[ZM2]

Originally Posted by AmuroRay

Are you running the stock spring rates, and do you know what they are?

Stock springs rates, not sure what they are. They are a bit stiff for around town, but excellent on track.

[AmuroRay]

See, I have a set of PSS springs here - they said (back in the E46 days) the rates between the PSS/10 were the same. Now I don't think that's the same between a M and non M (IE a M3's PSS spring rates aren't going to be the same as a 330i's PSS10)

I wonder what the spring rate differences are between them?

Anyhow while I was writing this, I found what I was looking for:

https://f87.bimmerpost.com/forums/sh...8&postcount=14

PSS10 M2 are supposedly 514F/800R Progressive?

I have PSS with Linear 350F/900/R for flat ride frequency.

I'll have less power and tire, and likely less total grip - and less race pace. How far off is all of this worth?

[medphysdave]

From a road and track feel I'm in love with the 295 square setup. I did upgrade the front sway and it really fits my driving style. It also helped with weight transition in corners.

[ZM2]

Originally Posted by AmuroRay

I've seen this test a while ago, but wanted to get actual road feel perspectives. Thank you!

265 on a 9.5” will certainly be a noticeable grip increase. 265 on a 9” will kill initial turn in and make the steering feel sloppy.

[RugbyBro]

Originally Posted by medphysdave

From a road and track feel I'm in love with the 295 square setup. I did upgrade the front sway and it really fits my driving style. It also helped with weight transition in corners.

I'm liking 295 on a 10.5in rim (albeit I'm running a 35 sidewall). Turn in is very sharp and I've got a lot of steering feeedback. Still, I do wonder if it would be even better on a 11in wheel which is hard to fit in front on any F8X.

[medphysdave]

Originally Posted by RugbyBro

I'm liking 295 on a 10.5in rim (albeit I'm running a 35 sidewall). Turn in is very sharp and I've got a lot of steering feeedback. Still, I do wonder if it would be even better on a 11in wheel which is hard to fit in front on any F8X.

I do get on the sidewalk more than I'd like. Even with significant front camber. I assume it's my suspension giving up and car rolling over. Would a wider wheel also help with this? I don't think I could go 11" wide at the moment. Maybe with an aftermarket suspension. Having an adjustable LCA helps. Increasing ride height a little, and playing with spacers, etc

[GasBurnlife(landapanda)]

Great conversation and I appreciate everyone’s feedback. Sounds like a 10.5” square will be doable given my camber settings with a larger spacer, and running a 275/35 tire on the wider rim should continue to enhance traction and feel.

Sounds like the 295/30 tire will potentially result in slower time as that tire would be better fitted on an 11” wheel. A 285/35 may be a good compromise on 10.5” wheels. I switched to Toyo RRs (275/35), and would like to try the R7 Hoosiers next. Both of them come in the 275 and 285 sizes.

[GJMills]

Has anyone here directly compared a 275/40/18 with a 295/35/18 in the rear?

[Juice ///M]

275/305 30 profile 19" on M2C working.

[ThreeStripes]

Originally Posted by Juice ///M

275/305 30 profile 19" on M2C working.

What tire? What width and offset on the wheels?

[Juice ///M]

Originally Posted by ThreeStripes

What tire? What width and offset on the wheels?

RT660

Apex 19"s for M2C Brakes. running 12MM spacer from Bimmerworld in the front on extended lugs.

[monstruo]

"... Impossible, no f-way, no room, etc.."
That's what every local M owner told me. But managed 295/35/R18 on 10.5J square setup, full lock without any rub, plus brake ducts.

[ZM2]

Originally Posted by monstruo

"... Impossible, no f-way, no room, etc.."
That's what every local M owner told me. But managed 295/35/R18 on 10.5J square setup, full lock without any rub, plus brake ducts.

Offset, alignment, ride height? Had it on track yet to test rub under compression?

My concern with 295 up front is more about throwing track debris down the side of my car. With that splitter you have, guessing that’s not a major concern for you.

[medphysdave]

Originally Posted by monstruo

"... Impossible, no f-way, no room, etc.."
That's what every local M owner told me. But managed 295/35/R18 on 10.5J square setup, full lock without any rub, plus brake ducts.

How did you get it to work? I'm running 295/30/18 and wondering what other tire options could be available with 35s

I'm at stock ride height which helps, but soon I'll be on coilovers and sitting a little lower.

[monstruo]

Originally Posted by ZM2

Offset, alignment, ride height? Had it on track yet to test rub under compression?

My concern with 295 up front is more about throwing track debris down the side of my car. With that splitter you have, guessing that’s not a major concern for you.

