POLL: 305/30 Square AutoX/Track Only Setup on 19" or 20"?
 

So one of my primary intentions with my purchase of the 1LE was to use it for HPDE and AutoX. To do this properly I plan on getting a dedicated set of racing tires and rims. I'd like to do a square setup for a few different reason, including the fact that there are more options for tires when you are only shopping for one size, and tires will last longer because of rotation.

I've looked at seanblurr tread "Mounted: 19x10.5/11 305 square MRR track wheels on 1LE" and i know that is a workable option. I also know Summit1le1ss' Tread "1LE square setup" has a lot of opinions thrown around but no real consensus.

What i'd like to know if the MRR FS01 would work up front, in the following configurations with no other modifications to the car or suspension components.

• 305/30/20 with a 20"x11"(or 10.5") +18. This would be 8 mm (0.3'') closer to suspension/brakes components, will stick out 12 mm (0.5'') farther & will fill out the wheelwell by extra 6 mm (.24").

• 305/30/19 with a 19"x11"(or 10.5") +18. This would be 8 mm (0.3'') closer to suspension/brakes components, will stick out 12 mm (0.5'') farther & will leaves even more wheelwell room than OEM.

The first option gives me more tire options and is doesn't change OEM gearing ratios. I know room is tight next to the front strut tower but its only .3" closer, and sticks out only .5". Seanblurr's setup is .2" closer to the suspension, sticks out .6" and .5" shorter than stock. So its very close. My concern with this setup is its proximity to the shock mount. I don't know how much space i have, but I know its not much.


The second option gives you more room from the suspension at the cost of some gearing and tire selection. I'm okay with that if fitment is better/safer.

I'm trying to keep the setup as close to stock as possible, as i need both suspension and fender clearance for tight bumpy courses.

I just don't see how those dimensions are going to fit. You need less offset to clear the strut, and even then, you'll also need camber plates to net appropriate camber with the wider tire.

What did Glamcem end up running when he was running 305's up front? He ran a 19x10.5 et 22 with a 5mm spacer (17mm effective), and had to grind the strut for clearance.

Your first option makes your front tire too tall. The second option improves your gear ratio, but obviously the offset is still too much. Just run known setups like seanblurr, Glamcem, or ZL1 1LE dimensions. The MRR ZL1 1LE reps in 19x10.5 et14 & 19x11 et38 is an option, those will fit 305/30-19's front and back, still assuming you're running camber plates.

I don't believe seanblurr had to use camber plates with his setup. I'm leaning more towards running the 19" setup, since it is shorter and leaves more head room in the wheelwell. I'd just be concerned with going to +14 on the offset. I'd want to know how the fender clearance is under full compression with that offset.

As far as gearing i'm not exactly looking for shorter gearing, but i'm ok loosing some mph if i can get the fitment i want.

I can reply more in detail later today, but the simple answer that you may not like is to just leave the car stock (wheels/tires). That was my most favorite setup on the SS 1LE.

Np, let me know the problems you had with it when you get a chance.

I don't know about all that but I'm gonna see how these 19x11s shod with 305/30 RE71s (had the wheels for weeks, just got the tires yesterday) are gonna fit tomorrow when I get off my ass and put em on.

I anticipate rolling the fenders a wee bit, otherwise I'm stoked. They's going on a 1SS non MRC.

Front ET should be +6, rear should be +35. I'm gambling a little bit, being a bit overextended and just now replacing my worn-out floor jack. Never got the chance to dry fit the wheels, oh well. **** it. I trust ya Paul and forgestar!

Waiting for pics. Curious to see how it turns out.

So took the car in to get its first alignment, and while it was up on the lift i got some pictures of the front wheels mounted. I can now see where fitment is close. The strut mount support only has about .25" of space between it and the rim. Making it difficult to go shorter and wider with the rim. The tire also already sticks out of the wheel well not leaving much room to go wider or have a lower offset, without contacting the fender. That said there is atleast about 1" of space between the spring seat and the top of the tire. I can easily see running 295/30 on a stock tire and even a +23 offset tire and not having any issues. I'm just trying to figure the math on custom offsets and widths that could work now.

(FYI: i did notice the spring spacer in it. The dealer decided to leave me a present)

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