2011 GT500 Boost issue

[2DaDarkZide PR]

My friend bought a 2011 gt500 a few weeks ago with just 4k miles. Did the shifter swap and eliminated the grinding.

It clunks like a bad lower ball joint bushing but Ford says "no issue found" despite acknowledging the clunk.

Anyway, the main issue is he installed a JLT 123MM intake and a Bama 93 tune. Those are the only mods. Boost went from 9.5 to 3.5

He called them, they said there was no issue with the tune. He called again, different person, same answer. So now he started emailing them to get the same rep at least and have a paper trail. They sent him a new tune and it is at 5 PSI now. He calls and emails them again and they say the issue is his car. But he removes the intake and loads the stock tune and psi goes right back up to 9.5.

He emails again, they send him some strategy tune and psi is now at 7.5 psi with intake and tune and 9.5 when reverted to stock. They basically have told him they have no idea and "tough luck".

Any suggestions? We even pointed them to the google results showing many threads with similar issues but bama stuck to it's guns saying "Don't know", even with data logs.

I referred him to my tuner and he has been talking to him but can't justify the dyno tune just yet so any ideas?

 

[RazorbackMustang]

Have him ditch the Bama tune and go with VMP or Lund. I think Bama is great for N/A and mild bolt on GTs...but that's it. When you're in that field it's time to step up to someone with more experience with those engines.

 

[2DaDarkZide PR]

I felt bad because I suggested the same shit since I was the one who put him up to bama after my success with my 3V GT but i agree, S/Cs seem out of their league.

 

[Foozeh]

Definitely have him look into VMP or Lund, their customer service is top notch.

 

[GallopingFord]

Bama is good, but wouldn't use it for a GT500. I used Lund for a TB, Intake and O/R for my 2013 GT500 and the tune was spot on. No revisions needed.

 

[stkjock]

I don't see how a tune would affect boost levels, boost is a measure of restriction, a mechanical combo creates this condition.


I would have it on a dyno for before and after comparisons.

That said, get a Lund Tune, their experience with the 5.4L motors trumps all.

 

[RazorbackMustang]

^ I couldn't really come up with a correlation either...except that when thr stock tune was put back on it the boost level returned to normal. Does the M122 have an electronic controlled bypass valve?

 

[19COBRA93]

Boost can be effected in many ways. The throttle body may not be opening all the way because of some hiccup in the tune, or if the tune is way off, the boost gauge will be very inaccurate as it doesn't read an actual boost signal, but rather an inferred signal off the maf and several other sensors.

I'd kindly ask for your money back, and go with a reputable GT500 tuner.

 

[2DaDarkZide PR]

I don't see how a tune would affect boost levels, boost is a measure of restriction, a mechanical combo creates this condition.


I would have it on a dyno for before and after comparisons.

That said, get a Lund Tune, their experience with the 5.4L motors trumps all.

^ I couldn't really come up with a correlation either...except that when thr stock tune was put back on it the boost level returned to normal. Does the M122 have an electronic controlled bypass valve?

Searching through Google I found many threads with the same issue from 2007-2014 but only a few incidents per year. So, not necessarily common, but happens often enough that there are several threads on it.

One I found on the SVT forums shows a couple of people resolve it after the dyno tune, but no specifics (that I saw) as to what parameters were adjusted.

I think he may just go Lund. And as for the boost gauge being off, how possible is that?

 

[stkjock]

Boost can be effected in many ways. The throttle body may not be opening all the way because of some hiccup in the tune, or if the tune is way off, the boost gauge will be very inaccurate as it doesn't read an actual boost signal, but rather an inferred signal off the maf and several other sensors.

i didn't consider a tune parameter affecting how a mechanical part functioned, particularity the TB, makes sense Sam.

And as for the boost gauge being off, how possible is that?

Factory Gauges are notoriously poor for accuracy

 

[Stetler17]

The factory boost gauge uses a few parameters to arrive at a boost number. If the tuner does not set these correctl you will get a bad reading on the factory guage. Surprised you did not find this on SVT search.

Does it feel like boost is not there, or just the guage reading?

 

[19COBRA93]

i didn't consider a tune parameter affecting how a mechanical part functioned, particularity the TB, makes sense Sam.

The throttle body is mechanical in end function, but electronically controlled. It can, and does, do things that aren't in parallel with what your foot is doing. This is how things like throttle response are controlled in the tune. As well as the Fail Safe Mode where it only opens the throttle body 25% regardless of what your throttle pedal is doing.

 

[stkjock]

The throttle body is mechanical in end function, but electronically controlled. It can, and does, do things that aren't in parallel with what your foot is doing. This is how things like throttle response are controlled in the tune. As well as the Fail Safe Mode where it only opens the throttle body 25% regardless of what your throttle pedal is doing.

yep, agreed 100%, just didn't click in my mind prior to your post.

 

[Stetler17]

http://www.svtperformance.com/forums/svt-shelby-gt500-150/943195-dash-boost-gauge-low.html

Some good information in this thread that may or may not apply to your situation.

 

[2DaDarkZide PR]

Seems like an inaccurate gauge is much more common than actual boost loss, by far