I want to eventually run these rims on a 91 Firebird. In another recent post, ChevyKen said he was running 17X9.5 all the way around with 5.5" backspacing in the rear and 5.25" in the front. I am wondering if that's the same backspacing I would need for some 275/40ZR17s to fit all the way around. I've talked to some people and said that I could not do this on a 91' bird. They said it would rub in the front. Keep in mind, that rims will not be the only new things. I'm doing a complete rebuild of the suspension with Eibach springs most likely unless I find a better company. I will also be running Baer 4 wheel disk brakes. Most likely the SS system. Someone else told me that I would run into trouble with the sway bar . . . would Spohn's 36 mm still fit with all that I plan to do? If I must have different backspacing than ChevyKen's IROC, could somebody please tell me how to measure for backspacing? I priced a set of 4 just like his and I can get rims and centercaps for $1270.36 . Thanks.

 

There is a great article in October 99 issue of CHP called Zig Zag part II where American Racing's own Tracy Robinson test fit a number of wheels (TT II)on an 91 Camaro that was lowered 1 inch and for 17X9.5 size wheel they used 5.5 inch backspacing front AND rear with 275/40R-17 tires and they said that it will clear the stock front-end components and does not rub.(the car had 0.95 skidpad digits)Hope this help.

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1987 IROC w/T56 and a 383 TPI in the works

 

I'd just like to clear up that I knew that article said 5.5" front and rear, but that I chose to go 5.25 in the front to get a little more clearance between the rim and the sway bar. I am very happy I did decide on that, because mine would have scraped the sway bar with 5.5" up front....


Ken

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Bright red 86 Iroc-Z Choo Choo Customs Convertible
17x9.5 TT II's w/ 275/40x17's, BMR stb, Lakewood APR, Jamex 1.5" Lowering Springs
ChevyKen's Cars (ALL new!!)

Administrator @ ChevyWorld.net (Now in a BRAND NEW Design)

 

Ken, how much space do you have on the inside in the rear and for that matter the front? I'll be choosing rims around that size soon, but I want to have mine tucked in a little farther than yours. My IROC is lowered and I want my wheels to stick out no more than 1/2" more than stock. My other wheels are offset about 1/2" more than my stockers, and I rub the 1/4 panel over bumps. When I get bigger wheels I'll roll the inner fender, but I still prefer the look with them tucked into the stock spot. Thanks.

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The IROC Homepage
<A HREF="http://www.rit.edu/~jli4307/camaro" TARGET=_blank>
View the restoration of an 85 IROC</A>
Custom Thirdgen Subwoofer Enclosures
"I didn't know a bored out Ford could go so slow" -Shenandoah

 

Jim,
I am still in Europe, so Im not able to get to the car and take a measure right at this moment. I will return to the States on monday though, and will be happy to get the exact numbers then.
However, in the front it is real close - I guess no more than 3/16", but don't quote me on that one.

Feel free to shoot me an email as a reminder if I do not respond again to this thread after the weekend.


Ken

 

I figured there was so much talk about these rims I would dig out the info for everyone. ENJOY.....
Here are some SIZE OPTIONS all info was found in the Oct.99 isue of Chevy High Perf.
Article ZIG ZAG PART II. page 90-95.

This is the simplest and least expensive option. There are no custom offsets needed and vette sized YOKOHAMA A520 255/50 tires can be used.
SIZE BACKSPACING TIRES
FRONT 17x8 4.5 255/40/17
REAR 17x8 4.5 255/40/17

Standars offset in the front. Custom offset in the rear which will cost a tad more.

FRONT 17x8 4.5 255/40/17
REAR 17X9.5 5.5 285/40/17 (A520)

This is the maximum for traction and control with 275's front and rear. This set up will clear stock front end components and does not rub, even with the car lowered 1inch all the way around.

