Boosting to 20 psi WOT NO MODS

[lilrob2069]

Here's the problem, if you check my mods list all i have done is removed the Boost Solenoid. Added a K&N, and 2.5 in downpipe to 3 in. after all the way back. I haven't really done any hard pulls. But the other night i decided what the Hell, Why not. So I'm getting on the Highway in 3rd gear and running about 3500 rpms, Gas it and push it to almost full throttle and watch my boost gauge shoot up to 15. Gave it a little more gas and it went to 20 psi. Thought maybe it was a fluke so I tried again. Sure enough it boosted to 20 again. So later the other night i decided to do a regular 3000 rpm pull and brought the boost level up to 15 in 2nd gear, 20-21 in 3rd gear, and 15 in 4th gear. What doesn't make sense is I thought that these cars were suppose to fuel cut at higher than 15 I maybe mistaken. Please anyone help me figure this out. I've checked vacuum lines though I'm not for sure what i am looking for.

 

[LandoAWD]

Yeah, that's odd...broken for me as well.

 

[DroopYeyeS]

It sounds more like creep than anything, but delta448 is on the same path I am. Double check full range of motion on the flapper arm, and also check the WG actuator with a vacuum pump to make sure it doesn't have a tear in the diaphram. If it's not holding the flapper full open, this could be causing your issue. Good luck on this sir.

 

[kchaazz]

Well, its creep if the boost is increasing more gradually with rpms, but if its instantly hitting 20 psi when you floor it, Id look into hooking an air source to the WGA. USE AN AIR PRESSURE REGULATOR and gauge and set air pressure to around 20 psi. Have a vacuum line hooked to the WGA. Jam the tip of an air gun into the opposite end of the vacuum line and fire air into it. If the arm on the WGA doesnt move, then the WGA isnt opening under boost conditions and is holding the wastegate shut thereby causing your overboost condition. Just something to check...

 

[lilrob2069]

Well, its creep if the boost is increasing more gradually with rpms, but if its instantly hitting 20 psi when you floor it, Id look into hooking an air source to the WGA. USE AN AIR PRESSURE REGULATOR and gauge and set air pressure to around 20 psi. Have a vacuum line hooked to the WGA. Jam the tip of an air gun into the opposite end of the vacuum line and fire air into it. If the arm on the WGA doesnt move, then the WGA isnt opening under boost conditions and is holding the wastegate shut thereby causing your overboost condition. Just something to check...

yea it's more like a gradual rise, not like it shoots directly to 20. i'm gonna do some more tests this weekend.


and according to what i read i think understand now that the MBC has to be hooked between the line that runs from the actuator to the j-pipe nipple Correct.

 

[DroopYeyeS]

Yes, that is correct. With an MBC set to the lowest possible setting or just the line it's self, you should not really be seeing more than 10psi, as this is what the stock WGA spring is set for.

 

[9!'clipseDOHC]

and according to what i read i think understand now that the MBC has to be hooked between the line that runs from the actuator to the j-pipe nipple Correct.

http://www.dsmtuners.com/forums/articles-turbo-system-intercooler/237982-best-way-install-mbc.html

Ok, that's what i thought, could it be possible that the thermal valve is broke causing coolant to come through it?

This is the thermo vacuum valve on the right. It could be leaking coolant from the threads but I don't think (at least under normal circumstances) that it could be leaking from the vacuum lines. There should only be air in those lines. If you do block off you EGR system you can also replace the thermo vacuum valve with a 3/8" pipe thread plug just to clean it up a little.

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[crazyracerz42]

does anybudy know how to set a manual boost control from ebay? can i use that to set my boost or do i need a gauge to?

 

[zero_wheeler]

you can hook it up, but youre gonna have NO IDEA what levels of boost youre running. Deffinily get a guage. Theyve got some at Harbor Freight for $20. No idea how reliable they are, but theyre deffinitly cheap.

and to the OP, When i got my car, the stock controller was gone, ran a line from the compressor to the wastegate, and it boosted about 10psi run a line. and for what its worth, i hit fuel cut at 16 :/

 

[9!'clipseDOHC]

does anybudy know how to set a manual boost control from ebay? can i use that to set my boost or do i need a gauge to?

Here is how you install it: http://www.dsmtuners.com/forums/newbie-forum/281518-how-install-turbosmart-tee-style-bleeder-style-mbc.html and yes you will need a boost gauge.

Please don't post the same questions in multiple threads and next time please do a search or create your own thread.

http://www.dsmtuners.com/forums/newbie-forum/391485-1990-tsi-turbo-awd-help.html#post152459036

anybudy know how to set a manual boost control from ebay for a eagle talon?