10.5J ET 35 square. 20mm front spacer to clear the strut body. I'm running a custom nitron R3 with heavy spring rates, don't remember the numbers off my head. Full SPL btw.
Alignment wise: 8.8 caster / F.camber 4.1 / R.camber 2.9.

Will be shaking down the car soon.

[monstruo]

Originally Posted by medphysdave

How did you get it to work? I'm running 295/30/18 and wondering what other tire options could be available with 35s

I'm at stock ride height which helps, but soon I'll be on coilovers and sitting a little lower.

I did try to do whatever math i could but in the end i just bite the bullet as 295/30 square wasn't an option due to my chassis mounted splitter. It would be next to impossible to clear the driveway

[M1500Z]

Originally Posted by monstruo

10.5J ET 35 square. Front needed 20mm spacer to clear the coilovers. I'm running a custom nitron R3 with heavy spring rates, don't remember the numbers off my head. Full SPL btw.
Alignment wise: 8.8 caster / F.camber 4.1 / R.camber 2.9.

Will be shaking down the car soon.

Cool to see it—I've been measuring and working out a 10.5" square setup on my car for a little while now—it's' definitely doable. The honest assembly car ran a 305 square setup at Super Lap Battle, and there is a guy I follow on IG that has a 295/35 square setup on 18x11s.

Did you set the car up yourself or did a shop do it and if you have front-lower arms, were they shortened? You're about spot on to the measurements I did with a 10.5 +37 and a 25mm spacer—I got about 7mm of clearance to my damper body with stock arms. I would probably need around -4º front camber to clear the fender. I am surprised you've gotten +8.8º of caster and have no rubbing though, that's pretty cool. For anyone curious, the difference in diameter from a 275/35-18 to a 295/35-19 is +.5", but the section width is a whole 1" wider unmounted.

If you're the kind of person to chase a setup, it would be really cool to see detailed setup notes (ride height, spring rate, roll bars, etc) and tire temps from your shake down.

[monstruo]

Originally Posted by M1500Z

Cool to see it—I've been measuring and working out a 10.5" square setup on my car for a little while now—it's' definitely doable. The honest assembly car ran a 305 square setup at Super Lap Battle, and there is a guy I follow on IG that has a 295/35 square setup on 18x11s.

Did you set the car up yourself or did a shop do it and if you have front-lower arms, were they shortened? You're about spot on to the measurements I did with a 10.5 +37 and a 25mm spacer—I got about 7mm of clearance to my damper body with stock arms. I would probably need around -4º front camber to clear the fender. I am surprised you've gotten +8.8º of caster and have no rubbing though, that's pretty cool. For anyone curious, the difference in diameter from a 275/35-18 to a 295/35-19 is +.5", but the section width is a whole 1" wider unmounted.

If you're the kind of person to chase a setup, it would be really cool to see detailed setup notes (ride height, spring rate, roll bars, etc) and tire temps from your shake down.

Initially, I purchased the BW steering rack stops, but in the end, we managed to clear the inner wheel liner with full lock without using them. That said, the workshop had to redo the inner liner and redesign the brake duct. I reckon I could run ET25 with the current alignment setup or my current ET with a less aggressive alignment setting. An 11J setup would be possible but would need to sacrifice full lock with a rack stop.

The SPL(s) are standard off-the-shelf items for the F87. The biggest hurdle is working out the clearance between your inner tire and damper body, reworking the inner liner and brake ducts, and getting your ideal caster. I ran a few caster tests from 10.8 to 8.8. In my previous staggered setup, I ran a range of caster from 7.4 to 8.4.

So far, 8.8 works well for 295 square setup (for now ). Will need to run more tests to figure out the nitty-gritty details.

[Doctor Sbaitso]

I went with:

M2C

Front: Apex 9.5 VS5RS ET22 + 265/30-19 P4S
Rear: Apex 10.5 VS5RS ET45 + 295/30/19 P4S
H&R Super sport springs
Vorschlag camber plates with -3 degrees front, -2 degress rear camber

Only reasons I could go ET22 up front was the negative camber. ET28 is better unless you have camber dialled in. I still had to roll the fenders, but all good at the track under compression. The car handles much better now than stock, has fantastic turn-in and mechanical grip. The stance is also badass.

[Track/S]

Originally Posted by monstruo

"... Impossible, no f-way, no room, etc.."
That's what every local M owner told me. But managed 295/35/R18 on 10.5J square setup, full lock without any rub, plus brake ducts.

That pic for Instagram is beautiful, in real life in strong compression areas you break the fender.

[MadM2C]

Anybody have any pics of a 18x10.5 squared setup running 295/30 square?


Trying to figure out what kind of offset I would need to make this work