[Tuxon_Speed]

Just talked with my tuner and he mentioned that he’s been having trouble recently with using the xHP flash on iDrive 8 cars. He mentioned it bricked a customers TCU. Quite a costly repair.

Curious if anyone has tried this on the G87 or if others have heard about these problems.

[M2Jorge]

Originally Posted by Tuxon_Speed

Just talked with my tuner and he mentioned that he’s been having trouble recently with using the xHP flash on iDrive 8 cars. He mentioned it bricked a customers TCU. Quite a costly repair.

Curious if anyone has tried this on the G87 or if others have heard about these problems.

Not sure why it would brick the TCU, but as of mid August, xHP has advertise full support for G87 M2, I’ll be tuning mine as soon as I’m able to transfer my xHP supra license to the m2

[Ravenseal]

What's a transmission tune?

[M_Power Rob]

Originally Posted by Ravenseal

What's a transmission tune?

Is that like:

Q: whats a henway

A: about 5lbs

[ILikeBimmers]

Originally Posted by Ravenseal

What's a transmission tune?

In this context, an xHP transmission tuning allows you to flash your TCU with a host of goodies like ignition cut, torque reduction/limiters, revmatching aggressiveness, line pressure bump, etc.

I have xHP and absolutely love it as it gets really good when you dial in the custom settings. I feel like the only way you brick your ECU is by being a moron and not having good reading skills to be frank.

Ignition cut is really nice for xHP as when combined with the right torque reduction setting, you can bring back upshift farts (braaap) and a small bit of overrun noise on a completely stock platform without sending your ECU on an all expense paid vacation to Finland.

[M2Jorge]

Originally Posted by ILikeBimmers

In this context, an xHP transmission tuning allows you to flash your TCU with a host of goodies like ignition cut, torque reduction/limiters, rematching aggressiveness, line pressure bump, etc.

I have xHP and absolutely love it as it gets really good when you dial in the custom settings. I feel like the only way you brick your ECU is by being a moron and not having good reading skills to be frank.

Ignition cut is really nice for xHP as when combined with the right torque reduction setting, you can bring back upshift farts (braaap) and a small bit of overrun noise on a completely stock platform without sending your ECU on an all expense paid vacation to Finland.

What custom settings did you put?

[ILikeBimmers]

Originally Posted by M2Jorge

What custom settings did you put?

I have a G42, so some setting might be different. I have stage 3, but the key settings I have are true manual (no auto shift on redline), torque reduction (to bring back upshift brap sounds), downshift aggressiveness (set to max without lurch). I also have some settings like the ability to come to a stop without it shifting into 1st, standstill decoupling to release a clutch when stopping to reduce small vibration, and I raised my torque limiters to a higher value within the ZF8HP's capability.

With xHP it really transforms and improves your transmission. With the ZF gear box it can let you achieve near DCT performance without some of the inherent downsides.

[VIERsr]

The G42 and G80 gearboxes are completely different transmissions, not just a different tuning.

[dxx]

Originally Posted by ILikeBimmers

I have a G42, so some setting might be different. I have stage 3, but the key settings I have are true manual (no auto shift on redline), torque reduction (to bring back upshift brap sounds), downshift aggressiveness (set to max without lurch). I also have some settings like the ability to come to a stop without it shifting into 1st, standstill decoupling to release a clutch when stopping to reduce small vibration, and I raised my torque limiters to a higher value within the ZF8HP's capability.

With xHP it really transforms and improves your transmission. With the ZF gear box it can let you achieve near DCT performance without some of the inherent downsides.

Did torque reduction brings bang back? Sound loud?

[ILikeBimmers]

Originally Posted by dxx

Did torque reduction brings bang back? Sound loud?

Yes xHP torque reduction can bring back the thunderous sound of clutch drops and the ignition cut sounds (brap), but it takes a lot of time to find the sweet spots for it. Too little and you get no sound, too much and you get a kerplumpfbfff sound a bit like a deflating a large balloon and noticable lift shift and not in a good way.

[M2Jorge]

Originally Posted by ILikeBimmers

Yes xHP torque reduction can bring back the thunderous sound of clutch drops and the ignition cut sounds (brap), but it takes a lot of time to find the sweet spots for it. Too little and you get no sound, too much and you get a kerplumpfbfff sound a bit like a deflating a large balloon and noticable lift shift and not in a good way.

