Hey guys, Ive noticed once in a while that in 4th gear under boost the tranny will slip as if it is shifting gear (but im in manual mode) and then lock up. Is anyone else seeing anything like this? Should I be concerned? Could it be software?

 

How many km's on your car? How many launches?

Could be software also but need more info.

 

do you mean you see the symptom of standard manual clutch slippage where RPMs climb without matching change in speed, when not shifting? then sounds to me yes, the clutches are slipping.

though, looking at your mod list and claimed hp/tq, i can't see how that would be possible. there's another thread talking about how much hp/tq others have with mr's.... and there's people with much greater numbers with no problem.

 

St1q, correct, engine rpms increase does not reflect the mph increase. you can feel and hear the rpms rise and then the clutch locks up rpms drop back down and no shifting is involved.

weelbes,
0 launches and less than 3k miles....

 

doesn't occur all the time just some times and have only noticed it in 4th. But I really don't have that much seat time in the car either. Do you think the tires could be breaking free? I don't think so, not at 50mph.

 

try flooring it in 5/6th.

sorry man, doesn't sound good. i'd take it in and have it looked at. my mr never did anything like that.

 

I have found it to be odd, this car has been a pain in my @ss. Dont get me wrong, I love what the car can do but these little issues keep piling up.

 

I'd guess software before clutch then. 3k miles no launches.....

 

Are you in normal mode when it does it? Try it out in sport mode and see if you can get it to do it. Normal mode has slower clamping speeds. Also are you doing any shifts around that time at all? Or is it cruising in that gear then stabbing the gas?

 

migs, in sport manual mode, no shifting, and stabbing the gas.

 

That definitely doesn't sound right. I'd return it to stock and see if it still does it. If it does, take it in immediately.

 

its normal ..

The ECU computes the engine speed to match the gearbox when you stab on it .. and typically you will see about 1-200rpms increase before the engine fully engages ..

Current generation ecu no longer use wired throttle to determine how much to open the throttle .. everything is computed ..

Rough way to look at the cycle is

APP -> torque request -> torque produced -> acceptance by gearbox -> power comes in .. during the acceptance ..the rpm actually goes up or down slightly to match the requested torque..

its like rev matching and then engaging in a way

 

well today I drove the hell out of it trying different things and have come to a conclusion, what I experienced is wheel spin. It only happens on one road that has a light dusting of dirt on it most of the time. I tried SSport and Sport modes on other surfaces and it seems to be hooking up without any fast increase followed by decrease of rpms, just a straight increase with a good pull. Thanks for the help and I hope its right!

 

thanks for the explanation! This happens to me all the time, on downshifts from 6th to 4th, nice to know its "normal" even though it does feel like serious slippage!

 

gunzo knows these evo's