E90Post
 


GetBMWParts
 
BMW 3-Series (E90 E92) Forum > E90/E92/E93 Marketplace (For Sale / Trade / Wanted) > SPONSORS Classifieds/Groupbuys/Specials Area > Turbo Engine / Drivetrain / Exhaust Parts > xHP Flashtool - Flash your automatic trans! Official thread



Reply
 
Thread Tools Search this Thread
      02-26-2018, 10:56 PM   #1937
Maniac0908
Major
Maniac0908's Avatar
United_States
155
Rep
1,428
Posts

Drives: Alpine White 07 335xi Sedan
Join Date: Feb 2013
Location: Towson, MD

iTrader: (2)

Does anyone else here have issues connecting with jb4 hooked up? I never used to. Now after updating from 32.5 to 32.10 I have issues..... And have to completely remove it to flash
Appreciate 0
      02-27-2018, 12:35 AM   #1938
Paanzerfaust
Private First Class
Paanzerfaust's Avatar
39
Rep
150
Posts

Drives: 07 E92 335i
Join Date: Jan 2018
Location: Chicago

iTrader: (0)

Quote:
Originally Posted by 2013_E92 View Post
It would be the case for both N54, and N55, ive owned both, n55 falls off hard at 5500 RPM depending on the tune, and N54 falls off hard around 5800 depending on the tune. (assuming stock turbocharger(s) for both cars)

http://www.e90post.com/forums/showthread.php?t=717262 here is a thread with the primary discussion point being optimum shift time for the n54.

The recommendations fall between 5500 RPM shift and 6300 RPM shift.

If you tell me which version and stage of MHD you have flashed if you are running one of the stock maps that come with MHD, I can check out some dynos and let you know where that flash starts to fall off @

Holding the gear to 7K RPM will not get you better acceleration on the n54 or the n55 with stock turbos. (this is also true for the car in the stock form even though BMW made the redline at 7,000 that isnt the optimal time to shift for 0-60.

Heres a thread with the N54 stock on the dyno http://www.1addicts.com/forums/showthread.php?t=432677, as you can see the engine starts loosing power and torque quite quickly after 6,000 RPMs meaning your outside the optimal power band if you held the gear all the way till 7k.

let me know if you have any other questions
Thanks for the info! I definitely see what you mean with the technical peak power dropping off after 6k, but even in the first thread my point was mentioned and then never addressed - doesnt shifting at a higher RPM (as in above that 6.2k sweet spot) keep you in the power band for the next gear, which would make sense as to why BMW programs the cars to shift there too? Isn't the goal with custom shift points to ensure you're consistently getting the most average power, I.e. if I shift at 6.2 where my turbos are making peak power, then the car will be at a lower point in the power curve for the next gear. Whereas if I shift at 6.9-7.1k I could potentially be in a better part of the curve for the next gear to continue the quick acceleration, rather than going Max power>shift, down below ideal point and have to build power again if I was shifting at 6K. If shifting at 7k, would I be going slightly past Max power cutoff>shift, in a better spot to make power in the next gear instead of taking a large drop in power after the shift because I shifted too early and now I'm way below peak torque and HP for the subsequent gear, thus causing a kind of cutoff or bog in the cars potential Max acceleration? Do you get what I'm saying?
Appreciate 0
      02-27-2018, 01:12 AM   #1939
YasF80_SLO
Captain
YasF80_SLO's Avatar
United_States
219
Rep
653
Posts

Drives: F80
Join Date: Oct 2016
Location: San Luis Obispo

iTrader: (0)

