LB7: lb7 475/stock low boost issue

[dirtydmax]

What's up fellas,Got an issue with my 475/stock twins on my lb7 and im confused as hell and need some idia's where to look.Have less than 1000 kms on my 475 and diy twin kit and just loaded my tunes from kory.The prob im having is I cant break 28 lbs boost on my max effort/wot pull,so I made up a valve for the gate so I could adjust it after reading Danzick's thread and seeing he had similar issues.So I started with it wide open and started cranking it shut and it made no difference open or shut so I am at a loss at this point,Have checked for boost leaks and found nothing.On separate note I have oil film in charge pipe and leaking and burning out of dp and don't know if it has anything to do with the boost issue but I thought I should through that out there as well.Thanks in advance.

 

[andy-stevenson]

What are you using to read boost?

 

[dirtydmax]

What are you using to read boost?

I have a 60 lb boost gauge with the censor plumbed into the intake pipe to the ihi,I am wondering if it's a tuning or hard parts prob,than again I had the same boost with the ppe before the dsp5 tunes so ?I'm lost on this but truck seems to scoot alright.Could it be maf related?

 

[clrussell]

I have a 60 lb boost gauge with the censor plumbed into the intake pipe to the ihi,I am wondering if it's a tuning or hard parts prob,than again I had the same boost with the ppe before the dsp5 tunes so ?I'm lost on this but truck seems to scoot alright.Could it be maf related?

The gauge is installed in the intake pipe to the factory turbo? You need it to be in the intake of the engine or cold side intercooler pipe.

 

[dirtydmax]

The gauge is installed in the intake pipe to the factory turbo? You need it to be in the intake of the engine or cold side intercooler pipe.

Put it in the y bridge tube.

 

[andy-stevenson]

Do you have more pictures of your whole twin setup?

 

[dirtydmax]

Do you have more pictures of your whole twin setup?

These are the mock up shots but this is basically the set up I have but .i have it all cleaned up now

 

[TROJAN366]

Does it feel like it is pulling harder? Might just be a bad gauge.

 

[dirtydmax]

Does it feel like it is pulling harder? Might just be a bad gauge.

Ya it pulls like a mofo on the wot pulls when locked with a max 28 psi,if the gauge is correct im only seeing half of the total boost I should be and if that's the case with full boost this thing will be a different animal.I feel no difference between the gate hose being closed or open with no fluctuation in boost,that right there confuses me.

 

[hntngkd]

I have a 60 lb boost gauge with the censor plumbed into the intake pipe to the ihi,I am wondering if it's a tuning or hard parts prob,than again I had the same boost with the ppe before the dsp5 tunes so ?I'm lost on this but truck seems to scoot alright.Could it be maf related?

You have the guage installed between the two chagers?

 

[dirtydmax]

You have the guage installed between the two chagers?

No, in the bridge to see overall boost,i should put 1 in the charge pipe to help diagnose the prob.

 

[andy-stevenson]

Stupid question but where do you have the MAF sensor located? Can you log it and send it to Kory?

 

[dirtydmax]

Stupid question but where do you have the MAF sensor located? Can you log it and send it to Kory?

I have it mounted in the 5" intake,just installed the dsp5 switch so had the batteries disconnected and set some maf codes on first drive to test tunes,thats when I started testing the boost and tuning made no change from ppe to ppei tunes.28psi maxd with the gate hose open or plugged,felt the same both way's but the 475 spools instantly with no lag so I don't know what to think.

 

[dirtydmax]

Could the gate be stuck open/shut?could I be seeing boost from just the atmo if that was the case?

 

[andy-stevenson]

Is it possible your tunes didn't load properly or your dsp switch isn't working? I remember not too long ago someone had a defective switch and it was stuck on their tow tune..

 

[LWATSON]

If the dsp5 switch isn't connected properly or doesn't work you will be on you base tune on all 5 settings.

 

[Cknight199]

If the dsp5 switch isn't connected properly or doesn't work you will be on you base tune on all 5 settings.

My money is on something with the dsp5 gone wrong. Or the maf not being calibrated

 

[dirtydmax]

Is it possible your tunes didn't load properly or your dsp switch isn't working? I remember not too long ago someone had a defective switch and it was stuck on their tow tune..

Checked pid with v2 and all is good there,1-5 is ok.Just put a manual boost gauge on the gate hose and my gauge is correct,now this is interesting,Hooked the same gate hose up to my compressor so I could gauge the psi to open the gate. Tried 30psi and nothing,40,nothing,50 opened it slowly and 60 opened it what I would call normally,didnt fly open just quickly and all the way.Is this normal?seems really high to me,so what does this mean?

 

[dirtydmax]

What would cause the gate to need 50 psi to open and am I seeing the 28psi from the ihi or the 475 ?I feel the truck should make a little more boost and pawa!,should I contact Kory about the maf calibration or look into a hard part prob,This is startin to piss me off after all the time into making this thing what it is.Thanks for all the replys as its helping narrow the prob down.

 

[Dirtymaxx03]

Sounds like your wastegate isn't funtioning properly. The gate should open around 23-28ish psi and start feeding exhaust to the big boy. It sounds like the primary isn't doing any work at all and the secondary is working it's ass off.