E92 M3 ZCP in SCCA Solo F Street

[PedalFaster]

Originally Posted by Cashmo

You never know who, what, when or why someone will protest you.

And here I was about to post that you should never make assumptions about how a protest committee will rule.

[PedalFaster]

Originally Posted by Tommysalami

We'll find out, I submitted the question.

I was going to write that a response from the SEB does not necessarily set precedent for protest committees unless it's accompanied by a rule change.

I happened to be reading Appendix F looking for something unrelated when I came across this wording:

Whenever a competitor remains unsure of the legality of certain configurations after studying the rules carefully, he/she is encouraged to obtain a clarification by writing the Solo® Events Board. The SEB will attempt to respond as soon as possible. If events require a deadline for a response, the SEB will attempt to accommodate that deadline.

The requesting member must be aware that clarifications are general statements of principle offered in good faith and are designed to clarify intent, but they do not afford specific cars permanent protection from subsequent protest and disqualification. Nor are the responses from the SEB inviolable instructions to protest committees. This is because in most cases the SEB is responding to a specific or limited question and operating only on information supplied by the interested party which cannot be guaranteed by the SEB to be complete. Photos and descriptions provided for the SEB’s consideration may not be clear or may not portray the information in the full light of issues of information that may subsequently be considered by a protesting party.

(Emphasis mine.)

To be clear, I think it would be a weenie protest to protest your solution, and I'd be surprised if someone did. But to Jeff's point above, anything that isn't squeaky clean is potential protest bait.

[Tommysalami]

Well then I guess I'll request they add a specific allowance for catching fluid overflow to the section that permits oil catch cans, and just disconnect this when I get to Lincoln in the meantime

[sgreer78]

If anyone wants to test the weenieness of their competitors, I have that reservoir, bought it for the car I sold, and I'll sell it.

[z3papa]

Would that be a weenie protest or an envy protest?

[Richbot]

If he protests you for it after he sells it to you it’s a seller’s remorse protest

[sgreer78]

I'd have to autocross to protest. Besides, I've went up a level of smugness and can't be seen talking to lowly BMW owners anyway.

[z06fun]

New to these E9X cars, and spent a lot of time reading through this very helpful thread. So if your autox wheels don't have tire pressure sensors, are there any issues with being able to change the drive settings & turn off the nannies etc?

Also I have read a bit about the diff and how it works, does it basically need some inside wheel spin before sending more torque to the outside? Watching some of your videos it *seems* like that is maybe the case but hard to tell from video.

Thanks!

[Richbot]

1) nope
B) You got it. There is a viscous fluid "puck" that does the locking, diff is open until there's enough speed differential between the axles to get the clutches pushing on eachother. I wouldn't say you need a lot of wheelspin for it to lock some, but the problem is a little wheelspin means a lot of lock all of a sudden as it lags your inputs so you'll see in a lot of videos turn-in -> throttle -> diff locks -> dorifto/unwind the wheel as it starts to push the car around the corner. Here's the manufacturer's primer on the diff: https://www.resyl.net/atvfiles/ViscoLok-engl.pdf

This diff would be absolutely hateful to drive on a turbo car (and, from the looks of it on the 1M, is indeed hateful) but with the V8's sensitive throttle and low torque it's not that bad and you can drive around it

[PedalFaster]

Originally Posted by Richbot

1) nope

Now that I think about it, I've had wheels with no sensors on them on my car for more than a month, and the car hasn't even thrown a TPMS warning yet. (?!?!) On some of my previous cars, if the stock wheels and sensors were stored in the same garage as the car, that would be enough to keep the car happy, but my stock wheels are in a shop on the other end of town. Weird.

Originally Posted by Richbot

a little wheelspin means a lot of lock all of a sudden as it lags your inputs so you'll see in a lot of videos turn-in -> throttle -> diff locks -> dorifto/unwind the wheel as it starts to push the car around the corner.

This. Slight four-wheel drifts at corner exit are driving nirvana, but I'm finding that there's no intermediate step in my car's corner-exit attitude between slight push and lurid sideways slides.

I am incompetent, though, so I'm sure that's a contributing factor.

[Richbot]

You basically have to lead it like a turbo car, but instead of boost you're leading the diff lockup, and instead accelerating harder on corner exit your reward is not taking out cones with the side of the car

[z3papa]

Originally Posted by PedalFaster

Now that I think about it, I've had wheels with no sensors on them on my car for more than a month, and the car hasn't even thrown a TPMS warning yet. (?!?!) On some of my previous cars, if the stock wheels and sensors were stored in the same garage as the car, that would be enough to keep the car happy, but my stock wheels are in a shop on the other end of town. Weird.



This. Slight four-wheel drifts at corner exit are driving nirvana, but I'm finding that there's no intermediate step in my car's corner-exit attitude between slight push and lurid sideways slides.

I am incompetent, though, so I'm sure that's a contributing factor.

