for all the help

 

[turboman38]

I have 15X8s on the back of my T with 275-50-15 BFGs. The rims have a 4 inch back space and I had to put a 3/8 spacer on to keep the tires from rubbing the frame.