Hey guys! it's been a long time seen i've been on the forums - life, kids, etc.. i won't bore you with the details.

This just started to happen in the last few months, can't say exactly when since the truck has become my weekend warrior and i don't go wide open very often. I'm losing all boost at WOT and running super rich, it just bogs down. I used to get 7-8 psi at WOT and the truck would pull hard through all gears. Now at partial throttle 50-70% I get around 3-4 psi, but as soon mash the pedal boost drops to 0, FPR goes to 10.0 or lower (bottoms out at 10) and the truck completely bogs down. Happens every time i go WOT from a complete stop or rolling/cruising. I've had the same tune for 5+ years, haven't changed anything. Everything was working cherry up until a few months ago. I replaced the bypass actuator thinking i was loosing boost for that, but no change after replacement. I replaced the belt as well thinking it was belt slip, but same issue after new belt installed.

i doubt its the tune since it's been the same for over 5 years and worked perfectly until recently. i'm thinking something mechanical, i just can't pinpoint it. Any ideas? any help would be appreciated.

 

Giant boost leak. Probably a popped off coupler. Cap off the compressor inlet and pressurize the system with an air compressor if there's nothing obvious visually.

 

thanks for the reply. i need to do a leak test.

but, if it was a big leak why would i make 3-4 psi boost at half throttle and then drop to 0psi at WOT? wouldn't a leak always leak, not just at very high PSI?

 

What supercharger do you have?

 

If you have silicone elbows on the intake, it could be sucking them shut at full throttle.

This just happened on my friends rock crawler. It has a long intake tube routing because of the cramped engine bay of the rock crawler and one of the elbows was being sucked closed at full throttle. With a new elbow now it's got an extra 150hp he said lol.

 

Radix MP112

 

sounds like a potential soft intake tube collapsing (more vacuum = more restriction)... but it's hard to imagine where'd be a soft tube for that blower on that truck. they're made for each other & have space for days to run all hard piping.

... unless there's something loose near your intake inlet / filter that gets sucked onto it & blocks all your incoming air when the suction gets strong enough.

... or you've got some gnarly belt slip

 

Wonder if your bypass valve is acting up?

 

I agree with FFDP. When I had my MP112 I had one coupling that was being sucked partially closed under WOT. I got some couplings that were lined with aluminum tubing and it fixed the issue. If you are seeing that much belt slip I would imagine black dust everywhere around that blower snout.

 

he mentioned recently replacing it