Garage List
2015 BMW M3  [0.00]
2018 Nissan Versa S  [0.00]
Quote:
Originally Posted by Paanzerfaust View Post
Thanks for the info! I definitely see what you mean with the technical peak power dropping off after 6k, but even in the first thread my point was mentioned and then never addressed - doesnt shifting at a higher RPM (as in above that 6.2k sweet spot) keep you in the power band for the next gear, which would make sense as to why BMW programs the cars to shift there too? Isn't the goal with custom shift points to ensure you're consistently getting the most average power, I.e. if I shift at 6.2 where my turbos are making peak power, then the car will be at a lower point in the power curve for the next gear. Whereas if I shift at 6.9-7.1k I could potentially be in a better part of the curve for the next gear to continue the quick acceleration, rather than going Max power>shift, down below ideal point and have to build power again if I was shifting at 6K. If shifting at 7k, would I be going slightly past Max power cutoff>shift, in a better spot to make power in the next gear instead of taking a large drop in power after the shift because I shifted too early and now I'm way below peak torque and HP for the subsequent gear, thus causing a kind of cutoff or bog in the cars potential Max acceleration? Do you get what I'm saying?
If you check out the graph from the second link I quoted: Direct Link to Graph It has a dyno run for both the stock N54 and a modded N54.

From the graph you can see that the start (AND Peak of the n54 torque curve is at 3200~ Rpms)

And if you check out this article on acceleration you can see how important torque is to your cars acceleration CarThrottle Article

Quote from the center
"More torque means more force you have to either accelerate your car or pull a load with, since torque is Force x distance (aka lb-ft or Newton-Meters). Power is basically how fast you can keep putting out that torque.


When it comes to acceleration, really power doesn’t matter all that much. Recall that acceleration is:

All about Horsepower, Torque, speed, and acceleration. - Blog
So if our goal is maximum acceleration, you can go about it two ways: Either increase the Force (torque) applied by the engine and transmission, or decrease the mass the engine has to move (your car)."

And if peak torque is around 3200~ RPMS, you would want to shift into a pretty low RPM, but even shifting at 6200 RPMS you still cant shift to 3200 RPM's

Check out this youtube video of a stock 335i shifting at 7,000 (redline)

as you can see shifting from:

first -> second @7000 = 4500RPM start in second gear
second -> third @7000 = almost 5000RPM start in third gear

these numbers are significantly higher than the 3200 RPM target to hit for peak torque.
Unless you have custom gearing or some really wierd sized tires/final drive swap, with stock turbos, no reason to shift at redline and certainly not over.

let me know if your still unclear about anything.
Appreciate 0
      02-27-2018, 01:42 AM   #1940
JMM
Private First Class
JMM's Avatar
Belgium
28
Rep
160
Posts

Drives: E92 335d
Join Date: Feb 2010
Location: Belgium

iTrader: (0)

Quote:
Originally Posted by Paanzerfaust View Post
Yes, stock turbos just Bolt ons and tunes.

Not calling you a liar and thanks for the reply but I just have some trouble believing that's the case for the N54 - why would BMW design an engine to rev that high and have WOT shift points anywhere near there then? .................................. but then why do BMW have it shift so high .................................................. ........................

Yea, and you can ask also: Why on earth BMW desided to use such a sluggisch transmision program instead of a more appropriate one, comparable to xHP or Alpina?

IMHO in both cases the same thought: it's incomprehensible and it doesn't make any sense.

Besides that, 99% of the cars have a useless redline and some far beyond there max. power output....but hey, they have to put somewhere a redline.
__________________
e92 335d: 350hp@4400rpm and 698NM/521 ft lb@2760 rpm.

Last edited by JMM; 02-27-2018 at 03:35 AM..
Appreciate 0
      02-27-2018, 07:04 AM   #1941
Sgop335
Lieutenant Colonel
Sgop335's Avatar
United_States
485
Rep
1,780
Posts

Drives: 07 335i e92, 08 535i
Join Date: Jun 2014
Location: MD

iTrader: (1)

