[M2siast]

Originally Posted by baron95

Would the MP Sports Suspension (Z58) ordered as a manufacturer installed accessory which comes listed in the sticker as a factory option, be considered a modified suspension for the purposes of classing?

I believe so because it’s not an option you can choose when buying the car, but an accessory.

[Lappy]

This is really a grey area, technically any PORT installed options are legal in street, dealer installed is not. However I'm fairly confident stuff like the adjustable springs will be put on the exclusion list the second someone shows up with them.

[Sherlock997]

I have looked into this a bit and have not come to a solid conclusion. What I do find interesting is the SCCA's definition of a standard part.

standard part An item of standard or optional equipment that could have been ordered with the car and delivered through a dealer in the United States. Manufacturer options that are dealer-installed, port-installed, or parts provided by the manufacturer are considered to be the same as those installed on the factory production line.

[Lappy]

Originally Posted by Sherlock997

I have looked into this a bit and have not come to a solid conclusion. What I do find interesting is the SCCA's definition of a standard part.

Yea it's really a toss up and imo will likely get excluded or the car with certain options will be reclassed.

"Manufacturer
options which are dealer-installed must be specifically listed in Appendix A in order to be eligible. Dealer options, accessories, or deletions
(except as required by factory directives), no matter how common or
what their origin, are not included in this definition. This definition
does not allow the updating or backdating of parts."

"The SEB may limit or offer separate classing for option packages within
the Street Category even though the base car is eligible for Street. Such
exclusions will be included in Appendix A (Automobile Classes)."

[Bryan_G87]

Decided to buy a set of Autocross dedicated wheels/tires.

Wheels: Vors TR4 19x10.5" ET22 (Squared) (Cheapest Wheels I could find due to fitment testing)

Tires: Advan A052 295/35/19 (Squared)

Fitment Issues:

The fender liner on the G8x chassis has been a problem with different people running aftermarket Wheel/Tire setups. With no spacer the tire clears the fender liner however the offset does not work with the clearance of the strut. It will fit with the lugs tight but just barely rubs the strut once you try to spin it. I already had a set of 15mm spacers for my stock wheels and decided to test fit the new wheel with those. With the 15mm spacer the tires have about 1/2" clearance from the strut, but then I run into an issue where I hit the fender liner at about 80% steering. I have ordered some 5mm spacers that should be here on Monday and I will see if those end up putting the tire in the sweet spot or if I will have to modify my fender.

Attached photos:
Comparison of the height of the stock rear 20" wheel with the new 19" wheel. (New wheel seems to be a few mil taller)


Strut Clearance (with no spacers it fits but rubs the strut when spun)


Fender gap (with no spacers there is clearance)


Fender gap (with 15mm spacers it hits)


Fender Poke (with 15mm spacers)


Car Overveiw

[Bryan_G87]

The 5mm spacer came in. The spacers gave me about 1-2mm gap to my strut, but near full lock it was still just barely touching the front fender liner. I was able to take a heat gun and push the fender liner forward giving me full clearance on the front side of the tire. I still touch on the backside of the tire but only at full lock. I test drove it a good bit and did not run into any rubbing issues. I am going to autocross it as is and see if I run into any issues.

[Squidget]

The fender clearance cracks me up. They give us like 6 inches of vertical distance that we don't need, but god forbid you want to put in wider tires.

The most modded part on this car are the fender liners lol.

[Bryan_G87]

Originally Posted by Squidget

The fender clearance cracks me up. They give us like 6 inches of vertical distance that we don't need, but god forbid you want to put in wider tires.

The most modded part on this car are the fender liners lol.

Its a joke, there was plenty of room to push the fender liner forward and out of the way. Seems like a pretty big design overlook.

[Lappy]

Originally Posted by Bryan_G87

Its a joke, there was plenty of room to push the fender liner forward and out of the way. Seems like a pretty big design overlook.

You need to be careful as towards the front that fender liner WILL rub through one of the aux coolers if its constantly making contact with it.

[aerobod]

Originally Posted by Bryan_G87

Its a joke, there was plenty of room to push the fender liner forward and out of the way. Seems like a pretty big design overlook.

No design overlook, fits the BMW specified wheels and tyres perfectly. There is no reason for BMW to design to accommodate aftermarket modifications.

[Squidget]

Originally Posted by aerobod

No design overlook, fits the BMW specified wheels and tyres perfectly. There is no reason for BMW to design to accommodate aftermarket modifications.

Yeah, not so much an overlook... as a cold shoulder to the enthusiast community. If BMW allowed for mild tire upsizing, that feels like an easy PR win to the gearheads. But hey, I'm just a dude on the internet, what do I know?

[M2siast]

Originally Posted by Squidget

Yeah, not so much an overlook... as a cold shoulder to the enthusiast community. If BMW allowed for mild tire upsizing, that feels like an easy PR win to the gearheads. But hey, I'm just a dude on the internet, what do I know?

Squidget, I get what you’re saying.
But when I think about this, I can’t help but think it’s a matter of “they gave us an inch, and we want to take a mile”.

In that, no matter what they did, people would ALWAYS try to upsize it. There’s no limit to it. I think what they did (at least for my use case) is: they maxed out what could/should be done. 275 section in the front. What previous model had that size in the REAR? Let alone the front… sky is the limit… they could’ve done 305, and we’d still want to shove 325s upfront…

Pretty happy with what they did. Completely unheard of. A giant leap, which is what gives this car its turn in and stability.

And of course they offer the 285/295 as an option as well.

[GT3M2]

Originally Posted by Squidget

Yeah, not so much an overlook... as a cold shoulder to the enthusiast community. If BMW allowed for mild tire upsizing, that feels like an easy PR win to the gearheads. But hey, I'm just a dude on the internet, what do I know?

We can fit 305 square tires under this car with just a heat gun.

That my friend, to me, is a huge gift.

Any small hole for performance aftermarket to sneak into a new OEM plakform is just more exposure for the OEM.

I think we did pretty good

-GT3M2

[Squidget]

Originally Posted by M2siast

Squidget, I get what you’re saying.
But when I think about this, I can’t help but think it’s a matter of “they gave us an inch, and we want to take a mile”.

In that, no matter what they did, people would ALWAYS try to upsize it. There’s no limit to it.

Haha true. It's like the offroad crowd who cut Jeep Wrangers apart and weld on custom roll cages. It doesn't matter how extreme it is, someone will always want more.

[Bryan_G87]

September Autocross was a success! No rubbing issues and the new tires made a huge difference! I managed to get top time of the day and the car has a lot more in it once I get used to the new driving characteristics. Not sure if it was the square setup or just adding that much more front grip, but there was absolutely no understeer. The car's turn in feels very agressive and I was actually finding the car to oversteer mid turn even when just coasting. This is gunna take some getting used to, but it is way more manageable than pushing through the turn instead... I am excited to dial in the chassis with some camber plates and other goodies.

The 2nd place guy was actually DP. He was running a gutted Miata on Slicks.