Track forum general chit chat.

[Shmelgy]

Originally Posted by dparm

I thought the Montana thing was only used to avoid sales tax on the initial purchase? Or do you have the property tax on vehicles thing in your state? I was speechless when I heard about that...I couldn't imagine paying 2-3% on my vehicles every year. F that.

A lot of states have aggressively started going after people who try the Montana thing since it is gray area of tax evasion.

Not just used to avoid the initial taxes, but my yearly registration is something like $80 compared to what it actually should be here in CA.

The LLC is registered to an address in Kalispell, Montana and not a PO Box.

I also never cared to figure out the insurance issue. I don't really drive the car on the streets, but it does have a plate on with current registration

[kayha12]

I know this topic has been covered but I wanted to showcase another example of what Euro MDM does with your brakes when it's active

Couple thoughts:
1) Yes I still drive with Euro MDM on because I'm a baby
2) I know when it REALLY kicks in, it does cut power... aka a completely botched corner, none in this video - does anyone know how to display this with AIM data? I was hoping TPS vs Pedal Position but they seem to be almost identical
3) From a lap times perspective, is there time being robbed? Or is there more merit to having extra stability (while the car is applying brakes) going through the corner, having a better exit, etc
4) I was actually expecting there to be more rear brakes being applied but it's almost like it's always the fronts? I'm on 295/30 square if that plays a factor in any of this

Welcomed to thoughts on all of the above. From a data perspective I want to turn it off and make comparisons however I know mentally I likely won't have the same confidence... yes yes I know it's probably best long term to turn it all off, but how did you go from TC On to Off? I may need to skip some TT sessions and just back into DE4, no competitive environment

[dparm]

Different braking pressures at each corner does not necessarily point to MDM -- it could simply be ABS. However, when I see you off the brake pedal and but one of the brakes is being lightly dragged, that is most likely MDM or CBC.

I think you need to give yourself more credit and just turn MDM off. If it's that big of a deal, try it out at a track with ample run-off in case you really fuck up.

I'll bet you a six-pack of your favorite beer that you will pick up time as soon as you turn it off.

[tsk94]

Originally Posted by kayha12

I know this topic has been covered but I wanted to showcase another example of what Euro MDM does with your brakes when it's active

Couple thoughts:
1) Yes I still drive with Euro MDM on because I'm a baby
2) I know when it REALLY kicks in, it does cut power... aka a completely botched corner, none in this video - does anyone know how to display this with AIM data? I was hoping TPS vs Pedal Position but they seem to be almost identical
3) From a lap times perspective, is there time being robbed? Or is there more merit to having extra stability (while the car is applying brakes) going through the corner, having a better exit, etc
4) I was actually expecting there to be more rear brakes being applied but it's almost like it's always the fronts? I'm on 295/30 square if that plays a factor in any of this

Welcomed to thoughts on all of the above. From a data perspective I want to turn it off and make comparisons however I know mentally I likely won't have the same confidence... yes yes I know it's probably best long term to turn it all off, but how did you go from TC On to Off? I may need to skip some TT sessions and just back into DE4, no competitive environment

I'm quite confident that everything off will be faster. But, it will only be so if you're comfortable pushing the car with everything off. Might take some time to adjust, maybe not.

I believe MDM cuts power rather then applying the rear brakes. Front brakes are used mainly to handle oversteer/understeer and settle or straighten the car up.

I think the main place you'd expect to see gains would be corner exit, being able to apply more throttle and accelerate a bit earlier and harder without the power cuts intervening. It will be minimal, but I think at the end of some straights it might be a mph or two. With a good LSD, this difference would be more noticeable too. You probably will be able to rotate the car better and easier with everything off, the system would try to reduce rotation to a certain extent. This depends much more on your driving style as to whether or not it would be beneficial.

Have you driven much with everything off to compare, data wise, to when you run with MDM?

[dparm]

BTW can you post a screenshot of AIM RaceStudio from that lap? Speed, accelerator, brake, Gsum, and time delta would be fine. Steering angle too, if that's available. Your brake trace looks a bit odd but it could be an artifact of the video.

[CorruptCommie]

Although the fun pedal is at 100% after apex on exit, sounds like the computer doesn't actually give it the beans. If you aren't comfortable driving TC off, do some weekends with street tires until you can control the car and move back up to sticky tires.

[Bartledoo]

The closest I ever got to spinning my car was with MDM on, granted it was within my first 10 track days ever, but both times the car snapped violently for some strange reason and I never again experienced that with DSC off…

I always say this, but the car feels so much better with DSC off. That little corner brake tap dance mdm does transmits foreign sensations through the car to you. I don’t think it’s good for confidence, unless you’re numb to it.

[Redd]

When I went DSC off, the sensation I got was more clarity in what the chassis and tires were doing. Even when MDM isn't activating, DSC off gave me more feedback. It felt like I was driving all the time wearing thick mittens to hold the steering wheel and sitting on a thick cushion (MDM), and then suddenly the mittens and cushion were gone and I was feeling the car for the first time.

For me the E9x M3 chassis is quite controllable. MDM is more for mental confidence but it does intrude a bit, even if the traction light isn't flashing.