FRONT 17X9.5 5.5 275/40/17
REAR 17X9.5 5.5 275/40/17

SKID PAD RESULTS
skidpad(Gs) Slalom(mph)

91 Camaro (stock) .88 61.7
91 Hotchkis Camaro .95 66.9

99 Vette .91 61.0
99 Ferrari 355 .98 64.3
99 Viper GTSR 1.02 65.0
99 BMW 528 S .83 63.1
99 Lincoln LS6 .83 63.6


(note all suspention is HOTCHKIS, here are all the parts #'s)
PARTS PN#

Adj. Tie rod ends 1601
Bilstein (shocks&Struts) B46-1021(I used KONI 5way Adjs here instead)

Hardware Kit(control arms) 1701(this kit is not needed. I didnt use it on my 92Z)

Lower Control Arms 1301
Strut Tower Brace 2001
Springs (600lb front) 1903
Springs (100-140lb Rear) 1903
Torque arm mount 1040G
Panhard Rod 1501
Subframe Connectors (82-92) 4001


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Chris
1992 25th Anniv Z28 W/383 Stroker
536 RWHP 569 FT LBS
(chassis dynoed at Ramsies Perf.) www.go.to/TPI383

 

I want to go with the 17X8 with the 17/40/255 tires American racing rims in the 17X8 size are made in a 4" offset and a 4.75 Do I have to have a custom wheel made with 4.5 offset?

 

So the 17X9.5 will fit up front in a firebird and not just a camaro right? The sway bar will not be stock; most likely Spohn. And the brakes and spindles will also not be stock. I'll be running Baer. Anyone forsee any trouble that I might have? Oh, and just one last question. I love the look of the TTII wheel but am afraid it might look a little out of place on a 91' Firebird. I priced HRE rims recently but really don't feel like spending $1200 per rim. http://www.americanracing.com/wheels...ture=Longboard

This is another one I am considering. It might look better than the TTII on a newer car. I really like the open-ness of the rims. It will really show off the brakes. But these only come in 17X8 and 17X10. I'd really appreciate input; good or bad. I'll have to talk to one of the photoshop masters one of these days, lol.

 

If I go with the TTII's, I'll go with ChevyKen's advice and go with 5.25" backspacing in front, because I will be running a big sway bar. But when I turn the wheels, maxed to either side will a 275/40/17 rub on the sidewalls?

 

Mine only rubs at full turn while backing, just like the original 245/50x16's did. Not when driving forward..


Ken

 

Hey, ChevyKen

What size wheels and tires are you talking about?

 

AustinT,
Im refering to the 17x9.5" TT II's with GoodYear Eagle F1 275/40x17 that I currently have on the car. (pics in the sig)


Ken

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Bright red 86 Iroc-Z Choo Choo Customs Convertible
17x9.5 TT II's w/ 275/40x17's, BMR stb, Lakewood APR, Jamex 1.5" Lowering Springs
ChevyKen's Cars (ALL new!!)

Administrator @ ChevyWorld.net (Now in a BRAND NEW Design)

 

Well dang, lol. I can't have any rubbing whatsoever. I won't stand for it. Is there any way to run a 275/40/17 up front on a 9.5" wide rim without it rubbing? If not, looks like I'll have to go with 17X8s or run some smaller tires up front but I want the same size all around. Oh, and I'm still open to opinions about the Longboards.

 

soulbound, what size rims/tires are you running currently...?
As I mentioned above, my original tires (245/50x16) rubbed the exact same way - no more, no less. It is at full turn while say backing out of a parking lot etc.

Just thought I would underline that so that you don't get surprised if you buy maybe 17x8" rims with 255/40x17's or something and still experience rubbing in the before mentioned situation.
Not saying it will happen, but it is possible..


Ken

------------------
Bright red 86 Iroc-Z Choo Choo Customs Convertible
17x9.5 TT II's w/ 275/40x17's, BMR stb, Lakewood APR, Jamex 1.5" Lowering Springs
ChevyKen's Cars (ALL new!!)

Administrator @ ChevyWorld.net (Now in a BRAND NEW Design)

 

Right now there are some Eagle Alloy's (15X7-don't know why the previous owner did that) on my car. I'm running the stock size, 215/65/15. And the 275s only rub when you go in reverse? Why not going forward too? Is the range of motion of the tire different? The two major problems I am concerned with, is sway bar clearance and tire rubbing. I'm pretty sure all the rims I'm interested in will clear the Baer brakes. I've been checking the tire fitment book and it seems I'll be able to run 255s up front without a problem.

 

Sorry to break into your post again soulbounder but Ive another question.
I am going with the 17X8 rims. I would Like to lower the car a little, to close up the fender gap. The problem is I drag bottom already theres no way I can go any lower. Can I run a little taller tire than a 17/40/255 so the fender to tire gap isnt as big?

 

AustinT, it's not a problem. That's why the board is so great. It's for all of us. I'm sure you could run a 255/45/17 and possibly bigger to help close up the gap but don't overdo it.