Help Why powershifting bog between shift ?????

[hybrixt]

Hey guys need help figure out why my car is bogging when I'm powershifting, it is not tuning issue car makes 456whp 11.4afr all accross the board...

If I baby it between gears there is no problem...

Is there any map that I need to adjust to prevent this issue...it feels like the engine shuts off between gear when I powershift...

thanks

[Nuke]

try different driving/shifting techniques?

[Freon]

What do you mean powershift? Like flat foot it? Or just get into the throttle way before you start letting the clutch back out?

456whp.. sound like a big turbo. Maybe it is just lag.

[hybrixt]

By power shifting i mean "Flat Foot" shifting, there is no lag on the car.
I've been reading and researching a lot on this subject, and i've seen some people had implemented a "Flatfoot" (FF) & "LaunchControl" (LC) option to the Enginuity software, however it hasn't been released yet or it won't be. The problem is everytime i try to powershift (engaging clutch between shifts without letting the gas off) the car DIES completely until the rpms drop a lot and then it resumes.
Any help in this matter will be really appreciated!
Thanks

-CentralFloridaTurbo.

[Freon]

Well, if you hold down the throttle while you shift, you will hit the rev limiter. The rev limiter turns off the fuel injectors completely.

When I tried programming my own LC I found that it isn't too quick about turning them back on either, which is a problem for trying to add LC/FFS. By the time the ECU catches up and turns them back on, you've bogged badly. That's why I put that aside for a while, but it will be revisited eventually.

Best solution would be to raise your rev limiter a bit or let off the throttle when shifting. You could also try altering your DBW throttle map so that the throttle closes itself almost all the way before your rev limiter can kick in. The stock mapping does this to a degree.

There is also a setting for how far the manifold pressure (boost) must fall before the injectors are allowed to turn back on. I think stock it is about 1.6 bar, or ~10psi. The map is in Enguinity defs at least. You can try raising it.

I have, however, flat footed the 1-2 shift and not had problems. Makes for great 300' times, but probably not great on the engine and tranny. I have not experienced the issue you describe while flat footing 1-2, but I've only done it a few times so maybe I just got lucky with the timing of the rev limit code.

[landikar]

hybrixt, what is your fuel system and fuel pressure regulator? See your fuel pressure.

[Dirty25rs]

i've noticed the same thing in my subaru. I am running a stock ECU i dont know if you are. The "hitting the rev limit" theory is a possibility in your case but not in mine.

In my case, i believe the source of the problem is the knock sensor. I have datalogged and seen that when i do a 1-2 flat shift, my knock sensor screams bloody murder. The knock sensor is picking up the vibrations from the shift. I have noticed it a lot more since I put coilovers on (they are more rigid so they absorb less vibrational energy). I've logged knock from the diff slapping the body of the car as well.

Solution: change your knock sensor listening range to something dumb like 7000-8000 where you shouldn't see knock anyways
Major concern: you are basically turning off the knock sensor, without a knock sensor the car won't protect itself from detonation and pre-ignition, so you better have rock solid tuning. Most real race-cars dont run a knock sensor because they have rock solid tuning and know they wont need one.

[hostile]

On a stock map the throttle duty goes down to 25% once you reach 7000. If your taking it all the way to 7000 then shifting, your throttle body is closing without you knowing it.