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Hi Ive got a late 99 with a 6637 airfilter stock muffler delete didn't have a cat. delete pipe sure looks like a 3 inch not 3.5. just ordered a 4" turbo back mbrp. It has a flashpac...ya ya ya I know.... that's always in the light tow mode. I have a pyro and use gauge pro to check boost. It makes 21 lbs of boost. thought I would try the redline mode but nothing changed 21 lbs of boost pulling a big long hill before and after. fairly fast to 2o-21lbs and sitts there. waste gate? cannt hear any blow off. Or do I need a really boost gauge? Or is something up? Thanks for any help.
stock turbo. should I look a changing it? its my hunting fishing pull my 25' traveltrailer truck. trying to keep egt down. its not a dd. I do plan on keeping as long as possible. just love it.
Is there a boost fooler on the map line? That may be limiting your OBD2 boost reading. I never see over 22psi on my Torque Pro app, even though my analog gauge sees over 40psi.
It has a flashpac...ya ya ya I know.... that's always in the light tow mode.
Why are you expecting more boost if you're in a light tow mode?
Pulling the red line from the wastegate actuator doesn't stop the wastegate from opening up. All that mod does is prevent the wastegate from opening sooner at lower boost pressures.
At higher boost pressures, you have rapidly increasing exhaust pressure. The stock wastegate isn't strong enough to overpower excess exhaust pressure, and it will still open.
Then on top of that you're only adding slightly more fuel than stock on a light tow tune. The stock turbo on a stock tune will see 16-18 psi of boost. Add just a tiny bit of fuel, and 21 psi sounds about right.
When my truck was stock (with exception of air in/out), I reached 22 PSI on stock tuning and the red line mod. It's possible the flashpac tricks the MAP signal, or maybe there is a boost fooler of one design or another.
With a 100% STOCK turbo 22 PSI is good. With a modified stock turbo (billet wheel, outlet, etc) 28 PSI is about your max before the turbo becomes very inefficient.
light tow is the 2nd most powerfull tune. I have never tried the performance tune. But it is time to upgrade some stuff. I was just expecting something to change with the redline mod. no I don't have a boost fooler.
thanks for the help
I thought that too, until I discovered a strange black wire connected to my MAP signal line. I'm not saying this is your case, but if you're not the original owner....