Quote:
Originally Posted by Paanzerfaust View Post
Thanks for the info! I definitely see what you mean with the technical peak power dropping off after 6k, but even in the first thread my point was mentioned and then never addressed - doesnt shifting at a higher RPM (as in above that 6.2k sweet spot) keep you in the power band for the next gear, which would make sense as to why BMW programs the cars to shift there too? Isn't the goal with custom shift points to ensure you're consistently getting the most average power, I.e. if I shift at 6.2 where my turbos are making peak power, then the car will be at a lower point in the power curve for the next gear. Whereas if I shift at 6.9-7.1k I could potentially be in a better part of the curve for the next gear to continue the quick acceleration, rather than going Max power>shift, down below ideal point and have to build power again if I was shifting at 6K. If shifting at 7k, would I be going slightly past Max power cutoff>shift, in a better spot to make power in the next gear instead of taking a large drop in power after the shift because I shifted too early and now I'm way below peak torque and HP for the subsequent gear, thus causing a kind of cutoff or bog in the cars potential Max acceleration? Do you get what I'm saying?
Most people give the same answer , power falls off and sure it does. But there is a merit to your question. And the answer is acceleration curve and gear ratio.
The goal is highest acceleration. Rougly speaking acceleration reduces as you increase gears and reduces by the gear ratio. First to secong drops almost to .6, 2nd to 3rd to .65, 3rd to 4th to .75, 4th to 5th to 0.76 and 5th to 6th to 0.79.
That should be the clue to pick shift points. How does the acceleration curve look like? Same shape as torque!
So in 2nd when the torque reduces to .65 highest value, one can shift because the highest acceleration expected in 3rd is only 0.65 of the peak at 2nd and so on. If i have time i will try to graph this. This is litlle complicated i guess and many ppl may not grasp this.
Key is to understand acceleration and how it reduces by gear.
__________________
Space grau metallic / Dakota red leather
335i 0-60 3.6s
535i 0-60 3.9s
Appreciate 0
      02-27-2018, 03:42 PM   #1942
Paanzerfaust
Private First Class
Paanzerfaust's Avatar
39
Rep
150
Posts

Drives: 07 E92 335i
Join Date: Jan 2018
Location: Chicago

iTrader: (0)

Quote:
Originally Posted by 2013_E92 View Post
If you check out the graph from the second link I quoted: Direct Link to Graph It has a dyno run for both the stock N54 and a modded N54.

From the graph you can see that the start (AND Peak of the n54 torque curve is at 3200~ Rpms)

And if you check out this article on acceleration you can see how important torque is to your cars acceleration CarThrottle Article

Quote from the center
"More torque means more force you have to either accelerate your car or pull a load with, since torque is Force x distance (aka lb-ft or Newton-Meters). Power is basically how fast you can keep putting out that torque.


When it comes to acceleration, really power doesn’t matter all that much. Recall that acceleration is:

All about Horsepower, Torque, speed, and acceleration. - Blog
So if our goal is maximum acceleration, you can go about it two ways: Either increase the Force (torque) applied by the engine and transmission, or decrease the mass the engine has to move (your car)."

And if peak torque is around 3200~ RPMS, you would want to shift into a pretty low RPM, but even shifting at 6200 RPMS you still cant shift to 3200 RPM's

Check out this youtube video of a stock 335i shifting at 7,000 (redline)

as you can see shifting from:

first -> second @7000 = 4500RPM start in second gear
second -> third @7000 = almost 5000RPM start in third gear

these numbers are significantly higher than the 3200 RPM target to hit for peak torque.
Unless you have custom gearing or some really wierd sized tires/final drive swap, with stock turbos, no reason to shift at redline and certainly not over.

let me know if your still unclear about anything.
Perfect, that video and your explanation afterward are exactly what I was looking for - maybe I'll mess with lowering the WOT shift points to 6.3-6.6k then? Does that sound reasonable?

Quote:
Originally Posted by JMM View Post
Yea, and you can ask also: Why on earth BMW desided to use such a sluggisch transmision program instead of a more appropriate one, comparable to xHP or Alpina?
As far as the transmission thing goes, I think that's because most BMW owners aren't fanatics like us and would rather have a smoother, more sluggish ride than the fast bang-shifts that xHP offers.
Appreciate 0
      02-27-2018, 03:53 PM   #1943
YasF80_SLO
Captain
YasF80_SLO's Avatar
United_States
219
Rep
653
Posts

Drives: F80
Join Date: Oct 2016
Location: San Luis Obispo

iTrader: (0)

Garage List
2015 BMW M3  [0.00]
2018 Nissan Versa S  [0.00]
Quote:
Originally Posted by Paanzerfaust View Post
Perfect, that video and your explanation afterward are exactly what I was looking for - maybe I'll mess with lowering the WOT shift points to 6.3-6.6k then? Does that sound reasonable?
I would set the WOT shiftpoint for 1st - 2nd at no higher than 6200RPM
I would set the WOT shiftpoint for 2nd - 3rd at no higher than 6000 RPM
and for the rest of the gears in WOT no higher than 6000RPM unless your encountering traction issues that are shift related.


