26 Vs. 28

[QTRPONY]

Just replaced my 275/50/15 DR's with 325/50/15 and found a couple of issues:

1. Tires rub on sharp turns.

2. ABS light comes on. I have seen on other threads where this is an issue with going to 28's but can't figure out exactly why.

Anybody found any fixes for the above issues?

[rguy3]

I had 305 45 18 Nitto DRs (28.8") that would rub constantly, installed Steeda adjsutable lower control arms & raised rear end to almost max of adjustment.
After that they rarely rubbed & the car had rake like a 60s hot rod...

A computer tuner like Diablosport might be able to tweak a chip to fix your dummy light, I used to ignore mine........but it did get annoying.

[BONESTOCK]

The reason the ABS light is on is because your real wheels are spinning at a different speed as your front wheels.

With the light on you no longer have ABS so be careful.

I don't have ABS because I removed the rear exciter rings when switching to 31 spline axles.

[DTMach1]

bang your fender lips up, ignore ABS light...just remember not to mash your brake pedal...and continue to drive as you did before.

[04azuremach]

Can some adjustments be made to the computer to prevent the ABS issue?

[QTRPONY]

Originally Posted by 04azuremach

Can some adjustments be made to the computer to prevent the ABS issue?

I have been told yes-that it can be configured to adjust for the difference in tire rotation. But I have not found someone that knows exactly how to do it.
Yet.

[mtm87tx]

if the computer knew what the rear tire size was, like via a tune, what would prevent the ABS from working properly? just wondering

[QTRPONY]

275/50/15's (26 in tire) in the two pics on the left and 325/50/15's in the two on the right for a side to side comparison. To clarify-far left 275/50, middle left 325/50, middle right 275/50, far right 325/50.

[QTRPONY]

More pics of 325/50/15's:

[QTRPONY]

Last one:

[mtm87tx]

looks mean dude, nice pics. any rubbing issues yet?

[Fosters]

Originally Posted by QTRPONY

I have been told yes-that it can be configured to adjust for the difference in tire rotation. But I have not found someone that knows exactly how to do it.
Yet.

Keith.

or you can take out that dang lightbulb (which is what i'll be doing soon, no abs rings with c clip elims..)

[vpMach1]

Thank you!

Why would you remove the rear exciter rings?

[vpMach1]

I have 28 Spline axles on the way and want to know why people would remove the rear exciters because I may do it.

[BIG4CAM]

Originally Posted by mtm87tx

if the computer knew what the rear tire size was, like via a tune, what would prevent the ABS from working properly? just wondering

If you enter the tire size as in Tuner software/Ford WDS it sets it for all four corners. So unless you have a very 28 inch tall front runner it won;t help ya much. Just don't lock up the tires, normal braking function is not affected by the ABS light being on, just they won't modulate. We all had to have driven something before your Mach that didn't have ABS.

[BIG4CAM]

So have you noticed yet that going from the 26 to 28 change your rpm through the traps? You might have to adjust rear end ratios accordingly.

[QTRPONY]

Originally Posted by BIG4CAM

So have you noticed yet that going from the 26 to 28 change your rpm through the traps? You might have to adjust rear end ratios accordingly.

Only made it to the track once with the 28'ers. Rpms were lower but I did not think to look to see exactly what it was.

Running 4:10's so with the blower I was probably geared a little low anyway. Just guessing that it is about like running 3.90's. Best trap and ET were about the same as best trap and ET with 26's. Need a few more passes to figure out differences i.e. launch rpm. shift points etc.

[BIG4CAM]

Originally Posted by QTRPONY

Only made it to the track once with the 28'ers. Rpms were lower but I did not think to look to see exactly what it was.

Running 4:10's so with the blower I was probably geared a little low anyway. Just guessing that it is about like running 3.90's. Best trap and ET were about the same as best trap and ET with 26's. Need a few more passes to figure out differences i.e. launch rpm. shift points etc.

No way to tell for sure with out number from the track, and a good dyno sheet showing power curve. You never know, maybe 4.30's will be the diff. Gotta laydown a good pass and watch the tach.