same size tires, ABS swap?

[lifespeed]

Will swapping the ABS to a GM unit allow running the same size tires on all fours? I remember running 255/55-18 in the rear and it seemed to trigger the ABS much easier than it should have. Seems like a heroic measure, but what else can you do?

I can't find the original BFGs anywhere online (yes I know there are alternatives, but I like BFG) and am suspecting they may not make them anymore. And I would like larger wheels to fit brakes. This staggered tire thing is just becoming a real drag. :(

[MOTOWN]

Will swapping the ABS to a GM unit allow running the same size tires on all fours? I remember running 255/55-18 in the rear and it seemed to trigger the ABS much easier than it should have. Seems like a heroic measure, but what else can you do?

I can't find the original BFGs anywhere online (yes I know there are alternatives, but I like BFG) and am suspecting they may not make them anymore. And I would like larger wheels to fit brakes. This staggered tire thing is just becoming a real drag. :(

Has nothing to do with the ABS unit , its programed into the PCM

[CrownVictorious]

can tire size be adjusted with a tune to keep the ABS from triggering?

[lifespeed]

Has nothing to do with the ABS unit , its programed into the PCM

Are talking about traction control or ABS? I'll admit to knowing nothing about that part of the car.

Read a post on here where Dennis Reinhart said the ABS unit could be swapped to address the issue . . .

[Comin' in Hot]

Are talking about traction control or ABS? I'll admit to knowing nothing about that part of the car.

Read a post on here where Dennis Reinhart said the ABS unit could be swapped to address the issue . . .

marauder rule #1: Don't believe anything Dennis says.

The abs unit is different in 300A and 300B cars but the logic can not be changed in the PCM and I'm sure it has everything to do with liability.

[MOTOWN]

Are talking about traction control or ABS? I'll admit to knowing nothing about that part of the car.

Read a post on here where Dennis Reinhart said the ABS unit could be swapped to address the issue . . .

I understand what you want to do , but I cant think of a way to get around this issue , the ABS , and Traction control are two separate systems.

I wouldn't believe DR if he told me the time!

[lifespeed]

marauder rule #1: Don't believe anything Dennis says.

The abs unit is different in 300A and 300B cars but the logic can not be changed in the PCM and I'm sure it has everything to do with liability.

Yeah, that's why I asked.

[WPG_Merc]

I can't find the original BFGs anywhere online (yes I know there are alternatives, but I like BFG) and am suspecting they may not make them anymore. And I would like larger wheels to fit brakes. This staggered tire thing is just becoming a real drag. :(
maybe try:burnout:
http://www.discounttiredirect.com/direct/filterTireProducts.do?sll=tssB estSeller&sortBy=btsd&qkf=bestSeller&mps=-50&yr=2003&ar=55&fqs=true&vid=008370&rd=18&cs=245:flag:

or my fav place :burnout:
http://www.1010tires.com/Tires/SearchByVehicle :canada:

[ctrlraven]

What size do you have on the front?

[lifespeed]

I understand what you want to do , but I cant think of a way to get around this issue , the ABS , and Traction control are two separate systems.

I wouldn't believe DR if he told me the time!

So what combination of 20" tire sizes do you run?

[ctrlraven]

When I looked at going to a 20" wheel the tire sizes I spec'd out were 265/35-20(Front) and 275/40-20(Rear), there is just a hair over 1.3" difference between the front and rear diameter.

[lifespeed]

When I looked at going to a 20" wheel the tire sizes I spec'd out were 265/35-20(Front) and 275/40-20(Rear), there is just a hair over 1.3" difference between the front and rear diameter.

I guess the rears would work if the added width were on the inside. 30mm more on the front (centered to maintain the scrub radius) would be 15 mm added towards the fender. I don't know if that would work. Might rub the sway bar at full lock also.

[MOTOWN]

So what combination of 20" tire sizes do you run?

315 35/20 in front and 305 50/20 in the rear , i got a little carried away with 305s! lol

currently getting the rears widened from 10" wide to 11.5" wide

[lifespeed]

315 35/20 in front and 305 50/20 in the rear , i got a little carried away with 305s! lol

currently getting the rears widened from 10" wide to 11.5" wide

Which wheels and offset in the front? Don't they scrape?

[MOTOWN]

Which wheels and offset in the front? Don't they scrape?

All 4 wheels are 20x10 on a +40mm offset , they don't scrape at all

[JohnE]

The traction control module has all 4 tire diameters and the rear end ratio programmed into it. The PCM has only the rear tire ratio and the rear end ratio programmed into it. These modules talk to each other. If the rear end gear ratios are not a perfect match, Traction Control is disabled. However the PCM has three entries for rear ratio, one is used for its calculations for vehicle speed and the other two are just to identify them with the TC module. Cool thing is you can tell the PCM the truth about your gears and lie to the TC module at the same time.

