Who tunes down power in 1st,2nd gears

[overlook637]

BM3 has pretty easy boost/power by tuning by gear. Has anybody tried the lowest boost/power setting in 1st and 2nd gear?

[TractionControlDelete]

Originally Posted by overlook637

BM3 has pretty easy boost/power by tuning by gear. Has anybody tried the lowest boost/power setting in 1st and 2nd gear?

I believe folks do this for better off the line traction then leave gears 3 and up normal as they're less likely to spin once at higher speeds

[hellokitty]

I use 30% reduction in 1st and 20% in 2nd on full e85 on cup 2 tires. I don't even bother trying to push it in first and 2nd gear is pretty sketchy unless the tires are hot.

[Silverlining_m2]

Yeah I'm on 20% reduction in 1st and 10% reduction in 2nd. Just standard pss tires, and it still spins them when I want it to. On my 435i it successfully lowered my 0-60 time from 4.4 sec to 4.2 sec just by doing it amd changing nothing else.

[Mike.]

I'm thinking about it...1st, 2nd, and third I spin

[Kilabyte]

I thought about it but I've read that when you shift to 3rd there is a bit more lag as the turbo wasn't spooled in the lower gear, being a manual it might be more pronounced.

[TopJimmy]

Originally Posted by Kilabyte

I thought about it but I've read that when you shift to 3rd there is a bit more lag as the turbo wasn't spooled in the lower gear, being a manual it might be more pronounced.

Just de-torque 1-2 or 1-2-3 as needed to keep grip, and shift all gears at 6200 for best dig launches. Even with a manual trans you'll still be above 4K after shift, which is prime powerband. On a DCT the gears will drop in around 5K since it shifts so fast. My BM3 de-torque settings are 30%-20%-10% for 1-2-3.

[slaughter.mode]

Originally Posted by overlook637

BM3 has pretty easy boost/power by tuning by gear. Has anybody tried the lowest boost/power setting in 1st and 2nd gear?

I have tried this. I ended up bumping up 10% at a time then 2% at a time until I felt good about it with DSC completely off. I ended up with -50% in 1st and -30% in second (with 20" 305x30x20 Michelin PS4s). I am sure I will adjust with 18s with thicker/grippier tires.

[overlook637]

Originally Posted by nv_f82

I have tried this. I ended up bumping up 10% at a time then 2% at a time until I felt good about it with DSC completely off. I ended up with -50% in 1st and -30% in second (with 20" 305x30x20 Michelin PS4s). I am sure I will adjust with 18s with thicker/grippier tires.

Wow, 50% reduction in 1st gear. Were you testing using hard launches or roll into it?

[heitzke]

I've been curious on how this changes 1/4 mile times, etc. Does anyone have any data around what the reduction in the first couple gears results in ET or trap-wise?

Naturally the assumption is 'spinning ain't winning' and hypothetically would be faster due to the car being able to hook up sooner. Or am I thinking too hard about this?

[slaughter.mode]

Originally Posted by overlook637

Wow, 50% reduction in 1st gear. Were you testing using hard launches or roll into it?

I really don't drag race at all actually, it's just sometimes I'll push it and the tires will just break loose, regardless of DSC mode. I was actually thinking of enabling the feature with xHP that allows me to start in 2nd all the time. It's just no fun in first anymore. Super jumpy and absolutely zero traction.

[Silverlining_m2]

Originally Posted by heitzke

I've been curious on how this changes 1/4 mile times, etc. Does anyone have any data around what the reduction in the first couple gears results in ET or trap-wise?

Naturally the assumption is 'spinning ain't winning' and hypothetically would be faster due to the car being able to hook up sooner. Or am I thinking too hard about this?

I don't have a dragy anymore. Got rid of it when I got my m4. But on my stage 2 435i I had boost reduction at 20% in 1st and 10% in 2nd.

I had tried forever to break 4.4 sec 0-60. The first run after boost reduction i ran a 4.2... It is a quantifiable difference that you can see in actual times.

Gotta hold true with an M car too. I have my boost reduction set the same now, but oddly enough I don't care what the times would be. Stage 1 m4 just feels fast, so I'm good.

[TopJimmy]

Originally Posted by heitzke

I've been curious on how this changes 1/4 mile times, etc. Does anyone have any data around what the reduction in the first couple gears results in ET or trap-wise?

Naturally the assumption is 'spinning ain't winning' and hypothetically would be faster due to the car being able to hook up sooner. Or am I thinking too hard about this?

I drag 1/4mi and without TQ reduction in 1st and 2nd the tires break free and you skip down the track. It's really hard on drivetrain, so best procedure is to start at 40-50% reduction and back it off till you skip, then add 10% back in. That's your good launch point. Others might say to feather the gas but it's hard to stay calm when you're in the launch seat.

[slaughter.mode]

Originally Posted by heitzke

I've been curious on how this changes 1/4 mile times, etc. Does anyone have any data around what the reduction in the first couple gears results in ET or trap-wise?

Naturally the assumption is 'spinning ain't winning' and hypothetically would be faster due to the car being able to hook up sooner. Or am I thinking too hard about this?

There is an absolute correlation with usable power with traction and 1/4 mile (sprint) times. Data is hard to plot in a scalable way for everyone but the general guidance is the amount of rubber in the rear. If I had some Mickey T's, I'd probably bump the boost up almost all the way in 1st and 2nd because I know I'm going to be digging into the pavement at that point.

[heitzke]

Thanks y'all, that's super helpful to know. It made sense conceptually but i'm also not a drag racer by nature. I'd like to do some 1/2 mile stuff but the acceleration concepts are still helpful to know.

[RElias21]

Originally Posted by TopJimmy

Just de-torque 1-2 or 1-2-3 as needed to keep grip, and shift all gears at 6200 for best dig launches. Even with a manual trans you'll still be above 4K after shift, which is prime powerband. On a DCT the gears will drop in around 5K since it shifts so fast. My BM3 de-torque settings are 30%-20%-10% for 1-2-3.

Jimmy, do you suggest this just in the E maps or even on 93 maps?

I am currently at 20%-10%-no reduction on 93.

Was thinking of going the opposite to 10-no reduction 2nd gear.

[TopJimmy]

Originally Posted by RElias21

Jimmy, do you suggest this just in the E maps or even on 93 maps?

I am currently at 20%-10%-no reduction on 93.

Was thinking of going the opposite to 10-no reduction 2nd gear.

Depends on tire grip. If you can still hook up then do it. I only de-torque if needed.