Help with getting the proper offset (with KW arms, toyota spindles and RX7 IRS)

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Help with getting the proper offset (with KW arms, toyota spindles and RX7 IRS)
impulse avatar
impulse
+1y
Edited: 4/5/2006 2:39:36 PM by iLLairgasm

Edited: 4/5/2006 2:38:11 PM by iLLairgasm


PLEASE READ THIS ENTIRE POST

I need to figure out what offset I need for a set of 18x7 wheels for my mazda (92 b2200).... the problem is I don't have the body or box on at the moment.


Here are the details though... im hoping someone can help me out here.


front setup....

Kustom Werks Control arms with Toyota spindles


Rear setup

87 RX7 IRS


I will be using 4x4 metal all around too.


Anyone able to give me the right number for the offset? I need to order my wheels ASAP.
impulse avatar
impulse
+1y
Anyone???
livinlow avatar
livinlow
+1y
45mm offset or 6.5" backspacing you'll be fine.
impulse avatar
impulse
+1y
Edited: 4/5/2006 12:24:19 PM by iLLairgasm

that leaves me with like no dish at all then hey.
livinlow avatar
livinlow
+1y
Edited: 4/5/2006 1:09:09 PM by Turbo32

nope, you find me a mazda with a wheel with a lip to it and you have found a miracle.

Mazda's have a FWD offset to them and in most cases it's alot more then any FWD car has. The rear you can go with a narrow'd rear end, but up front you're really not left with many options.
impulse avatar
impulse
+1y
Stupid Mazda's... haha...

So you think a +45 will be good front and rear, does it make a difference if its 4wd metal or not?
dssur avatar
dssur
+1y
a 7 inch wide wheel will only need a +37, +39 at most.

a 6.5 backspace 7 inch wide wheel does not equal +45, it equals +63.

the reason he is asking is because using toyota hubs/spindles on KW arms may or may not have changed the measurement from the inner fender lip to the mounting surface of the hub, where the backspace meeasurement is derived from.

It absolutely changed it in the rear where he is running an RX IRS. Camber will allow a little leeway.

Having 4x4 sheetemtal allows for an extra .75 inch of backspace or 17mm of offset, so if a 7 inch wide wheel with 2wd fenders needs 5.5 inches of backspace (~38mm offset), with 4wd sheetmetal it needs 4.75 backspace and +21 offset.

I wish I knew, I would answer his question. I think he was hoping someone with KW arms and toyo spindles would measure their lip to mounting surface dimension, and someone with an IRS would do the same, so he can calculate from there.
impulse avatar
impulse
+1y
Originally posted by Russ-D



a 7 inch wide wheel will only need a +37, +39 at most.

a 6.5 backspace 7 inch wide wheel does not equal +45, it equals +63.

the reason he is asking is because using toyota hubs/spindles on KW arms may or may not have changed the measurement from the inner fender lip to the mounting surface of the hub, where the backspace meeasurement is derived from.

It absolutely changed it in the rear where he is running an RX IRS. Camber will allow a little leeway.

Having 4x4 sheetemtal allows for an extra .75 inch of backspace or 17mm of offset, so if a 7 inch wide wheel with 2wd fenders needs 5.5 inches of backspace (~38mm offset), with 4wd sheetmetal it needs 4.75 backspace and +21 offset.

I wish I knew, I would answer his question. I think he was hoping someone with KW arms and toyo spindles would measure their lip to mounting surface dimension, and someone with an IRS would do the same, so he can calculate from there.

I wish you knew too! haha.

If only I could easily slap the body on and figure it out, but there's no chance in that for a while.

so many different numbers and no idea which ones are the correct one's to go with.
dssur avatar
dssur
+1y
Originally posted by iLLairgasm

so many different numbers and no idea which ones are the correct one's to go with.

well, to be fair, if there were a hundred trucks with KW arms, toyo sindles, and RX rears, this would be easy to get proper measurements, but what would be the use in doing something unique?



impulse avatar
impulse
+1y
Originally posted by Russ-D



Originally posted by iLLairgasm

so many different numbers and no idea which ones are the correct one's to go with.

well, to be fair, if there were a hundred trucks with KW arms, toyo sindles, and RX rears, this would be easy to get proper measurements, but what would be the use in doing something unique?





haha... very good point

and after this is all done we'll have an answer for anyone else who asks!

haha.

god damn i need to order my wheels asap!