Rather simple your rear wheel/tire combination is too wide, nothing to do with the suspension. You kept the same '30' height on a tire that is 20mm wider, eg. you not only have a wider tire but you also added 7mm to the radius of wheel/tire combination.
1 - 17 of 17 Posts
Man, somethings weird here, especially in the context of the stock Z51 wheel/tire was rubbing? You went 1 inch wider but your offset went from 79 (stock) to 71 ? Can you tell us the exact brand/style of wheel you purchase? Let us know what's going on here, looking to pull the trigger on a set of aftermarket wheels myself. 
Wheels are Forgestar cf5v. Something has got to be wrong. I feel like people are running similar spec setups with no problems on a stingray. When you shop for stingray wheels, any options that aren't stock or stock reproductions have very similar size and offset specs as the ones I purchased. I am going to have the suspension checked out as I am thinking there has to be something up with the suspension or maybe it is lowered on stock bolts.Man, somethings weird here, especially in the context of the stock Z51 wheel/tire was rubbing? You went 1 inch wider but your offset went from 79 (stock) to 71 ? Can you tell us the exact brand/style of wheel you purchase? Let us know what's going on here, looking to pull the trigger on a set of aftermarket wheels myself.
I hope you found the solution to the issue by now. But here is just a bit more info.
The rear mag ride suspension does not have a rubber bump stop. This action is done by making the shock go full hard at the end of its compression.
Because you state the wheel rubbing occured on the stock set up and on both rear wheels it is unlikely that both rear shocks are bad.
You didn't state you carry a lot of extra weight in the rear so that is not likely the cause. The springs could be bad but that is also very unlikely as the rear of your car would squat and tire wear would be bad.
The shock control unit is a seperate module from the ECU. This contoller is located on the driver side behind the vent. This unit runs hot. I don't know why but it is hot to the touch. The unit takes in a number of sensors from the cars BUSS. The unit has a few look up tables in it. Mainly a calibration table for each shock. It also has a table for each drive mode. In simple form all it does is figure out what spot in the mode table it should run and then looks at the calibration table to see what ampreage it should send to the shock to control the fluid. This is done for each shock independently so not likely a corrupted file which can and does happen, but could have corrupted the ride height. The most likely thing is the ride height is sensed wrong as this is one of the calculations done in the unit. There is only one or two lines in the shop manual on this. The dealer can reset the ride height and this could be why the bump stop is not working.
Or the unit could have been misprogramed from day one.
Does this occure in all drive modes?
This is a picture of the control unit. I replaced mine with a DSC contoller so I reprogram mine for different tracks and conditions.
Hope this helps.
![Hood Window Rectangle Wood Stairs]()
The rear mag ride suspension does not have a rubber bump stop. This action is done by making the shock go full hard at the end of its compression.
Because you state the wheel rubbing occured on the stock set up and on both rear wheels it is unlikely that both rear shocks are bad.
You didn't state you carry a lot of extra weight in the rear so that is not likely the cause. The springs could be bad but that is also very unlikely as the rear of your car would squat and tire wear would be bad.
The shock control unit is a seperate module from the ECU. This contoller is located on the driver side behind the vent. This unit runs hot. I don't know why but it is hot to the touch. The unit takes in a number of sensors from the cars BUSS. The unit has a few look up tables in it. Mainly a calibration table for each shock. It also has a table for each drive mode. In simple form all it does is figure out what spot in the mode table it should run and then looks at the calibration table to see what ampreage it should send to the shock to control the fluid. This is done for each shock independently so not likely a corrupted file which can and does happen, but could have corrupted the ride height. The most likely thing is the ride height is sensed wrong as this is one of the calculations done in the unit. There is only one or two lines in the shop manual on this. The dealer can reset the ride height and this could be why the bump stop is not working.
Or the unit could have been misprogramed from day one.
Does this occure in all drive modes?
This is a picture of the control unit. I replaced mine with a DSC contoller so I reprogram mine for different tracks and conditions.
Hope this helps.
My Stingray Z51 Set Up that works fine:
Below from another post:
www.stingrayforums.com
![Font Screenshot Number Parallel Document]()
- Wheels: Front 19 x 9.5 and Rear 20 x 11
- Tires: Front 275/30/19 and Rear 305/30/20
- Front Stock: 8.5 vs. My Front: 9.5
- Rear Stock 10.00 vs. My Rear: 11.00
Below from another post:
C7 Stingray Wheel Options
Looking to get aftermarket wheels for my 17' Stingray with Z51 wheel package. Front 19" and rear 20". Options seem to be fairly limited for this car. I know the bolt pattern is 5x120.65. Would a 5x120.7 work? I know these cars can be very temperamental with wheels. I like Variant Radon...
www.stingrayforums.com
A ton of wheel manufacturers make 20x11 wheels for the rear of the Stingray. Even when you go put your year/make/model/wheel option into their website it will spit out this size. Buyer beware if you wrap a 20x11 in the recommended tire size that fits them (305/30/20). It WILL rub without alterations in the form of negative camber and/or trimming/shaving the top of the inside of the fender arch. Pretty sure 285/30/20 and 295/30/20 tires would rub as well on the same wheel. Wouldn't put 285's on them anyway as it stretches them too much, but included that size in my statement since it is the stock tire size.My Stingray Z51 Set Up that works fine:
- Wheels: Front 19 x 9.5 and Rear 20 x 11
- Tires: Front 275/30/19 and Rear 305/30/20
- Front Stock: 8.5 vs. My Front: 9.5
- Rear Stock 10.00 vs. My Rear: 11.00
Below from another post:
C7 Stingray Wheel Options
Looking to get aftermarket wheels for my 17' Stingray with Z51 wheel package. Front 19" and rear 20". Options seem to be fairly limited for this car. I know the bolt pattern is 5x120.65. Would a 5x120.7 work? I know these cars can be very temperamental with wheels. I like Variant Radon...
View attachment 284580
1 - 17 of 17 Posts
