[Serial BoX]

I've been poking around with the idea of going to a stage II turbo, ditching my JB4 and moving onto a full tuning system like BM3 or MHD (etc etc) And have seen some people rumbling about removing some sort of torque limiter that can really hinder power increases over 300? Do any of the tuning systems have this option available on them already making one better than the other?

Im looking for a little more info on that if anyone is smarter and more well informed than myself. Thanks in advance.

I have a 430i, Xdrive 8speed automatic tranny.

JB4 running stage II
intake, downpipe, 91 octane (best around for now)

[anotheran]

Bm3 includes a tcu tune made from a M235i mapping that removes the torque limited on 3rd and 6th gears. It lugs the n20/B48 but it's a free map so worth trying to see if you'd be happy with it.

Xhp tcu tune is much much better for the n20/B48 as they're tunes for the specific engines

[thejeremyman9]

XHP is the best transmission tune, period.

[n55david]

xhp.. nothing else

[Wires]

Originally Posted by Serial BoX

I've been poking around with the idea of going to a stage II turbo, ditching my JB4 and moving onto a full tuning system like BM3 or MHD (etc etc) And have seen some people rumbling about removing some sort of torque limiter that can really hinder power increases over 300? Do any of the tuning systems have this option available on them already making one better than the other?

Im looking for a little more info on that if anyone is smarter and more well informed than myself. Thanks in advance.

I have a 430i, Xdrive 8speed automatic tranny.

JB4 running stage II
intake, downpipe, 91 octane (best around for now)

Not sure about your car, but the latest BM3 maps for my B58 disables that torque limiter so you may just need to get the BM3 and nothing else.

[AMG KLR]

xHP stage 1, anything over that is extra strain on the tranny

[Skyhigh]

Originally Posted by AMG KLR

xHP stage 1, anything over that is extra strain on the tranny

Is there a consensus about that yet?
According to RB Tuning - it is not, at least not for Stage 2.
Only seen one source which claims the opposite.

This said, in reality even removing torque limiters (Stage 1) is extra strain - they are there for a reason you know...

[Serial BoX]

Originally Posted by Wires

Not sure about your car, but the latest BM3 maps for my B58 disables that torque limiter so you may just need to get the BM3 and nothing else.

Thats the kind of info I'm looking for, but I've been researching the xHP also, sounds like its really an indepth tune for just a couple of hundred bucks thats really focused on the just the transmission itself. I'll probably be going BM3 and the xHP this spring. I really appreciate all the info and help guys. Goes a long way to avoiding "shoulda coulda woulda's" later on. Like just installing a JB4, not knowing that it's not really a tune, just tricking the ECU boost level. I should have researched that way more before just pulling the trigger and buying and installing.

[Wires]

Originally Posted by Skyhigh

Is there a consensus about that yet?
According to RB Tuning - it is not, at least not for Stage 2.
Only seen one source which claims the opposite.

This said, in reality even removing torque limiters (Stage 1) is extra strain - they are there for a reason you know...

My "issue" with that blog post is they don't really compile together what the customer had configured the transmission for. Was it just OTS maps, did they grab all sliders and yank them all to the right? etc. Was it people that spend all day dragging their cars? No clue.

xHP doesn't explicitly say what they do in the map, but if you assumed they just overlayed with more features, the line pressure boost starts in stage 1, and then its just more aggressive shifting as you go up in stages.

Anyways, I was at stage 3, and went back to stage 2. Partially due to the fear mongering of the post, and partially due to when driving in manual mode, stage 3 always has a pretty harsh 2->1 shift which gave me some concern around icy roads and loss of traction coming to a stop.

[anotheran]

Originally Posted by Wires

My "issue" with that blog post is they don't really compile together what the customer had configured the transmission for. Was it just OTS maps, did they grab all sliders and yank them all to the right? etc. Was it people that spend all day dragging their cars? No clue.

xHP doesn't explicitly say what they do in the map, but if you assumed they just overlayed with more features, the line pressure boost starts in stage 1, and then its just more aggressive shifting as you go up in stages.

Anyways, I was at stage 3, and went back to stage 2. Partially due to the fear mongering of the post, and partially due to when driving in manual mode, stage 3 always has a pretty harsh 2->1 shift which gave me some concern around icy roads and loss of traction coming to a stop.

All from https://www.xhpflashtool.com/blog/ho...mission_works/

They say they do their "development on the street".

