[Team Tonka]

Finally was able to do a launch, but it was colder out. 42F outside. Tires were cold even after driving 10mi or so.

Could feel the rear tires hop/spin. But couldn't really tell if front were spinning. I did it in 4WD mode vs 4WD SPORT as I believe in 4WD mode more power is sent to the front vs. 4WD SPORT correct? Figured with cold tires that would help? Thoughts on how to do better? PZero OEM tires. Stock car, just drop in panel filters with charcoal filters removed. Just a 0-60mph run. Too much darn traffic ;-(

[ominousM4]

The Pzero is the weak point. In cold weather they will spin the fronts on launch. They don't make a screech noise, so you might not notice it at first.

[Team Tonka]

Should I try 4WD Sport or is 4WD better when colder? Should I reduce tire pressure a bit too?

Originally Posted by ominousM4

The Pzero is the weak point. In cold weather they will spin the fronts on launch. They don't make a screech noise, so you might not notice it at first.

[forcefed]

Originally Posted by Team Tonka

Finally was able to do a launch, but it was colder out. 42F outside. Tires were cold even after driving 10mi or so.

Save your launches for the summer.

[McLaren720s]

I think most people use 4WD Sport. The system is fully variable regardless, it should send power wherever is needed.
You aren't going to get the best times in 40 degree weather.

[Bimmerfun82]

Get those tires over 100 degrees, hard to do in 40 degrees. My Pirellis hop and spin on the front when cold. Still a nice run there. I've done 1 launch control, and I'm nervous to do it again… was rather violent. The car is so fast w/o launch start.

[BMWRacer523]

Your tire temps are the limiting factor here not the mode you're in. Not enough heat in them to generate sufficient traction. Needs to be +65 ambient unless you have warming blankets like F1 teams

[Hendo741]

You could come down in tire pressure as well. I think most people have been in the 30-32 range warm for maximum grip.

The Pirellis (and PS4S for that matter) are summer tires and will not perform well sub 60 degrees. From the PZ4 page on tire rack:

Pirelli's warranty does not cover tires that develop compound cracking due to use in ambient temperatures below 45° Fahrenheit (7° Celsius), so the P Zero (PZ4), like all summer tires, is not intended to be serviced, stored nor driven in near-freezing temperatures, through snow or on ice.

Get some UHP All seasons (DWS 06+ or PS4 AS) for cooler weather.

[Bimmerfun82]

Glad someone revived this thread. I nailed a 3.05s with Pirellis and about 70 degrees outside. Tires were warm, but normal PSI. I've done LC <10 times.

[dbvallett]

Originally Posted by M3macster

Glad someone revived this thread. I nailed a 3.05s with Pirellis and about 70 degrees outside. Tires were warm, but normal PSI. I've done LC <10 times.

Is this a shot of the drive recorder I didn’t get?

[Bimmerfun82]

Originally Posted by dbvallett

Is this a shot of the drive recorder I didn’t get?

No, this is the M performance analyzer, a $250 option. You can order it from the bmw store online. It plugs into the dash.

[forcefed]

Originally Posted by M3macster

No, this is the M performance analyzer, a $250 option. You can order it from the bmw store online. It plugs into the dash.

That should be built into the car
Rather spend the money on a dragy

[Limegrntaln]

Look around for it. I just found it for $145. part number: 61432450841

[Bimmerfun82]

Originally Posted by forcefed

That should be built into the car
Rather spend the money on a dragy

it was included in someone's build for a convertible that I picked up in April off a boat, kept it for the M. The app is nice, and it stores track recordings, accelerations, etc., which is super helpful when someone says "the M3 doesn't go 0-60 in 3 seconds flat."

[BulkBen]

Originally Posted by M3macster

Glad someone revived this thread. I nailed a 3.05s with Pirellis and about 70 degrees outside. Tires were warm, but normal PSI. I've done LC <10 times.

Has anyone verified the internal timer vs Dragy?

Other internal timers have been known to be a whopping 4-5 tenths optimistic.
I’d expect BMW to be more accurate, but be good to know for sure.

[forza1976]

Originally Posted by BulkBen

Has anyone verified the internal timer vs Dragy?

Other internal timers have been known to be a whopping 4-5 tenths optimistic.
I’d expect BMW to be more accurate, but be good to know for sure.

No. But Dragy against actual nhra timing at my strip has Dragy and time slips near identical. The bmw option probably does not sample at the same rate as the standalone gps timers. I would not represent real world acceleration times based upon bmw hardware. IMO

[Bimmerfun82]

Originally Posted by BulkBen

Has anyone verified the internal timer vs Dragy?

Other internal timers have been known to be a whopping 4-5 tenths optimistic.
I’d expect BMW to be more accurate, but be good to know for sure.

Joe Achilles, Mat Watson, and C&D have all gotten 3.1s or less in a comp x drive m3/m4. So my time was more convincing myself that my car is also in the ballpark.