Close

Page 2 of 2 FirstFirst 12
Results 26 to 50 of 50
  1. #26
    Join Date
    Apr 2011
    Posts
    151
    Rep Points
    70.0
    Mentioned
    2 Post(s)
    Rep Power
    0


    Yes Reputation No
    ...

  2. #27
    Join Date
    Feb 2010
    Posts
    2,185
    Rep Points
    2,132.4
    Mentioned
    25 Post(s)
    Rep Power
    22


    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    I really like that it won't upshift on its own, very nice.
    yeah only in "C" or "S" will it upshift.
    Current:
    14 Viper TA
    Wsir - 1:28:9
    Buttonwillow C13 - 1:54:1

  3. #28
    Join Date
    Feb 2010
    Location
    OH
    Posts
    1,454
    Mentioned
    2 Post(s)
    Rep Power
    0


    1 out of 1 members liked this post. Yes Reputation No
    One of the downfalls of the M156/722.9 combo is that the tach is optimistic by 400rpm at redline. That means when a car with a stock tune shifts at an indicated 7000rpm it's actually 6600rpm, and after a tune when the limiter is raised to an indicated 7400rpm in Manual mode it's an actual 7000rpm. Ironically MB rates peak HP @ 6800rpm which would never be reached without an aftermarket tune. It's an unfortunate fact of life we all have to life with, and it was done so with trans preservation in mind.

    Thanks

  4. #29
    Join Date
    Feb 2010
    Posts
    2,185
    Rep Points
    2,132.4
    Mentioned
    25 Post(s)
    Rep Power
    22


    Yes Reputation No
    Click here to enlarge Originally Posted by MHP LLC Click here to enlarge
    One of the downfalls of the M156/722.9 combo is that the tach is optimistic by 400rpm at redline. That means when a car with a stock tune shifts at an indicated 7000rpm it's actually 6600rpm, and after a tune when the limiter is raised to an indicated 7400rpm in Manual mode it's an actual 7000rpm. Ironically MB rates peak HP @ 6800rpm which would never be reached without an aftermarket tune. It's an unfortunate fact of life we all have to life with, and it was done so with trans preservation in mind.

    Thanks
    WOAH! Thats crazy, WTF, thats like being short changed, ripped off and robbed!

    I do see when I race in "M" it lets me go pretty deep into redline, i.e. when doing 60-130 runs and pushing 4th gear past 130mph I think the speedo reads around 135 but vbox around 132mph.

    but maybe diff on my car cause its p31
    Current:
    14 Viper TA
    Wsir - 1:28:9
    Buttonwillow C13 - 1:54:1

  5. #30
    Join Date
    Feb 2010
    Location
    OH
    Posts
    1,454
    Mentioned
    2 Post(s)
    Rep Power
    0


    Yes Reputation No
    Click here to enlarge Originally Posted by DD GT3 RD Click here to enlarge
    WOAH! Thats crazy, WTF, thats like being short changed, ripped off and robbed!

    I do see when I race in "M" it lets me go pretty deep into redline, i.e. when doing 60-130 runs and pushing 4th gear past 130mph I think the speedo reads around 135 but vbox around 132mph.

    but maybe diff on my car cause its p31
    Do you mean pre or post aftermarket tune?

    Yes it is like being shortchanged. It's BS actually. I want 7400 actual rpm!!!

  6. #31
    Join Date
    Aug 2010
    Location
    California
    Posts
    32
    Rep Points
    41.2
    Mentioned
    0 Post(s)
    Rep Power
    0



    Yes Reputation No
    Wow that's good to note. Thanks for the information. Wouldn't it be possible to make the redline 7,800rpm post-tune so that it actually shifts at 7,400rpm? I find it very un-Benz like to fit a transmission that is unable to handle the power of the engine supplied with the car. Has anybody run into trans problems with a tune? I know 335i steptronics that are modified can slow down shift times over time to preserve the gearbox.