If your car has enough grip ( sticky enough tires ) to handle being dropped into more torque on a first -> second shift, id try to get the first -> second shift slightly lower then 6,000RPM (if your on an OTS map 5800-5900 is ideal), Becuase of the more aggresive torque spike when shifting early on the N54, you may not have enough traction to handle it.

id test out the above numbers, and continue to drop them until you either:

a: start spinning tires on the shift
b: get to 6,000RPM WOT shiftpoint

IE if 6200 has no slip in the shift, drop it to 6100, still no slip, drop to 6000

Because your on stock turbos, as long as your running summer tires you should have no issue setting the second -> third shift @ 6000 from the get go.
Appreciate 0
      02-28-2018, 04:04 PM   #1944
Sgop335
Lieutenant Colonel
Sgop335's Avatar
United_States
485
Rep
1,780
Posts

Drives: 07 335i e92, 08 535i
Join Date: Jun 2014
Location: MD

iTrader: (1)

Incorrect. Tidbits from here and there.
Btw, i have graphed acceleration for the n54 thru the gears for shift points. If anyone interested let me know, may be that will be easier to grasp or carry on lol
__________________
Space grau metallic / Dakota red leather
335i 0-60 3.6s
535i 0-60 3.9s
Appreciate 0
      02-28-2018, 07:13 PM   #1945
IllSic_Design
Major
IllSic_Design's Avatar
United_States
752
Rep
1,424
Posts

Drives: 09 E92 335i
Join Date: Jun 2016
Location: Northern California

iTrader: (1)

Quote:
Originally Posted by Sgop335 View Post
Incorrect. Tidbits from here and there.
Btw, i have graphed acceleration for the n54 thru the gears for shift points. If anyone interested let me know, may be that will be easier to grasp or carry on lol
Post your data/graph please.
Appreciate 0
      02-28-2018, 07:15 PM   #1946
YasF80_SLO
Captain
YasF80_SLO's Avatar
United_States
219
Rep
653
Posts

Drives: F80
Join Date: Oct 2016
Location: San Luis Obispo

iTrader: (0)

Garage List
2015 BMW M3  [0.00]
2018 Nissan Versa S  [0.00]
Quote:
Originally Posted by Sgop335 View Post
Incorrect. Tidbits from here and there.
Btw, i have graphed acceleration for the n54 thru the gears for shift points. If anyone interested let me know, may be that will be easier to grasp or carry on lol
please post your graphs / data I was fairly confident in my response, if you have found something else I'm very curious.
Appreciate 0
      02-28-2018, 08:29 PM   #1947
Sgop335
Lieutenant Colonel
Sgop335's Avatar
United_States
485
Rep
1,780
Posts

Drives: 07 335i e92, 08 535i
Join Date: Jun 2014
Location: MD

iTrader: (1)

Quote:
Originally Posted by IllSic_Design View Post
Post your data/graph please.
Quote:
Originally Posted by 2013_E92 View Post
please post your graphs / data I was fairly confident in my response, if you have found something else I'm very curious.
No problem guys. I graphed this in excel w data from my car. As mentioned earlier acceleration curve has same shape as the torque curve (i can demonstrate that) but their values vary vastly gear to gear due to gear ratio as shown below. Based on the analysis below One may appreciate high revving cars and in general the importance of transmission, gear ratios etc.
The analysis is a reasonable representation and explains the basics but obviously has assumptions.
1. No traction loss
2. Gear ratios used are 6spd auto from 2007 e92
3. Redline 7k, and no ecu nannies like torque limit
4. Shape of curve below will vary based on your tune etc.
5. No drag (altho drag will only make the higher gears worse)
and few more im sure

Graph below shows acc on yaxis and rpm on x. The shape of the curve which mirrors the torque curve will depend on your car. I have shown dashed lines to demonstrate if the torque falls off at a faster rate after 6k.

