M3post member in the trophies in F Stock in his '08 after day 1 of Solo Nats!

[Richbot]

Good luck Mark!

Check results and live timing/video at scca.com/solo

[klammer]

Awesome! Who is it? On the boards that is....Love seeing our car do well

[Maypo]

Thanks, Rich and Klammer.

So, here is how it went:

Tuesday's course was 56+ seconds, and favored 'momentum.' I didn't quite get it done that day, probably leaving 4-6 tenths out there -- a combination of missing my line in two places, plus a little difficulty with rear traction. I ended up fourth, .9 seconds off the leader. Still, I was looking forward to day 2, where the longer course offered more opportunity for making up ground.

Wednesday's 76+ second course had several turn-and-go spots, heavy braking, plus lots of transients. The car was happier and the course was a lot of fun. During the run-up to Wednesday's competition, the torque advantage of the Mustang's was talked about now and then, and I think the M3 was definitely considered to be at a disadvantage. In light of those murmurings, putting .4 seconds on the class was especially gratifying.

My final position was third, .255 seconds off the leader, who won by .063.

My wife and daughter finished second and fourth out of five in F Stock Ladies. Jill just couldn't get close to the fast gal who won the class; and Caitlin's general shortage of autocrossing experience and first-Nationals jitters led to a disastrous first day of competition.

There were two issues with the car, one could be 'driven around,' so to speak, the other potentially debilitating.

The first was brake-fade on the long course, notably in the final heavy braking zone that set you up for powering through the finish -- this cost us a few tenths. I guess we found the limits of OEM pads/rotors with 30k miles on them.

The other was a sporadic flat spot in throttle, where the car would stop accelerating. Strangely/happily (although not for the victim), it only affected one of our four drivers, my co-driver, Fred Pascual. All we could figure was that the car's complex throttle control was objecting to Fred's throttling behavior. Fred's normal ride is a CP Mustang that has lightning throttle response, and we think Fred was 'attacking' the M3's pedal. The problem essentially ruined his chance at a goo d finish on day one. On day two, we turned on the Power button and Fred made a point of not stomping the pedal. No issues after that.

The car has had an ongoing issue with ragged starting and throwing codes -- the endless details of which I won't go into here -- but, it must be related to Fred's trouble with the car.

I've attached a picture of the car in our paddock space.

[dngo]

Awesome. I love that you made such a strong showing.

Someday I will make my way out there, as a tire warmer if nothing else. Of course I have been saying this for about 15 years.

Dave

[CSBM5]

Mark,

Great to see an M3 at Nationals, and congrats on doing so well! I see you captured fastest time in F-stock on day 2 -- simply awesome.

Too bad there might have been issues with the car, at least for your co-driver. It almost reminded me of my daughter driving my car in preparation for autocrossing the first time, and she complained that the throttle wouldn't respond enough when she was blipping for heel-toe downshift rev matching (we had throttle map in sport mode, middle setting). She was used to driving her E46 and was stabbing the throttle too quickly as I have never had the issue she was having. When she just slightly slowed down that stab, the issue she was having went away.

Changing subjects -- would you mind talking about car setup? Front sway bar? Wheels and tires? I assume you were on 18s with A6s, probably similar to Rich's setup? 285/305?

Speaking of torque of the M3 for a moment -- comparing it to my E39 M5, the M5 just is always itching to spin the rears on an autox course coming off of elements, etc. It has so much more midrange torque that it takes a lot of concentration to properly modulate the throttle in those situations. Conversely, the M3 has such a flat and smooth torque curve that I've found it to be somewhat of an animal on course with great ability to hook up well off of elements and build into that crescendo of power up top. My simpleton observation was this was a big plus for me driving it in street tire class (on BFG Rivals btw).

Regards,
Chuck

[InterJon]

Congrats. Please sure what size/brand tire. Are you running 18s, what size and square?

I am still confused if SCCA rules allow our cars to run 18x10 square.

[Richbot]

Stock class means you have to run the stock wheel widths/offsets. 18x10's would move the car to SP or ST

Mark - Congrats, that's a great result against some tough drivers.

Could be low fuel pressure switch, throttle actuators on the way out, or maybe idle control valve causng startup issues. I've also found the M3 doesn't like digital on/off throttle inputs from the driver, I think it has to stop taking commands after a few of those to let itself catch up. The fact that it only happened to one person suggests that might be what was going on?

Were you on the 295/315 Hoosiers? Looks like it, the rears look taller and more pinched than the 295's would on 9.5's in that photo

I think this car's power delivery is going to make it the car to have in F Street, just so perfectly driveable

Brake fade on an autocross course! Wow. That's amazing, even if you were using the OE pads

[fsmtnbiker]

I was also very excited to see a new M3 doing so well in FS as I was following solo nats this year. I've been debating running limited-prep STU in mine next season, but if it can get it done in F-Street that is even better (cheaper..)

+1 on setup info. I drove mine totally stock and it was fun but definitely understeered if you got on the front bumpstops.

Congrats!!

