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Tire diameter % difference effect on ABS

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YOUR RESEARCHTire diameter % difference effect on ABS

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Run some non-oe tire diameters

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Suggestion · Original poster
I am planning on running some non-OE tire diameters on my 996 coupe for track and AX duty.
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Tire diameter % difference effect on ABS

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Leading evidence: 'Run some non-oe tire diameters' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Run some non-oe tire diameters' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

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Run without confusing the abs

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Suggestion · Original poster
What is the largest % difference I can run without confusing the ABS?
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Tire diameter % difference effect on ABS

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Run some non-oe tire diameters

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Suggestion · Original poster
I am planning on running some non-OE tire diameters on my 996 coupe for track and AX duty.
Original post Read captured discussion
Tire diameter % difference effect on ABS

Run without confusing the abs

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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Discussions that contain suggestions: 1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

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Suggestion · Original poster
What is the largest % difference I can run without confusing the ABS?
Original post Read captured discussion
Tire diameter % difference effect on ABS

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POST 1 / ORIGINAL POSTEROriginal post

I am planning on running some non-OE tire diameters on my 996 coupe for track and AX duty. Is there a % difference front to rear that effects the function of the ABS...? What is the largest % difference I can run without confusing the ABS? I'm looking at 245x40x17 front with overall diameter of 24.7" 265x40x17 rear with overall diameter of 25.4" 1999 996 C2 Thanks

POST 2Original post

c2 or c4?

POST 3 / ORIGINAL POSTEROriginal post

1999 996 C2.

POST 4Original post

C2,....Probably doesn't much matter for ABS,.... PSM/TRAC(virtual LSD), certainly. ABS reacts to the rate the tire is slowing during braking, circumference has little or no effect.

POST 5Original post

Quotes source post: 9018903

have you lowered your car? those diameters are within acceptable range.

POST 6Original post

I would say no problem,...but what is the goal...softer ride?

POST 7Original post

as wwest said ABS doesn't care about diameter. Those fronts are fat compared to the rears 245/265. I doubt you'll have to worry about understeer. I moved from 205/255 to 225/255 and it helped reduce understeer quite a bit.

POST 8Original post

PCA website usually states the 4% is the rule of thumb for front/rear error.

POST 9Original post

Some 996's I know of run up to 6% difference without issues.

POST 10 / ORIGINAL POSTEROriginal post

Quotes source post: 9020791

The goal is to reduce understeer and improve turn in for AX and track duty. Also on corner exit this should also help free up the rear end a bit. Later next year I will be installing ROW M030 to help decrease body roll and help with overall car balance.

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