I believe someone has coded out your TPMS warnings much you can code out the absence of a CAT if you were running a test pipe. There is no magic pill otherwise. If they are not there or are there and not active for the car to see, the car tells you.

[CSBM5]

I don't find it "too" diabolical in that transition to power on coming off an apex. It's not like you feel/hear the inside tire spinning a lot before it's hooking strongly, so it's fairly smooth. I do like it being mostly open on corner entry as it makes the car more neutral and happy to turn-in. I find I can really lean on that outside rear tire once the diff is locking on corner exit, and it's very controllable. It's probably (lol) not quite the fastest corner exit, but on higher speed exits, that nice tail out attitude with the S65 screaming is just too enticing not to enjoy.

On the wet skidpad, it basically locks and stays that way once you get sideways making for nice controllable drifting. However, on the wet surface you can sense some inside wheelspin as you're getting on the throttle for just a moment. The M2C with its active LSD is a whole different story on the skidpad - it's like it already knows wth you're up to, and it's waiting and ready for you getting on the throttle.

[Richbot]

I think if you get a feel for it you can drive it without harsh lockup. But if you're used to going deep into the throttle with the wheel cranked and letting the diff sort things out predictably you're in for a fun time

[z06fun]

Thanks for the info, that is a great pdf on the diff.

I had seen some talk in this thread about using a DCT at a Pro. Does this work ok? I read about the steps to get launch control engaged, and it sounds like it may not always be available depending on conditions etc. Not sure if I was understanding that right though.

[PedalFaster]

Originally Posted by z06fun

I had seen some talk in this thread about using a DCT at a Pro. Does this work ok?

I've never done a Pro in my DCT car, but my understanding is that the answer is a resounding "no".

Selected quotes from another forum that I think you're also on (and featuring two of the regulars here):

Originally Posted by DocWalt

It's not consistent doing that. You'll want to off yourself for buying the DCT it's that bad.

Originally Posted by sgreer78

DCT is amazing for everything except pros. It could be great for that too, but BMW have it so it will only give you LC when IT wants too. It’s one of the reasons I’m not autoxing the car anymore.

Originally Posted by Richbot

It’s not consistent but yes it will lock you out above a certain trans temp and also just if too many too close together. Then it starts locking you out of the clutch and gear pack it thinks is too hot so you can be left without 1/3/5/7 or 2/4/6.

If it were me I’d never both with LC but 1st fear clutch takeup can be iffy and hard to predict when you just mash the gas in 1st in manual mode

Originally Posted by schickane

As for the launch control, when you mash the throttle it preloads the clutches and the car begins to move forwards. Aside from it only allowing LC to be engaged under very specific temperature conditions, this aspect of it would make ProSolo launches nigh impossible to avoid red-lighting.

I believe all of those guys are trophy-at-Nats-level drivers, and the last guy, with the incompetent-looking launch-then-spin video, is the reigning DSP national champion, so I believe them.

[PedalFaster]

Originally Posted by schickane

As for the launch control, when you mash the throttle it preloads the clutches and the car begins to move forwards.

My region is really fond of straight-line starts, so I've gotten a lot of practice launching my car, albeit not with lights.

You can see what schickane's talking about in this video:

I'm not using launch control here; I'm just pushing the gas pedal through the detent. This causes the revs to rise, then the clutch to engage, which breaks the rears loose; after this happens I'm backing off and modulating the wheelspin. If you scroll through frame-by-frame, the car creeps forward for a full ten frames (0.33 seconds?) before the clutch drop hits and acceleration begins in earnest.

If you tried this at a tree, I imagine that the initial creep would break the beam, after which you'd be sitting at the line largely immobile for another third of a second. Not good.

Edit: On the previous topic (aggressive diff locking), I experienced a surprising amount of power oversteer at moderate throttle openings at 0:14 and 0:20 in that video.

[z06fun]

Thanks for the info and videos showing it, Really helpful
Strange the way the car rolls with the LC engaged, hard to picture a case where that may be useful. Soon I will have the car and can try these things out

[sgreer78]

My TPMS light would take around 30 miles to come on. I went an entire weekend at Lincoln without it ever coming on, so if you made little trips to and from the event site, that could be the case.

[PedalFaster]

How does your tire wear compare front to rear?

After five driver-events, I was quite surprised to find that my rears are wearing faster than my fronts -- my fronts are at about 5.25/32", while my rears are at about 4.5/32". Is this typical?

I'm not running much toe on either end, so I don't think that's a major contributor. As mentioned before, pretty much all that starts at our local events involve a full-on Pro-style launch, so I'm guessing that's contributing hugely to my rear tires' wear.

[z3papa]

Layton is putting a beat down on FS at the Bristol Match tour.

[Tommysalami]

Drove like ass today and Cathers killed it. Cant go out there and drive conservatively, or you end up leaving over a second on the table. Tomorrow will be fun though