RallyMachine Posted August 20, 2013 Share Posted August 20, 2013 I recently changed from a Borla header and Perrin Big Tube UP to a Maddad header/UP combo. The Perrin UP has a ID of 1.875" and the Maddad has a 1.77" velocity stack which I think might be contributing to the problem. I also replaced the turbo inlet with a Perrin. Turbo is a VF52. The car runs good and starts to spool quick, but it takes FOREVER to reach peak boost (~4600rpm) and is generally coming about 1psi short. Is this just a tuning issue? I have virtually 0 knock, but I noticed that my WGDCs start small and increase during the spool. If I understand correctly, shouldn't those values be large tapering to small? (IE large values close the wastegate to feed the turbo faster and then go small to vent excess gas.) This is with the stock boost solenoid. Here are 2 logs I did. First is a 3rd gear pull starting low RPM and the second is in 5th cruising with a slight pull/spool.pull.csv5th Gear Low RPM Light Pull.csv Link to comment Share on other sites More sharing options...
iNVAR Posted August 20, 2013 Share Posted August 20, 2013 First, don't pull 3rd gear or above at WOT 1600 RPM. That's just being mean to your car... What does your LearningView look like? AND did you EVER log prior to replacing the parts? What did those logs look like? Link to comment Share on other sites More sharing options...
RallyMachine Posted August 20, 2013 Author Share Posted August 20, 2013 First, don't pull 3rd gear or above at WOT 1600 RPM. That's just being mean to your car... What does your LearningView look like? AND did you EVER log prior to replacing the parts? What did those logs look like? Ok good to know...thought this was just the rule for 4th and 5th. I attached the LV and a pull from before. The old log cuts out before 5k and theres no TD but you get the idea. Looks to be the same WGDC theory.old pull.csv Link to comment Share on other sites More sharing options...
iNVAR Posted August 20, 2013 Share Posted August 20, 2013 Who tuned your car? The tuner should be able to tell you some more honestly. TDI being maxed out indicates your WGDC is too low, yes. But the cause of that could be a few things. Intake leak (which is why I asked for an LV. Your AF trims don't appear very far off , well within limits.) Improperly tuned (ask your tuner) Tuned correctly but always were low like this and you didn't realize. They might've sacrificed 3rd gear to prevent spiking and what not in 4th and 5th. Your WG actuator is too weak and opening up You have a pre-turbo exhaust leak causing the turbo to make less boost Link to comment Share on other sites More sharing options...
RallyMachine Posted August 20, 2013 Author Share Posted August 20, 2013 The car was tuned by IPS motorsports in Columbus. I figured I would need a retune after putting on parts so I have an e-tune base map already that I haven't flashed. I was thinking the same thing about controlling boost spike. I'm guessing since the UP is more restrictive its throwing the WGDC off since it was tuned to open early and the gas isn't flowing the way it used to. Anyway, could the idle fuel trim be off because of the new inlet? I sprayed some of the major vac connections with carb cleaner and didn't hear a change in idle. I also notice it goes down to +6 when the car is warming up and then returns to 8 after the tgvs open up. Link to comment Share on other sites More sharing options...
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