Well i think the graph shows it, riding on 1st acceleration is the highest, you can go 6500rpm+ on 1st and still have higher acc than anwhere in 2nd! notice this shift point advances forward (meaning shift rpm keeps dropping as can clearly be seen by the arrows) as you move UP thru the gears since the acceleration in the next gear keeps getting closer. Make sense?
Also notice the dashed lines - if your torque falls off quicker obviously the shift rpm reduces as can be seen clearly.
Something missing in this whole graph? HP.
Attached Images
 
__________________
Space grau metallic / Dakota red leather
335i 0-60 3.6s
535i 0-60 3.9s

Last edited by Sgop335; 02-28-2018 at 09:18 PM..
Appreciate 2
86merc45.00

      03-01-2018, 10:51 AM   #1948
lowerednlifted
bubblehead
lowerednlifted's Avatar
United_States
8
Rep
18
Posts

Drives: 2008 335xi 6AT
Join Date: Feb 2018
Location: Colorado

iTrader: (0)

Don't want to derail your convo here...but I can't seem to find any info on my issue.

I have MHD Stg1 and XHP Stg3 flashed. Everytime I make ANY adjustment to MHD it messes up my XHP tune. i.e. when I turned burble off, my trans threw 4wd codes and wouldn't shift proper. Same thing has happened for wastegate rattle adjustment and a couple other things. I found that as long as I did a reflash of XHP Stg3 after anything MHD then I was good to go.

I installed DCI this past weekend and reset the intake mass flow. I didn't get a 4wd error and the car drove perfectly fine the first time. After that it stopped acknowledging S mode. Doesn't matter where the shift selector sits, I can only get D mode. The paddles and shifter will still do manual, but as I'm sure you know, D pops back in rather quickly.

I've reflashed the MHD Stg1 and XHP Stg3 maps multiple times with no adjustments, and I still have the same issue. I'm going to flash both back to stock and then reflash the tuned maps and see if that works.

Just wanted to see if anyone else has experienced anything similar. Also wanted to semi-complain to XHP that I'm disappointed in the compatibility between MHD and XHP. They work great together, but they also seem to work against each other sometimes. Can we get this addressed?
__________________
2008 335xi 6AT - MHD Stg1+ - XHP Stg 3 - VRSF DCI - VRSF Catless DPs - Style 230 Staggered
Appreciate 0
      03-01-2018, 02:57 PM   #1949
techwhiz
Colonel
techwhiz's Avatar
United_States
420
Rep
2,922
Posts

Drives: e90 335i Sedan - Arctic
Join Date: Feb 2012
Location: Bay Area, Ca

iTrader: (4)

Quote:
Originally Posted by lowerednlifted View Post
I installed DCI this past weekend and reset the intake mass flow. I didn't get a 4wd error and the car drove perfectly fine the first time. After that it stopped acknowledging S mode. Doesn't matter where the shift selector sits, I can only get D mode. The paddles and shifter will still do manual, but as I'm sure you know, D pops back in rather quickly.

I've reflashed the MHD Stg1 and XHP Stg3 maps multiple times with no adjustments, and I still have the same issue. I'm going to flash both back to stock and then reflash the tuned maps and see if that works.
Sounds like the dreaded harness issue.
Pull your center console and look at the shifter harness.
I have $10 says you have at least one broken wire in there.
__________________
Arctic Metallic\CF Splitters, Spoiler, Mirror Covers\LED Tails\LSD\Tinted\Coded\Apex EC7-19"\LED Angel Eyes\Gloss Black Grill\Integrated V1 & Galaxy Tab\M-Performance Brakes\Cobb Tuned\xHP Flash\Resonator Removed and -> is your friend.
Appreciate 0
      03-01-2018, 03:11 PM   #1950
lowerednlifted
bubblehead
lowerednlifted's Avatar
United_States
8
Rep
18
Posts

Drives: 2008 335xi 6AT
Join Date: Feb 2018
Location: Colorado

iTrader: (0)

Quote:
Originally Posted by techwhiz View Post
Sounds like the dreaded harness issue.
Pull your center console and look at the shifter harness.
I have $10 says you have at least one broken wire in there.
Dang, that doesn't sound fun. :-/ I guess I'll give that a shot this weekend. Thanks.

