To 315.... or not to 315?????? SP edition
 

Well I keep going back and forth. Trying to decide if going from 285 to 315 with Street Prepared rules makes any sense. Has anyone tried this on a 8/9 with the limitations of SP? I know it is possible in SM, but will it be too wide, how to make the front fit... are all the questions that keep running through my head... I am about to just say F it and just get wheels/tires and see if this works... Who knows... any thoughts? (I have come to terms with the cutting that would be necessary)

Cutting fenders is totally legal in SP though I dont recall if overfenders are cool or not. Seems if you have enough weight to over heat the tires then you need more tire. And we can roast 285s dual driven.

Heres a clip from SCCA SP rules. Seems like Kens car (315's) below meets some of the rules, but his front fenders would not be allowed

His SSB susp modifications would not be allowed

https://cimg0.ibsrv.net/gimg/www.evo...a728588d4b.jpg
https://cimg1.ibsrv.net/gimg/www.evo...1cd43b7c23.jpg

Certainly diminishing returns as you go wider but the 285s we can over heat them so quickly that Im spraying every run 2x just to slow it down. Its true though, you will have to turn further around elements but that should be more than offset by increased cornering speed. We're also still pretty narrow compared to an F-body. My reference is usually the GTRs and my buddies CAM mustang which are around 75-77". I can get 315s on the car and still be under 70 with an ASP Evo probably 71".

Im SM trim I think I can get 335s to around 71" but thats going a little beyond what the average person may have access to.

The width of the car is a concern for sure but I do think it will be out weighed by the grip improvement. We can cut fenders and have flares but cannot replace complete fender... I am fine with that. We cannot modify anything for fitment inboard of the wheel hub, so that makes ride height a little bit of an issue. Front will have to be raised to get everything to fit..

In ASP, you should probably raise the car a bit anyways. If you look at Tom Berrys car, they are a nearly stock ride height up front with the rear run quite a bit lower. This is to keep the geometry from getting all crazy. And that car use to be low, so I can only assume Tom/Marshal tried both and they agreed not screwing the geometry was more beneficial than lowering CG.

Just to contrast to SM, the fender replacement is usefull so you arent cutting "front bodywork" width which is measured at the centerline of the front wheels. That effects how wide you can get the front aero. ASP doesnt have that same need, so cut away and bolt on some universal overfenders like Zack (wanabgts here)

https://www.flickr.com/photos/158261786@N07/42323353151/

Those fender overs dont bother me. Car looks agressive as hell.

He says they are the $30 flares from Amazon/eBay.. but the only ones I can find are flat on the bottom, so don't allow the wheel/tire to tuck at all. The bright side would be no need to cut the quarter panel.. the downside is they wouldn't really work LOL
Anyone know of a decent, functional, and cheap-ish set? If I find some, then I wouldn't need to wait on offset rear control arms. I really like how these look:

I have wanted to put 315's on Tom's car for a long time. I don't think the fronts will fit legally with SP rules. It is contact in the area behind the wheel when steering that limits it.

Ive had an idea for an offset spherical bushing using a delrin base to push the wheel forward but that does have the negative aspect of causing sticktion in the front bushing. Would have to also melt out all the rubber from the OE bushing to make sure that weight is less than a spherical + spacer weight. It might be legal if done right. Or just bring Tom to SM... the waters warm ;)

Well dang... I have a set of wheels and tires (borrowed) that I am going to test fit once our events are over for the year... They are 18x12's but I was contemplating 18x11... Who knows..

Are they the Rota P45 18x12 +20 or something different? Along the 315 topic, im trying to figure out wheels right now too. Im leaning towards Forgestar F14s in 18x12 around +32.

Not familiar with SP rules but you're not gonna fit 315s with stock trailing arm without flares.