how are track widths measured?

Depending on offset/backspace/wheel width - it Could be rotor to rotor...
Just adding to confusion...
Cheers - Jim
 
I am asking mainly due to my c4 suspension graft I will be doing. C4 is Front 59.6 Rear 60.4 & C3 is Front 58.7 Rear 59.4

So I have a .9" and 1.0" track difference .... So I am curious are the rotors the same surface to surface. Although at 1.0" that adds .5" to each wheel one way or the other so they should still remain under the wheel wells because I really don't like flares and have no desire for them on my car.

Also being I am going with modern C4 offset style wheels can I order the offset different to bring the wheels in a bit if necessary? Or would this affect the whole suspension geometry granted even if it is off some it will probably be light years still ahead of the c3 stuff.

I actually want this car to handle the best it can so I even have FE7 30 & 26mm sway bars, 88 Z51 springs and plan on at least 17x9.5 rim size.
 
I am asking mainly due to my c4 suspension graft I will be doing. C4 is Front 59.6 Rear 60.4 & C3 is Front 58.7 Rear 59.4

So I have a .9" and 1.0" track difference .... So I am curious are the rotors the same surface to surface. Although at 1.0" that adds .5" to each wheel one way or the other so they should still remain under the wheel wells because I really don't like flares and have no desire for them on my car.

Also being I am going with modern C4 offset style wheels can I order the offset different to bring the wheels in a bit if necessary? Or would this affect the whole suspension geometry granted even if it is off some it will probably be light years still ahead of the c3 stuff.

I actually want this car to handle the best it can so I even have FE7 30 & 26mm sway bars, 88 Z51 springs and plan on at least 17x9.5 rim size.

Jeff, all I can say is that my '72 has '89 vette wheels on all 4 corners, they are 17x9.5 all around, fitting 255/50/17 rubber, they use 2.5" thick VBP wheel adapters all around, in fact I"m the guy who set the spec on the thickness requirement, back in '95.....I had wonderful cooperation from them in the swaps back and forth.....I kept the same wheel/tire centerline because of rear hub wear concerns and suspension jacking/extra stresses....

but a whole suspension?? I dunno shit.....all you all dun left this olde phardt back on the trail somewhere......:devil:
 
What a good question. I have built several cars and trucks with non-stock suspensions and found that in the OEMs there's no agreement as to how they measure track width.

The aftermarket, for the most part is bolt flange to bolt flange... but even that's not completely reliable. It gets you close - but if you're dealing with a front suspension caster will change the dimension. Thus one person's 56" MII suspension is not the same as another's 56". With brake rotors that dimension varies by as much as 1 1/2"
 
I am asking mainly due to my c4 suspension graft I will be doing. C4 is Front 59.6 Rear 60.4 & C3 is Front 58.7 Rear 59.4

So I have a .9" and 1.0" track difference .... So I am curious are the rotors the same surface to surface. Although at 1.0" that adds .5" to each wheel one way or the other so they should still remain under the wheel wells because I really don't like flares and have no desire for them on my car.

Also being I am going with modern C4 offset style wheels can I order the offset different to bring the wheels in a bit if necessary? Or would this affect the whole suspension geometry granted even if it is off some it will probably be light years still ahead of the c3 stuff.

I actually want this car to handle the best it can so I even have FE7 30 & 26mm sway bars, 88 Z51 springs and plan on at least 17x9.5 rim size.

Jeff, all I can say is that my '72 has '89 vette wheels on all 4 corners, they are 17x9.5 all around, fitting 255/50/17 rubber, they use 2.5" thick VBP wheel adapters all around, in fact I"m the guy who set the spec on the thickness requirement, back in '95.....I had wonderful cooperation from them in the swaps back and forth.....I kept the same wheel/tire centerline because of rear hub wear concerns and suspension jacking/extra stresses....

but a whole suspension?? I dunno shit.....all you all dun left this olde phardt back on the trail somewhere......:devil:

Yes it is going to have full c4 suspension, post pics of the wheel wells, I am curious how they will fit in there. Why did you run 255's and not 275's?
 
I am asking mainly due to my c4 suspension graft I will be doing. C4 is Front 59.6 Rear 60.4 & C3 is Front 58.7 Rear 59.4

So I have a .9" and 1.0" track difference .... So I am curious are the rotors the same surface to surface. Although at 1.0" that adds .5" to each wheel one way or the other so they should still remain under the wheel wells because I really don't like flares and have no desire for them on my car.

Also being I am going with modern C4 offset style wheels can I order the offset different to bring the wheels in a bit if necessary? Or would this affect the whole suspension geometry granted even if it is off some it will probably be light years still ahead of the c3 stuff.

I actually want this car to handle the best it can so I even have FE7 30 & 26mm sway bars, 88 Z51 springs and plan on at least 17x9.5 rim size.

Jeff, all I can say is that my '72 has '89 vette wheels on all 4 corners, they are 17x9.5 all around, fitting 255/50/17 rubber, they use 2.5" thick VBP wheel adapters all around, in fact I"m the guy who set the spec on the thickness requirement, back in '95.....I had wonderful cooperation from them in the swaps back and forth.....I kept the same wheel/tire centerline because of rear hub wear concerns and suspension jacking/extra stresses....

but a whole suspension?? I dunno shit.....all you all dun left this olde phardt back on the trail somewhere......:devil:

Yes it is going to have full c4 suspension, post pics of the wheel wells, I am curious how they will fit in there. Why did you run 255's and not 275's?

HEHEHE....Having owned a '87 vette, I used to turn a corner into a gas station I hung out at for decades, on and off, depending on the FEMALE shituation at the time, and it was a U turn, not THAT way damnit....

and the '87 vette could not make the turn....it was a 3 pointer....

the '72 had no sweat making the turn, ever, even with stock shit the way I bought it.....

SO upon switching to the C4 wheels, First change was with a 200 buck set of wheels from a '92 vette, WITH GOOD TIRES but of course 40 series and looked funny as being too small....then NITTO came out with 275/50/17 for the rear, which fit just FINE, but they are NLA these daze, damnit.....and I can't find another maker....

SO 255/50/17 was always on the front of the shark in that they did not rub, and in fact had a narrower turning radius than my '87,.....so go figger....I never did a actual parking lot and tape measure type gig on this, just a street driving observation....

:surrender:
 
C4 and C3 are a good example because the rotor to rotor dimension is 3" wider, yet because of the tire offset are functionally the same. your issue of getting into the parking lot shows the problem of wider brake/brake width because the car can't turn as sharp because the tire will contact the fender sooner.
 
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