    A lot of good info in this thread, thanks for sharing guys

  7. #32
    Join Date
    Feb 2010
    Posts
    2,185
    Rep Points
    2,132.4
    Mentioned
    25 Post(s)
    Rep Power
    22


    Yes Reputation No
    Click here to enlarge Originally Posted by MHP LLC Click here to enlarge
    Do you mean pre or post aftermarket tune?

    Yes it is like being shortchanged. It's BS actually. I want 7400 actual rpm!!!
    I mean pre tune, its currently stock.
    Current:
    14 Viper TA
    Wsir - 1:28:9
    Buttonwillow C13 - 1:54:1

  8. #33
    Join Date
    Jan 2010
    Posts
    638
    Rep Points
    567.0
    Mentioned
    7 Post(s)
    Rep Power
    6


    Yes Reputation No
    Click here to enlarge Originally Posted by Mahzari Click here to enlarge
    Wow that's good to note. Thanks for the information. Wouldn't it be possible to make the redline 7,800rpm post-tune so that it actually shifts at 7,400rpm? I find it very un-Benz like to fit a transmission that is unable to handle the power of the engine supplied with the car. Has anybody run into trans problems with a tune? I know 335i steptronics that are modified can slow down shift times over time to preserve the gearbox.

    A lot of good info in this thread, thanks for sharing guys
    This is also done to preserve the tranny specifically in first gear, as the engine revs up way too fast in first gear for the gauge to catch up. And I'm sure Mercedes didn't want a bunch of people messing up their trannies and complaining about it. In all other gears, the car does not rev up as fast and the problem is alleviated.
    Last edited by Exeenom; 04-20-2011 at 05:19 PM.
    2007 E63 P30
    Click here to enlarge

  9. #34
    Join Date
    Aug 2010
    Location
    California
    Posts
    32
    Rep Points
    41.2
    Mentioned
    0 Post(s)
    Rep Power
    0



    Yes Reputation No
    In sport mode where does it shift? I'd assume the computer knows what it's doing and won't over-rev the car by itself. And that makes sense about first gear, I've noticed that even the shift light comes on very early in first to make up for the driver's (lack of) reaction time.

  10. #35
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    120,249
    Rep Points
    32,700.6
    Mentioned
    2130 Post(s)
    Rep Power
    328


    Yes Reputation No
    Click here to enlarge Originally Posted by Mahzari Click here to enlarge
    In sport mode where does it shift? I'd assume the computer knows what it's doing and won't over-rev the car by itself. And that makes sense about first gear, I've noticed that even the shift light comes on very early in first to make up for the driver's (lack of) reaction time.
    DD GT3 RD stated it will only not upshift on its own in M mode. so in S I take it will upshift at redline as it should.
    Chrome Space Bar Issue: http://www.boostaddict.com/showthrea...338#post738338


    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  11. #36
    Join Date
    Jan 2010
    Posts
    638
    Rep Points
    567.0
    Mentioned
    7 Post(s)
    Rep Power
    6


    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    DD GT3 RD stated it will only not upshift on its own in M mode. so in S I take it will upshift at redline as it should.
    Yes in S mode and C mode, the car will up-shift on its own exactly at red line for all shifts except the 1st to 2nd shift. At WOT, that specific shift happens early.... sometimes way too early Click here to enlarge
    2007 E63 P30
    Click here to enlarge

  12. #37
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    120,249
    Rep Points
    32,700.6
    Mentioned
    2130 Post(s)
    Rep Power
    328


    Yes Reputation No
    Click here to enlarge Originally Posted by Exeenom Click here to enlarge
    Yes in S mode and C mode, the car will up-shift on its own exactly at red line for all shifts except the 1st to 2nd shift. At WOT, that specific shift happens early.... sometimes way too early Click here to enlarge
    Likely to prevent hitting the limiter or even more likely that the tach is off and not keeping up with the actual revs.
    Chrome Space Bar Issue: http://www.boostaddict.com/showthrea...338#post738338


    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  13. #38
    Join Date
    Aug 2010
    Location
    California
    Posts
    32
    Rep Points
    41.2
    Mentioned
    0 Post(s)
    Rep Power
    0



    Yes Reputation No
    I get it now, I thought the car shifted in every gear 400rpm early which would cheat us out of speed in gear. This sparks another question... Does the TCU fix this problem or is it still present on MHP modded cars?