[Exclusivs]

Do88 guys:

Does radiator need complete pull to access PS cooler?

As in, lines off & opening cooling system? If so I'll save it for a time ambitious enough to install do88 rad too

[b4hand]

DSC off is the way. Turned it off at my last BMWCCA session at Cresson here in TX and learned a lot. I actually felt in control and I learned how to feel the edge of traction a bit better. DSC caused a bunch of weirdness and was never predictable.

[Jive]

Originally Posted by Shmelgy

Not just used to avoid the initial taxes, but my yearly registration is something like $80 compared to what it actually should be here in CA.

The LLC is registered to an address in Kalispell, Montana and not a PO Box.

I also never cared to figure out the insurance issue. I don't really drive the car on the streets, but it does have a plate on with current registration

Is your mailing address still in CA?

[Shmelgy]

Originally Posted by Jive

Is your mailing address still in CA?

Check out https://www.49dollarmontanaregisteredagent.com/

Anything that gets sent to their address, is scanned and then I get notified by email to log onto their website to see it.

[Ximian]

Originally Posted by Exclusivs

Do88 guys:

Does radiator need complete pull to access PS cooler?

As in, lines off & opening cooling system? If so I'll save it for a time ambitious enough to install do88 rad too

I believe so. Not sure how you'd get to it otherwise as the oil cooler is at the bottom and has an air diverter blocking access above.

Cooling system is easy to (self-)bleed, there are instructions posted on here on how it works.

[Exclusivs]

Originally Posted by Ximian

I believe so. Not sure how you'd get to it otherwise as the oil cooler is at the bottom and has an air diverter blocking access above.

Cooling system is easy to (self-)bleed, there are instructions posted on here on how it works.

^Just lazy I guess. will see if I can tilt it. Woulda planned entirely different had I known. Impulse buy I suppose. For the right cause of course, shoulda done some hw.

[Ximian]

Originally Posted by Exclusivs

^Just lazy I guess. will see if I can tilt it. Woulda planned entirely different had I known. Impulse buy I suppose. For the right cause of course, shoulda done some hw.

Do it with the oil cooler and radiator if you don't have those yet as they're all right there. Aluminum undertray as well.

Reinstalling the wheel well liner is the most difficult part of the job for me so I try to avoid removing it as much as possible.

[dogbone]

Originally Posted by kayha12

1) Yes I still drive with Euro MDM on because I'm a baby
2) I know when it REALLY kicks in, it does cut power... aka a completely botched corner, none in this video - does anyone know how to display this with AIM data? I was hoping TPS vs Pedal Position but they seem to be almost identical
3) From a lap times perspective, is there time being robbed? Or is there more merit to having extra stability (while the car is applying brakes) going through the corner, having a better exit, etc
4) I was actually expecting there to be more rear brakes being applied but it's almost like it's always the fronts? I'm on 295/30 square if that plays a factor in any of this

Welcomed to thoughts on all of the above. From a data perspective I want to turn it off and make comparisons however I know mentally I likely won't have the same confidence... yes yes I know it's probably best long term to turn it all off, but how did you go from TC On to Off? I may need to skip some TT sessions and just back into DE4, no competitive environment

1) Don't ever let anyone shame you into turning traction control off if you're not comfortable doing so. I ran MDM for 4 years. Everyone gave me a hard time. I didn't care. The way I look at it: if someone is willing to write the check if I mash up my car, then I'll do what they say. No? Then I don't give a crap what people think.

If you do have the desire to turn traction control off, I recommend a gradual transition. I think going to a skid pad and practicing throwing the tail out and catching it and doing all kinds of crazy ass stuff--tossing the car around like an idiot, figure 8s, putting a single cone down and trying to drift around it--so that you can gain some perspective on what it takes to catch a car is a great and safe way to start. Then, build gradually---back off max pace on track, find some open track, start driving with it off. When I first started driving without traction control, I would only allow myself to do it when no one was breathing down my neck. As soon as I got into traffic, I would turn it back on. It took me a year to make the transition to full-time traction off.

The gas pedal will startle you when you turn MDM off. It will be much more responsive because the computer is not holding power back. There's a difference between "cutting" power in the middle of a screwed up corner, and "holding" power back. Cutting power means in the middle of an acceleration, the computer senses danger and takes away all the power that was being applied. It's abrupt and you wonder if something is wrong with the engine. Holding back power means you press the gas, but the computer isn't comfortable with allowing the power, so it brings the power on slowly until it feels the danger has passed. This is VERRRRRY subtle and sneaky. You don't really notice it. This is why the MDM-off gas pedal feels more responsive---the power is always there. (The picture below illustrates what I'm talking about.)

2) The best way I can think of to see how MDM holds back power is to look at the gas pedal position and how the RPMs are responding. And the really best way to see it is to compare a lap with MDM on and then Traction off. I've made an AIM screenshot for you to illustrate.

In the picture below, the Blue lap is Traction Control off and the red lap is MDM-on. The top chart is RPMs and the bottom chart is the gas pedal position. This is exiting the Bus Stop corner at Buttonwillow. It's a pretty dramatic left turn that traction control is very wary of.