My passenger airbag light randomly turns on and off, and for the first time my trunk light came on yesterday while driving. Potentially related? I came from the audi world and we always joked about the bimmers and their bad wiring, haha.
__________________
2008 335xi 6AT - MHD Stg1+ - XHP Stg 3 - VRSF DCI - VRSF Catless DPs - Style 230 Staggered
Appreciate 0
      03-01-2018, 04:08 PM   #1951
techwhiz
Colonel
techwhiz's Avatar
United_States
420
Rep
2,922
Posts

Drives: e90 335i Sedan - Arctic
Join Date: Feb 2012
Location: Bay Area, Ca

iTrader: (4)

Quote:
Originally Posted by lowerednlifted View Post
Dang, that doesn't sound fun. :-/ I guess I'll give that a shot this weekend. Thanks.

My passenger airbag light randomly turns on and off, and for the first time my trunk light came on yesterday while driving. Potentially related? I came from the audi world and we always joked about the bimmers and their bad wiring, haha.
Not sure about the airbag.
The trunk is probably the harness that goes from the body to the trunk.
I've had to patch it when I had my E30 M3, E36 M3 and now my E90 335.
The trunk harness will give you backup and other light errors as well as the trunk open.

The shifter hardness is not too bad.
Google "bmw 335i shifter harness repair".
It's a common problem.

I'm ready to get the flash but I don't want to buy them all when I'll probably just settle on one. Trying to decide between 2 and 3.
I might get stage 3. I don't hear many people on the forum talking about stage 2.

Hmmmmm........
__________________
Arctic Metallic\CF Splitters, Spoiler, Mirror Covers\LED Tails\LSD\Tinted\Coded\Apex EC7-19"\LED Angel Eyes\Gloss Black Grill\Integrated V1 & Galaxy Tab\M-Performance Brakes\Cobb Tuned\xHP Flash\Resonator Removed and -> is your friend.
Appreciate 0
      03-01-2018, 04:36 PM   #1952
lowerednlifted
bubblehead
lowerednlifted's Avatar
United_States
8
Rep
18
Posts

Drives: 2008 335xi 6AT
Join Date: Feb 2018
Location: Colorado

iTrader: (0)

Quote:
Originally Posted by techwhiz View Post
Not sure about the airbag.
The trunk is probably the harness that goes from the body to the trunk.
I've had to patch it when I had my E30 M3, E36 M3 and now my E90 335.
The trunk harness will give you backup and other light errors as well as the trunk open.

The shifter hardness is not too bad.
Google "bmw 335i shifter harness repair".
It's a common problem.

I'm ready to get the flash but I don't want to buy them all when I'll probably just settle on one. Trying to decide between 2 and 3.
I might get stage 3. I don't hear many people on the forum talking about stage 2.

Hmmmmm........
Yeah, I looked it up. Should be an easy fix. I guess it's just crazy coincidence that there's a physical failure at the same time that I'm doing module programming, haha. Sh!tty.

I went ahead and just bought the super license. I went this route so that I can get all the updates for free and what not. However, I went straight to Stg3 and haven't looked back. I saw some posts on here about people preferring to run Stg2, but me personally I wanted that super quick shifting with the paddles. When the wife and baby are in the car, I just switch it to D and all is good.
__________________
2008 335xi 6AT - MHD Stg1+ - XHP Stg 3 - VRSF DCI - VRSF Catless DPs - Style 230 Staggered
Appreciate 0
      03-01-2018, 07:24 PM   #1953
YasF80_SLO
Captain
YasF80_SLO's Avatar
United_States
219
Rep
653
Posts