Can you show us what your xHp set up is

[ILikeBimmers]

Originally Posted by M2Jorge

Can you show us what your xHp set up is

Unfortunately I don't drive an m2, but an m240ix running with the b58 loaded with the ZF8HP50. I would imagine that the sweet spots are different on the S variant and it sounds like you may have a beefier version of my transmission.

My suggestion would be to start within the range of +10 to +30 for the first few gears. Each gear and the power transmitted seems to create a unique "sweet spot" for sounds. Keep in mind that these sounds are sort of the after effect of torque reduction. There are three major ways to implement torque reduction: throttle reduction, timing retardation, and sweet ignition-cut, which xHP enables.

Obviously the best way to maximize ignition cut sounds is with ECU tuning and overrun, but since most of us aren't sending our ECU for a holiday in Finland, we can't do that.

Ignition cut brap on the m240 comes out when there is a good amount of boost pressure built up, I don't have the exact boost figures, but it starts showing up at around 4k rpm on the b58 platform and heavy throttle. Shifting nearer to redline starts reducing the ignition cut sounds replacing it with a pleasant thunderous sound. It also seems that the ignition cut sounds are more pronounced when the engine is still coming up to temp, but the exhaust is warm, which I refer to (perhaps erroneously) as "warm up mode".

I'm still for finalizing my upshift brap torque reduction tune and plan on introducing a guide on the G42 subform once complete. Here are my most current G42 torque reduction settings for reference.

1-2 +20
2-3 +27
3-4 +25
4-5 +25
5-6 +30
6-7 +30
7-8 +50

Most of my tuning has been optimized gears 1- 4 as this takes me to speeds over 100 mph. I haven't really pushed it past this due to limitations of my testing occuring in "Mexico".

It seems that the torqueier gears more readily produce ignition cut sounds with lower torque reduction values. It's entirely possible the sweet spots for the G87 m2 could be closer to +10.

However I can assure you that since my goal has been to maximize ignition cut sounds, I've been able to achieve volumes levels that could be reasonably construed as obnoxious, and on the stock platform no less. I have no doubt you can achieve the same on an m2.

[dxx]

Will torque reduction damage the car,

Also the sound loud enough? Are you tried turn off ASD and test?

[ILikeBimmers]

Originally Posted by dxx

Will torque reduction damage the car,

Also the sound loud enough? Are you tried turn off ASD and test?

From a technical standpoint torque reduction will absolutely not damage your car. Torque reduction is standard tech in DCT cars as it's my understanding it's best not to let the clutches slip which is why it's employed in the first place. In our ZF automatics this means that the tranmission requests a torque reduction to the ECU. As discussed above there are a couple methods to reduce torque, but the one that's desired here is ignition cut. Obviously cutting ignition to let gas combust in the turbo/downpipe/exhaust causes slightly more wear but technically so does the standard pops and bangs as that is part of the overrun tune inside your ECU engine timing maps. Technically adding torque reduction should actually increase the life of your clutches slightly. As this is the same as lift shifting in a manual, where in our case we don't have a single clutch, but multiple clutch packs.

The sound is very loud. In my car running iDrive 8, ASD options were replaced with a toggle called "Iconic sounds" which from my understanding reading from other people causes the exhaust valve to be closed among other things and actually effects more than just sound piping. I have not turned the setting off.

That being said I usually drive with my windows down and can tell the difference between ASD and true crackles pops, and upshift braps. The ASD sounds like a bunch of large marble spheres coating in felt shaking around in the trunk. A side effect of enabled ignition cut for xHP seems to be that there is a bit of overrun on the fuel bringing back a few real cracks and pops though I'm usually downshifting as early as possible with a heated exhaust and "cold mode" to produce those.

[dxx]

Originally Posted by ILikeBimmers

From a technical standpoint torque reduction will absolutely not damage your car. Torque reduction is standard tech in DCT cars as it's my understanding it's best not to let the clutches slip which is why it's employed in the first place. In our ZF automatics this means that the tranmission requests a torque reduction to the ECU. As discussed above there are a couple methods to reduce torque, but the one that's desired here is ignition cut. Obviously cutting ignition to let gas combust in the turbo/downpipe/exhaust causes slightly more wear but technically so does the standard pops and bangs as that is part of the overrun tune inside your ECU engine timing maps. Technically adding torque reduction should actually increase the life of your clutches slightly. As this is the same as lift shifting in a manual, where in our case we don't have a single clutch, but multiple clutch packs.

