OK i will do this and report back tomorrow. Thanks for the help.

 

try disconnecting the boost contoroller from the bov and running it to the turbo if it does not have a nipple on the end of it use a zip tie and wip tie it to the vacum pipe befor cutting the end of the zip tie off use a needle nose pliars and grab the adjustment part of the zip tie and twist it to ensure its tight and then test drive.

 

No dice Sparky, I woke up early to try this this morning. I loosened the wastagate arm so that it could freely slide on and off of the flapper on the turbo and then ran a direct boost/pressure source to the mbc and my results were the same. Boost would go to 19-20psi until about 4500-5000rpm and then it would rocket to 25psi of boost and hold. I dont know what else to do besides take off the hotside and port out the hole for the wastegate gas. Do you think this is my solution?

 

bump

 

Try slapping on the stock cat (if you're running a TP or HFC) and see if it still boost creeps. That should answer whether or not what you're experiencing is plain old boost creep vs something wrong w/ your wastegate ( I'd also check to make sure that the flapper is free to move and not catching on something.)

 

Maybe try this. Put the stock compressor discharge pipe on )I'm assuming you have the Buschur with no nipple). Then you can run you MBC off that and see if it helps.

 

Have you talked to Robert at Forced Performance about your boost creep problem with 20G-LT? Maybe he can suggest something. I just hadn´t read of anyone else experiencing creep with the 20G-LT.

I think that the LT comes with the single flapper HS. I know that my EvoGreen has the single flapper, so yours should as well. Porting the 10.5 single flapper is pretty straight forward. Are you gonna do it yourself?

What strikes me as strange in your particular case though, is that you can´t get base wastegate pressure down below 16-18 PSI. You should be able to get it down to 11-12 PSI. Call Robert and ask him what the normal, base wastegate pressure should be on the 20G-LT.

The reason I suggested disconnecting the turnbuckle and wiring the flapper valve completely open(I wasn´t joking ). Was because this way you would eliminate the Forge or standard WGA from being contributing factors.

If you still can´t get boost to settle down to 11-12 PSI with the flapper valve wired open, then your problem would be for sure in the turbine housing like you say, either in the WG bypass port or the turbine outlet, which is shrouded and thus, restrictive .

Maybe a local turbo shop or the manufacturer, would test your two WGA´s to see if they are functioning properly. Or some shop´s will bench test your turbo with everything and WGA connected to verify WGA function and set your WG opening pressure.

 

Yeah i talked to robert at FP about it and he was pretty stumped after all the things i told him i had tried. What gets me is why with no MBC hooked up at all and no pressure/boost source to the wastegate it will run a steady 22psi. But as soon as i hook up my MBC i can get it to run 24-25psi. With no pressure source to the wastegate shouldnt i run alot more boost than 22psi, like its doing?

Anyways on Sunday i am going to take the hotside off to inspect everything and then have my buddy port it out some for me. He is really good as porting things and has done lots of manis and superchargers.

 

Still stumped on this one guys: Let me recap and see if anyone else has any suggestions:
1. If I accelerate from a low RPM i will boost to 21psi and then creep to 24psi
2. If I accelerate from a high RPM it will just go right to 24psi and be ok
3. With no vac line to the wastegate at all i will boost only 21psi
4. With a boost line to the wastegate and no MBC it will go to 19psi and then spike to 24psi
5. Hook my Hallman back up and things go back to number 1 and 2.
By the way this happens on my stock wastegate and Forge wastegate with preload on it and no preload on it.