Bog at 4k RPM during WOT... but only in 4th gear

[Static_Awesome]

It's weird issue, I think it's just lack of pressure from the turbo, but I'd like to know if anyone else has had this, or has some insight. Seems to only happen in 4th, while on the Map #3 for the TSP Stage 1 tune. Mod list:

Ktuner 1.2, TSP Stage 1
AWE Track Edition Exhaust (stock downpipe)
27WON Intake
PRL Intercooler and Charge Pipes

I've watched the TunerView Lite, no KControl, the car runs right near STFT and LTFT 0 unless it's cold out, and when it's cold out it is always adding fuel. Temps during most recent testing were under 100F for IAT and IAT2.

Is my car just running out of steam? It only bogs for .25-.5 seconds, then powers through. It's not clutch slip I don't think, because the car's RPMS don't shoot up, they just stutter/bog/sit for a second right around 4K, and only in 4th. Need to test more to see if it's happening in 3rd but the closer ratio powers through it faster or something.

If ya'll have any insight I'd really appreciate it. Thanks!

Edit: I tested #2 and #3 maps, it happens there, but not in the stockalike/#1 map. DIFP and DIFP target looked close together, so don't *think* it's fuel. May run injector cleaner, clean MAF, and check air filter just in case it's starved for air or fuel, despite running a 11.5-12.0 AFR

Sponsored

 

[Hajidub]

I tested my stock Si for you issue, your problem requires a downshift or slower depression of the gas pedal. It’s between the power band at 4K, turbo isn’t ready.

 

[Static_Awesome]

Appreciate your reply. It accelerates fine between 3500 and 4000, but then it bogs for a split second, hesitates, then goes back into acceleration. Boost lag or depleting available boosted pressure does make a little sense, but watching it doesn't look like boost drops appreciably. I'll do some logging to check your theory though!

 

[Hajidub]

4th gear at 40 mpg produced 3.5 secs of lag before it started really moving.

 

[fenix-silver]

Appreciate your reply. It accelerates fine between 3500 and 4000, but then it bogs for a split second, hesitates, then goes back into acceleration. Boost lag or depleting available boosted pressure does make a little sense, but watching it doesn't look like boost drops appreciably. I'll do some logging to check your theory though!

Logs would be helpful. It's not boost lag if you are already hitting target boost by the point you hit 4K rpm.

 

[Static_Awesome]

I guess it would help if I'm more descriptive. If I WOT/pedal to the floor in 4th gear at 3000k or later, it'll accelerate great, then at 4k it'll pause, then resume climbing at a good rate again. AFR looked good, I monitored that for sure. I'll get some logs next time I have a chance and check DIFP and DIFP target and MAP and TC boost levels as well.

 

[fenix-silver]

Have you changed anything recently? Try reflashing to stock or the ktuner base map and see if the same issue persists?

 

[Static_Awesome]

Have you changed anything recently? Try reflashing to stock or the ktuner base map and see if the same issue persists?

Nope, nothing new recently. I have noticed it's less prominent in Map 2 and not noticeable at all in Map 1. I don't think it's clutch slip because the rpms don't rise and then catch back down. If anything it just feels like a slight loss of power. I may clean the intake filter and clean the MAF while I'm at it, it has been a bit, it might just be air starved?

 

[Static_Awesome]

Update! I'm an idiot, it's fucking clutch slip, albeit very minor. My own fault, I have dogged the OEM clutch pretty bad with no-lift shifting and clutch drops when drag racing. I'll look into getting an FX350 or ACT, depending on research and forum reading. On the plus side, nothing else is wrong, then!

 

[fenix-silver]

lol, welcome to the club

 

[Static_Awesome]

lol, welcome to the club

Thanks, feelsbadman lol

Sponsored