[28m5]

Hi everyone,

So been trying to run stage 2 map on my M5C. Installed the Supersprint catless Downpipes and Eventuri Intake.

Tried running a DME Tune and found absolutely no difference in drag times. So I thought it was only DME, then tried out with Superchips UK still no luck. Also neither of them are able to tune the TCU.

So long story short I'm getting consistent 10.8 sec quarter mile times running both the maps and on stock tune as well.

Before installing the Downpipes and Intakes was consistently running 11.2 (bone stock). So clearly the intakes and Downpipes have made a difference but the tunes haven't.

All data logging is done on dragy and racebox.

My questions:
Since it's a 2020 M5C and the TCU isn't tuneable for the moment is it causing restrictions to the power being put to the ground? Looking forward to getting into the low 10s. Any suggestions would be extremely helpful.

Cheers!

[BMWM12045]

I don’t think you would have got a .4 sec improvement from just dp and an intake, so the tune might be on there, maybe you’re have trouble flashing back to stock? It’s definitely not a tcu tune issue as there are tons of folks running good times (even 9’s) without it

A lot of people manage to run 10.8-10.9 stock (good DA, warm tires with correct pressures, good gas) and then move down to 10.4 with a tune intake and dp - so your gains of .4 seem consistent with everyone else’s. People running under 10.3 have put in some more effort to get there (custom tunes, lighter wheels, lighter exhaust, etc)

Sorry if you already know some of this info but check your DA and compare it to others on here (there is a calculator for adjusting times for higher DA on google) if it’s over 3500 usually it might be hard to get the lower times you want consistently

TCU tune seems to be good for .01 sec max but the 2020 transmission is better the older ones so not sure if that is your hold up

It might be your pressures? Try dropping them down to 28 psi in the rear (when warm) and make sure to get some heat in them before launching (no need for a burnout, spirited driving usually does the trick)

It might be your launch technique? Try to launch right when the flag pops up - no need to build any excess boost when it’s tuned, seems to just cause wheel spin

Good luck in your quest for low 10’s!

[edwarjejeega]

Originally Posted by 28m5

Hi everyone,

So been trying to run stage 2 map on my M5C. Installed the Supersprint catless Downpipes and Eventuri Intake.

Tried running a DME Tune and found absolutely no difference in drag times. So I thought it was only DME, then tried out with Superchips UK still no luck. Also neither of them are able to tune the TCU.

So long story short I'm getting consistent 10.8 sec quarter mile times running both the maps and on stock tune as well.

Before installing the Downpipes and Intakes was consistently running 11.2 (bone stock). So clearly the intakes and Downpipes have made a difference but the tunes haven't.

All data logging is done on dragy and racebox.

My questions:
Since it's a 2020 M5C and the TCU isn't tuneable for the moment is it causing restrictions to the power being put to the ground? Looking forward to getting into the low 10s. Any suggestions would be extremely helpful.

Cheers!

What is your trap speed (MPH) at the end of the quarter? That will really tell you the difference (if any) the tune made

Here's some stock ET's and trap speed for reference on a 2021 M5C

[mike@x-ph.com]

Post before and after datalogs from the tune to compare boost and ignition timing

[28m5]

Downpipes, Eventuri and Stock map (dragy)

Stock (racebox data)

[Holset]

Originally Posted by 28m5

Downpipes, Eventuri and Stock map (dragy)

Stock (racebox data)

So what's the trap speed with the tunes?

[28m5]

Originally Posted by Holset

So what's the trap speed with the tunes?

Originally Posted by Holset

So what's the trap speed with the tunes?

10.7 @ 210 Kmph

[Sophisticated Redneck]

What fuel are you running? All tunes add power by upping the timing and boost, both require higher octane fuel or the DME will just pull the timing when it senses knock and your performance can actually be worse or no improvement at all over stock.

To see if this is your issue, get some data logs of your timing and boost or just run a 50/50 mix of race 100 octane and 91 or 93 and see if your draggy times improve. Alternatively you can mix a boostane or other high quality octane booster with 91/93 gas. Shoot for a minimum octane of 96 ((R+M)/2, not RON).

[Holset]

Originally Posted by 28m5

10.7 @ 210 Kmph

Okay same as stock tune that doesn't seem right.
What i have seen you should be around 219 km/h /136mph with stage 2 but of course it depends on conditions and fuel but it should definitely be higher than with stock tune.

