Off-season, thinking CS (763M) wheels + slicks, brake replacement

[FormulaMMM]

Thinking about a 2nd set of wheels w/ slicks. Drawn to maintaining BMW wheel specification/stagger on the GTS, so the 763M wheels look like a good option.

Lose 0.5" of wheel width out back, but the 285 section Hoosier R7's that I'd want to fit are 0.2" narrower than the 285 section star spec Cup 2's.

If BMWPARTSPROS are accurate with their weights, a 763M setup would be notably lighter than the GTS 666M.

3.25# less front per corner
5# less rear per corner
16.5# reduction overall

763M by FormulaMMM, on Flickr

Add to the mix rear Hoosier R7, which save another 2# per corner. (Front R7's are equal to the OE Cup 2's.)

20.5# reduction overall

Thoughts? Overlooking anything? Seems like a nice middle ground between stock and BBS FI-R… (https://f80.bimmerpost.com/forums/sh....php?t=1155359)

Long way off hopefully, but on the subject of carbon ceramic brake replacement, this the best published deal out there? https://www.ecstuning.com/b-genuine-...t/34112358378/

I see from some past threads that BMWPARTSPROS sold the retrofit for 10k. Seems like a "good deal" as compared to front disk replacement alone at almost 8k. https://www.ecstuning.com/b-genuine-...SABEgJZefD_BwE

Only catch being that the GTS pads are a different compound than the standard carbon ceramic kit, I think.

[CanAutM3]

It’s an interesting thought. I do like the 763M wheels a lot. However, if it were me, I’d actually go wider for dedicated track wheels: 10”~10.5” front and 11” rear to be able to fit wider tires. Wider tires will heat less and therefore grip more, be more consistent and wear less.

As for the pads, if I’m not mistaken, only the GTS rear pads are different than the non-GTS CCB.

[FormulaMMM]

Originally Posted by CanAutM3

It’s an interesting thought. I do like the 763M wheels a lot. However, if it were me, I’d actually go for wider for dedicated track wheels: 10”~10.5” front and 11” rear to be able to fit wider tires. Wider tires will heat less and therefore grip more, be more consistent and wear less.

As for the pads, if I’m not mistaken, only the GTS rear pads are different than the non-GTS CCB.

Appreciate the thoughts and pad info. I think that's right https://f80.bimmerpost.com/forums/sh....php?t=1554508

Yeah, counter to my natural instincts too. Never stayed OE tire specs or gone with a narrower wheel on a track setup.

This is based on 2 track days so far with the GTS. Agree that more tire never hurts, but found rear traction pretty much ideal.

It understeered, but that's because about the outer 1/3 of the front tire contact patch was working for me. Camber plates, especially in combination w/ slicks, should resolve.

I'm afraid to change the balance of the car, put bulkier wheels + tires on, lose any tactility, etc. Also don't know about clearance and geometry issues.

So anyways, I'm not finding much of a performance need to deviate from OE wheel + tire specs, like was an obvious requirement on the E90. Any wider aftermarket wheel + tire setup will come with a weight penalty. This potential setup saves pretty substantial weight and the R7's are right there for the taking in OE sizes.

Oh, and vanity. I like the 763M…

Thanks for the thoughts.

[Darth One]

Wouldn’t it be better to go to someone like Forgeline and have them make an even lighter wheel to exactly the spec you want? They’re pricier than OEM, though.

[FormulaMMM]

Originally Posted by Darth One

Wouldn’t it be better to go to someone like Forgeline and have them make an even lighter wheel to exactly the spec you want? They’re pricier than OEM, though.

Yeah, probably FI-R price territory at that point.

Here's an unconventional fitment: https://f80.bimmerpost.com/forums/sh...2&postcount=31

Believe that was before Apex made a 19" wheel that was a fit for the rear. New Apex SM-10 is available 19x10 front and 19x11 rear. Great looking specs, seems like a good option to me this a.m. Nothing but positive experiences with Apex wheels. Could probably run R7's in 295 front, 315 rear. Based on projected SM-10 weights, would still end up with a net loss vs 666M.

I'm just nuts enough that the narrower 763M rear wheels and corresponding loss in tire section width will probably bother me, so moving away from that idea.

[airwave808]

I am thinking about getting Forgeline GS1 or GA1R 19x9.5 + 29 offset and 19x10.5 + 38 offset with R7s.

[FormulaMMM]

Originally Posted by airwave808

I am thinking about getting Forgeline GS1 or GA1R 19x9.5 + 29 offset and 19x10.5 + 38 offset with R7s.

So you'd stick with 265 front 285 rear?

[airwave808]

Originally Posted by FormulaMMM

So you'd stick with 265 front 285 rear?

295 in the back and 265 in front is what I am being told is the option with R7. Should have mentioned earlier.

[FormulaMMM]

Originally Posted by airwave808

295 in the back and 265 in front is what I am being told is the option with R7. Should have mentioned earlier.

Yeah, believe that’s the ticket. I’m thinking fitted to 19x10 up front, 19x11 Apex SM-10 in the rear.

https://www.apexraceparts.com/shop-b...-10-wheel.html
https://www.apexraceparts.com/shop-b...-10-wheel.html

Tried to get a good glimpse of the inboard clearance yesterday. Jacked up the front end and snapped some pics. This is with 275 Cup 2’s fitted – 11” of section width as compared to 10.7” for the OE 265, tread width of 9.5” vs 9.2” for OE 265.

