E92 M3 ZCP in SCCA Solo F Street

[z3papa]

Originally Posted by Richbot

Same and e9x has the same adjustment procedure in the book somebody has posted a link to the tis procedure in this thread or maybe the suspension forum. Should net -1.5 to 1.8 total on a ZCP car.

No "bolts" on these. Front strut just slides into a yoke on the knuckle

It is a different suspension geometry than prior gen mac-strut suspensions which makes the concept of camber bolts a non-starter anyway, but also limits camber gain at the extremes. Pretty ingenious really.

[FrozenCali]

New to the forum, but have enjoyed reading everyone's advice in this thread and others about your autocross shenanigans. I bought my E92 ZCP last year and began autocross with the local Spokes club with top of class results and finished 2nd in overall pax during last weekend's divisional. Getting ready for the upcoming SCCA championship tour in college station at the end of the month and I have a question regarding the legality of using carbon fiber front spoiler lips: https://www.turnermotorsport.com/p-3...-pair/?pdk=AgE

I purchased the car with these already installed, and while it was not an explicit option from the factory, it appears they were a dealer installed option for ZCP M3's from BMW. It seems to fall under a grey area of potentially being legal for FS. Would hate to remove them, but would really hate to have them be a reason for being pushed out of stock class at the upcoming tour event.

[The Nebulizer]

Originally Posted by GhettoCowboy

New to the forum, but have enjoyed reading everyone's advice in this thread and others about your autocross shenanigans. I bought my E92 ZCP last year and began autocross with the local Spokes club with top of class results and finished 2nd in overall pax during last weekend's divisional. Getting ready for the upcoming SCCA championship tour in college station at the end of the month and I have a question regarding the legality of using carbon fiber front spoiler lips: https://www.turnermotorsport.com/p-3...-pair/?pdk=AgE

I purchased the car with these already installed, and while it was not an explicit option from the factory, it appears they were a dealer installed option for ZCP M3's from BMW. It seems to fall under a grey area of potentially being legal for FS. Would hate to remove them, but would really hate to have them be a reason for being pushed out of stock class at the upcoming tour event.

Dealer installed options are not strictly legal. It could be protested, but I don't think anyone would bother. If it were protested, I would try the comfort and convenience clause as a defense. If dealer installed, it could prove difficult to remove without causing bumper damage as it is attached with adhesive. I would very much like to add a full bumper spoiler to mine not so much for styling or performance, but for bumper protection.

[Rassilon]

+1 for bumper protection, I am on my 3rd underbody tray and 2nd pair of side covers... I am thinking about adding a cheap urethane eBay lip.

[Richbot]

You're supposed to miss the cones guys +2 doesn't mean +2 experience points

Heroes hit the cones with the rear bumper, much sturdier

[Wisco M3]

Originally Posted by Richbot

You're supposed to miss the cones guys +2 doesn't mean +2 experience points

Heroes hit the cones with the rear bumper, much sturdier

Its more fun if you can catch them with the rear wheels and launch the cones. No cone marks and you keep the corner workers on their toes.

Our old BSP car with 335 wide Hoosiers was great for this.

[Richbot]

Yes and there's a chance it might land in the box and upright which earns you legend status

[dnoble37]

I saw a cone get flung up onto the roof of a building that way. It was pretty sweet.

[z3papa]

Richbot -- good to see you out in your Sky yesterday. Sorry we didn't get the time to chat as you were pretty busy with your co-driver.

[Richbot]

Originally Posted by z3papa

Richbot -- good to see you out in your Sky yesterday. Sorry we didn't get the time to chat as you were pretty busy with your co-driver.

lol that wasn't me common mistake

Perhaps Richard Wise?

[z3papa]

Originally Posted by Richbot

lol that wasn't me common mistake

Perhaps Richard Wise?

Yes -- that makes me feel better as they put a beating on that poor Sky.

[z3papa]

On a different front, in preparation for buying, mounting and install of new tires, I test fit 18x10's with 285/30-18's up front knowing full well that the legal street size is 18x9 which would mean the tire would be narrower and slightly pinched. My wheels for this application (Apex EC7's) are 25ET, and while they were marginally within the wheel well, and clear the strut and the front/rear wheel liner, it became pretty damn clear that if the tire can be mounted on a 9" wheel which I've been told it can, it's completely doable. Just a little FYI for the peanut gallery as I head out to either go 285 square or mount 265/285 setup this weekend.

[dnoble37]

That's good to hear. Thanks for doing that.

I'm in the apex arc8 group buy right now. So when my 18x9 fronts come in, my plan was to buy two 285/30r18 re71r and try to squeeze them on the 18x9. If i get lucky and they do mount, I'd order two more 285 for the 18x10 rears. If the tire mounting shops can't make it happen, I was going to then have them take the 285s and put them on the 18x10 rears. Then I would order two 275/35 for the front.

[The Nebulizer]

Originally Posted by z3papa

On a different front, in preparation for buying, mounting and install of new tires, I test fit 18x10's with 285/30-18's up front knowing full well that the legal street size is 18x9 which would mean the tire would be narrower and slightly pinched. My wheels for this application (Apex EC7's) are 25ET, and while they were marginally within the wheel well, and clear the strut and the front/rear wheel liner, it became pretty damn clear that if the tire can be mounted on a 9" wheel which I've been told it can, it's completely doable. Just a little FYI for the peanut gallery as I head out to either go 285 square or mount 265/285 setup this weekend.

