LB7 Hitting 37lbs Of Boost With No Boost Mods

[Mad Maxx]

So the LB7 I'm Tuning is Hitting 37lbs of Boost.

It doesn't have a Boost Fitting, no Wastegate Mods, nothing.

The Person has their Boost Gauge Tap on the Short Line that goes from the Turbo Outlet to the Wastegate Inlet Port.

The only Mods done to the Truck are an Intake (with a DIRTY Filter) and Straight 4" Exhaust.

Any Ideas why it's Boosting so High?

 

[Pepperidge]

I would try a manual vacuum/boost gauge to verify the boost level...the lb7 turbo's don't last but a few passes at that level...anything above 32# and you are flirting with danger ...

 

[Mad Maxx]

It is a Manual Boost Gauge. The Vacuum Tee is In the Line from the Turbo Outlet to the Wastegate.

...or are you Talking about another Type of Gauge?

 

[Pepperidge]

then try another gauge...if it is really putting out that much boost that turbo will let go soon enough...

 

[Mad Maxx]

What should LB7's Boost to Stock?

I got another Gauge I can Throw In, but IIRC, it only goes up to 25 or 30lbs.

 

[Mad Maxx]

Ok, now it's Hitting 25lbs.

37lbs was on the Old Motor that Died.

He was Confused.

 

[Pepperidge]

I can't see how it's holding 37#...you would need a boost fooler or a big head for that to be accomplished...thats why I think something may be wrong with the gauge that location for the sensor IIRC someone said reads a little on the high side...but not 8 or 9 #'s high... either something is not right or he is on the verge of a catastophic turbo failure...the IHI is not designed to handle that much boost...

ASFAIC I'm running the best tunes made for an LB7 and even before I put on the Big Head wastegate, it never saw above 30# and my boost gauge is in the same spot as he has his... I'd try that other gauge...JMHO


on edit I see you posted while I was typing my post...for teh record though I can't see how the other motor was pushing 37#'s...unless his turbo is what took that motor out...but he had to be running something to fool the truck to run the boost that high...

 

[THEFERMANATOR]

Ok, now it's Hitting 25lbs.

37lbs was on the Old Motor that Died.

He was Confused.

25 isn't bad, but like Pepp said 37 will grenade a stock LB7 turbo. Boost on that tune Isent you should be around 24-27 with a stock wastegate set-up.