  14. #39
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    120,249
    Rep Points
    32,700.6
    Mentioned
    2130 Post(s)
    Rep Power
    328


    Yes Reputation No
    Click here to enlarge Originally Posted by Mahzari Click here to enlarge
    I get it now, I thought the car shifted in every gear 400rpm early which would cheat us out of speed in gear. This sparks another question... Does the TCU fix this problem or is it still present on MHP modded cars?
    It depends if the problem is the tach not keeping up or being accurate or if it is truly shifting early.
    Chrome Space Bar Issue: http://www.boostaddict.com/showthrea...338#post738338


    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  15. #40
    Join Date
    Sep 2010
    Location
    CA and AZ
    Posts
    237
    Rep Points
    148.7
    Mentioned
    12 Post(s)
    Rep Power
    2


    Yes Reputation No
    Click here to enlarge Originally Posted by Mahzari Click here to enlarge
    I get it now, I thought the car shifted in every gear 400rpm early which would cheat us out of speed in gear. This sparks another question... Does the TCU fix this problem or is it still present on MHP modded cars?
    Andy has answered this question...
    Click here to enlarge Originally Posted by MHP LLC Click here to enlarge
    One of the downfalls of the M156/722.9 combo is that the tach is optimistic by 400rpm at redline. That means when a car with a stock tune shifts at an indicated 7000rpm it's actually 6600rpm, and after a tune when the limiter is raised to an indicated 7400rpm in Manual mode it's an actual 7000rpm. Ironically MB rates peak HP @ 6800rpm which would never be reached without an aftermarket tune. It's an unfortunate fact of life we all have to life with, and it was done so with trans preservation in mind.

    Thanks
    The MHP TCU tune does raise shift points however at redline the tach will always read 400rpm high.

  16. #41
    Join Date
    Sep 2010
    Posts
    612
    Rep Points
    420.1
    Mentioned
    1 Post(s)
    Rep Power
    5


    Yes Reputation No
    Click here to enlarge Originally Posted by Mike@MHP Click here to enlarge
    Andy has answered this question...


    The MHP TCU tune does raise shift points however at redline the tach will always read 400rpm high.
    So it's a tach calibration problem, then? If you slowly bring the car up to redline, it redlines at 7000 on the tach but the engine is only at 6600 rpm? How was this figured out, datalogging the ECU vs. tach signal at redline?

    Interesting stuff.

  17. #42
    Join Date
    Aug 2010
    Location
    California
    Posts
    32
    Rep Points
    41.2
    Mentioned
    0 Post(s)
    Rep Power
    0



    Yes Reputation No
    Is it 400rpm in every gear or only in 1st and 2nd as stated by Exeenom? And if the tach reads 400rpm high, why would you not counter this by setting the redline 400rpm above what you want? For a 7,200rpm shift, you would set it at 7,600rpm. I also don't see how these extra rpms would harm the transmission, maybe the engine (although this one is very mildly tuned from the factory) but why would it effect the trans? I understand that bouncing off the limiter is bad but why would the solution be having an optimistic tach? By no means is the C63 the world's fastest revving car either. Please correct me if I'm wrong, I'm just trying to understand.

    Itís effortless and stress-free, and it runs into its 7200-rpm redline with astounding ease.
    -Car and Driver


    Manual-mode shifts are slightly quicker, and you can happily bounce along on the 7300-rpm redline if you so choose.
    -Motor Trend


    For all the apparent athleticism, it is smooth, running up to the 7000-rpm redline without any strain.
    -Autoweek

  18. #43
    Join Date
    Sep 2010
    Location
    CA and AZ
    Posts
    237
    Rep Points
    148.7
    Mentioned
    12 Post(s)
    Rep Power
    2


    Yes Reputation No
    Click here to enlarge Originally Posted by c32AMG-DTM Click here to enlarge
    So it's a tach calibration problem, then? If you slowly bring the car up to redline, it redlines at 7000 on the tach but the engine is only at 6600 rpm? How was this figured out, datalogging the ECU vs. tach signal at redline?