The sound is very loud. In my car running iDrive 8, ASD options were replaced with a toggle called "Iconic sounds" which from my understanding reading from other people causes the exhaust valve to be closed among other things and actually effects more than just sound piping. I have not turned the setting off.

That being said I usually drive with my windows down and can tell the difference between ASD and true crackles pops, and upshift braps. The ASD sounds like a bunch of large marble spheres coating in felt shaking around in the trunk. A side effect of enabled ignition cut for xHP seems to be that there is a bit of overrun on the fuel bringing back a few real cracks and pops though I'm usually downshifting as early as possible with a heated exhaust and "cold mode" to produce those.

You are an expert!

Would you mind record a video or something for the fart?

[ILikeBimmers]

Originally Posted by dxx

You are an expert!

Would you mind record a video or something for the fart?

I've tried to get some recordings of the ignition cut brap, but I don't really have a good mic setup, and my phone doesn't really capture the noise too well, especially since keeping the windows down would best capture the noise and then the wind just kind of takes over.

It seems that with ignition cut and torque reduction I'm able to somewhat restore/revert the ignition cut sounds to to the g20 variant of the m240 which had the better sounding ECU map and ignition cut noises, whereas the stock setup hardly makes any pops and bangs and certainly no braps. BMW completely blew this map away as part of an "emissions" update. Whatever politicians made that happen can go jump into the sea and leave my car alone . My upshift braps more or less sound like this video at the 1:05 mark minus the pops and bangs:

[dxx]

Originally Posted by ILikeBimmers

I've tried to get some recordings of the ignition cut brap, but I don't really have a good mic setup, and my phone doesn't really capture the noise too well, especially since keeping the windows down would best capture the noise and then the wind just kind of takes over.

It seems that with ignition cut and torque reduction I'm able to somewhat restore/revert the ignition cut sounds to to the g20 variant of the m240 which had the better sounding ECU map and ignition cut noises, whereas the stock setup hardly makes any pops and bangs and certainly no braps. BMW completely blew this map away as part of an "emissions" update. Whatever politicians made that happen can go jump into the sea and leave my car alone . My upshift braps more or less sound like this video at the 1:05 mark minus the pops and bangs:

Thanks!

I think its the time for me to try XHP.

I really like the fart, but i don't know why BMW remove them for S58,
I do believe the PFL x3m,x4m have very loud fart for stock car, but after 2021, all the fart only come out from the speaker...

[Crazyotter]

I just want to xHP website and entered my vin number and for some reason it says my car (2025 G87) isn’t supported.
Anyone know why?

[M_Power Rob]

Originally Posted by Crazyotter

I just want to xHP website and entered my vin number and for some reason it says my car (2025 G87) isn’t supported.
Anyone know why?

May be due to new model year.

[Crazyotter]

Originally Posted by M_Power Rob

May be due to new model year.

Yeah that’s what I was thinking too

[techwhiz1]

Originally Posted by VIERsr

The G42 and G80 gearboxes are completely different transmissions, not just a different tuning.

They are both variants of the ZF 8HP.
To say they are "completely different" is not accurate.

https://www.zf.com/products/en/cars/products_64238.html

The main difference is HP/ torque capability.

Fundamentally all ZF 8HP transmissions are the same. The mild hybrid and hybrid transmissions encompass an electric motor and are part of their modular kit.


What I don't understand is why folks are striving for ignition cuts and the farts? That's going to make noise and slow you down.

Normally the transmission is tuned for faster shifts, higher pressure and holding gear longer.

[Crazyotter]

Originally Posted by techwhiz1

They are both variants of the ZF 8HP.
To say they are "completely different" is not accurate.

https://www.zf.com/products/en/cars/products_64238.html

The main difference is HP/ torque capability.

Fundamentally all ZF 8HP transmissions are the same. The mild hybrid and hybrid transmissions encompass an electric motor and are part of their modular kit.


What I don't understand is why folks are striving for ignition cuts and the farts? That's going to make noise and slow you down.

Normally the transmission is tuned for faster shifts, higher pressure and holding gear longer.

If you don’t do the ignition cuts will the xHP make you significantly faster?