My dumptube is loud at idle.

[genxxxracer]

It sounds like instead of the exhaust going out of the main passage it is coming out of the dumptube. Is this possible. My exhaust manifold is highly ported and the 02 dumptube is also, they are matted to the frank 2 20g setup. Any ideas or am I just new to the wonderfully exciting sounds of the dumptube.

 

[-=TWITCH=-]

it should only make noise out of the dump tube when the waste gate is open! sounds like to me your waste gate isnt closing like it should>?

 

[genxxxracer]

If you had the mbc installed flowing the wrong way would it do that. I am trying to figure out if my mbc is installed correctly. Its a RRE unit. So far the only way it gets much over 10lbs of boost is if the valve is closed all the way. Then it just meanders up to 25 or so. Not creeping just steadily built to that level. The pocketlogger didnt show timing being pulled at that level so I guess no harm done. Also egt's have not gone over 700 degrees celcius.

 

[Mindslayer]

I had the same problem check and make sure your bolts are tighten again. when you tighten them and the car heat up sometimes it losen the bolts. just retighten them again.

 

[j.d.roost]

When I did my 34mm flapper I had it too tight on the wg. arm. It leaked a little and would vent out of the o2 dump. If your gate is internal ( I dont know if it is) start the car with the actuator off the wg.and pull on it (wg arm) with some vice grips pliers ect. If it still leaks out the dump it sounds like you have the same problem.
You can put your hand over the dump after its started and see if its leaking out of there if your not sure. ( make sure the car is cool
)
jd

 

[candela]

Hey Bret, when I came over I put my hand over the pipe to see if it was leaking out and I didnt find anything. I dont think that anything (maybe a tiny bit, which is normal part of wear/maintenecae that you just have to fix) is leaking out. It is louder than stock regardless, even though the flapper is closed its still going to be loud there and you will here the turbo like that. Its just part of having the dumptube. But ofcourse it shouldnt be really loud and flow exhuast out when before you really get on it and the flapper opens.

Anyhow I know we really didnt get a chance to drive it last time =). I didnt see the mbc instuctions but what I said last time is right. That one line is hooked up correctly. You said that you felt air, which is normal... when the motor is at idle it pulls vacuum, it doesnt always boost. If they were backwards then the mbc would have no ill effect on the w/g at all.