Wider Wheels/Tires Experience?

TimeForACobra · #1 (**permalink**) 01-30-2015, 04:20 PM

Hello,

Backdraft Racing Roadster #785, delivered in Summer 2009. I have a set of wheels with street tires and a set of wheels for autocrossing.

For autocrossing, I have a set of Vintage Wheels HA17 Hallibrand replicas 17x8.5 fronts and 17x10.5 rears. I'm running Hoosier A6 275/40ZR17 on the front and 315/35ZR17 on the rear.

Does anyone have any experience running wider wheels/tires. Vintage Wheels has new 17x9.5 for the fronts and 17x11 for the rears. I assume I could fit 295 on the front? Has anyone tried 335 on the rear?

Does anyone have any experience with running Avon 17" Radial Slicks? According to the specs, the Avon 290/645R17 tread is 12.2" wide, the A6 316/35ZR17 tread width is 11.4" wide. The Avon Rim choice is 9-11", so I could go square and run the same size tires front and back? Though I'm not sure I can get the Avons. Or, I will pickup the new Hoosier A7.

Any thoughts/advice?

Thanks...

jeffnolan · #2 (**permalink**) 01-30-2015, 05:01 PM

this may not be the definitive answer to your question but it's a data point. I have 20x11 Radenergie wheels for the rears on my Mercedes and run 305/25ZR-20 tires. I could get 315s on that wheel but I'd be hesitant to try 335s... however, with a 35 series tire this may be doable.

Grey 65 · #3 (**permalink**) 01-30-2015, 06:52 PM

Quote:

Originally Posted by TimeForACobra

Hello,

Backdraft Racing Roadster #785, delivered in Summer 2009. I have a set of wheels with street tires and a set of wheels for autocrossing.

For autocrossing, I have a set of Vintage Wheels HA17 Hallibrand replicas 17x8.5 fronts and 17x10.5 rears. I'm running Hoosier A6 275/40ZR17 on the front and 315/35ZR17 on the rear.

Does anyone have any experience running wider wheels/tires. Vintage Wheels has new 17x9.5 for the fronts and 17x11 for the rears. I assume I could fit 295 on the front? Has anyone tried 335 on the rear?

Any thoughts/advice?

Thanks...

Switch to 18x9's and 18x11's and run either Falken 615's or BFG Rivals and run in the SCCA CAM-S class.

If you are going to run 335's you will need at least an 11.5" wide wheel otherwise you are pinching the tire and will have less grip than a 315 would have on the same wheel.

Kevin.....

TimeForACobra · #4 (**permalink**) 01-31-2015, 08:17 AM

Thanks for the info/advice.... Not yet sure what I'm going to do. I need to "finish" my A6's which shouldn't take long as I'm planning on attending Evolution Performance schools (levels 1 and 2) in addition to a local school/practice.

Thanks again.

Bailey · #5 (**permalink**) 02-19-2015, 05:26 AM

The A6s work well, burned through several sets and the R6s too. 275s on the front (17 x 10), 335s on the rear (17 x 12). You may have to open up the front fenders to run 295s. Ran the 295s at Run and Gun s few years back, no noticeable difference. In a straight line you're fine, but you will have interferance when turning hard. I found 275s to work best on a 10" wheel. We couldn't get the tire temps up on the 295s
BTW, I have a used set for sale with a set of R6s and A6s with 3 heat cycles on them if interested. (they are bolt on, not peg drive)
PM sent

vatdevil · #6 (**permalink**) 02-19-2015, 03:46 PM

Quote:

Originally Posted by Grey 65

Switch to 18x9's and 18x11's and run either Falken 615's or BFG Rivals and run in the SCCA CAM-S class.

If you are going to run 335's you will need at least an 11.5" wide wheel otherwise you are pinching the tire and will have less grip than a 315 would have on the same wheel.

Kevin.....

Cobra replicas are allowed in CAM-S?

TimeForACobra · #7 (**permalink**) 02-19-2015, 06:44 PM

Yes I too have heard Cobra Replicas will be allowed in CAM-S. I'm watching for the next Fastrack as there may be a response to a letter asking for clarification. However we typically have 3-4 Cobras (replicas) and a 2 driver Daytona at most of our events so I would run whatever class everyone else is running to keep the competition.

Grey 65 · #8 (**permalink**) 02-19-2015, 06:52 PM

Quote:

Originally Posted by vatdevil

Cobra replicas are allowed in CAM-S?

Cobras are in CAM-S.

Kevin.....

vatdevil · #9 (**permalink**) 02-19-2015, 07:56 PM

Quote:

Originally Posted by Grey 65

Cobras are in CAM-S.

Kevin.....

Min weight is 2600 lbs?

http://www.scca.com/assets/2015%20CA...%20B%20(2).pdf

cycleguy55 · #10 (**permalink**) 02-19-2015, 08:00 PM

Quote:

Originally Posted by vatdevil

Min weight is 2600 lbs?

http://www.scca.com/assets/2015%20CA...%20B%20(2).pdf

I noticed that too. Some people are going to be looking for lead bars to bolt on.

vatdevil · #11 (**permalink**) 02-20-2015, 05:46 AM

Quote:

Originally Posted by cycleguy55

I noticed that too. Some people are going to be looking for lead bars to bolt on.

Are your local regions running the separate CAM classes, or one single class?

Grey 65 · #12 (**permalink**) 02-20-2015, 12:57 PM

Weight for CAM-S is 2,350lbs without driver. Doug Gill will be correcting the CAM rules...

Kevin.....

TimeForACobra · #13 (**permalink**) 02-21-2015, 01:12 PM

Not sure how the CAM classes will be run locally.

Btw, My Backdraft Racing Roadster with 1/2 tank of gas, no driver, Roush 427 SRTW and TKO-600 is 2,567 lbs.

Grey 65 · #14 (**permalink**) 02-25-2015, 12:38 AM

See Updated Rules 2015 Classic American Muscle (pdf)

Kevin.....