They alter:
- shift points (probably need to look at their map editor for specific cars to see the shift point)
- clutch pressures inside and outside of shifts,
- clutch-timing on shifts (which greatly influence the shift-comfort) the slip of the Torque Converter Clutch,
- clutch-stress calculations,
- traction management during Launch Control

[thejeremyman9]

Originally Posted by AMG KLR

xHP stage 1, anything over that is extra strain on the tranny

Provide evidence because this runs contrary to the intention of the fundamental changes XHP makes to the operation of the transmission. Aside from drag mode (or whatever the most recent thing is called) that specifically has a disclaimer about using it frequently, the OTS maps with default settings do NOT put extra strain on the transmission. Infact, if you are tuned and making more power than stock they should prevent extra wear and tear from microslip, etc.

[Skyhigh]

Originally Posted by thejeremyman9

Provide evidence because this runs contrary to the intention of the fundamental changes XHP makes to the operation of the transmission. Aside from drag mode (or whatever the most recent thing is called) that specifically has a disclaimer about using it frequently, the OTS maps with default settings do NOT put extra strain on the transmission. Infact, if you are tuned and making more power than stock they should prevent extra wear and tear from microslip, etc.

Only source stating that, which I am aware of:
https://www.puredrivetrainsolutions....YyZeukePdyHjbQ

I can't say it is surprising. You ask for more - you pay the price with more wear / decreased safety margins. This said the real question is "By how much?". xHP has been around for many years. People have driven many thousand kilometers on the different stages, with different setups, mostly without trouble.

I am myself about to install xHP and am hesitant about the stages too. Sounds like Stage 2 is probably the most balanced.

[Wires]

Originally Posted by anotheran

All from https://www.xhpflashtool.com/blog/ho...mission_works/

They say they do their "development on the street".

They alter:
- shift points (probably need to look at their map editor for specific cars to see the shift point)
- clutch pressures inside and outside of shifts,
- clutch-timing on shifts (which greatly influence the shift-comfort) the slip of the Torque Converter Clutch,
- clutch-stress calculations,
- traction management during Launch Control

What I was meaning was if they used higher pressures in the stage 2 or stage 3 maps. Maybe they do, I have no idea, but I haven't heard anyone posting about their tranny grenading because of it, so who knows.

Running BM3, and turning the burbles to canon explosions will destroy the cats. Doesn't mean "responsible" use and configuration does though.

[thejeremyman9]

Originally Posted by Skyhigh

Only source stating that, which I am aware of:
https://www.puredrivetrainsolutions....YyZeukePdyHjbQ

I can't say it is surprising. You ask for more - you pay the price with more wear / decreased safety margins. This said the real question is "By how much?". xHP has been around for many years. People have driven many thousand kilometers on the different stages, with different setups, mostly without trouble.

I am myself about to install xHP and am hesitant about the stages too. Sounds like Stage 2 is probably the most balanced.

First, that article only mentions Gen1 B58 and 6HP, technically neither of which are the 8AT in the N55 which uses a slightly different HP45 transmission (although one could argue similar principles might apply to N55 transmission, its not explicitly mentioned).

Second, LPB is not in the XHP OTS maps by default. It's an additional option that you enable and if you read the manual its generally not recommended for a FBO/stock turbo car just running OTS DME maps. You should not enable LPB unless you need it, and if you do so you should already be aware that you are far exceeding the transmissions rating. But this has no correlation to XHP OTS maps or claims of anything above stage 1 increasing wear.

Third, the blog says "The same goes for shift times, the quicker you attempt to disengage one gear to engage the next the quicker you will wear some parts out." So, by that logic, we all need to drive around in ECO mode because when we go in S/Sport + (even with stock software) we are going to increase wear and tear on our transmission. Or, if we consider a more nuanced approach that a generic statement such as that then you realize shift time can be increased from the stock settings without any appreciable wear and tear. This is fundamentally how the XHP OTS maps are built - they are derived from how the ZF8 is configured in other vehicles/manufacturers to adjust the parameters within safe limits.

(The exception of course is the new drag mode which clearly as a disclaimer on wear and tear - but talking here about OTS maps with default settings).

We all need to be comfortable with some level of increased wear and tear when tuning a car outside of OEM spec but making a blanket statement like "Anything passed the stage1 you are sacrificing reliability for performance and I will talk about a few of these things below" seems a bit much, especially when LPB isnt a part of the OTS maps and the generic logic for the 2nd point doesnt consider what the threshold is for increased wear via faster shifts. It really comes down to what XHP say - "Your driving style and proper maintenance have the biggest impact on the life-time of transmission components."