Rear tire upsize??? Please help:)
11-17-2018, 07:53 AM
#1
3rd Gear
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Rear tire upsize??? Please help:)
Can anyone please tell me if it’s ok to upsize my rear tires on a 2017 grand sport 8 speed automatic from the stock 335/25/20 to a 345/30/20? People have mentioned that it could play a part in traction control? ABS? Shifting? Launch control???
This is a attempt to stop my rear rims from cracking like the last 2 sets I just replaced
and I like beefier tires
please help. Thank you
This is a attempt to stop my rear rims from cracking like the last 2 sets I just replaced
and I like beefier tires please help. Thank youLast edited by Mike Watroba; 11-17-2018 at 07:54 AM.
11-17-2018, 08:00 AM
#2
You're going to change the overall diameter of the wheel which might or might not affect tc or ptm I believe.
if you dont want to crack wheels you have to go forged or go with a better tire.
the factory run flats on our cars have super stiff sidewalls which is good for the track, not for street driving. I switched to conti and it made everything better. For STREET use.
if you dont want to crack wheels you have to go forged or go with a better tire.
the factory run flats on our cars have super stiff sidewalls which is good for the track, not for street driving. I switched to conti and it made everything better. For STREET use.
11-17-2018, 10:15 AM
#4
Make sure you change all four tires to the same type. Mix and matching the fronts with different rears will not be a fun driving experience for you.
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Z0HS1CK (11-17-2018)
11-18-2018, 02:51 PM
#5
Melting Slicks
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^^^^This. If these are for street driving, it will be dangerous mixing MPSS with different brand (rubber) in rear. They will have widely varying handling characteristics which COULD end up with fronts griping better/worse than rear different rubber especially if fronts are ZPs & rear are non-ZP. JMO.
Last edited by madrob2020; 11-18-2018 at 02:52 PM.
11-18-2018, 03:09 PM
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Can anyone please tell me if it’s ok to upsize my rear tires on a 2017 grand sport 8 speed automatic from the stock 335/25/20 to a 345/30/20? People have mentioned that it could play a part in traction control? ABS? Shifting? Launch control???
This is a attempt to stop my rear rims from cracking like the last 2 sets I just replaced and I like beefier tires please help. Thank you
This is a attempt to stop my rear rims from cracking like the last 2 sets I just replaced
and I like beefier tires please help. Thank youThe tire will be about 3/4 inch larger in radius, 1.5 inch larger in diameter. You will need to think about clearance issues when going over bumps. The larger rear diameter may delay activation of traction control as the larger diameter will cause the rear tire to rotate at a slower rate. I don't think you will have the Engine Drag Control situation that occurs with C6s where the EBCM interprets slower rotating rear tires off throttle conditions as meaning the tires are sliding on the pavement thus adding throttle to spin them up to regain traction.
Activation of Stability Control is based on steering inputs and the car's reaction to them not wheel speeds although wheel slower than normal rear wheel speeds may affect the brake applications used by the EBCM to control yaw.
Bill
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Z0HS1CK (11-19-2018)
11-20-2018, 01:14 AM
#8
Racer
If you have mag ride don't do it. mag ride doesn't like anything larger than 27" in rear. It confuses mag ride calibration and handling goes to crap. Not to mention the rubbing. Anything over 27" will rub and the harder you drive the harder you'll rub.