[swissarmyknife]

I had the Kerma S1 tune since last March and have been expressively happy with it. Throttle response is up, overall turbo lag is reduced and gas mileage is better if you drive with the same habits as before - which believe me is difficult to do. I posted acceleration times from the same stretch of road before and right after the tune was applied and the numbers don't lie..

https://f30.bimmerpost.com/forums/sh...2&postcount=45

One thing though bothered me and that was the transmission seemed to shift sluggish and in my opinion not at the best shift points optimized for the tune.

So at this point you have three options:
1. You leave it be and your happy with the current results
2. You go all the way with Kerma S2 which is tailor made for their ECU tune along with their remap of the transmission
3. OR you go the hack way, which is what I chose for now and get xHP and try to adopt some shift point adaptations based on dyno data (that I posted here: https://f30.bimmerpost.com/forums/sh...8&postcount=18)

I got the base license obviously and the 3 stage map licence for my specific VIN config. I drove it yesterday for the first day without pushing it as it states to give the trans about 30-50mils to relearn the adaptations. Upfront also, I used bimmercode to start the car in ECO mode (auto start/stop turned off) and I applied Stage 2 from xHB and moved the the shift up points down by a given % to more closely represent the torque curve. All of this is obviously very subjective and I have no real world way to gather good and repeatable data, but the Stage 2 xHB tune just by itself makes a huge difference without modifing the shift points yet. That just gives me additional tweaking ability to fine tune against the Kerma stage 1 tune.

So what are my first impressions:
In Eco mode the shifts are very early and I like that. The shifts occur around 1700 RPM but if you step on it a bit more they hold until about 2000 RPM. Overall this is good as it maintains fuel economy.
In Sport + mode the shifts are very crisp and considerably quicker. I have not done any kick down, again since this is still during the initial break in period.
One thing to note is that on a couple of engine starts the LED's on the shifter do not come in, telling me if I am in park, reverse or drive. It appears to be random at this time and has not shown any other effects, but if this persists I will reach out to xHP to find out what this could be.

The Kerma stage 2 will be still the better option for 99% of anyone considering getting the max out of their car who is already on Kerma Stage 1. For me this was an opportunity to tinker with my car and see if I can fine tune it to my personal liking and so far xHB does not disappoint.

[eugene89us]

swissarmyknife Great write-up, thank you for contributing and sharing your results. Once ZF relearns its adaptations, it would be interesting to see how it performs during high demand. I think the ability to tinker with shift points is very enticing, since you can make the car shift the way you like it and possibly also maximize efficiency with the engine. I usually run my car in Comfort 99.9% of the time, and Sport in 0.01%, so those are my common categories to compare with.

We (the BimmerPost Community) have a few dynos to compare S1 and S2 posted around this place, so if you have time and resources, would be interesting to see the dyno results for S1 vs. S1+xHPbase vs. S1+ modified xHP. In the past, a few forum members' "butt dyno" did not fare well on the real dyno, so a proof of concept would be nice. Almost wondering if xHP would be able to "sponsor" your study?

[swissarmyknife]

Originally Posted by eugene89us

swissarmyknife Great write-up, thank you for contributing and sharing your results. Once ZF relearns its adaptations, it would be interesting to see how it performs during high demand. I think the ability to tinker with shift points is very enticing, since you can make the car shift the way you like it and possibly also maximize efficiency with the engine. I usually run my car in Comfort 99.9% of the time, and Sport in 0.01%, so those are my common categories to compare with.

We (the BimmerPost Community) have a few dynos to compare S1 and S2 posted around this place, so if you have time and resources, would be interesting to see the dyno results for S1 vs. S1+xHPbase vs. S1+ modified xHP. In the past, a few forum members' "butt dyno" did not fare well on the real dyno, so a proof of concept would be nice. Almost wondering if xHP would be able to "sponsor" your study?

I might try to connect with FaRKle! as he's further up in the bay area and has used AWD dyno's up in his area. I've never had any of my cars dyno'd so that would be cool. Need to understand the cost involved (unless and very unlikely xHB would be willing to flip the bill) to do a few runs with different settings.

I can't promise this will be something I can accomplish anytime quick tough. Lot's of stuff going on at work recently and weekends are for the family.

[bigshooter]

Originally Posted by swissarmyknife

I might try to connect with FaRKle! as he's further up in the bay area and has used AWD dyno's up in his area. I've never had any of my cars dyno'd so that would be cool. Need to understand the cost involved (unless and very unlikely xHB would be willing to flip the bill) to do a few runs with different settings.

I can't promise this will be something I can accomplish anytime quick tough. Lot's of stuff going on at work recently and weekends are for the family.

This is the thread I've been looking for!

Wondering if you have an update since you've learned adaptions? Have we been able to compare Kerma Stage 2 vs stage 1+ xHP?

Has anyone done DUDMD stage 1 + xHP tranny software? DUDMD claims more gains with stage 1 than Kerma but I read someone reported preferring Kerma for drivability.

[AndrewC1989]

Originally Posted by swissarmyknife

One thing though bothered me and that was the transmission seemed to shift sluggish and in my opinion not at the best shift points optimized for the tune.

Did you have the sport auto transmission to begin with, or the standard base one?