Drives: F80
Join Date: Oct 2016
Location: San Luis Obispo

iTrader: (0)

Garage List
2015 BMW M3  [0.00]
2018 Nissan Versa S  [0.00]
Quote:
Originally Posted by Sgop335 View Post
No problem guys. I graphed this in excel w data from my car. As mentioned earlier acceleration curve has same shape as the torque curve (i can demonstrate that) but their values vary vastly gear to gear due to gear ratio as shown below. Based on the analysis below One may appreciate high revving cars and in general the importance of transmission, gear ratios etc.
The analysis is a reasonable representation and explains the basics but obviously has assumptions.
1. No traction loss
2. Gear ratios used are 6spd auto from 2007 e92
3. Redline 7k, and no ecu nannies like torque limit
4. Shape of curve below will vary based on your tune etc.
5. No drag (altho drag will only make the higher gears worse)
and few more im sure

Graph below shows acc on yaxis and rpm on x. The shape of the curve which mirrors the torque curve will depend on your car. I have shown dashed lines to demonstrate if the torque falls off at a faster rate after 6k.

Well i think the graph shows it, riding on 1st acceleration is the highest, you can go 6500rpm+ on 1st and still have higher acc than anwhere in 2nd! notice this shift point advances forward (meaning shift rpm keeps dropping as can clearly be seen by the arrows) as you move UP thru the gears since the acceleration in the next gear keeps getting closer. Make sense?
Also notice the dashed lines - if your torque falls off quicker obviously the shift rpm reduces as can be seen clearly.
Something missing in this whole graph? HP.
Could I copy this and paste it over in the 1/4mi section on some other forums? if this is true, im very surprised, because everyone I know on stock turbos short shifts this platform in drag races.
Appreciate 0
      03-02-2018, 12:30 AM   #1954
Paanzerfaust
Private First Class
Paanzerfaust's Avatar
39
Rep
150
Posts

Drives: 07 E92 335i
Join Date: Jan 2018
Location: Chicago

iTrader: (0)

Quote:
Originally Posted by Sgop335 View Post
No problem guys. I graphed this in excel w data from my car. As mentioned earlier acceleration curve has same shape as the torque curve (i can demonstrate that) but their values vary vastly gear to gear due to gear ratio as shown below. Based on the analysis below One may appreciate high revving cars and in general the importance of transmission, gear ratios etc.
The analysis is a reasonable representation and explains the basics but obviously has assumptions.
1. No traction loss
2. Gear ratios used are 6spd auto from 2007 e92
3. Redline 7k, and no ecu nannies like torque limit
4. Shape of curve below will vary based on your tune etc.
5. No drag (altho drag will only make the higher gears worse)
and few more im sure

Graph below shows acc on yaxis and rpm on x. The shape of the curve which mirrors the torque curve will depend on your car. I have shown dashed lines to demonstrate if the torque falls off at a faster rate after 6k.

Well i think the graph shows it, riding on 1st acceleration is the highest, you can go 6500rpm+ on 1st and still have higher acc than anwhere in 2nd! notice this shift point advances forward (meaning shift rpm keeps dropping as can clearly be seen by the arrows) as you move UP thru the gears since the acceleration in the next gear keeps getting closer. Make sense?
Also notice the dashed lines - if your torque falls off quicker obviously the shift rpm reduces as can be seen clearly.
Something missing in this whole graph? HP.
See, this is exactly what I had in mind when I made my first few posts "arguing" about how it wouldn't make sense to shift at 5.8k on an engine made to rev up to 7k. I understand the that higher boost=more power=more acceleration so I understand the thoughts that prioritize that but people often underestimate gearing etc.

