Toyo R888 question
Thread Starter
Instructor
Joined: Nov 2007
Posts: 178
Likes: 0
Toyo R888 question
Im trying to verify if running Toyo R888 305/30/19 in the rear throw any codes and/or affect the AH/TC/ABS when switching from the stock size?
I tried to search but couldnt find the answer I was looking for; maybe not searching correctly. Also, how is this scenario long-term? I found many posts stating it was ok, but havent seen anything about long-term effects.
Thanks in advance,
Adam
I tried to search but couldnt find the answer I was looking for; maybe not searching correctly. Also, how is this scenario long-term? I found many posts stating it was ok, but havent seen anything about long-term effects.
Thanks in advance,
Adam
Melting Slicks
Joined: Nov 2005
Posts: 2,345
Likes: 2
From: Houston 06 C6 Ysi SC 402 fgd TX
for any tire size mod, you gotta make sure the ratio front to back is pretty much same as stock. for example if the front and the back tire diameters are the same eventually the sensors will relay the infor to the computer which will "interpret" spinning and will give warnings and decrease power.
however, that can be defeated by turning most of the active handing off....not sure which ones
I have 335 on rear and 295 on front both 18" wheels
however, that can be defeated by turning most of the active handing off....not sure which ones
I have 335 on rear and 295 on front both 18" wheels
Thread Starter
Instructor
Joined: Nov 2007
Posts: 178
Likes: 0
Thanks for the info. I looked at a tire diameter website and the difference between front and back for stock tires is 1.2 (F 25.7/ R 26.9). The new rear size would be .5 (F 25.7/ R 26.2)"
Would this cause an issue?
Thanks
Would this cause an issue?
Thanks
Melting Slicks
Joined: Nov 2005
Posts: 2,345
Likes: 2
From: Houston 06 C6 Ysi SC 402 fgd TX
I really dont know but i have "heard" a rule of thumb of 5% difference. If you calculate your new size .5 divided by 25.7 you get 2% so I would suggest that it would make a difference.
however i did have a set of front rear toyo proxes 4 that seemed too small but i did not get any warnings. see this pic
Thread Starter
Instructor
Joined: Nov 2007
Posts: 178
Likes: 0
ok. Thanks.
I've read a few posts on here about people putting the 305/30/19 on back with no fitment issues, but I didnt see anyone talking about putting any new tires on the front.
My assumption was that people were simply mounting the 305/30/19's on and were on their way.
If anyone else has any experience with this, please let me know.
Thanks,
Adam
I've read a few posts on here about people putting the 305/30/19 on back with no fitment issues, but I didnt see anyone talking about putting any new tires on the front.
My assumption was that people were simply mounting the 305/30/19's on and were on their way.
If anyone else has any experience with this, please let me know.
Thanks,
Adam
Burning Brakes
Joined: Nov 2005
Posts: 1,228
Likes: 44
From: Houston MN
St. Jude Donor '10
ok. Thanks.
I've read a few posts on here about people putting the 305/30/19 on back with no fitment issues, but I didnt see anyone talking about putting any new tires on the front.
My assumption was that people were simply mounting the 305/30/19's on and were on their way.
If anyone else has any experience with this, please let me know.
Thanks,
Adam
I've read a few posts on here about people putting the 305/30/19 on back with no fitment issues, but I didnt see anyone talking about putting any new tires on the front.
My assumption was that people were simply mounting the 305/30/19's on and were on their way.
If anyone else has any experience with this, please let me know.
Thanks,
Adam
Re: tires
--------------------------------------------------------------------------------
Quote:
Originally Posted by Mikeg4572
Yes, I did stick with the stock size fronts. I am on my third set of 305/30/19 rears with no problems.
Melting Slicks
Joined: May 2008
Posts: 2,802
Likes: 38
From: A galaxy far, far away...
St. Jude Donor '12 thru '26
Many folks here pair the 305/30's with 265/35's on the front. That way your closer to OEM tire diameter differences & you get two (2) sizes wider tires on both ends so the car maintains the same handling characteristics.
Generally only positive comments from members on this combo with no long-term issues. When my F1’s are gone, I’m going with the R888’s in those sizes
Generally only positive comments from members on this combo with no long-term issues. When my F1’s are gone, I’m going with the R888’s in those sizes
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Tech Contributor
Joined: Oct 1999
Posts: 41,055
Likes: 9,817
From: Charlotte, NC (formerly Endicott, NY)
If the rear tires are perceived to be spinning faster than they should be the EBCM (not the PCM) sends a request to the PCM to reduce power. If the PCM cannot reduce power enough then the EBCM applies the rear brakes. No way to program around this issue as programmers cannot access the EBCM. Just make sure the rear tires have a larger diameter than the fronts and you can avoid the issue. People have been falling into this issue since the 97 Vette came out. To test this yourself just swap front and rear tires and let the car coast down a hill in nuetral with the engine on and traction control engaged. The car will come to a stop as the rear brakes are applied to keep the rear wheels from spinning faster than the fronts.
Bill
Bill
Speedy
Joined: Mar 2007
Posts: 6,110
Likes: 931
From: Tn
2024 C8 of the Year Finalist - Modified
Many folks here pair the 305/30's with 265/35's on the front. That way your closer to OEM tire diameter differences & you get two (2) sizes wider tires on both ends so the car maintains the same handling characteristics.
Generally only positive comments from members on this combo with no long-term issues. When my F1’s are gone, I’m going with the R888’s in those sizes
Generally only positive comments from members on this combo with no long-term issues. When my F1’s are gone, I’m going with the R888’s in those sizes
Safety Car
Joined: Sep 2007
Posts: 4,359
Likes: 6
From: Los Alamitos California
St. Jude Donor '09
Thread Starter
Instructor
Joined: Nov 2007
Posts: 178
Likes: 0
Many folks here pair the 305/30's with 265/35's on the front. That way your closer to OEM tire diameter differences & you get two (2) sizes wider tires on both ends so the car maintains the same handling characteristics.
Generally only positive comments from members on this combo with no long-term issues. When my F1’s are gone, I’m going with the R888’s in those sizes
Generally only positive comments from members on this combo with no long-term issues. When my F1’s are gone, I’m going with the R888’s in those sizes
I wanted to make sure as Im sure I will need rear tires before the fronts are done.
Safety Car
Joined: Sep 2007
Posts: 4,359
Likes: 6
From: Los Alamitos California
St. Jude Donor '09
http://toyotires.com/tire/pattern/proxes-r888
San
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
I have stock sized BFG KDW's in front and 305/30/19 R888's out back. Every now and then in the middle of third TC will kick in for no good reason. I assume it's because of the difference in fronts and backs. When I replace the BFG's (I won't be replacing them with R888's because I don't feel like I need them up front) I'll upsize the front to match.
Racer
Joined: Feb 2008
Posts: 311
Likes: 4
From: Roanoke VA
I had 245/40/18 fronts and 295/30/19 rears. You will not get a code, but the traction control will sense the wheels slipping at about 120 mph and apply the brakes. This was scary the first time it happened and was eliminated by going into competition mode.
