Supercharger help, PLEASE

[yooper1]

I'll try to explane everything as best I can. it is a MPI stage I

It seems difficult to receive over 4 psi of boost at 3/4 throttle. If I set
rear of sled on a stand and burp the throttle, boost doesn't follow throttle
input, but instead raises for about 3 seconds after I let off throttle , but
still doesn't reach over 4psi. I see/feel no air leaks between supercharger and
throttle bodies .

Does the traction oil physically drive supercharger, or does it just act as a
lubricant for a planetary drive?

If i remove Supercharger oil return line banjo bolt at oil tank, oil flow at an
idle is a stream about 3/16 inch diameter. If I hold my fingers over banjo
fitting you can feel good pressure building. Is flow sufficient or should it be a full line?

What could be having it act this way?

Any help please!

Mike

 

[irondave86]

Is all this happening on the stand, or will it not build boost on the trail too?

 

[jsjk-4-stroke]

supercharger

oil return is about right you need to put sled on snow and watch boost it will read diff under load. when i ran mine on stand my boost was way to high use bubbles to check for air leaks

 

[yooper1]

It does this on the trail too. Will look more tonight, not sure what it could be.

 

[SPEED]

Oil seems Ok, Check your S/C belt, are both pulleys tight ?? BOV stuck open?
You will not build boost on a jack stand the same as sled under load.

Oil does not drive charger (just lubricates) charger is driven off crankshaft

 

[yooper1]

Belts are tight, will check the BOV. Could we have hooked it up wrong?

 

[mulot30th]

Oil seems Ok, Check your S/C belt, are both pulleys tight ?? BOV stuck open?
You will not build boost on a jack stand the same as sled under load.

Oil does not drive charger (just lubricates) charger is driven off crankshaft

rotrex use oil as as 'traction' coating.....

 

[blowyam]

apen too my my intercoler was crack uder and was very hard too see

 

[kinger]

Sounds like a air leak either its not seated on the boots right or there is a crack in the system some where. Its bleeding off boost some where.

 

[machzed]

Check to make sure you havent stripped any cogs of the belt.

 

[yooper1]

It appears the blow off valve on the intercooler in the problem.

I tried to manually open and close it with a "straw" (vac hose) and it appears to be frozen
Allen Ulmer informed me that it was a Mitsubishi blow off, it is attached to the bottom of the inter-cooler.



Were pulling it out/off to confirm the problem, it now will build NO boost. :-(

 

[yooper1]

real quick note, belt it fine and tight, so are the gears.

 

[team ducktape]

It appears the blow off valve on the intercooler in the problem.

I tried to manually open and close it with a "straw" (vac hose) and it appears to be frozen
Allen Ulmer informed me that it was a Mitsubishi blow off, it is attached to the bottom of the inter-cooler.



Were pulling it out/off to confirm the problem, it now will build NO boost. :-(

If the BOV is "frozen" can you feel air coming from it at idle? The Mitsubishi BOV is not a bybass valve so you should feel nothing coming out of it at idle. All the BOV does is dissapate the boost when the throttle is "lifted". If your NOT building boost the BOV is not the problem, unless it is leaking. It is a release valve, if you want to see if the BOV is leaking take it off the intercooler and block off the hole. Run the sled to see if it builds boost. If it doesn't build boost you have other issues.

 

[yooper1]

Right ducktape, we were getting 4 psi and played with it and now nothing.

Will keep you all posted as the facts come.

 

[yooper1]

Here is the latest email from my buddy/installer. Guy's what in the #^& are we missing here. Were both pretty smart.

After you left I remembered that in order to remove the intercooler, i would
have to remove the bars, steering stem, radiator etc. I figured that I would
start at the air source itself, the supercharger. I removed the compressor
outlet hose leading into the intercooler. I then removed the cold air intake.
I felt the intake fins of the supercharger as I rocked the primary clutch back
and forth. The fins are definitely turning at a much higher ratio than the
input, which is good. I started the engine and felt the supercharger output.
At an idle it's blowing like the equivalent to a hair dryer. If I rev the
engine, it is almost like it blows less.?? Very confusing because it is not a
variable geometry setup, nor is it wast-gated. It makes me wonder are the
tolerances bad so it will not compress or what. I guess it comes down to asking
MPI if they have ever experienced a situation like this. I don't see why it
wouldn't be working. I was going to contact the manufacturer (rotrex) but there
web site says any troubleshooting questions should be directed toward the
aftermarket dealer. I have seen diesel turbos where the shaft play gets so bad
that the turbine fins self destruct from rubbing the housing and compressing
capabilities are lost, but why is ours blowing so good at an idle but loosing
boost as it spins faster? That's how it acted from square one. It was making
boost down low but if I accelerated I was gaining no boost and fuel/air mixture
ran extremely rich.