Backspacing/Wheel sized EXPLAINED
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Backspacing/Wheel sized EXPLAINED
Most of yall know what this is, but I see a lot of questions about what drag wheel will fit with what tire.
On a very basic level the F-Body needs x-amount on the backside of the wheel (backspacing) and 2.5" on the front side (total width minus backspacing). Here's a quote from me in another thread:
"Here's the Backspacing deal as I see it. Instead of everyone trying to see what fits, just stick to what works. 8" wide Weld needs 5.5" BS. 10" Weld's need 7.5" BS. 7.5" wide Centerlines need 5" BS. See the correlation? It seems the F-Body needs X-amount of BS and 2.5" of wheel in front of the brake. stick to that and you should be fine. Oh and run the widest wheel within the x-amount to y-amount wheel size recommendation. For instance, if a Hoosier 26x10" wants 9-10" of wheel, run a 15x10" wheel. You'll get more contact patch."
As I said, I go by Jeg's wheel size recommendations after selecting a tire to use. Say you want to run a 28x10" Hoosier Slick, www.jegs.com says they recommend a rim size 8-10". Go with the 10". Other case may come up like ET Drags. They actually do not list a rim size. Id try to match the width listing and rim width up to 10". For example, if you have a 26x10" slick or 26x12" slick, go with a 10" rim.
A little more detail about Centerline wheels. A Convo Pro come in a 7.5" width and 8.5" width. BOTH carry a 5.5" backspacing. Going by what I said before, the 8.5 with stick out an inch, and the 7.5" with duplicate what an 8"-wide Weld wheel would look like with 5.5" of backspacing. Warriors only seem to come in 8.5" so either narrow your rear (like Joe K. did), or get ready for them to stick out. Also, Centerlines should not stock out or need spacers/grinding to clear the brakes. Weld wheels, however, will need some work. On the front, you can either grind or throw on a 5/16" spacer. The rear will need both. More or one with eliminate the other.
Front drag wheels: Centerline uses a 15x4" with 1.75" of backspacing. They seem to fit and not rub and not overly stick out at all. Weld i believe uses a 15x3.5" with similar backspacing. They need the modification listed in the above paragraph.
***Our bolt pattern is 5 x 4.75"
Hope this helps, and please feel free to correct me or add your experiences.
Ryan
[ January 25, 2002: Message edited by: The Underdog ]</p>
On a very basic level the F-Body needs x-amount on the backside of the wheel (backspacing) and 2.5" on the front side (total width minus backspacing). Here's a quote from me in another thread:
"Here's the Backspacing deal as I see it. Instead of everyone trying to see what fits, just stick to what works. 8" wide Weld needs 5.5" BS. 10" Weld's need 7.5" BS. 7.5" wide Centerlines need 5" BS. See the correlation? It seems the F-Body needs X-amount of BS and 2.5" of wheel in front of the brake. stick to that and you should be fine. Oh and run the widest wheel within the x-amount to y-amount wheel size recommendation. For instance, if a Hoosier 26x10" wants 9-10" of wheel, run a 15x10" wheel. You'll get more contact patch."
As I said, I go by Jeg's wheel size recommendations after selecting a tire to use. Say you want to run a 28x10" Hoosier Slick, www.jegs.com says they recommend a rim size 8-10". Go with the 10". Other case may come up like ET Drags. They actually do not list a rim size. Id try to match the width listing and rim width up to 10". For example, if you have a 26x10" slick or 26x12" slick, go with a 10" rim.
A little more detail about Centerline wheels. A Convo Pro come in a 7.5" width and 8.5" width. BOTH carry a 5.5" backspacing. Going by what I said before, the 8.5 with stick out an inch, and the 7.5" with duplicate what an 8"-wide Weld wheel would look like with 5.5" of backspacing. Warriors only seem to come in 8.5" so either narrow your rear (like Joe K. did), or get ready for them to stick out. Also, Centerlines should not stock out or need spacers/grinding to clear the brakes. Weld wheels, however, will need some work. On the front, you can either grind or throw on a 5/16" spacer. The rear will need both. More or one with eliminate the other.