I made a tire clearance calculator. I culled through data about fitment on this forum to find the limits for the formula. From this I had figured a 285 would fit up front, but at et25 it might stick out a couple millimeters. At stock offset of et31, the tire might not clear the struts (neglecting pinch - which might be enough to clear the struts). The ideal from my calculations is probably about et28 to fit under the fenders and not hit the struts at -1.6 camber.

On my e46 M3 I run 255 on 17x8" wheels. It was not too pinched.
285 would be slightly more pinch, but also less sidewall. 285 on 9" will be a challenging fit.

How badly do you feel the e9x needs more front tire? I have only a handful of runs in, but at 265 square (9" all around as that's what I had in the basement) on damp asphalt last weekend, I felt the rear needed more tire and I had to be more cautious with the throttle with a fair amount of powersliding, but I never felt the front washing out. (This is also coming from a pushy e46 M3).

[Richbot]

I hear you, and that's one of the reason I'm intrigued by the 305/30-19 RE71R on the back of one of these. I doubt the 275 is giving up much to the 285 in overall performance it'd be more of a "do you think the car needs more steady-state grip up front" and I think the answer when facing cars with 10" front wheels is "probably". Can always toe the rear in a bit more

[Wisco M3]

I don't think the College Station tour results are something to base a decision on this early in the season, but it was interesting that they were all on Bridgestone.

Has anyone started to play with any of the new crop of tires? I'm really hoping for someone else to do some R&D for me..

[dnoble37]

Not exactly scientific but someone in my region posted this to Facebook

http://www.tracktuned.com/feed/2017/...nd-hankook-rs4

[CSBM5]

Originally Posted by dnoble37

Not exactly scientific but someone in my region posted this to Facebook

http://www.tracktuned.com/feed/2017/...nd-hankook-rs4

Seems surprising that the Rival S was essentially turning the same times as the R888R. I assume the R888R is very similar to the NT-01 however, so not too surprising I suppose.

I'd like to figure out the best tires to use for a medium speed event with no classing (run what you brung) -- using 10x18 ARC8s. I assume BFG R1S in 275/35-18 or 285/30-18?

[z3papa]

Originally Posted by The Nebulizer

I made a tire clearance calculator. I culled through data about fitment on this forum to find the limits for the formula. From this I had figured a 285 would fit up front, but at et25 it might stick out a couple millimeters. At stock offset of et31, the tire might not clear the struts (neglecting pinch - which might be enough to clear the struts). The ideal from my calculations is probably about et28 to fit under the fenders and not hit the struts at -1.6 camber.

On my e46 M3 I run 255 on 17x8" wheels. It was not too pinched.
285 would be slightly more pinch, but also less sidewall. 285 on 9" will be a challenging fit.

How badly do you feel the e9x needs more front tire? I have only a handful of runs in, but at 265 square (9" all around as that's what I had in the basement) on damp asphalt last weekend, I felt the rear needed more tire and I had to be more cautious with the throttle with a fair amount of powersliding, but I never felt the front washing out. (This is also coming from a pushy e46 M3).

While at 8.5-9/10's the car feels pretty planted early to mid apex, it definitely develops understeer when really pushed early. It's my opinion the more speed you carry into and through the mid-apex, the less hard the roll on throttle mid-apex to track out of corner you need to maximize total speed. This is a theory and will be determined. By the way, it was Dave Whitworth of SPS who said he's mounted 285's on a 9" wheel using his Hunter machine.

Originally Posted by Richbot

I hear you, and that's one of the reason I'm intrigued by the 305/30-19 RE71R on the back of one of these. I doubt the 275 is giving up much to the 285 in overall performance it'd be more of a "do you think the car needs more steady-state grip up front" and I think the answer when facing cars with 10" front wheels is "probably". Can always toe the rear in a bit more

While I like the concept of thinking outside the box, the 305/30-19 is .6 taller than the 275 and 4# heavier. I think this would really bog the M3 down in slower corners and only pay dividends at very high speed events. For clarity, the shop I get my RE71R's at sells them to a limited group below anywhere you can get them, mounts them for less, and is willing to stock tires so if the 285's don't fit up front, I only take two and use the pair of 265's I bought for $438 shipped.

[z3papa]

Originally Posted by Wisco M3

I don't think the College Station tour results are something to base a decision on this early in the season, but it was interesting that they were all on Bridgestone.

Has anyone started to play with any of the new crop of tires? I'm really hoping for someone else to do some R&D for me..

The BFG's in our size went unchanged. While they may be good on concrete, I can tell you they sucked on asphalt and really sucked at Miller Park. Your results may vary. I was the only one at the Tripod on them in the top 25 and sold mine after that one weekend for cheap, cheap, cheap if that tells you anything.

[Richbot]

Yeah I'm thinking the 305 would be your fast course tire. Same height as stock so you get the stock 70mph 2nd gear but 2" wider so you don't have to slow down much for slaloms if you don't get behind Might be better to use with the 275/35 to maintain the diameter stagger somewhere in the realm of reasonable

[CSBM5]

Originally Posted by Richbot

Yeah I'm thinking the 305 would be your fast course tire. Same height as stock so you get the stock 70mph 2nd gear but 2" wider so you don't have to slow down much for slaloms if you don't get behind Might be better to use with the 275/35 to maintain the diameter stagger somewhere in the realm of reasonable

What you're thinking about here is running 275/35-18 front and 305/30-19 rears?