new around here, please help with explaining offset for my application
01-16-2006, 11:16 PM
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Car: 1991 Z28
Engine: LB9
Transmission: terrible700r4
new around here, please help with explaining offset for my application
hows it going, im new around here, i tryed to figure out the whole thing about backspacing and offset, but im still a little lost.
bascially what i want to do is put either C5Z06 rims for a 4th gen or torque thurst2s, 17/9.5 up front and 18/10.5 or 18/11s out back. but heres the things im having a hard time finding out. im planning on dropping in a ls1 rear end, i want rear discs and posi, seems like the best way to go. and also im planning on putting the turbo iroc wide body kit on it. so im not sure how far out that juts the fenderlip. im mainly worried about caliper fitment, shouldn't be a problem with 18s right? and i want it to be flush or set in slightly to the fenderlip so i don't roll it. any advise or tips or easy way to read rim backspacing and offset, i tryed on another sight, but lets just say im more of a hands on learner.
but i still need the 2inch adaptor for the front then correct?
and whats this i though i heard about ls1 front brake conversions? sorry i know wrong forum but i couldn't find it on the searchs
bascially what i want to do is put either C5Z06 rims for a 4th gen or torque thurst2s, 17/9.5 up front and 18/10.5 or 18/11s out back. but heres the things im having a hard time finding out. im planning on dropping in a ls1 rear end, i want rear discs and posi, seems like the best way to go. and also im planning on putting the turbo iroc wide body kit on it. so im not sure how far out that juts the fenderlip. im mainly worried about caliper fitment, shouldn't be a problem with 18s right? and i want it to be flush or set in slightly to the fenderlip so i don't roll it. any advise or tips or easy way to read rim backspacing and offset, i tryed on another sight, but lets just say im more of a hands on learner.
but i still need the 2inch adaptor for the front then correct?
and whats this i though i heard about ls1 front brake conversions? sorry i know wrong forum but i couldn't find it on the searchs
01-16-2006, 11:43 PM
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Car: 91 Z/28, 89 RS Race Car
Engine: 305 stock / ZZ4 AFR 195 9.7:1
Transmission: T5 / t10 / Jerico
Axle/Gears: 10blt w 3.42, 9 in w /3.80 DL
If we are measuring back spacing the same way...
Meaningful Back Spacing is the distance from the outermost point on the rim of the wheel to the mounting surface.
But the wheel measurment folks measure wheels sizes to the tire mounting point not the outside of the rim.
A wheel with a stated size of 9.5 wide it is really 10.5 wide as measured by the ruller when laid flat on the ground.
Many wheel sellers only measure the tire mounting surface which is inside and of NO DAMN consequece at all when considering clearence.
So
a 9 inch wheel may really be 10 inches and a
9.5 may really be 10.5 inches
Here is where we are going...
10.5 less back space of 5.5 or (52% offset) = 5 inches from the furtherst outboard part of the wheel to the mounting surface.
10.0 less back space of 5.5 (or 55% offset)= 4.5 inches from the outboard part of the wheel to the mounting surface.
You need to know how the wheel sellers are measuring their wheels to do the math. Most dont know the dimensions of what they are selling. Ask them the width of the tire mounting point and then the overall width. Ask them what is the distance from the mounting point to the ground when the wheel is unmounted and face up.
Meaningful Back Spacing is the distance from the outermost point on the rim of the wheel to the mounting surface.
But the wheel measurment folks measure wheels sizes to the tire mounting point not the outside of the rim.
A wheel with a stated size of 9.5 wide it is really 10.5 wide as measured by the ruller when laid flat on the ground.
Many wheel sellers only measure the tire mounting surface which is inside and of NO DAMN consequece at all when considering clearence.
So
a 9 inch wheel may really be 10 inches and a
9.5 may really be 10.5 inches
Here is where we are going...
10.5 less back space of 5.5 or (52% offset) = 5 inches from the furtherst outboard part of the wheel to the mounting surface.
10.0 less back space of 5.5 (or 55% offset)= 4.5 inches from the outboard part of the wheel to the mounting surface.
You need to know how the wheel sellers are measuring their wheels to do the math. Most dont know the dimensions of what they are selling. Ask them the width of the tire mounting point and then the overall width. Ask them what is the distance from the mounting point to the ground when the wheel is unmounted and face up.
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