Big Turbo Question

[theswoleguy]

So here is a brief discription on my problem and hopefully you guys can help.

My setup:
Airdog II, ITP Reg Return, hypermax 225s, 72mm Charger.

When i run my tow/street tune (Innovative Diesel) the turbo is slow to light down low (understandable) and runs decent up top, so im ok with this tune.

My xtreme race tune Problem
Lights better down low, up-top power especially in 5th is slow

I am use to manuals and know nothing about autos. I am thinking Exhaust Back Pressure Sensor. When you roll on it-into full throttle down low 1-3 it pulls hard as hell but up top (going floored), if it downshifts, you see boost spike to 35-40ish the truck acts likes its going to go but accelerates slowly (probably slower than the tow/street tune) and rpms increase slowly with speed-it's like the truck is struggling to pick up speed. So maybe this is my "manual" mindset but if the tranny was taking a poop wouldn't it rev out as if a "clutch or clutches" were slipping?

Maybe it is over fueling so much that it is bogging the motor/turbo down?

Like i said the tow tune runs decent up top, probably as fast if not slightly faster than my stock inj/turbo setup on extreme race but its crappy till about 3rd/4th, power is pulled as its more of a tow setup according to eric down low.

ALso i have noticed on my FPR Gauge the fuel dives down to 50psi from 72, not sure if this helps but more info is better than to little. only on the race tune, holds fine on tow/street

[06powerstroke06]

What is the boost doing?

[theswoleguy]

Originally Posted by 06powerstroke06

What is the boost doing?

boost hits 37-40psi (needle has a tremble/shake to it) and thats it, i can do that (37) on the tow tune but it is solid.

[theswoleguy]

Originally Posted by theswoleguy

boost hits 37-40psi (needle has a tremble/shake to it) and thats it, i can do that (37) on the tow tune but it is solid.

Here is a video, you can see it hits about 35 and the needle starts to tremble and shake... also you can watch the fuel pressure gauge drop from 72 to around 58.

You Tube

You Tube

[06powerstroke06]

im not quite sure but you might be havent a back pressure issue or getting out of your turbo's efficacy range. I had that problem with my 190s and powermax. the boost would jump to 49psi and the truck didnt have power.

know anything about the exhaust side of the turbo? wheel size, AR, t3 or t4, open or divided?

[theswoleguy]

Originally Posted by 06powerstroke06

im not quite sure but you might be havent a back pressure issue or getting out of your turbo's efficacy range. I had that problem with my 190s and powermax. the boost would jump to 49psi and the truck didnt have power.

know anything about the exhaust side of the turbo? wheel size, AR, t3 or t4, open or divided?

sadly i do not, i'm going to try a pressure test the intake system and see if there are any leaks... i was hoping and told by lead foot i should be able to hit 50 bc that is what he was doin on his truck (where my setup came from). the exhaust side is small though

I know this doesnt help but using it to show the small side.

[06powerstroke06]

yeah there is no way to tell from the pictures. might need to just contact the guy doing the tuning.

[theswoleguy]

yea im do a pressure test at the turbo inlet and see if there are any leaks and then go from there. Sent the video to eric to see what he thinks as well.

[theswoleguy]

could it be a bad maf, i know on my vw when the maf is dying (not triggered a code) you get very strange boost response.

[06powerstroke06]

are you getting your boost reading from the elbow or the map hose?