Taller tires screw up asr???

[Bolling]

I just installed a set of C6 Z06 on my 92 ZR1. The rear tires are much taller and now I'm getting service ASR and service ASB. Are the taller tires the reason or is it something else?

[mike100]

Possibly... assuming that you did not increase the diameter of the fronts in the same proportion.

[Bolling]

Possibly... assuming that you did not increase the diameter of the fronts in the same proportion.

I'm sure there not the same proportion.

[XfireZ51]

I just installed a set of C6 Z06 on my 92 ZR1. The rear tires are much taller and now I'm getting service ASR and service ASB. Are the taller tires the reason or is it something else?

Mine does not and I am using same wheels w 285/18F an 325/19R tires. My rear tires are about an inch taller than stock.

[Bolling]

Mine does not and I am using same wheels w 285/18F an 325/19R tires. My rear tires are about an inch taller than stock.

Mine are front 275/35/18 rear 345/30/19

[Bolling]

Mine does not and I am using same wheels w 285/18F an 325/19R tires. My rear tires are about an inch taller than stock.

What size spacer are you running in the rear?

[98indypacer]

Almost 6% revs/mile difference may be a problem for ASR.

Diameter
Front = 25.6
Rear = 27.1
Difference = +5.9

Width
Front = 10.83
Rear = 13.58
Difference = +25.4%

Sidewall
Front = 3.79
Rear = 4.07
Difference = +7.4%

Circumference
Front = 80.3
Rear = 85.2
Difference = +6.1%

Revs/Mile
Front = 788.9
Rear = 743.2
Difference = -5.8%

[Bolling]

Almost 6% revs/mile difference may be a problem for ASR.

Diameter
Front = 25.6
Rear = 27.1
Difference = +5.9

Width
Front = 10.83
Rear = 13.58
Difference = +25.4%

Sidewall
Front = 3.79
Rear = 4.07
Difference = +7.4%

Circumference
Front = 80.3
Rear = 85.2
Difference = +6.1%

Revs/Mile
Front = 788.9
Rear = 743.2
Difference = -5.8%
Is there any way of fixing it through the computer?

[Jagdpanzer]

The constant difference between front and rear wheel speed is to much (more than 4.5%) which triggers the ABS and ASR systems check lights.
I had the same problem after changing to my Fikse wheels with staggered tire sizes 285/35R18 fronts 345/30R19 rears. Solved the problem by machining a set of 50 tooth count ABS reluctor rings for the rear spindles which compensated for the diffence in wheel speed the ABS and ASR systems see. Now life is good again.

[XfireZ51]

What size spacer are you running in the rear?

18mm

[XfireZ51]

My rear tires stand 26.7". That seems to be within the 4.5% stagger Phil states is within the operating range. Maybe go w a bit taller front tire.

[Bolling]

Almost 6% revs/mile difference may be a problem for ASR.

Diameter
Front = 25.6
Rear = 27.1
Difference = +5.9

Width
Front = 10.83
Rear = 13.58
Difference = +25.4%

Sidewall
Front = 3.79
Rear = 4.07
Difference = +7.4%

Circumference
Front = 80.3
Rear = 85.2
Difference = +6.1%

Revs/Mile
Front = 788.9
Rear = 743.2
Difference = -5.8%

How would it calculate if I put 325/30/19 on back and 285/35/18 on the front?

[edram454]

18mm.. that is a lot of spacer. hope you are running hubscentric billet spacers on that thing.

ed ramos #3028

[98indypacer]

How would it calculate if I put 325/30/19 on back and 285/35/18 on the front?
Better, about 3% difference. Try this website to play around with different sizes.
http://tire-size-conversion.com/tire-size-calculator/

[Bolling]

Will it hurt anything if I just run it with the codes each time.
Will the ASR and ABS still work properly?

[RICKYRJ1]

im running the same sizes as Dom, and asr never showed up on mine

[XfireZ51]

18mm.. that is a lot of spacer. hope you are running hubscentric billet spacers on that thing.

ed ramos #3028


18mm is < 3/4". And yes running hub AND wheel centric spacer w GM Racing studs.

[edram454]

18mm is < 3/4". And yes running hub AND wheel centric spacer w GM Racing studs.

those are the spacers I have on mine. mine are 14mm and are billet aluminum. it cost me a fortune but I wanted the best spacers just in case. I did not put racing studs since the spacers were not that aggressively big. You will have NO problems.

ed ramos #3028

[XfireZ51]

Mine are also billet, cost about $150 for the pair. Well made. They fit very snug onto the studs and center.

[edram454]

Mine are also billet, cost about $150 for the pair. Well made. They fit very snug onto the studs and center.

great price. I paid a lot more than that. I found this race shop that custom makes them and they charged me a custom made price. I think I paid $250.00. that is alot for spacers I thought. Oh well.. as long as they are well made is all that matters.

ed ramos #3028

[XfireZ51]

For those looking at wheel spacers.

http://wheeladapter.com/wheel_spacers.php

[-=Jeff=-]

Will it hurt anything if I just run it with the codes each time.
Will the ASR and ABS still work properly?

Actually ASR and ABS are working properly, meaning the computer thinks there is an issue so those systems are deactivated..

once you correct the % difference front to rear, it should 'correct' itself and the lights will shut off

[JimZRyd]

Just came across this thread, so I have a question... I'm about to pull the trigger on a set of Fikse Profil 5's in 18/19 sizes. Going with 345/30/19's in the rear. Been torned between 285/35 and 295/35 18's for the front. Only .3 inches in height difference. Anybody got any advice? Much appreciated.

[Bolling]

Just came across this thread, so I have a question... I'm about to pull the trigger on a set of Fikse Profil 5's in 18/19 sizes. Going with 345/30/19's in the rear. Been torned between 285/35 and 295/35 18's for the front. Only .3 inches in height difference. Anybody got any advice? Much appreciated.

If you go with the 345's you might have the same problems I'm having throwing codes. After some research I think the perfect combo is 325/30/19 rear and 275/40/18 There is only a .1% difference and your combo there is a 3.8% difference. My rims came with the 345's but if I was buying new I would go with combo mentioned and definitely not the 345's

[JimZRyd]

Maybe but I feel a 275 front is too small and there's nothing cooler than a big fat 345 outback! Many guys out there with a 285/345 combo and no problems. I'll go with one or the other. More than likely the 285.

[Bolling]

Maybe but I feel a 275 front is too small and there's nothing cooler than a big fat 345 outback! Many guys out there with a 285/345 combo and no problems. I'll go with one or the other. More than likely the 285.

Good luck

[JimZRyd]

Thanks. To you as well. Actually haven't heard anyone that has the combo I'm looking at mention anything about codes. I'll let you know how mine works out👍

[Jagdpanzer]

I tried 285/40R18 on the front and though it did solve the ABS/ASR alarm light problem I just couldn't stand the "thick" look of side wall.
From my experience if you want to avoid the potential ABS/ASR issues I would recommend 285/35R18 fronts, 10" wheels with 60mm offset and 325/30R19 rears, 12" wheels with 37mm offset. As several have mentioned with this combo the difference between front and rear wheel speed is within the erro band tolerated ABS/ASR systems. Running the Michelin Pilot SS 345/30R19 rear tires which are a little on the plus side dimensionally I had to trim the wheel well liner in couple places and cut down the heads of the forward lower dog bone bolts about 1/8" so they would not rub on he inner sidewall of the tires during hard cornering.

[Bolling]

Here is a few pics

[FU]

Looks great :cheers: