E92 M3 ZCP in SCCA Solo F Street

[Richbot]

I lithium greased the poop out of my rd bar's bushings and it doesn't make noise from there anymore. The end links are turner and they are noisier than stock, but worth it for the preload issue. I think I have it on medium at one end to soften it up just a little and I. like it there.

I think the trick is going to be getting it to turnin without making it too loose when you feed in throttle because it's definitely possible to get it to turn. That was the genesis of my thread on that other board. Got it to turn, ok, now what? Oh, drift show, cool! *peace sign* I miss Hoosiers.

[z3papa]

Originally Posted by UNCbigM

I autoxed my E90 for the first time on Saturday. I had a blast but definitely have a learning curve coming out of an STR Miata. With time I'll get used to more power and weight.

Power oversteer at will is nice for a change. The biggest thing I need to figure out is the massive understeer I experienced (to the point I had chatter coming from the front tires). I think there were three contributing factors:

1) Old PS2s - I probably ran incorrect pressures too.
2) Dinan bar set to full stiff (I'm thinking this was too stiff for the PS2s, and should hopefully improve with a better tire in a couple months. I may try the middle setting. I also did not disconnect the bar and reconnect once on the ground to remove preload, as not having a 4 post lift or ramps makes this particularly difficult.
3) The final contributing factor is my bad habit of driving too deep into a corner and not giving it up enough early enough. This hurts more than it did in the Miata due to the extra weight. I'm working on it...

Thoughts?

Otherwise I had a blast and can't wait to hit it again soon!

I suspect I'll be experiencing the same learning curve as you describe going from an extremely well set up STR car where you can dial out nearly all understeer to one where it is camber limited. Real tires will help immensely I suspect.

[CSBM5]

Just had a blast yesterday at the Performance Center CCA autocross in the M3. Mike driving the F80 and I were battling for FTD but I had the tire advantage . My car has the original Dinan non-adjustable bar (65% stiffer than stock), pins out max camber up front, and I was using 10x18 ARC8s with 275/35 NT-01s. No understeer problems for me! The car was essentially perfect. I was instructing and giving ride alongs, and numerous people couldn't believe how well balanced it is. In fact, I can't fathom driving this thing with the stock front bar as it would be way too loose on the high speed turns there I would imagine (with the square 10"/275 NT01s).

(note: I've never driven it super hard on my street stagger 19" (255/275 PSS) as my F-street setup is 275 Rivals all around on 18s and then I have this square NT01 setup).

I'm guessing your issue is old tires/stagger setup/overdriving the front end? I can't identify with the Miata transition since I've been autocrossing/tracking BMW sedans including my heavy M5, for, well, since forever ago (closing in on 40 years of this stuff pretty soon ).

EDIT: BTW, that chattering from the front PS2s likely means they were overinflated...anything over 38 hot or so is probably too high. Then again, they could be well heat-cycled also...

[UNCbigM]

Thanks for the input all.

Yes, I want to tweak the front bar settings.

The PS2s in the front were done. The inner portion of both are pretty much bald. I ran pressures around 34/30 f/r.

I'm not going to wait for the new Rivals, so my choice are effectively Star Specs or RS-3s. The Dunlops were my favorite on the Miata by far. I'm assuming in a larger size and with more weight they'll behave entirely differently, so I'm considering the RS-3s since they'll be about $200 cheaper. Since I'll only do 5-7 autoxes this year and most if not all one driver, the tires I expect to last well into next season. Plus I assume I'll need rears again before fronts, so whatever I pick I'll be fairly committed to.

Thoughts?

[Richbot]

You might be surprised. I did cord the outsides of my fronts first, though it was close, my rear wear was more even. Especially with RS3's I would think you will go through the outside front edge first. Of course it will take more than the 80 runs it took on Hoosiers most likely

[UNCbigM]

Let me also clarify that I'm definitely not settled on one tire versus the other, so I'm looking for opinions/experiences with the two. And it looks like it's actually a $150 difference, so not too much in the grand scheme of things.

[CSBM5]

You'll most likely destroy the outside edges of the RS3s looooong before you would Rivals; on a heavy camber challenged car, perhaps 1/3 the number of runs you'd get from Rivals.

[CSBM5]

Jay's thread on sccaforums in this link has some of his experiences running RS3 vs Rivals on his E39 M5 (which of course is more of a brute on front tires than the E90 M3 with a good bit more weight and less negative camber). On page 3 of that thread he compares edges on some RS3s with less runs on them than the Rivals.

[Richbot]

Also e39 has worse dynamic camber

[CSBM5]

Originally Posted by Richbot

Also e39 has worse dynamic camber

...and only 8" front wheels (in stock class). On my M5 I'm running -2.3 camber and 9.5/275 all around, and it could still use more camber but that's max'd out GC camber plates at my current ride height. E90 is definitely a better suspension design, front and rear, imo.

[z3papa]

I honestly think the Dunlops with their stiffer sidewall will actually stand up better than the RS3's and net out less costly in the long run. I suppose you could argue the Rivals would benefit from the ridiculous side tread but I'm just not a fan of them.

[CSBM5]

Speaking of edge wear...I'm really impressed with the E90 M3's front suspension in stock form (of course other than the Dinan bar and pins out for -1.4 camber). Below are pics of the NT-01, 275/35-18 on 10" wheels, after about 25 total runs at the long and high speed Performance Center CCA autocross course. The edge wear is definitely less than my M5 on the same tires running -2.3 camber (likely due to a less favorable camber curve under compression and probably more roll too even though the M5 has Dinan springs/Konis) although you definitely tell it's bearing on those edges...

[Blue Gumby]

Hey Guys. I'm a former E46 M3 owner now driving NC MX-5 in STR. Probably gonna pick up a ZCP for F street in next couple of month. I autocross for around 7-8 years now did a couple of Pro Solo and Tour event, so not a complete noob. I was considering a DCT, so I have a quick question. All Pro Solo sites I attended have at least one side where you have to hold the e-brake while waiting for the light (uneven surface). Can you launch the DCT in situation like that or am I just screwed if I go this route?

[Richbot]

I don't have any personal experience but i don't see why you couldn't just put it in 1st and rely on the ebrake. LC in the DCT just dumps the clutch at a given rpm which is way too high for street tires on an unprepped non-dragstrip surface

I think the dct has a hill holder feature too

[z3papa]

The hill holder function will do the trick. I'm not generally a fan of such "assistance" but can really see the benefit of it at a site like the DC Pro or a few other venues where you are at an incline. On a separate note, as parts seem to be flying off my Z3 in the partout, I am getting the itch for 18x10's and tires.

[Blue Gumby]

Thanks for the response guys. I've started searching around with a budget around 45g for a 2011. Seems like they are coming off lease and there are a descent amount available. Finding one with no moonroof and comp package around my area is pretty rare right now. Unless I'm flying or have the car shipped. There is one that is a full stripper car, I mean nothing on it, no moonroof, no comp package, speed cloth. Is the extra weight saving of guessing 100-150 worth over the bigger wheel width?

[CSBM5]

Originally Posted by Blue Gumby

Thanks for the response guys. I've started searching around with a budget around 45g for a 2011. Seems like they are coming off lease and there are a descent amount available. Finding one with no moonroof and comp package around my area is pretty rare right now. Unless I'm flying or have the car shipped. There is one that is a full stripper car, I mean nothing on it, no moonroof, no comp package, speed cloth. Is the extra weight saving of guessing 100-150 worth over the bigger wheel width?

Are you looking for an E90 or E92? It took me almost a year to find an E90 w/o sunroof, 6MT, non-EDC but most all other options (comfort access and heated seats were requirements too). I've had it two years now, and I'm really happy I didn't compromise on anything except the color. It turns out that only about 180 2011 E90 models were sold in the US with 6MT and no sunroof, so I didn't realize I was sampling such a small dataset.

I bought the car from a BMW dealer who had it returned early from a 2 year lease with 16k miles on it; they CPO'd the car too. I rented a car and drove 500 miles to the dealer, and my wife and I had a fun trip picking up the car. Factory warranty just expired last month -- never needed for any repair, only all the free maintenance.

[Richbot]

Slicer - the very restrictive near-stock Street rules dictate the extra wheel width you get from the ZCP wheels can only be used if you have a ZCP car. This is to avoid a cascade of unintended consequences if people were able to mix and match option packages to greatest advantage. It's also irritating as hell but thems the breaks

Edit: Ninja post delete!

[z3papa]

Here's my thought on the competition package benefits and deficits. The comp only came on 2011 and later models which had different bearing shells. The competition package had higher spring rates, slightly lower COG and wider wheels but typically EDC which may have little benefit but higher cost. When you are stuck with no camber allowances, wider wheels have more importance. Weighing that relative to running in class was a choice. You can run the same width tire on a 1/2" narrower wheel, just not as effectively. That's why picking the right car is important. Believe me, I picked the wrong car to start auto crossing and have paid for it for years.

[Richbot]

All ZCP cars were equipped from the factory with EDC. Good way to spot somebody using the wider wheels on a car that didn't come with ZCP originally is to look for that button. If that button isn't there they haven't completed the retrofit

[CSBM5]

Originally Posted by CSBM5

The "problems" for 2015 are the wild cards lying out there with no specificity yet: (1) new compound Rival possibility, (2) the report from a Monterey Michelin talk where it was claimed they said the Pilot Sport Cup 2 tire was going to be TW200 in 2015 along with a large number of sizes available, and Michelin was targeting street tire class.

In any event, who wants to bet that *prices* for these ultra-high-end street tires will easily reach $400/tire and more in short order?

It appears that the information that member heard in the post linked above was incorrect...at least for 2015. I asked Michelin directly through their USA web site about the PSC2, and here is their reply:

Originally Posted by Michelin USA reply to inquiry

We do not have any Pilot Sport Cup 2 tires coming out with a TW of 200.

They are all 180 for the Pilot Sport Cup 2.

We are sorry that you were given incorrect information.

We appreciate your business and thank you for choosing Michelin.

So at least "for now", we won't have TW200 $400+ tires...

[z3papa]

Not that I was going to run Yokohamas but AD08R's in 295 variety are $380.