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Lazy Revs

Messages
27
Likes
31
Location
Atlanta, GA, USA
#1
Has anyone managed to fix the excessive rev hang and the "lazy" feeling our engine has when revving?
I have a lightweight flywheel, an unsprung lightweight clutch, and a lightweight pressure plate. Even with all that that weight removed, the engine seems to rev just as slow as it did with the heavy dual-mass flywheel. The engine still "continues" revving for a moment while shifting, I decided to log this, and while using FFS, the engine is still increasing its revs for a while after the clutch has been pressed 100% in. When shifting at lower rpms, if you don't wait a while for the rpms to drop and just let the stage 5 clutch grab, it's so violent it feels like the engine is trying to throw itself out of the engine bay.

At this point, I'm confident that it must be something tune related, I don't think the rotating assembly in the engine is that heavy to cause this. My other cars don't have anywhere near this much rev hang; however, they have standalone ECU's. I purchased ATR, and I'm in the process of completing the program, but I wanted to ask here first if anyone has figured it out.

Any help is appreciated.
 


Messages
303
Likes
269
Location
Springfield
#3
I watched that video when it first released, and if I remember correctly, it has to do with how the ecu is tuned for the purpose of reducing emissions or something...
 


PhoenixM3

Senior Member
Messages
806
Likes
510
Location
Colorado Springs
#4
I explained this issue to my tuner on a previous tune. I stated that the car feels lazy before boost engagement. I know he adjusted fuel pressure and perhaps other parameters, but the car revs more eagerly now. In short, I agree with OP that this is at least partially tune related.
 


Rocketst

1000 Post Club
Messages
1,272
Likes
842
Location
Chesapeake, VA, USA
#5
Your tuner can disable rev hang as well as up ignition timing. Ignition timing will also allow the car to rev faster because your advancing more timing and fuel and boost.

Sent from my moto z4 using Tapatalk
 


SteveS

1000 Post Club
Messages
1,291
Likes
1,567
Location
Osage Beach, MO, USA
#6
I watched that video when it first released, and if I remember correctly, it has to do with how the ecu is tuned for the purpose of reducing emissions or something...
This is exactly why cars do this. If you close the throttle all the way between shifts, the car pollutes more. When we had carburetors they called the device a dashpot. Now with electronic fuel injection it's just how they tune it. You can thank the EPA regs for that.
 




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