silicone hose collapsing

[barneybrendan]

I have supercharged my 2jzge engine using an eaton m90.I did have it blowing into the original throttle body .Now i have the throttle body befor the charger ,the charger feeds into the front mount intercooler and then piped to the intake plenum.The top hose going to the plenum is the one that collapses.If i disconect the pipe the engine revs away with itself

[Michael]

Is this silicone hose an "odd" shape, or is it simple enough that you might be able to replace it with an a thin-walled aluminum tube of the same diameter? It'll take a lot to cause the aluminum tube to collapse.

[barneybrendan]

My fault i forgot to give the idle speed control valve an air feed ,so was basicly starving the engine of air.

[barneybrendan]

pipes are still sucking flat even with the idle speed control valve sorted.Why would this be happening now and not before

[Michael]

I've re-read your original post, and I want make sure I understand how you have your system setup. Starting from the air filter, the way I read it your setup is as such:

Intake Tube --> Throttle Body --> Supercharger --> 1st Discharge Tube (high temp) --> Intercooler --> 2nd Discharge Tube (low temp) --> Intake Plenum

Do I have it correct? If not, do you think you can post a picture and possibly indicate which tube is collapsing?

If what I've typed is correct for describing your system, which of the three tubes is collapsing? I would assume - based on basic forced induction operation - only the first Intake Tube would be the one collapsing since both Discharge Tubes would be under pressure when on boost. But the way you're describing the problem, it sounds like it's the 2nd Discharge Tube that's collapsing.

[barneybrendan]

http://www.youtube.com/watch?v=QOa_CCNdjh8

hope the link helps.All 3 90 degree bends are collapsing.

[Michael]

Actually, that helps A LOT! Thanks for posting.

The first thing that comes to mind is that MUST stop driving that vehicle until you fix this problem! You're starving the engine of air, and that's not good for your emissions equipment and general health of the engine.

You are experiencing a condition whereby the air's internal pressure is so low that it's creating a vacuum condition causing the pipes to collapse. This internal pressure drop is related to the speed at which the air is traveling through those pipes, and not necessarily with the vacuum the engine is pulling (if that makes sense). Your particular situation is kind of a fluke, whereby three separate factors have aligned themselves to cause this problem; the specific air speed coupled with the internal diameter of the tubes and possibly the fact the tubes might be a bit worn out is contributing to the problem you're experiencing. You can test my theory by changing any (or all) of the tubes with ones that have a slightly larger diameter. By going with a larger diameter tube, you'll slow the air down and increase the internal air pressure.

Now that I see the issue first hand, I resort back to my original recommendation and strongly suggest that you consider swapping those tubes for aluminum sections or even hard plastic sections. You can keep the same diameter tubing, or go with a slightly larger diameter to help lower the air's internal pressure which would place less strain on the tubes.

[barneybrendan]

cheers just orderd 3 aluminium bends.The car is not driveable at the moment and wont be driving it until it goes off for its next dyno day.
this link is the dyno when it was blowing into the standard throttle body.

http://www.youtube.com/watch?v=4gipN...eature=related

[barneybrendan]

replaced the silicone but there is still something add happening with this setup i have a rescent youtube link.

http://www.youtube.com/user/barneybrendan

I have also noticed that my rubber bend on the intake pipe is also getting sucked flat.
The charger has had its bearings replaced and spins nicely with no knocking,but ofter it was run for a while it started making a funny noise so i shut it off removed the belt and rocked the pulley.It was now knocking as i rocked it.The charger was extremely hot and i could not touch it,would this be be due to air starvation.Now the charger is cool it is perfectly fine again no play at all.
You will also notice on the video that the revs dont drop but hang for a while once its revved.Anybody have ay ideas as to why this could be.On my bypass valve i have the vacum pipe to the actuator from the intake /manifold ,the larger bore for the vent off and there is another small pipe (where would this connect it seems to be after the diaphram.)
This has been a 2 year project now and im getting stumped at this last little bit.