Front drag wheels: Centerline uses a 15x4" with 1.75" of backspacing. They seem to fit and not rub and not overly stick out at all. Weld i believe uses a 15x3.5" with similar backspacing. They need the modification listed in the above paragraph.
***Our bolt pattern is 5 x 4.75"
Hope this helps, and please feel free to correct me or add your experiences.
Ryan
[ January 25, 2002: Message edited by: The Underdog ]</p>
#3
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Re: Backspacing/Wheel sized EXPLAINED
My list of rims I have had:
16x9 Draglite XP
-6.5 offset
-Great size for 11.5x15x26 ET Streets
-No grinding, fit great.
15x8 Prostar
-5.5 offset
-Great size for 10.5 ET Streets, or 275x50x15 Nitto Drag radials. 15x9 with 6.5 backspace would be perfect IMO.
-Major grinding to fit w/o spacers. The fins are GONE.
15x10 Prostar
-7.5 offset
-Great size for 11.5x26x15 ET Street.
-same grinding at 15x8.
-----------------------
CENTERLINE
15x8.5
-Will be flush with quarterpanel, but most cars won't squat that much and cut up the tire. If so I reccomend getting a airbag and trying 10-20psi.
15x10.5 Centerline Autodrag
-7.25 backspace. I recently owned a set of these for a day. <img src="gr_stretch.gif" border="0">
-They are also flush. Same as above. I sold them to Larry at www.ls1speed.com since he already runs Auto drag 15x9's in back, I'll squeeze to post pics.
16x9 Draglite XP
-6.5 offset
-Great size for 11.5x15x26 ET Streets
-No grinding, fit great.
15x8 Prostar
-5.5 offset
-Great size for 10.5 ET Streets, or 275x50x15 Nitto Drag radials. 15x9 with 6.5 backspace would be perfect IMO.
-Major grinding to fit w/o spacers. The fins are GONE.
15x10 Prostar
-7.5 offset
-Great size for 11.5x26x15 ET Street.
-same grinding at 15x8.
-----------------------
CENTERLINE
15x8.5
-Will be flush with quarterpanel, but most cars won't squat that much and cut up the tire. If so I reccomend getting a airbag and trying 10-20psi.
15x10.5 Centerline Autodrag
-7.25 backspace. I recently owned a set of these for a day. <img src="gr_stretch.gif" border="0">
-They are also flush. Same as above. I sold them to Larry at www.ls1speed.com since he already runs Auto drag 15x9's in back, I'll squeeze to post pics.
#4
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Re: Backspacing/Wheel sized EXPLAINED
I also owne a pair of 16x8 Draglite XPs but cannot remember the offset. Fit great but the 16x9s looked awesome. Looked as good as my current 15x10 prostars.
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Re: Backspacing/Wheel sized EXPLAINED
The Warriors come in 15x5.5, 15x7, 15x8, 15x8.5, 15x9, 15x10 as modulars, and 15X4, 15X12, 15X14, 15X14.5, 15x15, 15x16 as race only.
Convo Pros come in 15x6, 15x7, 15x7.5, 15x8.5, 15x10 as modulars, and 15X4,15X12, 15X14, 15x15, 16x15, 16x16 race only.
I have 15x8.5 Convo Pros on the rear of my [url=http://www.eastfork.cc/images/Galleries/MyZ/Hoosiers]car[/url with 26x9.5 Hoosier QTPs. No grinding, stick out about a 1/2" past the fender.
Convo Pros come in 15x6, 15x7, 15x7.5, 15x8.5, 15x10 as modulars, and 15X4,15X12, 15X14, 15x15, 16x15, 16x16 race only.
I have 15x8.5 Convo Pros on the rear of my [url=http://www.eastfork.cc/images/Galleries/MyZ/Hoosiers]car[/url with 26x9.5 Hoosier QTPs. No grinding, stick out about a 1/2" past the fender.
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Re: Backspacing/Wheel sized EXPLAINED
This is good information guys! Thanks for taking the time to write it up. I like to see the real numbers before I go out and spend the money. learned the hard way one time already!
