Major Boosting Issues, please Help

[EXTREMEPT]

Car details: 91 talon awd 2.0,with gt35r,tial 38mm external wg (6psi spring)mounted off manifold,880cc,magnus intake,70mm tbody,272 hks cams, ported head,evo 3 ported exh.manifold,greddy type rs bov,hallman mbc,b-shafts removed,extremepsi race fmic,3"gm maf conversion w/ maf translator..etc...

Before removng old fmic, and upgrading to the new bigger one.the car was running great on 18psi pump gas,now that i got it all back together i can only get 7psi out of it.doesnt matter what gear i m in or what rpm i take it up too..i have check all vacuum lines,even changed all of them just to make sure.checked the wastegate diaphram and spring,checked the hallman mbc ,and the bov all seem to be ok....i ve pulled the pressure line from the turbo to run it w/o the controller and still wont boost over the 7psi..i even pulled a compression check and double checked the timing to make sure all was good and it was all fine...i triple checked the vacuum lines again and the silicone couplers on the i/c pipes and checked for any loose t clamps,they are all good..i even changed the gm maf out just to make sure of that was nt bad..the car is running fine at idle and runs fine on the street,but just cant get it to boost over 7psi...I cant think of anything else to do or check....let me know what you guys can think of..i appreciate the help in advance...


from a tired and worn out dsmer-------

 

[wishihadatalon]

Did you do a boost leak test? Check the welds on your intake manifold and your intercooler.

 

[EXTREMEPT]

the fmic is brand new and i checked the welds on it before i installed it.I havent checked the magnus intake welds though,but i will do that today.no i havent done a boost leak test yet, i need to get a tester gauge first.

 

[wishihadatalon]

the fmic is brand new and i checked the welds on it before i installed it.I havent checked the magnus intake welds though,but i will do that today.

Its completely possible to pop them once the fmic is on.

 

[EXTREMEPT]

but since i just installed the new fmic its has nt boosted over 7psi,i dont think 7psi is gonna bust a weld,but i will double check that again today as well..

 

[dustyduff]

Did you do a boost leak test? Check the welds on your intake manifold and your intercooler.

More than likely a boost leak, but could be a problem with the I/M or I/C too. I've heard horror stories with welds breaking on the Magnus Intake manifolds, but it may be something as simple as an unsecured coupler. Good luck.

 

[EXTREMEPT]

i hope its not the welds on the i/m...and i dont think its any of the couplers, i triple check all of them and made sure they are all secure and the t clamps are very tight.

 

[Spoolio]

Typically a problem like this sounds like a coupler you mistakenly missed while installing all of this, i have done this plenty of times and my car wouldnt boost past 7-8psi.

Second, i suggest if you have the time take your intake manifold back off and really scope it out good, look at all the welded beads along with your I/C.

 

[EXTREMEPT]

i hope it is something simple like a coupler i missed, after checking 3 times...

 

[EXTREMEPT]

ok, guys still need your help here...i have checked all couplers and clamps..even take the pipes and couplers off and re assembled everything.Did a boost leak test had a leak,fixed it! replaced all vacuum lines with quality silicone lines.made sure my wastegate lines are routed correctly.i even took the new tial wg off and checked the diaphram, all is good..ordered a different rated spring,still will only hit 7-8 psi in 1st, and 2nd gears and then in 3rd at around 6k it will hit 10 psi, that is it..I am using a hallman manual bc and i have checked it out as well..all is good, i ve adjusted it from open to closed..Could it be the controller ? i dont know what else it could be any ideas??

 

[EXTREMEPT]

also tried to double up on the spring on the tial ..used the small red and the large blue..still the same boost???????????

 

[GVR4592]

It could be a few different things. Can you describe how you have the vacuum lines routed to the wastegate? Did you install the valve seat that came with the wastegate? If those things are both done correctly, eliminate the MBC from the setup. Run a boost/vacuum source directly to the wastegate. This should get you whatever the spring pressure is. If you have a large blue and a small red that should be around 20 psi.

 

[EXTREMEPT]

the wg valve seat is installed...Right the small red it 5.80 and the big blue is 14.50 so yea it should be just over 20psi...i have the hallman mounted on the fan shroud,the side outlet hose on the hallman goes to the side outlet on the tial wg. the top vent on the wg is open to atmosphere.the bottom line of the hallman goes to the pressure hose coming off the turbo and t's into the hose coming from the magnus intake manifold.also the same hose coming from the magnus intake manifold t's into the bov hose.Let me know what you think ?

 

[EXTREMEPT]

To eliminate the hallman mbc should i just run a line from intake mani and t it off to the pressure side of the turbo and then to the wastegate ? i never had to do that, so i am not certain on how to bypass it correctly

 

[EXTREMEPT]

ok, guys i am completely confused...i started off the next test by removing the mbc from the car, i ran the pressure line to the turbo.finally saw more than 7 psi in 2nd i saw it spike to 14psi, i got the car in 3rd and saw 12-13 psi..did nt see it creep up past that..i thought that was kinda odd that it would nt see more boost considering the mbc was off the car and the springs in the wg should allow 20 psi.so i pulled the line from the wg and and block the t fitting off,made a run and still the same amount of boost, so next i left the line off the wg, and then pulled the pressure line off the turbo compressor housing and let it run open..still the same amounts of boost..this absolutly makes no sense to me...why will it not boost more? why in the hell since i pulled the line off the turbo will it not get crazy amount of boost? i am now leaning towards the actual gt35r turbo unit...what do u guyus think..

 

[GVR4592]

Have you checked the turbo for shaft play?

 

[EXTREMEPT]

yeah i checked itand all seams to be ok....minimal normal play ....but, its a brand new turbo...it has less than 300 miles on it...

 

[GVR4592]

At what RPM does the turbo reach full boost?

 

[EXTREMEPT]

to get over 10 psi its about 5k and to get to 12-14 its almost 6k..which seems to be to high in the rpms

 

[EXTREMEPT]

imo the turbo should hit harder and should boost sooner at a lower rpm than what its doing now.

 

[EXTREMEPT]

after i hit the 14 psi with the mbc off i was thinking it had to be the mbc, but after i pulled the pressure line off the turbo, and did nt get anymore boost..could it be the turbo ?

 

[EXTREMEPT]

today i tried to hook up the wastegate according to tials instructions on there website,and the that hallman has it on there website.The hallman way i (venting the top nipple on the wg to atmosphere i can only get about 10psi out of the car) with the tial instructions i can reach 12-13 and hold it in 3rd gear ..But i can not get anymore boost out it anyway..I have even put a stiffer spring in the hallman, still the say results....

 

[fwdeclipse]

This happened to me when I installed my 60trim.Make sure you dont have any pre turbo exhaust leaks.That made it so I could not boost over 12psi and it spooled super slow.Probably not your problem but thought I would throw that out there.

 

[EXTREMEPT]

hmmm,i do have a slight leak from the manifold stud that snapped off in the head..it is the bottom bolt on the closest to the timing belt..it makes a slight tick when cold then when warms up it goes away..Now that i think about it, yes that could cause exactly what its doing..slow spool time, not hitting full boost and boost falling off...thanks man..i ll keep all of you posted once i drill and tap the stud out the head...fun fun cant wait!!...

 

[EXTREMEPT]

well i yanked the turbo manifold off and the manifold has for surely has been leaking, now to get the broken stud out..the stud is broken off inside the head so i cant anything on it to get it out..i drilled the center out with a drill bit installed the extractor, it snapped off inside the hole of the stud,i redrilled the hole again and installed another extractor, and it snapped off inside the stud again.Now i have to drill the complete stud out of the head..Fun Fun ...