So judging by your post mixed with 2013_E92 I should kind of mix-and-match your techniques right? Short shifting in the later gears to keep myself in that nice torque curve but holding out on the first and second gear maybe?
__________________
07 E92 335i - Sport package, aFe Stage-2 Pro 5R CAI, VRSF Catless Downpipes, H&R Race Springs. MHD Stage 2, xHP Stage 3
Appreciate 0
      03-04-2018, 07:30 PM   #1955
asiflicious
Captain
asiflicious's Avatar
516
Rep
907
Posts

Drives: 2010 6AT 135i
Join Date: Aug 2017
Location: Portland, OR

iTrader: (0)

Quote:
Originally Posted by siphor1989 View Post
Where are you guys reading that xHP stage 3 removes the limiter? From what I read, with stage 3, the transmission will not automatically upshift once at the limiter like the OEM tune would. Like the OEM tune, xHP still will not allow the transmission to downshift into a gear that would cause an over-rev situation.
This is where I got the information
Attached Images
 
Appreciate 0
      03-04-2018, 11:20 PM   #1956
Toome
Member
Toome's Avatar
United_States
151
Rep
436
Posts

Drives: 2012 E92 335i M-Sport
Join Date: May 2017
Location: San Diego, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by asiflicious View Post
Quote:
Originally Posted by siphor1989 View Post
Where are you guys reading that xHP stage 3 removes the limiter? From what I read, with stage 3, the transmission will not automatically upshift once at the limiter like the OEM tune would. Like the OEM tune, xHP still will not allow the transmission to downshift into a gear that would cause an over-rev situation.
This is where I got the information
From my experience, that's correct. I can bang the engine off the rev limiter when doing a hard launch, but the car won't allow me to over rev a downshift.
__________________
12’ E92 335i 6AT - Alpine White M-Sports Package
Mods - | MHD Stage2+ ACN91 OTS Map | K&N Drop-in | VRSF Kittenless D0wnpipe | VRSF CP | VRSF 7” FMIC | xHP Stage 3 | Euro Headlight Switch | Avant Garde M359 | Michelin PS4S
Appreciate 0
      03-04-2018, 11:22 PM   #1957
asiflicious
Captain
asiflicious's Avatar
516
Rep
907
Posts

Drives: 2010 6AT 135i
Join Date: Aug 2017
Location: Portland, OR

iTrader: (0)

Quote:
Originally Posted by Toome View Post
Quote:
Originally Posted by asiflicious View Post
Quote:
Originally Posted by siphor1989 View Post
Where are you guys reading that xHP stage 3 removes the limiter? From what I read, with stage 3, the transmission will not automatically upshift once at the limiter like the OEM tune would. Like the OEM tune, xHP still will not allow the transmission to downshift into a gear that would cause an over-rev situation.
This is where I got the information
From my experience that is correct. I can the engine off the rev limiter, but the car won't allow me to over rev a downshift.
So you'd have to really be trying to hurt to car to cause any damage? You won't be able to overrev on accident?
Appreciate 0
      03-04-2018, 11:28 PM   #1958
Toome
Member
Toome's Avatar
United_States
151
Rep
436
Posts

Drives: 2012 E92 335i M-Sport
Join Date: May 2017
Location: San Diego, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by asiflicious View Post
Quote:
Originally Posted by Toome View Post
Quote:
Originally Posted by asiflicious View Post
Quote:
Originally Posted by siphor1989 View Post
Where are you guys reading that xHP stage 3 removes the limiter? From what I read, with stage 3, the transmission will not automatically upshift once at the limiter like the OEM tune would. Like the OEM tune, xHP still will not allow the transmission to downshift into a gear that would cause an over-rev situation.
This is where I got the information
From my experience that is correct. I can the engine off the rev limiter, but the car won't allow me to over rev a downshift.
So you'd have to really be trying to hurt to car to cause any damage? You won't be able to overrev on accident?
The only way you'll hit the limiter is if you do not upshift either intentionally or if you forget you're in manual mode. A mechanical over rev is impossible, so you'll never go above the 7k redline in any situation.
__________________
12’ E92 335i 6AT - Alpine White M-Sports Package
Mods - | MHD Stage2+ ACN91 OTS Map | K&N Drop-in | VRSF Kittenless D0wnpipe | VRSF CP | VRSF 7” FMIC | xHP Stage 3 | Euro Headlight Switch | Avant Garde M359 | Michelin PS4S
Appreciate 0
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 01:56 PM.




e90post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST