PCM Diagnostics & Tuning HP Tuners | Holley | Diablo
Sponsored by:
Sponsored by:

ABS INOP with larger tires on rear....?

Thread Tools
 
Search this Thread
 
Old 06-06-2006, 08:56 AM
  #1  
SDB
10 Second Club
Thread Starter
iTrader: (7)
 
SDB's Avatar
 
Join Date: Mar 2003
Posts: 2,327
Likes: 0
Received 2 Likes on 2 Posts

Default ABS INOP with larger tires on rear....?

I understand that when you have significantly different size tires on front and rear that this light will come on. I put on 325-45-17 on rear and 275-45-17 up front.

Is there a way around this light issue, and will the ABS actually work?

Thanks

SDB
Old 06-06-2006, 10:01 AM
  #2  
TECH Addict
iTrader: (10)
 
SSpdDmon's Avatar
 
Join Date: Jun 2004
Location: Commerce Twp, MI
Posts: 2,918
Likes: 0
Received 0 Likes on 0 Posts

Default

You put a 26-inch tire up front and a 28-inch tire out back? Why? I know some have run Vette rims (17" front/18" back) without issues. But, I've never heard of such a difference with 17" rims all around...

...unless there was a typo and you meant 315/35/18 for out back???
Old 06-06-2006, 10:04 AM
  #3  
TECH Resident
iTrader: (17)
 
ZL1Killa's Avatar
 
Join Date: Sep 2004
Location: NC - Charlotte area
Posts: 3,747
Likes: 0
Received 0 Likes on 0 Posts

Default

no, the lights should not come on. not that i know of. Just get the computer changed for correct tire size. My friend installed a moser rearend(kept his same tire size) and he had the car on the jacks and put it in gear and let the rear tires move and rotate to check his rearend and gear; then the ABS inop and TCS off lights came on, it was simply because the front tires weren't moving and the rear were. he took it down the street and the lights went back to being normally off
Old 06-06-2006, 11:07 AM
  #4  
TECH Junkie
iTrader: (50)
 
oange ss's Avatar
 
Join Date: Jan 2005
Location: Texas
Posts: 3,231
Likes: 0
Received 5 Likes on 4 Posts

Default

you mean 315-35-17 ? i've never seen a 325-45-17
Old 06-06-2006, 12:32 PM
  #5  
TECH Fanatic
iTrader: (6)
 
SMOKINV8's Avatar
 
Join Date: Jan 2002
Location: Springfield, IL
Posts: 1,194
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by SDB
Is there a way around this light issue, and will the ABS actually work?
Calibrate your speedometer for the bigger tires and you should be set.
Old 06-06-2006, 12:38 PM
  #6  
8 Second Club
iTrader: (16)
 
soundengineer's Avatar
 
Join Date: Jul 2003
Location: Chicago IL
Posts: 4,651
Likes: 0
Received 9 Likes on 9 Posts

Default

teh light comes on when it can see a bigger error than expected...if you go up to far and mph doesnt match teh expected values..then its thinks it has a problem..and your ABS light comes on
Old 06-06-2006, 04:14 PM
  #7  
TECH Addict
 
technical's Avatar
 
Join Date: Mar 2004
Location: Fat Chance Hotel
Posts: 2,336
Likes: 0
Received 0 Likes on 0 Posts

Default

You can't spin the back tires faster (bigger diameter-> longer circum-> faster angular velocity) than the front and expect the ABS to understand why the front tires seem like they're locking up.
Old 06-06-2006, 04:39 PM
  #8  
TECH Senior Member
 
horist's Avatar
 
Join Date: Nov 2001
Location: Lake Zurich, IL
Posts: 7,036
Likes: 0
Received 1 Like on 1 Post

Default

^^^ what he said... computer sees different spinning rates, thinks there's a problem basically... this isn't a function of the PCM so can't currently be tuned out

You'll also run into this issue if running a full slick... I run 26" slicks in back, 26" tires in front... but since the slicks become taller the faster you go... at highway speeds I'll get an ABS Inop etc...
Old 06-06-2006, 07:13 PM
  #9  
SDB
10 Second Club
Thread Starter
iTrader: (7)
 
SDB's Avatar
 
Join Date: Mar 2003
Posts: 2,327
Likes: 0
Received 2 Likes on 2 Posts

Default

To clarify,...they are 325-45-17..brand new M&H Drag Radial (kick *** tires as far as I can tell so far). 88 in circumferece, REALLY soft and sticky, nearly 28 in tall. I have them on 17X11 rims. I will post pics soon...

So, does my ABs still work when the light is on? Can I simply ignore the light (pull bulbs). Thanks

SDB
Old 06-06-2006, 08:06 PM
  #10  
Moderator
iTrader: (11)
 
jimmyblue's Avatar
 
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,605
Likes: 0
Received 6 Likes on 6 Posts

Default

10% difference in circumference is about where you will
run into problems. The ABS doesn't know from tire size
and the PCM will not enlighten it.
Old 06-06-2006, 08:24 PM
  #11  
On The Tree
 
Purrvert's Avatar
 
Join Date: Dec 2004
Location: Satellite Beach, fl
Posts: 100
Likes: 0
Received 0 Likes on 0 Posts

Default

If you have Active Handling like me and put too large a tire on the back agressive cornering becomes next to impossible, the outside front tire when cornering is hauling *** compared to the allowed compared speed and the brake grabs that tire making for some interesting maneuvers.
Old 06-07-2006, 08:18 PM
  #12  
TECH Fanatic
iTrader: (9)
 
SPEEDYws6's Avatar
 
Join Date: May 2005
Location: Longview, TX
Posts: 1,085
Likes: 0
Received 0 Likes on 0 Posts

Default

I pulled the abs fuses, and popped the led's out of the cluster, no more lights. 28" tire in back and 26" on the front also.



Quick Reply: ABS INOP with larger tires on rear....?



All times are GMT -5. The time now is 02:56 AM.