(Print this one for the files) <img src="gr_grin.gif" border="0">
(like Joe K. did)
[ January 25, 2002: Message edited by: 2000 Camaro SS ]</p>
(Print this one for the files) <img src="gr_grin.gif" border="0">
(like Joe K. did)
[ January 25, 2002: Message edited by: 2000 Camaro SS ]</p>
#7
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Re: Backspacing/Wheel sized EXPLAINED
I'd like to see a Centerline person chime on on whether grinding is needed or spacers are neede for the 15x7.5, 15x8.5 etc. sizes.
One more note on the grinding. It's a lot. I know that JSears8 has pics on his website of what they look like.
One more note on the grinding. It's a lot. I know that JSears8 has pics on his website of what they look like.
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Re: Backspacing/Wheel sized EXPLAINED
My story:
I have Centerline Warriors w/ 15x5.5 front (3.5 bs) and 15x10 back (6.5 bs). The fronts, mounted on 205-75/15's have the same fender clearence as the stock 16's and required NO grinding or spacers. The backs, mounted on 305-50/15's stick out about 1.5" (for Camaro. I believe Firebirds should have less tire sticking out because of more fender flare?) and required some grinding of the calipers, about 1/8". Doing the math before I ordered this setup, I determined that the rear would stick out the same amount as a set of 17x11's with 7.5 bs (11-7.5=3.5 front space / 10-6.5=3.5 front space) and would stick out ~ 2" more than the stock 16x8's (8-6.5=1.5 front space).
I have Centerline Warriors w/ 15x5.5 front (3.5 bs) and 15x10 back (6.5 bs). The fronts, mounted on 205-75/15's have the same fender clearence as the stock 16's and required NO grinding or spacers. The backs, mounted on 305-50/15's stick out about 1.5" (for Camaro. I believe Firebirds should have less tire sticking out because of more fender flare?) and required some grinding of the calipers, about 1/8". Doing the math before I ordered this setup, I determined that the rear would stick out the same amount as a set of 17x11's with 7.5 bs (11-7.5=3.5 front space / 10-6.5=3.5 front space) and would stick out ~ 2" more than the stock 16x8's (8-6.5=1.5 front space).
#10
Re: Backspacing/Wheel sized EXPLAINED
Underdog,
Would you think the following would fit without sticking out too far?
CLL-075705547 15 in. x 7 in., 5 x 4 3/4 in. bolt circle, 5 in. backspacing, polished, Warrior wheel
Those should tuck under nicely right? I will probably run a 26x8.5 or 26x9 inch slick with them.
Thanks,
Chris
Would you think the following would fit without sticking out too far?
CLL-075705547 15 in. x 7 in., 5 x 4 3/4 in. bolt circle, 5 in. backspacing, polished, Warrior wheel
Those should tuck under nicely right? I will probably run a 26x8.5 or 26x9 inch slick with them.
Thanks,
Chris
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Re: Backspacing/Wheel sized EXPLAINED
[quote]Originally posted by Chris ARE 360:
<strong>Underdog,
Would you think the following would fit without sticking out too far?
CLL-075705547 15 in. x 7 in., 5 x 4 3/4 in. bolt circle, 5 in. backspacing, polished, Warrior wheel
Those should tuck under nicely right? I will probably run a 26x8.5 or 26x9 inch slick with them.
Thanks,
Chris</strong><hr></blockquote>
Perrrrrfect! do they not have a 7.5" wheel in the Warrior? hmmm...but yes, they will fit just fine.
<strong>Underdog,
Would you think the following would fit without sticking out too far?
CLL-075705547 15 in. x 7 in., 5 x 4 3/4 in. bolt circle, 5 in. backspacing, polished, Warrior wheel
Those should tuck under nicely right? I will probably run a 26x8.5 or 26x9 inch slick with them.
Thanks,
Chris</strong><hr></blockquote>
Perrrrrfect! do they not have a 7.5" wheel in the Warrior? hmmm...but yes, they will fit just fine.
#12
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Re: Backspacing/Wheel sized EXPLAINED
Grinding required to run a 15x8 prostar with 5.5" backspacing AND a 5/16th spacer on the rear ( http://jsears8.cz28.com/prostars/grinding ).
Justin
Justin