At the far left edge of the picture, you can see that the RPMs and the gas pedal positions of both laps are almost identical, so we have a fairly common starting point between the two laps. But now, let's look inside the green circles. In the bottom chart, you can see I MASH the gas pedal on the MDM-on lap (the red lap), but look at the RPMs, they don't go up very much given that I'm at full throttle. Now look at the blue lap--I'm much more carful with the gas pedal, but look at the RPMs; they are higher than on the red lap because the car is actually responding to my gas pedal input. (When people talk about traction control giving you bad habits, this is what they are referring to---you get used to mashing on a gas pedal and the computer slowly brings the power on as it feels it's safe, and you don't realize it.)



So, this is a way to see how the computer holds back power.

3) In my experience, in an E9x M3, I believe the stock Traction Control system is ultimately slower than when you drive DSC off. Now, notice I am saying specifically the stock system of an E9x M3. The reason I say that is because the traction control system of this platform was never designed to work on a race track at maximum pace with a ton of mods on the car. We add all these things to the car that make it much more capable than the stock car---things like aero, tires that are much wider and stickier than stock, suspension, additional power, weight reduction......these things drive the traction control system crazy because it was never meant to deal with them. HOWEVER, if you had a traction control system designed specifically for a race car and racing, then I believe that car could go faster with it on. A few years ago, I was chatting with a race car builder, and he was talking about how sophisticated the Motec traction control system was----it had 10 levels of traction control, all fully programmable. And even within those 10, you could do other stuff. It sounded insane.

4). Check out a post I made a few years ago about how traction control activates the brakes. The AIM data from several tracks shows the front brakes doing 99.9% of the work. https://www.m3post.com/forums/showpo...&postcount=747


A couple weeks ago, I had a funny moment with traction control. I have been driving for 5 years now without traction control. My car still has all the sensors, so I have to turn it off every time I start the car. It was a practice day and I had been sitting in a ton of on-track traffic, so I pitted the car, stayed in the hot pits, turned the engine off for a few minutes and just sat there. Then, I turned the engine back on and go out on track. Guess what I forgot to turn off? So, I'm driving and the car is just acting super funny----the gas pedal felt sluggish....I'm like, what the heck is going on. Then I go around a corner and I can easily feel the brakes engaging because these days I have high torque pads. And I'm like, what the hell is going on? And I look at the dash and the traction light is blinking like crazy.......ohhhhhhhhh hahahaha oops. Turned DSC off and all was right with the world again.

[gmx]

Originally Posted by Bartledoo

The closest I ever got to spinning my car was with MDM on, granted it was within my first 10 track days ever, but both times the car snapped violently for some strange reason and I never again experienced that with DSC off…

I always say this, but the car feels so much better with DSC off. That little corner brake tap dance mdm does transmits foreign sensations through the car to you. I don’t think it’s good for confidence, unless you’re numb to it.

And that's the problem with aids that aren't advanced enough or adjustable, invites overdriving. That leads me to my next point. It's harder and a finer line to unlearn habits after you've already thrown stickier tyres, aero, power at it than just practicing and getting to know the chassis without it in a more basic form. TC = throttle control, aka your right foot.

Does MDM off disable CBC or keep that on?

[dparm]

Originally Posted by gmx

And that's the problem with aids that aren't advanced enough or adjustable, invites overdriving. That leads me to my next point. It's harder and a finer line to unlearn habits after you've already thrown stickier tyres, aero, power at it than just practicing and getting to know the chassis without it in a more basic form. TC = throttle control, aka your right foot.

Does MDM off disable CBC or keep that on?

AFAIK you cannot disable CBC since it is part of the ABS system, like EBD.

[gmx]

Originally Posted by dparm

AFAIK you cannot disable CBC since it is part of the ABS system, like EBD.

Reasonable. Without any high level equipment, I think I've encountered once only on a damp section and asking too much front the car (steering + braking).

[dparm]

Originally Posted by gmx

And that's the problem with aids that aren't advanced enough or adjustable, invites overdriving. That leads me to my next point. It's harder and a finer line to unlearn habits after you've already thrown stickier tyres, aero, power at it than just practicing and getting to know the chassis without it in a more basic form. TC = throttle control, aka your right foot.

My coach told me the same thing: don't bother with Hoosiers and other changes until you are running without electronic assistance because you'll never take advantage of their improved performance.

[romero1990]

I plan to start going to hpde. I wonder what are the maintenance items need to be done on a track car. Specifically at what intervals.
I've heard something like oil change every 3 track weekends and brake fluid change every year. Are there other items need shorter intervals to keep the car healthy?

Thx

[redpriest]

Originally Posted by romero1990

I plan to start going to hpde. I wonder what are the maintenance items need to be done on a track car. Specifically at what intervals.
I've heard something like oil change every 3 track weekends and brake fluid change every year. Are there other items need shorter intervals to keep the car healthy?

Thx

Brake pads and rotors.
You want to inspect the car for loosening bolts and other track wear.
Brake fluid (unless castrol srf)