[RiXst3r]

Did a "simulated" 4th gear dyno run in my steptronic e92 335i. I was able to do a full throttle 4th gear runout from 1300 RPM (~27mph) all the way up to 130mph when I ran out of road... but i beleive it was very close to redline. I am not sure why all the people dyno'ing steptronic 335i's are having downshift issues, the only thing I can do to replicate it, is if I push the kickdown button. Just dont hit the kickdown, and you will be fine. Edmunds/Shiv, not trying to say you don't know what your doing, but I just had to see this "limitation" for myself, and as I thought, it does not exist.

The only downshift limitations are if the car is going less that 20mph, it will downshift into 3rd, and less than 10mph it will downshift into 2nd... but 4th gear at 30mph is 1400rpm, so no issues there.

Simple answer, dont hit the kickdown button under the gas pedal. I have verified with several sources in the past, on this forum, and through other channels, that even without the kickdown, you are at 100% throttle.

[OpenFlash]

I'm pretty sure the engine was kicking down well before I hit the kickdown button at the end of the pedal travel. I'm thinking that the Steptronic transmission may rely on different shift logic when the front wheels aren't spinning (like on a dyno).

-shiv

[RiXst3r]

did you pull the shift lever over to DS mode, and then use the lever to get into fourth, or did you just leave it in D, and use the paddles? Paddle shifts are not the same as shifts on the stick if you dont use the stick first. The speed pulse sensor is not on the front wheels, I dont think any sensors, (other than TPMS and DTC/TCS) are on the front wheels/hubs... they look to just free-spin... makes no sense to me why that would alter shifting points...

When you said it downshifts unless you are over 4000 RPM, thats exactly my results with kickdown mode... it downshifts unless I am above 4000 RPM...

The only reason I am so interested in getting this solved, is because...

1: I want to know how much torque gain the AT cars can expect with the XEDE.
2: I plan on taking my car to a local dyno, and want to be prepared. (for a before and after XEDE self install without custom tune)

[OpenFlash]

Originally Posted by RiXst3r

did you pull the shift lever over to DS mode, and then use the lever to get into fourth, or did you just leave it in D, and use the paddles? Paddle shifts are not the same as shifts on the stick if you dont use the stick first. The speed pulse sensor is not on the front wheels, I dont think any sensors, (other than TPMS and DTC/TCS) are on the front wheels/hubs... they look to just free-spin... makes no sense to me why that would alter shifting points...

When you said it downshifts unless you are over 4000 RPM, thats exactly my results with kickdown mode... it downshifts unless I am above 4000 RPM...

The only reason I am so interested in getting this solved, is because...

1: I want to know how much torque gain the AT cars can expect with the XEDE.
2: I plan on taking my car to a local dyno, and want to be prepared. (for a before and after XEDE self install without custom tune)

The shifter was in DS mode and both paddles and shifter were used to set the gear. When the car is on the dyno, an ABS warning light comes on. As well as a traction control fault. This could potentially change the shift logic. I'd like to get it solved as well. Surely people have dyno tested Steptronic cars in the past, no? I would like to know if or how they did it without it kicking down a gear. Until then, holding 1/2 to 3/4 throttle until 4000rpm isn't a viable option

shiv

[RiXst3r]

Thanks for the details... With all the faults/warnings, I am not surprised the tranny would go into a different "mode" that would override your input. It makes more sense now.

[OpenFlash]

Originally Posted by RiXst3r

Thanks for the details... With all the faults/warnings, I am not surprised the tranny would go into a different "mode" that would override your input. It makes more sense now.

It does make sense but then again, it's just a guess It would be nice if someone with Steptronic dyno testing experience can jump in here. I'd like to learn more as well.

Shiv

[Insider]

Originally Posted by shiv@vishnu

It does make sense but then again, it's just a guess It would be nice if someone with Steptronic dyno testing experience can jump in here. I'd like to learn more as well.

Shiv

Well Car and Driver was able to Dyno the 335D, which comes in automatic only. http://www.caranddriver.com/features...art-page2.html Looking at the dyno, looks like they had no problems.

[CassiesMan]

If you are getting the traction warning light on the dyno, then I think if you turn off (all the way off) the DSC/TC, you should be fine in that respect. I'm not positive, but I think it reads that the rear wheels are spinning, the front aren't, so it just wants you to know that. The car doesn't know its on a dyno, it think it is just driving normally.

[OpenFlash]

With traction control fully turned off, the car still knows that it is on a dyno due to the ABS fault it throws. It goes away soon as you drive off and get the front wheels spinning again.

-shiv

[uhaulball]

theyve done dyno's with auto 330i and 325i before, ask ksfrogman for details. for them i think they held the DSC button to completely turn off traction control, and then they used DS-to-manual mode and it stayed in 4th for them i believe... not sure why its not working for the 335. another solution is an AWD dyno to get the front wheels moving too?

[RiXst3r]

Someone that has dyno'd an automatic e90/e92 will hopefully have some input on this... It must be possible... since we have seen dyno graphs of autos.

[williamf]

I am very interested in the solution to this question and I thank Shiv for all his efforts in achieving this goal. What a great guy.

[OpenFlash]

Originally Posted by williamf

I am very interested in the solution to this question and I thank Shiv for all his efforts in achieving this goal. What a great guy.

aw shucks... quit it I'm going to be dyno tuning another Steptronic today and will try out some of the new ideas being tossed around. William-- I may give you a call to talk more about what you mentioned the other day regarding holding a gear.

-shiv

[CassiesMan]

You might need to actually find an AWD dyno even if the car is RWD. I expierenced the same problem earlier today, we've had a ton of snow up here in the past few days, and when I went to move the car, my DSC/TC/ABS lights came on, showing a Traction Controll Failure. Only one wheel would turn when I touched the gas. However, once I got it on solid concrette, and the front wheels could turn, all the codes went away. I think it might be something with the traction controll system that is causing it to kickdown. Keep us updated, because I'm planning on getting a 335i with the steptronic/paddle shift and I want to know whats gonna happen when I get the XEDE.

[radgator1]

Originally Posted by shiv@vishnu

aw shucks... quit it I'm going to be dyno tuning another Steptronic today and will try out some of the new ideas being tossed around. William-- I may give you a call to talk more about what you mentioned the other day regarding holding a gear.

-shiv

Cool, is this in Cali, that is is this the first stage 0 step 91 octane tune? Also is it an e90 by any chance? Not that we expect any difference but looking forward to the first e90 data as well.

Looking forward to the updates and graphs