Can changing tire size effect older ABS systems ???
08-01-2007, 11:37 PM
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Can changing tire size effect older ABS systems ???
I saw this in the Sept 07 issue of Excellence in the Tech Notes section. Someone had a 2001 996 Turbo and wanted to install the wheels from a 2002 GT2. Here's their reply ...
" It is important to keep overall diameter of the tires within 4% of each other on your turbo - both from front to rear and from the stock 225/295's to the GT2's 235/315's - to keep the ABS and all wheel drive systems happy."
The all wheel drive isn't a concern of course, but I have a 89 8V with ABS. It was ordered with option M164 215/60 VR 15, but the PO installed a set of cup wheels. So I got her with 17 x 7.5 and 235/45 in front, and 17 x 9 with 255/40 out back. It's new tire time and I'm wondering if I need to keep that 4% ratio mentioned above in mind to keep my ABS "happy"
or does that matter less or even more with my older ABS system?
-----------------------------------------------------
Alex Portanova
1989 944 N/A
1999 Chrysler 300M
1992 Harley FXSTC
" It is important to keep overall diameter of the tires within 4% of each other on your turbo - both from front to rear and from the stock 225/295's to the GT2's 235/315's - to keep the ABS and all wheel drive systems happy."
The all wheel drive isn't a concern of course, but I have a 89 8V with ABS. It was ordered with option M164 215/60 VR 15, but the PO installed a set of cup wheels. So I got her with 17 x 7.5 and 235/45 in front, and 17 x 9 with 255/40 out back. It's new tire time and I'm wondering if I need to keep that 4% ratio mentioned above in mind to keep my ABS "happy"
or does that matter less or even more with my older ABS system? -----------------------------------------------------
Alex Portanova
1989 944 N/A
1999 Chrysler 300M
1992 Harley FXSTC
08-02-2007, 01:12 AM
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I remember reading that article as well and wondering if the wheels on my car (17" 996) are messing with the system at all... I hit the brakes pretty hard last weekend when a dog ran into the street and I did manage to lock up my front tires, so there might be some truth to it (or maybe my abs is shot).
08-02-2007, 01:59 AM
#5
Burning Brakes
The diameter of the wheels does not matter as long as they are the same on all four wheels, if it differ the wheel rpm will differ and the abs will not work on any car.