[Richbot]

Believe Mark is using TCK DA konis, rd sport front bar, and apex wheels. There is an autocross nerd thread with both of our setups in it

Front bar is a necessity and you need to drive the car on the rear tires, slow in sideways out. My opinion is the stock shocks are sufficient but not ideal and compression has been a very useful tuning tool

[Maypo]

"slow in sideways out" -- lol, pithy. Rich has my setup correct. The RD bar is 3-position and I run it full hard. 295/315 18" A6s on Apex wheels. I'm pretty happy with the TCK Konis, but it looks like I'll need to have the fronts re-valved, because I've discovered that the front grip improves every time I increase the compression, and I have run out of adjustment. However, I am wondering if that issue may resolve itself now that 'R' compound tires are no longer allowed, beginning next year.

[CSBM5]

Originally Posted by Richbot

I think this car's power delivery is going to make it the car to have in F Street, just so perfectly driveable

I agree, but this brings up the street tire situation and tire sizes (in my mind again).

Due to lack of availability of the 275/35-18 Rival back in Feb, I went with 245/40-18 all around (on TRMotorsport stock widths, 8.5/9.5). Surprisingly this worked out pretty well especially on slower and tighter autox courses as rotation was very nice and controllable. Even with this huge (and non-adjustable) Dinan front bar, understeer issues have been non-existent for me.

So...the question now that I'm stuck with is do I go with 275/35 Rivals all around? The other option is to go to staggered 245/275. It's clear that high end street tires like these do not take kindly to Hoosier-type-stuffing-monster-width-tires-onto-narrow-wheels setup. It's extremely unclear where that dividing line is between section/tread width and wheel width (and adding that such a line is likely different between different tire brands/designs, and is also perhaps course dependent meaning if there are lots of transitions/slaloms, an oversized floppy tire setup is likely worse off than if the course was wide open with high speed sweepers, etc, perhaps).

The other option, assuming they would fit, would be to totally ignore all of this and try 275/35 front and 295/35 rear Rivals. Both of these are significantly oversized for the wheel widths of course. I guess this is the "floppy-tire" option. I tell ya, having the 245/40 Rival stretched onto the 9.5" rear wheels makes for a nice, tight response in the rear -- it's very easy to feel and trust what's going down back there, especially in high speed transitions. At a BMW CCA autocross at the Performance Center back in April, I really missed having wider rears for the first time. That course is wide open, very few cones and the need to lay down the power at higher speeds had me missing some wider rears in a number of places.

Ideas, thoughts, plans?

Regards,
Chuck

[Maypo]

Changing directions -- I am planning to submit a letter to the SEB shortly, requesting that the car be moved from ASP to ESP. Support welcomed.

[Richbot]

Giggity. Work up a letter and I will copy it and add my thoughts. Im thinking the car is around 400whp, 3200lbs in SP, and will fit the 315 on 11.5's pretty easily with the plastic front fenders pretty simple to flare and might not need much more than a pull in the rear.

The current GT is about the same weight, except it can use a bigger tire and probably makes closer to 435 at the wheels with almost as much torque in SP. Only reason it shouldnt be in ESP is fear of the unknown IMO

[Maypo]

3200 lbs would be lovely, but... Lighter seats, battery, springs, exhaust -- sounds like 3350-3400 to me. But, I'll take it.

[Richbot]

My car is at 3500 with light fuel? Your coupe should be closer to 3470, theres at least 35-40 lbs in a barely sound compliant catless exhaust, 25 lb of ac, backdate to single hump dash if applicable around 10-15, remove stereo 10 or so, humongo wheels and tires are a couple lbs, maybe 10, seats are good for 80-100 depending on the seats (aluminum). Wilwood or similar calipers could net another 20lbs. Only need 5lbs of battery if you go li-ion, thats 50+ saved. If you start taking advantage of the other free allowances (fasteners, flares) there's your fudge factor. But you have to go nuts. Im talking a real SP build here, not the kind you drive to events. Have to class cars based on what they can achieve not what most people will do, or what is sane, lol

[Maypo]

Good point -- all-out prep should be the target. I haven't weighed my car yet, just assumed/hoped it was 3550-3600. I'll check that in the next week, or so.

Remove the A/C? I might, but I remember being disappointed when I took the A/C and lines out of my ASP-prepped Exige: 9 lbs. A "race day" battery is a good idea. I've been wanting to experiment a little with that.

I checked out the ESP cars pretty closely in Lincoln and was a little surprised how modestly they were prepared. I wasn't able to judge the drivetrain improvements but, from what I could see, the suspension preferences seemed fairly standard across the class, and it almost looked like there was some sort of gentlemen's agreement on 315s and 10.5" wheels. It's possible I'm just not familiar enough with class to appreciate the actual preparation. Except for our local driver Kit Gauthier's orange 2012 Boss, though, I didn't see anything that made me go, "oh, wow."

Jill and I really don't want to leave R-compound tires behind, so our interest in Street Prepared has ratcheted up even more.

[Richbot]

LOL. Exige ac is light noway

Most ESP cars seem to be sanely prepped, Strano has won with a pretty mild build in the past. Fun class to watch too.

Interesting your findings on front compression, I started to get past the point of no return with about 4 clicks left to go on the MCS struts. Big help though. Wonder if part of that is I can run whatever n2 pressure I want so I don't need the help from the compression damping that you might?