06 STi (K&N drop in, Catless Mid-pipe & axle back) (my MAF is dry and clean) Car pulls awsome from 2K to 7K RPM. I havent gotten on the car for a couple of days. Today I ran 2nd and 3rd to 7K RPM and felt little hesitation between 6,500-7,000 RPM. It was slight, but enough to notice. Never felt this before... Whats going on? I've had the mods for 2,000 miles and never felt any hesitation. Could it be bad gas? Thanks for your help guys...you are always a big help here in this forum.:bowdown:
Ok, went out again and did a few runs. This time 1 out of 5 pulls I felt this slight hesitation. I'm thinking it depends how much is the turbo charged prior to WOT. If is charged up enough, it wont hesitate at all. If ridding around and not spooling, then all the sudden WOT, there is a bit oh hesitation. I guess this is it. Anyone else notice this????
Sure, clutch is fine. Car has 2,000 miles and always driven good. Is just a little nick poopie hesitation every so often. It will be solved with tunning. Maybe is nothing and that I'm just a paranoid F***. Meredith, my wheels will be here on Jan-10th. I will call your Hubby so you can take the wheels... Thanks !:wavey:
Bad gas is definately a possiblility, but I'm leaning towards fuel cut due to the lack of the catalytic converter... You might be getting slight compressor stall
Stole this from NASIOC "With the countless threads about boost creep problems with turbobacks on the 2.5l STI, I think this thread should be helpful as a quick summary to those planning on moddifying their STI. Q) What is boost creep? A) Boost creep occurs when the wastegate is physically unable to bypass enough exhaust around the turbine on the turbo. Q) Is boost creep harmful? A) Yes, boost creep is one of the worst problems you can have with a turbo engine. Boost creep means that there is NO way for the boost pressure to be controlled. Boost pressures in excess of 20psi!!! have been recorded on STIs with TBE before the ECU cuts fuel. Q) What causes boost creep? A) Installing a turbo back exhaust whether aftermarket catted or not will in almost all cases cause boost creep to a certain extent. Q) Are there any other options to prevent boost creep besides porting the wastegate? A) Yes, Installation of an exhaust that either keeps the stock OEM muffler or one of the stock cats should not cause boost creep. Q) How do I know if I have boost creep? A) If you have a full TBE, then you probably have it. A boost gauge will tell you what pressure you are at as well. Fuel cut occurs when the ECU senses boost in excess of 17.5psi for 2-3s. Fuel cut in my experience is a very violent "stutter" from the engine that resembles extreme knock, followed by CEL. Q) What is the overboost CEL? A) (P0244) Wastegate malfunction Q) Is there anything else I can do besides porting the wastegate to prevent the creeping....MBC, EBC, engine management etc? A) This problem is isolated to the wastegate only. The wastegate is a mechanical system. There are no current workarounds or "fixes" besides this. The 2.5l just flows too much exhaust through the turbo once a turbo back has been added for the wastegate to control boost. If you think of it as a hierarchy, then it should make sense. level 1) wastegate controls boost pressure level 2) boost solenoid controls wastegate level 3) MBC/EBC/ECU controls boost solenoid Using this logic, if the problem resides on the 1st level, no matter what you do on top of it, you will still have the problem. Whatever (MBC, EBC, UTEC, ECUTEK) is controlling the wastegate CANNOT prevent boost creep if the WASTEGATE is UNABLE TO FLOW ENOUGH EXHAUST to prevent boost creep. A fuel cut defender will not eliminate the boost creep problem, but it will stop the fuel cut. Your boost will still creep up to 20psi, but the ECU won't be able to tell due to the altered signal from the FCD. Q) My car seems to boost creep when it is cold out. Why is that? A) Ambient temperature plays a huge role in how well your engine runs. In general, the cooler ambient temperature, the better your engine runs due to the laws of thermodynamics. The colder air causes your engine to make more HP (more work under the curve with lower temps), therefore more energetic exhaust gases, therefore your car is more prone to boost creep when it is cold out. If you live in an area that does not see colder temperatures (AZ for example) too often, then boost creep may never become a problem. Q) I want to port my wastegate. What do I do? A) Can you remove and install a turbo? If yes, there are a couple of options. You can send it to Deadbolt (www.deadboltspeed.com) for porting, have a local machine shop port it, or do it yourself with a "Dremmel like" tool."
UPDATE ! I guess it was bad gas, cause I ran hard yesterday all day and didnt hesitate at all. I guess my STi is not a morning car :hsnono: He will only boost correctly after 10AM before that, she is asleep. Thank you guys for the feedback and support on this site...
I think it has something to do with the load the ECU is seeing. My car used to do that. If I was already in a little boost and then hammer the throttle or if I went 3/4 throttle then WOT it would be fine. But if I was in vaccuum and then all of a sudden got WOT it would hesitate slightly. Since my last tune it doesn't do that at all. Also my car only did that in 4th gear.