[70chevelleSS]

I have a 2017 SS that I put 1le wheels/ tires (stock 1le sizes) on. I’m looking to put a rear only drag tire setup. With the 285/30/20 front, will a 305/45/17 rear tire cause issues with the abs/stabilitrak, etc due to the height difference?

Just looking for options here for a rear tire/wheel setup only. Not interested in running skinnies in the front for the time being unless I have to.

Anything we can do in HPtuners to help with this issue? Tia

[Kerry]

Well I had an experience tonght and wondering the same thing. So I know I can still go into launch mode with out rear pressure sensors. I know that if bthere are no fronts then it will not let you. Low yes gone no.
So in doing some tire sizeing I had a 28 in tire on the back and a 27 on the front. When I first pulled out and got up to about 40 or 50 I noticed the traction control blinking. I though O great this wont work. Now heres the funny thing, I drove around 30 minutes fast slow from a dig ect It never came on again. Recon it learns for like the sensors when you say go to the track with different tirs with no sensors maybe they make an allowence for a taller tire as well? Can any one confirm. thanks obtw if you go the other way big front small back it will hit traction control so hard on a stomp it will close the throttle. Turn traction control off and no problems.

[Kerry]

But if you turn off tractin control or in launch mode it wont hender you.

[70chevelleSS]

Interesting. I just don’t want to buy the right setup the first time around.

I wonder if it “learns” form driving around

[KingLT1]

Keep the front and rear within a inch on height and it will be fine. No it doesn't learn.

[asthmamax11]

Will car pull timing if tp sensors are dead ?

[BDPhoto519]

KingLT1 are you running tire sensors in your front & rear drag wheel setup?

[KingLT1]

I'm not running a drag wheel setup, just 305/35/20 555r DR's on stock rear wheels and stock fronts....tpms sensors on all 4 corners.

[Yosh6]

Originally Posted by 70chevelleSS

I have a 2017 SS that I put 1le wheels/ tires (stock 1le sizes) on. I’m looking to put a rear only drag tire setup. With the 285/30/20 front, will a 305/45/17 rear tire cause issues with the abs/stabilitrak, etc due to the height difference?

Just looking for options here for a rear tire/wheel setup only. Not interested in running skinnies in the front for the time being unless I have to.

Anything we can do in HPtuners to help with this issue? Tia

70chevelleSS

This topic keeps coming up and for good reason. I'm no expert, but I do have considerable experience with this issue. Overall observation: There is no one answer across all models and all years. My 2016 SS is very picky about TPMS and matching tire height front and rear. I have read several posts from other owners that say their cars run fine with or without TPMS sensors; some say "all or none works". Not this car. It wants all. As for tire height, I can't argue too much with KingLT1 on keep it within 1 inch, although I've never had more than a 1/2 inch difference. My car will go into Safe/Limp Mode with ANY TPMS sensor missing. My car will also go into Safe/Limp Mode with 26" tires on the rear and 28" tires on the front. Right now I'm matched at 28" front and rear, all four TPMS sensors are installed and all is well.


One thing you may want to check into with your tuner is the fact that changing rear tire height from stock changes the Speedo calibration. This can be corrected in the Speedo section of HP Tuners. I don't know how to do it because my tuner made these changes when we changed tire height. I just know it is important because it does more than correct the speedometer reading, it also impacts transmission shifting.

[KingLT1]

Yes you have to measure actual tire height with a tape measure and straight edge and tire load bearing then input the measured size into the ECU. The 305/35/20 555r is rated 28.4" tall but that is with no weight on the tire. It measures right around 27.9-28.0 loaded.

If I remember correctly, if you don't run tpms sensors then you need to pull the abs stabilitrak fuse. I think you lose power steering though.

[KingLT1]

Originally Posted by Yosh6

Yes, all correct as far as I know.


While we are on the subject of TPMS another hard lesson learned with my car (again, may not be the same with yours) was with TPMS sensors installed in the rear wheels with DR's, the car would go into Safe Mode when the psi got down in the low 20's -error message stating something like low tire pressure hazard. That won't work, obviously when you are trying to run 18 psi. I'm not willing to pull the fuse because I don't want the Stabilitrak warning light glowing all the time. Solved the issue by putting two TPMS sensors programed to the car in a 3" by 12" long Sch 40 PVC pipe capped on both ends and with a shrader value. This "canister" is placed in the center of the trunk under the felt covered floor. Use the TPMS Learn tool to learn the sensors in the canister. The car's computer will then read the sensors in the canister (there are no sensors in the rear wheels) and "think" the tires are aired up to 35 psi or whatever pressure is in the canister. No warning lights, no TPMS codes, no safe mode, have power steering and all is well.

I get a low tire light warning under 28psi....I haven't noticed it going into Reduced Power mode either but normally I run between 24-26psi in my 555r's.

That is a pretty good idea. I'll keep that in mind if I ever get a drag pack and need to run really low Tire pressure. What I found with the 555r's is they don't really hook any better lower then 23-24psi so it doesn't appear I will run into the same issues but I am not trying to hook this car on a track like you either. Mine is just a fun street car. I would like to eventually buy some lighter wheels though. Might do some forge line 18's of some sort.