    Interesting stuff.
    I believe MB would call it a calibration safety net put forth at redline! Put in place to preserve the 722.9 throughout the lifetime of the vehicle. Also the bean counters probably had their two cents included in the final decision. Make no mistake this tranny has shown great strength and durability through even the best n/a modifications.

    Click here to enlarge Originally Posted by Mahzari Click here to enlarge
    Is it 400rpm in every gear or only in 1st and 2nd as stated by Exeenom? And if the tach reads 400rpm high, why would you not counter this by setting the redline 400rpm above what you want? For a 7,200rpm shift, you would set it at 7,600rpm. I also don't see how these extra rpms would harm the transmission, maybe the engine (although this one is very mildly tuned from the factory) but why would it effect the trans? I understand that bouncing off the limiter is bad but why would the solution be having an optimistic tach? By no means is the C63 the world's fastest revving car either. Please correct me if I'm wrong, I'm just trying to understand.
    The 400rpm difference is at redline regardless of gear. I believe what Exeenom is stating is that for the 1/2 shift the tranny will shift prior to redline based on how quick the 6.2 in 1st gear, while the other gears will upshift at redline. I am assuming the 7400 rpm is high as you can go. Without correcting the tranny's safety measure the 7k rpm(7400 rpm shown) shift is as high as you can go.

  19. #44
    Join Date
    Feb 2010
    Location
    OH
    Posts
    1,454
    Mentioned
    2 Post(s)
    Rep Power
    0


    Yes Reputation No
    Click here to enlarge Originally Posted by c32AMG-DTM Click here to enlarge
    So it's a tach calibration problem, then? If you slowly bring the car up to redline, it redlines at 7000 on the tach but the engine is only at 6600 rpm? How was this figured out, datalogging the ECU vs. tach signal at redline?

    Interesting stuff.
    Brett,

    It's amazing a fact like this goes unnoticed by so many for so long but was evident to me the first time I strapped mine down to a dyno. Notice that all dyno runs are done in manual mode (which allows for a tach indicated 7400rpm rev limiter) but when you read the sheets you only see 7000rpm. I guess it goes in line with the 63 nomenclature lol.

    On the other hand I'm sure others have noticed it and just not said anything, it makes all M156s look bad.

    When I dyno'd my car stock in manual mode it only went to 6600rpm, imagine how pissed I was to see that LOL! This may have been something that was changed with later firmware versions--stock manual mode being able to rev higher than 7000rpm indicated--I'm really not sure.


    Click here to enlarge Originally Posted by Mahzari Click here to enlarge
    Is it 400rpm in every gear or only in 1st and 2nd as stated by Exeenom? And if the tach reads 400rpm high, why would you not counter this by setting the redline 400rpm above what you want? For a 7,200rpm shift, you would set it at 7,600rpm. I also don't see how these extra rpms would harm the transmission, maybe the engine (although this one is very mildly tuned from the factory) but why would it effect the trans? I understand that bouncing off the limiter is bad but why would the solution be having an optimistic tach? By no means is the C63 the world's fastest revving car either. Please correct me if I'm wrong, I'm just trying to understand.

    -Car and Driver


    -Motor Trend


    -Autoweek
    Truthfully speaking mainstream automotive journalists don't do the kind of testing necessary for them to assess the actual redline of an engine. Max speed is 7000rpm in all gears, actual rpm after tuning in Manual mode which is also a tach indicated 7400rpm.

    You can also bounce of the rev limiter all day long if you wish (not that I'd recommend it Click here to enlarge) it's not going to hurt anything.

    There are limitations in the ECU which simply cannot be overcome and raising the shift point/rev limiter beyond what we do is one of them unless you run standalone engine management. There just isn't any more room left in the ECU to raise the limit further.