[IMG]IMG_1610 by FormulaMMM, on Flickr[/IMG]

[IMG]IMG_1616 by FormulaMMM, on Flickr[/IMG]

295 R7 up front with 11.5” of section width, and 10.5” of tread width seems iffy. Not sure if that GTS above was running spacers, wasn’t lowered, adjusted ride height for optimum clearance, something.

265 R7’s are +0.3” tread width vs OE 265 Cup 2. 295 R7’s are +0.1” tread width vs OE 285 Cup 2. In combination with 10” wheels front, 11” wheels rear, should be a nice expanded footprint front & rear with handling balance kept pretty consistent.

[airwave808]

Originally Posted by FormulaMMM

Yeah, believe that’s the ticket. I’m thinking fitted to 19x10 up front, 19x11 Apex SM-10 in the rear.

https://www.apexraceparts.com/shop-b...-10-wheel.html
https://www.apexraceparts.com/shop-b...-10-wheel.html

Tried to get a good glimpse of the inboard clearance yesterday. Jacked up the front end and snapped some pics. This is with 275 Cup 2’s fitted – 11” of section width as compared to 10.7” for the OE 265, tread width of 9.5” vs 9.2” for OE 265.

[IMG]IMG_1610 by FormulaMMM, on Flickr[/IMG]

[IMG]IMG_1616 by FormulaMMM, on Flickr[/IMG]

295 R7 up front with 11.5” of section width, and 10.5” of tread width seems iffy. Not sure if that GTS above was running spacers, wasn’t lowered, adjusted ride height for optimum clearance, something.

265 R7’s are +0.3” tread width vs OE 265 Cup 2. 295 R7’s are +0.1” tread width vs OE 285 Cup 2. In combination with 10” wheels front, 11” wheels rear, should be a nice expanded footprint front & rear with handling balance kept pretty consistent.

Thanks. this is very useful. I will actually get the setup checked likely in another week or so and will tell you what actually works better.

[FormulaMMM]

Originally Posted by airwave808

Thanks. this is very useful. I will actually get the setup checked likely in another week or so and will tell you what actually works better.

Have 19x10 ET25 fronts on order from Apex. Should arrive next week. I'll mount without tire first to see what clearance looks like and report back as well.

Ran 18x10 ET25 front (w/ 275s) for years on my E90 with KW Clubsports and Eibach springs, so thinking it should be just about perfect.

[schnell325]

Originally Posted by FormulaMMM

Have 19x10 ET25 fronts on order from Apex. Should arrive next week. I'll mount without tire first to see what clearance looks like and report back as well.

Ran 18x10 ET25 front (w/ 275s) for years on my E90 with KW Clubsports and Eibach springs, so thinking it should be just about perfect.

285/30 pscup2s fit perfectly up front on the 19x10 ET 25 APEX wheels I run on my GTS

Unfortunately I’ve never snapped any pictures :/

[FormulaMMM]

Originally Posted by schnell325

285/30 pscup2s fit perfectly up front on the 19x10 ET 25 APEX wheels I run on my GTS

Unfortunately I’ve never snapped any pictures :/

Nice! Thanks. What are rear wheel + tire specs? Do you have the Apex SM-10s?

[FormulaMMM]

Originally Posted by schnell325

285/30 pscup2s fit perfectly up front on the 19x10 ET 25 APEX wheels I run on my GTS

Unfortunately I’ve never snapped any pictures :/

Also, you running the TPC spec run flats in that size? https://www.tirerack.com/tires/tires...omCompare1=yes

[schnell325]

Originally Posted by FormulaMMM

Nice! Thanks. What are rear wheel + tire specs? Do you have the Apex SM-10s?

I am actually running a square setup, so same specs on the rear. I’m using their PS-7 wheel.

[schnell325]

Originally Posted by FormulaMMM

Also, you running the TPC spec run flats in that size? https://www.tirerack.com/tires/tires...omCompare1=yes

I’m not using the above RFT size

[schnell325]

[CanAutM3]

Originally Posted by schnell325

Attachment 1946196

Any pics with those wheels on ?

[schnell325]

Originally Posted by CanAutM3

Any pics with those wheels on ?

Silly me

Added one of them on my F80.

[FormulaMMM]

Originally Posted by schnell325

Attachment 1946229

Hmmm... you've got me thinking now. This looks all kinds of right. Not sure why a square setup wouldn't be excellent on the GTS too. Especially if a 285 up front is possible.

I can't find any spec Cup 2 in size 285/30-19 other than that run flat linked above. You have a Canada special?

Nice plate, by the way.

[schnell325]

Originally Posted by FormulaMMM

Hmmm... you've got me thinking now. This looks all kinds of right. Not sure why a square setup wouldn't be excellent on the GTS too. Especially if a 285 up front is possible.

I can't find any spec Cup 2 in size 285/30-19 other than that run flat linked above. You have a Canada special?

Nice plate, by the way.

That is so odd!!!

I get mine from Costco Canada. I’m not sure the production date code, but they’re still listed

[FormulaMMM]

Originally Posted by schnell325

That is so odd!!!

I get mine from Costco Canada. I’m not sure the production date code, but they’re still listed

Attachment 1947057

Yep 94Y, believe those are Vette spec run flats (ZP). Looks like it based upon the tread characteristics in your actual pics too.

Like them and the square setup? Did you run the OE star spec Cup 2's and stagger initially, i.e. can you compare the two setups?

Thanks