offset for wheels on IRS car

FSTMRFR

FaST MotheR Fuc keR
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I am trying to figure out what size wheel offset and tires I can get on my IRS car...

I want a 15x10 wheel, but want to go 7.5" back space, and think I would need a 1/2 in spacer as long as I have the MM button head bolts installed (which I already do) ... If I cannot do a 7.5" BS, then I guess the 6.5" is the way to go, please help me out on this...

I am looking to run MT P325/50R15 28 X 13.50R15 (preferably) or P295/55R15 28 X 12.50R15 (alternative choice) tires on the car...

any help from you guys would be greatly appreciated... car is lowered but has coil overs on IRS, and quarter lips have already been rolled...

thx

car in SIG is what this is going on... the Alumastar 17's just not doing the trick

I am going to keep the 17 fronts, and just go to 15's for rear...
 
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Hood Rich
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15x10 with 6.5" backspace is correct for IRS. If you want to run the 7.5" backspace it will work with a 1" spacer. I fully condone that look you're after. I ran 15x10s and 17x4s on my Camaro and love the setup. I want to do the same setup for my Cobra. If only they used the same bolt pattern :(

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FSTMRFR

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thx for the reply... that is why I was thinking the 7.5" with a 1/2 inch spacer but what size tire can I get away with....?? I have yet to find someone (which surprizes me) that has done this, or is willing to divolge the info....
 

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Hood Rich
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We did 15x10 with 6.5" backspace and no spacers on my buddies twin turbo 99 Cobra. We used a 28x10.5 tire which is equivalent to a 325/50/15 radial.

5072551771_799a5c61b4_b.jpg


5072564227_caff0b8fe9_b.jpg
 

FSTMRFR

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THAT IS FU CKING SWEET!!!!!!!!!

that is exactly what I was looking for!!!!

did you need the button head bolts for the IRS cage?

what is your rear suspension set up... coil overs or springs... and did you roll your quarter lip???

also, do you have any scrubbing issues in the wheel wells inside or at top or where the side skirts bolt into
the inside of the quarter lip down below???


thanks for the info...!!!
 
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Screamin'04

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vbgarage1.jpg


15x10x6.5 is what I have on my non-irs GT. That being said, I don't see a difference in running the 6.5 bs with no spacer and a 7.5 bs with spacer, other than a visual difference with the mounting pad location in relation to the depth of the outter portion of the rim. Most people prefer the deeper look of a shallower bs. Perhaps I'm missing something with that though.

One thing to keep in mind; assuming that the axle flange width (or track width) of the IRS car is the same as that of the non-IRS car. I found that my 15x10x6.5 rims with Mickey Thompson 325R drag radials stuck out too far. It wasn't atrocious or bad looking, just a tad too far for me. Every time I articulated the rear suspension to pull into the driveway, the tire would tuck up into the rolled fender and rub/cut itself a bit. The solution was to narrow my rear end .75” on both sides and then beat the inner fenders a bit.

Badass camaro, that thing is sick. Not in love with the cobra, maybe it's the combination of the Red (not my fav) and the Rim (not my fav), or maybe it's the 99 side scoops (not my fav).. LOL...
 
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FSTMRFR

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well, first off, i dont have the option to narrow my half-shafts 3/4 of an inch on both sides as you stated... and seccond I hope you dont have 10x15x6.5 rims on your car... lol ... and the articulation is different per SRA and IRS...

you ever noticed the cobras from the front/side view, and seen the wheels tucked in farther than the front wheels... now compair that to a gt/SRA set-up... they dont tuck nearly as much as the IRS cars... obviously your statement is not the case... so what you did is narrow your rear end match that of an IRS car because you stated this "assuming that the axle flange width (or track width) of the IRS car is the same as that of the non-IRS car" which is the reason for this thread... i am not going to assume anything... need cold hard facts....

.... but you do have the wheels and tires i am trying to see if they fit... so if you get your over to my house, and see if they fit, this thread would have never been necessary... thx for replying....

as if you could not have sent this to me in an email....
 
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Screamin'04

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Bro, you're snorting too much sand over there... the track width is the same. Remember, I own a Cobra and a GT and at one point, both cars had identical rims (albeit different colors), and both cars sat the same with wheel offset. So my assumption on both track widths being the same is more of an educated guess....******. But since I know your next response already, i'll be sure to bring a plumbob and a tape measure when I put my rims on your car.

And I posted in here instead of emailing it to you because I was soliciting additional input on the subject from any other SVTP members with experience in the subject...

You're such a diva when you're hungry, go get a snickers.... :)

And don't ****ing hate on my 10" rims that are 15" wide... I hook ok still and trap at 8,600 with 2.78 gears.

Sent from my HTC Inspire biotch...
 

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Hood Rich
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Any more pictures of the yellow car on RTS's? Can't decide between polished or black RTS wheels for my screaming yellow 04, so some better pictures of yours may be my deciding factor.
 

FSTMRFR

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****** huh???

so, check this out... problem is...you are you "soliciting" (as you put it) your "plumbob" with your tiny/fat wheel combo... kinda like being hung like a campbell soup can... wheels on your ride...


and for the record, I asked to do this a year ago, but your a$$ wouldnt come off your rims for a couple of hours, so now you stuck doing it by yourself, while I am over here snorting sand and GSR (gunshot residue)... and drinking near beer, while walking everywhere on rocks, and living in termite infested building, with electricity that only works when the US purchases gas for the generator, and has hot water like twice a month, to include heater/air conditioning free environment, yup...life quality is dreamy here... sooo WHATCHA gots ta say now my friend....or should I say ******....

peace be with you....
 

FSTMRFR

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Any more pictures of the yellow car on RTS's? Can't decide between polished or black RTS wheels for my screaming yellow 04, so some better pictures of yours may be my deciding factor.



just for the record, before he gets his panties in a bunch, they are the Weldstar RT's, not RTS's... and they are the black ones... and they look SICK!!!!! fyi... I am sure he will thread jack this, and post pics for you to enjoy....



screamin'04 - ball is in your court....
 

Screamin'04

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****** huh???

so, check this out... problem is...you are you "soliciting" (as you put it) your "plumbob" with your tiny/fat wheel combo... kinda like being hung like a campbell soup can... wheels on your ride...


and for the record, I asked to do this a year ago, but your a$$ wouldnt come off your rims for a couple of hours, so now you stuck doing it by yourself, while I am over here snorting sand and GSR (gunshot residue)... and drinking near beer, while walking everywhere on rocks, and living in termite infested building, with electricity that only works when the US purchases gas for the generator, and has hot water like twice a month, to include heater/air conditioning free environment, yup...life quality is dreamy here... sooo WHATCHA gots ta say now my friend....or should I say ******....

peace be with you....
Don't forget the snickers bar... Liza Minnelli-Diva's Snickers Commercial(HDTV).mpg - YouTube

And keep your head down bro... want you back here safe (you whiney bastard)
 

Screamin'04

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And these are from before I narrowed the rear to tuck them in further. The right side sticks out further than the left.

DSCF0131.jpg


DSCF0148.jpg


DSCF0248.jpg


DSCF0227.gif


[/unjack]
 
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Hood Rich
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just for the record, before he gets his panties in a bunch, they are the Weldstar RT's, not RTS's


I noticed that after looking at this thread again from a computer. Car looks good Screamin! I want to do the same setup only with 17" front runners like on my Camaro.
 

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