    MB/AMGs reasoning for this likely has to do with what Mike stated about transmission durability/longevity. RPM is the number 1 killer of transmissions and drivelines, 2nd is heat. So basically marketing, no one wants to admit their cutting edge 4v V8 only sees 6600rpm at redline stock. Click here to enlarge

    Thanks

  20. #45
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    120,249
    Rep Points
    32,700.6
    Mentioned
    2130 Post(s)
    Rep Power
    328


    Yes Reputation No
    Click here to enlarge Originally Posted by MHP LLC Click here to enlarge
    RPM is the number 1 killer of transmissions and drivelines, 2nd is heat.
    Very true, and these two are why high revving motors are tough for dual clutch transmissions in particular.
    Chrome Space Bar Issue: http://www.boostaddict.com/showthrea...338#post738338


    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  21. #46
    Join Date
    Feb 2010
    Location
    OH
    Posts
    1,454
    Mentioned
    2 Post(s)
    Rep Power
    0


    Yes Reputation No
    Click here to enlarge Originally Posted by Sticky Click here to enlarge
    Very true, and these two are why high revving motors are tough for dual clutch transmissions in particular.
    I have no doubt the S65 and S85 would have passed OEM durability testing reving to 9000-8800rpm respectively. Ultimately the trans is the limiting factor in most modern applications. Hopefully you have the brickshithouse of DCTs otw. Click here to enlarge

  22. #47
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    120,249
    Rep Points
    32,700.6
    Mentioned
    2130 Post(s)
    Rep Power
    328


    Yes Reputation No
    Click here to enlarge Originally Posted by MHP LLC Click here to enlarge
    Hopefully you have the brickshithouse of DCTs otw.
    Well, I intend to find out Click here to enlarge
    Chrome Space Bar Issue: http://www.boostaddict.com/showthrea...338#post738338


    Stage 2 or 2.5 E9X M3 S65 V8 supercharger kit for sale
    : http://www.boostaddict.com/showthrea...r-kit-for-sale

  23. #48
    Join Date
    Sep 2010
    Posts
    612
    Rep Points
    420.1
    Mentioned
    1 Post(s)
    Rep Power
    5


    Yes Reputation No
    Click here to enlarge Originally Posted by MHP LLC Click here to enlarge
    Brett,

    It's amazing a fact like this goes unnoticed by so many for so long but was evident to me the first time I strapped mine down to a dyno. Notice that all dyno runs are done in manual mode (which allows for a tach indicated 7400rpm rev limiter) but when you read the sheets you only see 7000rpm. I guess it goes in line with the 63 nomenclature lol.

    On the other hand I'm sure others have noticed it and just not said anything, it makes all M156s look bad.

    When I dyno'd my car stock in manual mode it only went to 6600rpm, imagine how pissed I was to see that LOL! This may have been something that was changed with later firmware versions--stock manual mode being able to rev higher than 7000rpm indicated--I'm really not sure.
    Thanks Andy - good info. Would be curious to see what '09s, '10s, and '11s were able to dyno stock... if they could get over 6600 rpm.

    Dodger, Dads, Propain, PetroC63, DD GT3 RD, et. al... did you guys get stock baselines, and if so, where'd you redline at?

  24. #49
    Join Date
    Feb 2010
    Location
    OH
    Posts
    1,454
    Mentioned
    2 Post(s)
    Rep Power
    0


    Yes Reputation No
    Click here to enlarge Originally Posted by c32AMG-DTM Click here to enlarge
    Thanks Andy - good info. Would be curious to see what '09s, '10s, and '11s were able to dyno stock... if they could get over 6600 rpm.

    Dodger, Dads, Propain, PetroC63, DD GT3 RD, et. al... did you guys get stock baselines, and if so, where'd you redline at?
    Brett, you're right that would be interesting info. FWIW mine was a 2009 P30 and I picked up in August '08.

    Thanks!

  25. #50
    Join Date
    Aug 2010
    Location
    California
    Posts
    32
    Rep Points
    41.2
    Mentioned
    0 Post(s)
    Rep Power
    0



    Yes Reputation No
    Okay thank you for clearing that up, this is all good information to know. It seems like the MHP tune is really a complete package. And 7,000rpm for a big 6.2L V8 sounds like plenty, especially with 7 gears

Page 2 of 2 FirstFirst 12

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •