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biketsai
09-29-2009, 06:40 PM
Just picked up a Profec and got it hooked up today and went out to try different settings. As some of you know my car has been hitting full boost pretty late (5000rpm) and I got an EBC to see if that might make it go away. I set the Profec at 17lbs, gain at 10%, and I tried the Set GAIN at 0 and 150. Between the different SET GAINS, there was no difference in how the boost came on. The car still spooled up slow till it gradually hit full boost (17-18lbs @ 5200) but it did successfully hold the boost till redline.

Any ideas?
Wastegate?

TIA

samx
09-29-2009, 07:01 PM
Not saying that this is your problem, but take a look at my post about half way down:

http://forums.audiworld.com/showthread.php?t=337113

Jeff
09-29-2009, 07:04 PM
Just picked up a Profec and got it hooked up today and went out to try different settings. As some of you know my car has been hitting full boost pretty late (5000rpm) and I got an EBC to see if that might make it go away. I set the Profec at 17lbs, gain at 10%, and I tried the Set GAIN at 0 and 150. Between the different SET GAINS, there was no difference in how the boost came on. The car still spooled up slow till it gradually hit full boost (17-18lbs @ 5200) but it did successfully hold the boost till redline.

Any ideas?
Wastegate?

TIA

Which Profec unit are you running? Does it have self-learn adaptations? If so, turn it off. (HKS uses Fuzzy-Logic...which makes things run "fuzzy" from past experience...GReddy uses their own self-learn feature as well, APEXi's AVR-R is no different) I would try to bypass the EBC solenoid, and try either putting a MBC in there, or simply leave the WG disconnected, but BE CAREFUL upon doing so, for your boost will overshoot...simply try to stay at part throttle, and monitor to see if boost response changes.

One last thing, how is the solenoid hooked up, and what wastegate are you running? If you are running an external (such as TiAL), leave the top nipple open and disconnected, using only the bottom one going to NC (or NO depending on what the Profec specifies), and connect COM to your boost/vacuum source.

biketsai
09-29-2009, 07:06 PM
Which Profec unit are you running? Does it have self-learn adaptations? If so, turn it off. (HKS uses Fuzzy-Logic...which makes things run "fuzzy" from past experience...GReddy uses their own self-learn feature as well, APEXi's AVR-R is no different) I would try to bypass the EBC solenoid, and try either putting a MBC in there, or simply leave the WG disconnected, but BE CAREFUL upon doing so, for your boost will overshoot...simply try to stay at part throttle, and monitor to see if boost response changes.

One last thing, how is the solenoid hooked up, and what wastegate are you running? If you are running an external (such as TiAL), leave the top nipple open and disconnected, using only the bottom one going to NC (or NO depending on what the Profec specifies), and connect COM to your boost/vacuum source.

I do not believe this Profec has a self-learn adaptation process. I used to run a MBC, which was worse (boost spike, then would die off,same late boost).
I am running an internal wastegate on my T28 with the Com and No ports connected.

biketsai
09-29-2009, 07:10 PM
Not saying that this is your problem, but take a look at my post about half way down:

http://forums.audiworld.com/showthread.php?t=337113


From the pic (where the line is pointing), doesnt that piece normally move?

http://www.mnaudi.com/gallery2/d/44260-1/193b.jpg?

How can I check for that gap with the turbo off?

samx
09-29-2009, 07:27 PM
What you're seeing is a sleeve that is press fit into the cast housing. The wastegate flapper arm fits inside the sleeve.

I would open and close the wastegate by hand and see if it seats properly.

biketsai
09-29-2009, 07:31 PM
What you're seeing is a sleeve that is press fit into the cast housing. The wastegate flapper arm fits inside the sleeve.

I would open and close the wastegate by hand and see if it seats properly.

I do recall a couple months ago when I pulled my turbo that the flapper (turbo out of car)had some play in it and would move without much/any effort. It didnt seem to completely shut, I suppose that is not right and would cause late boost? Could you possibly PM me with what exactly I need done?

Chris

AudiRacerS4
09-29-2009, 07:34 PM
I do recall a couple months ago when I pulled my turbo that the flapper (turbo out of car)had some play in it and would move without much/any effort. It didnt seem to completely shut, I suppose that is not right and would cause late boost?

yes if the wastegate is loose it will cause late boost since it will always stay cracked open and not allow all the gases to spin the wheel causing a laggy feeling turbo

samx
09-29-2009, 07:36 PM
Sounds pretty similar to what my turbo was doing before I found the problem. Very late boost onset, about 5000 RPM. Once boost did come on, however, it did build to normal levels.

Otherwise, more recently, my car had trouble building boost. The problem in that case was a bad piston ring. A compression test would help to rule that out.

biketsai
09-29-2009, 07:41 PM
Tomorrow Im going to remove my testpipe and remove the vac hose to the actuator and double check that it is the flapper loose.

biketsai
09-29-2009, 07:52 PM
Sounds pretty similar to what my turbo was doing before I found the problem. Very late boost onset, about 5000 RPM. Once boost did come on, however, it did build to normal levels.



Crazy that you have the exact issue, I guess the T28 just has that issue? Where were you a year ago?!?! haha

Jeff
09-30-2009, 12:39 PM
Crazy that you have the exact issue, I guess the T28 just has that issue? Where were you a year ago?!?! haha

I've seen this issue on the old PES T28 kits as well. Glad you found the problem.

biketsai
09-30-2009, 02:27 PM
Found the culprit earlier today. The flapper inside the exhaust housing is loose and has some play. What would fix this is a new actuator adjusted so that there is no more play, the only issue is finding the right bracket/actuator combination since the PES T28 uses their own custom bracket.

mike-2ptzero
09-30-2009, 04:08 PM
Found the culprit earlier today. The flapper inside the exhaust housing is loose and has some play. What would fix this is a new actuator adjusted so that there is no more play, the only issue is finding the right bracket/actuator combination since the PES T28 uses their own custom bracket.

[:D]

biketsai
09-30-2009, 07:27 PM
Would something like this work? ATP
http://www.atpturbo.com/mm5/graphics/00000001/Catalog%20Images/Wastegate/InternalWgtBracket-225225.jpg

Link to more:
http://www.atpturbo.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=tp&Category_Code=WGT

Oceanside
09-30-2009, 08:30 PM
i have a couple adjustable wastegates and brackets ive aquired ill pm you with pics

biketsai
09-30-2009, 08:40 PM
K cool!