The TC module expects the acceleration rate to be different to a certain percentage between the front and the rear. If they differ past that trip point, it kicks in and tries to manage a loss of traction.


I highly expect that a non-Marauder panther TC module will allow you to run the same diameter tires on all four corners. You need to match the PCM settings for that particular TC module. Another possibility is to flash the TC module with non-Marauder settings. You need a Ford tool for that, which dealers have as well as some shops as well.


John

[lifespeed]

The traction control module has all 4 tire diameters and the rear end ratio programmed into it. The PCM has only the rear tire ratio and the rear end ratio programmed into it. These modules talk to each other. If the rear end gear ratios are not a perfect match, Traction Control is disabled. However the PCM has three entries for rear ratio, one is used for its calculations for vehicle speed and the other two are just to identify them with the TC module. Cool thing is you can tell the PCM the truth about your gears and lie to the TC module at the same time.

The TC module expects the acceleration rate to be different to a certain percentage between the front and the rear. If they differ past that trip point, it kicks in and tries to manage a loss of traction.


I highly expect that a non-Marauder panther TC module will allow you to run the same diameter tires on all four corners. You need to match the PCM settings for that particular TC module. Another possibility is to flash the TC module with non-Marauder settings. You need a Ford tool for that, which dealers have as well as some shops as well.

There isn't any possibility of addressing the issue as it relates to ABS, is there? This is probably the more significant problem.

[lifespeed]

All 4 wheels are 20x10 on a +40mm offset , they don't scrape at all

Pictures, wheel part numbers? I have to admit I am really surprised that wheels and tires that wide fit without clearance issues.

[JohnE]

Just to be clear, ABS and Traction Control are both integrated into the same module, which is mounted on the ABS hydraulic unit.

[tbone]

I am so thankful I do not have traction control.

I run 255/55r18's in the rear and have no abs issues.

[MOTOWN]

Pictures, wheel part numbers? I have to admit I am really surprised that wheels and tires that wide fit without clearance issues.

Look in my madness thread , I posted pics there

[RF Overlord]

JohnE, thank you for that info above.

People like you help make this such a great site. :up:

[lifespeed]

The traction control module has all 4 tire diameters and the rear end ratio programmed into it. The PCM has only the rear tire ratio and the rear end ratio programmed into it. These modules talk to each other. If the rear end gear ratios are not a perfect match, Traction Control is disabled. However the PCM has three entries for rear ratio, one is used for its calculations for vehicle speed and the other two are just to identify them with the TC module. Cool thing is you can tell the PCM the truth about your gears and lie to the TC module at the same time.

The TC module expects the acceleration rate to be different to a certain percentage between the front and the rear. If they differ past that trip point, it kicks in and tries to manage a loss of traction.


I highly expect that a non-Marauder panther TC module will allow you to run the same diameter tires on all four corners. You need to match the PCM settings for that particular TC module. Another possibility is to flash the TC module with non-Marauder settings. You need a Ford tool for that, which dealers have as well as some shops as well.


John

I'm off to find a Grand Marquis ABS module. Can you provide any further information as to what might need to be done in the PCM and who is most qualified to do this? I have not done anything other than download a canned Lidio tune using an SCT X3.

[JohnE]

Get a 2004 ABS if you want traction control. Stay away from the newer PowerPC cars, computer on driver fender. Find out the catch code for the computer on the donor car, that way your tuner can just lookup what the axle settings were easily.


*Note that I've never done this, however I expect it to work.

[MOTOWN]

Get a 2004 ABS if you want traction control. Stay away from the newer PowerPC cars, computer on driver fender. Find out the catch code for the computer on the donor car, that way your tuner can just lookup what the axle settings were easily.


*Note that I've never done this, however I expect it to work.

I doubt very seriously this will work , but we shall see!

[lifespeed]

I doubt very seriously this will work , but we shall see!

I wonder. But I guess nobody has ever tried.

[MOTOWN]

I wonder. But I guess nobody has ever tried.

Looking forward to seeing how this turns out , hope it works out for you.

[lifespeed]

When I looked at going to a 20" wheel the tire sizes I spec'd out were 265/35-20(Front) and 275/40-20(Rear), there is just a hair over 1.3" difference between the front and rear diameter.

It looks like this 5% combo is available in Pirelli P Zero. Continental also has some tires in that size, don't for sure if they're matching.

[Krytin]

You DON'T need to do anything for the ABS when running the same size tires front and rear - I've been running 255/45 - 18 on all 4 wheels for 7 years and 100k miles now. The ABS has only kicked in under VERY hard breaking on dry pavement or on ice and it has worked flawlessly every time. I have never found anything referencing tire size in the ABS system. Save your time and money!

[lifespeed]

When I ran 255/55-18 on the rear the ABS would kick in prematurely.