SRT-10 ABS sensitivity to tire diameter

[j-rho]

Hi guys,
Wondering who has "pushed the limits" of wacky tire diameter differences on their SRT-10 to see where the ABS gives up. Generally I've found factory ABS systems to allow at least a few % diameter difference from Stock, wondering how the Viper does.

For instance,
Factory front tire height: 25.7"
Factory rear tire height: 27.4"
Ratio: 25.7":27.4 " or .9379

I have run 315/30-18 fr and 345/30-18 rr Hoosier A6 with no problems in ABS. They are:
Front: 25.6"
Rear 26.8"
Ratio: 25.6:26.8 or .9552

That's about 1.8% different from stock. I am thinking of trying a new tire combination where the fronts and rears are even closer-
Front: 26.4"
Rear: 26.9"
Ratio: 26.4:26.9 or .9814

That is a more substantial 4.6% difference from stock. I am worried the ABS computer may give up at that % difference. What's people's experience running non-standard tire diameter ratios on the SRT-10, and the ABS system's response? Does anybody have a known-bad-to-ABS setup, like with some weird drag radials or something?

Thanks,
J-Rho

 

[JonB]

Its a pretty smart system in SRt10. It compares ABS Tone ring speed with engine revs and the computer sorts it all out. I have seen 6% smaller rolling circumfrence cause no ABS Lite problems

 

[j-rho]

Thanks for the reply Jon. Just so I'm clear, was the 6% smaller circumference just with the rear tires, or all four tires?

 

[GR8_ASP]

I have used the folloowing with no ABS issues:

Front Rear
807 757 Stock
833 765 Sport Cups
827 809 V700

These are revs/mile and are directly related to dynamic rolling radius. As you can see I have gone from stock to a much smaller front (bigger number means smaller size) and somewhat smaller rear to much smaller rear. All were 18" except the stock which are 18/19 combo. I have also heard of people going the other direction (must be for appearance ) with 19/20 combos which must go larger in diameter.

 

[j-rho]

Thanks for the above. The setup I'm looking at is 790 front and 772 rear in the Ecsta V710. That ratio (.977) is a hair on the closer-to-stock (.938) side of your V700 setup (.978). I think that answers my question, thanks again for your data and experiences.

 

[Alan Patterson]

FYI,
last year I ran 315/30-18 fronts and 335/30-18 rears (Hoosier A6) with no problems...
Front: 25.6"
Rear: 25.6"
Ratio: 1.0

 

[j-rho]

Thank for that Al. Will I be seeing you out at any National events this year?

 

[Alan Patterson]

I hope to make it to the San Diego Tour or El Toro Pro Solo...
But cost is an issue!