What are your tunes? Have you talked to the tuners?

[ellisina4]

I would try Noelle tune… I heard it does wonders …

[28m5]

Originally Posted by Holset

Okay same as stock tune that doesn't seem right.
What i have seen you should be around 219 km/h /136mph with stage 2 but of course it depends on conditions and fuel but it should definitely be higher than with stock tune.

What are your tunes? Have you talked to the tuners?

I'm running 100 octane and 28 C temperature. Tunes were DME and Superchips both stage 2. Found throttle response difference in both but power still felt restricted. Superchips has tuned my Range Rover Sport and Cayenne (both diesel) they have made a world of a difference.

Have a JB4 on the way, fingers crossed I have better luck with that.

[Holset]

Originally Posted by 28m5

I'm running 100 octane and 28 C temperature. Tunes were DME and Superchips both stage 2. Found throttle response difference in both but power still felt restricted. Superchips has tuned my Range Rover Sport and Cayenne (both diesel) they have made a world of a difference.

Have a JB4 on the way, fingers crossed I have better luck with that.

Alright Good Luck!

[dcali]

Originally Posted by edwarjejeega

What is your trap speed (MPH) at the end of the quarter? That will really tell you the difference (if any) the tune made

Here's some stock ET's and trap speed for reference on a 2021 M5C

this is messed up. im stage 2, 2019 non comp and i got 2.95 (not on the drag strip tho). Im thinking of tcu tune since im 2019, seems very restricted in first 2 gears, and it wont launch at 3k rpm just 2.5

[28m5]

Originally Posted by dcali

this is messed up. im stage 2, 2019 non comp and i got 2.95 (not on the drag strip tho). Im thinking of tcu tune since im 2019, seems very restricted in first 2 gears, and it wont launch at 3k rpm just 2.5

8/2019 onward cars the tcu cannot be tuned. That's what I've been told. Correct me if I'm wrong. I strongly feel that the transmission is restricting the extra hp produced by the engines after the tune.

[dcali]

Originally Posted by 28m5

8/2019 onward cars the tcu cannot be tuned. That's what I've been told. Correct me if I'm wrong. I strongly feel that the transmission is restricting the extra hp produced by the engines after the tune.

8/19 as in august 2019? yes its retricting, im supposed to have 730awhp with eurochargedd stg 2 and i get 2.9 0-60.

Even stock i felt like 1-2 was meh then 3rd onwards was fast. my car was producted 10/2018 so i should be good.

Im just afraid bmw restricts the power for a good reason lol, dont want my tranny to die

[28m5]

Originally Posted by dcali

8/19 as in august 2019? yes its retricting, im supposed to have 730awhp with eurochargedd stg 2 and i get 2.9 0-60.

Even stock i felt like 1-2 was meh then 3rd onwards was fast. my car was producted 10/2018 so i should be good.

Im just afraid bmw restricts the power for a good reason lol, dont want my tranny to die

Yes august 2019. Try running a tcu map along with ecu stage 2 and see. Post dragy data, I'm curious 😁.

[dcali]

will do, im taking it to the shop on the 21st and will tell em to put it

[EgemenComertoglu]

https://www.n54tech.com/forums/showthread.php?t=65639

here's my thread on other forum check if interested , no gains after JB4 installation.

[28m5]

Originally Posted by EgemenComertoglu

https://www.n54tech.com/forums/showthread.php?t=65639

here's my thread on other forum check if interested , no gains after JB4 installation.

Just installed JB4 and running map 2. Significantly more faster. The app is flawless finally some improvements. Just some dragy numbers. Quarter mile down to 10.44, 100-200 down to 6.11. Running on stock P Zeros and warm weather.

[Simon H]

Originally Posted by 28m5

Just installed JB4 and running map 2. Significantly more faster. The app is flawless finally some improvements. Just some dragy numbers. Quarter mile down to 10.44, 100-200 down to 6.11. Running on stock P Zeros and warm weather.

Wow, that is quick !. Is this on an LCI car, and from standing start, no roll out ?.

[28m5]

Originally Posted by Simon H

Wow, that is quick !. Is this on an LCI car, and from standing start, no roll out ?.

Pre LCI Comp. standing start.

[LongBeachDinanFan]

You'd have to record logs of your 1/4 mile runs to see how boost, timing, AFR, and throttle use. Having a JB4 might be handy so you could tweak the tuning yourself on the fly for maximum gains.