accordexchange

i finally got my custom drag 3 kit in for my 94 accord f22b1... i went for the tial 35mm wastegate upgrade and noticed that i was missing the "dump tube" i guess... my questions are: "is it necessary..? what does it do exactly..? what are the pros and cons..?" i've heard that without the dump tube, boost spike or boost creep can occur... but it also depends on each application... other people don't have a dump tube and have had no problems... any information on this..? -thanks in advance...

IMALLSLO

Very simply the dump redirects the excess(waste) back into the exhaust. You can either leave it open or direct back into the exhaust. If do leave it open it will be a litle louder under the hood. Kinda like a small exhaust leak at full boost. Now boost spike occurs when the orifice of the dump is to small for the amount of boost going out the dump. At small amounts of boost you shouldnt have any problems.

accordexchange

thanks for your reply... at the moment i plan to boost 6-6.5psi and hopefully 10psi in the future with the VAFC/450cc hack... i don't really care about the noise levels under the hood... but as for the small exhaust leak at full boost-will i be losing a lot of horsepower..? who's got a dump tube and who doesn't..? i also heard that by leaving it open, some of the parts in the engine bay will begin to melt cause of all the heat...

accordexchange

anyone..?

zojirushi

i blew up my a/c line and it was melting my radiator. i had to make a heat shield for my radiator.

SoulSurfer

Im going to run it closed loop just to prevent the horrible smell.

Quick 200k Mile Motor

At low boost settings (anything lower than 1bar), all external WG's with open dump tube have that "flappy" sound ..am I right? Pullin' out lots of boost. Sounds like a flappy exhaust leak, or sprinkler going back and forth. ..Hard to explain the sound. I can make the sound using my mouth but I'll probably spitt all over someones face trying to explain them.

Im thinking closed loop would sound the best.

accordfreak

you'll have a nice black engine after a few thousand miles

Armed Ferret

if you want, just weld a flange onto a 90-degree elbow with about 8-10 inches of pipe leading downward. this will keep exhaust fumes and engine nasties away from your engine bay, while maintaining an open-loop setup.

$.02

accordexchange

just to sum up what i've read so far... i thought having an open setup gives you more power..? again i don't mind the sound or the smell (i have a test/straight pipe-no cat)...

WHAT DUMP TUBE DOES:
- very simply the dump redirects the excess (waste) back into the exhaust.

OPEN (CONS):
- it will be a litle louder under the hood. kinda like a small exhaust leak at full boost.
- horrible smell.
- at low boost settings (anything lower than 1bar), all external WG's with open dump tube have that "flappy" sound
- blew up a/c line and it was melting radiator. had to make a heat shield for radiator.

CLOSED (CONS):
- boost spike occurs when the orifice of the dump is to small for the amount of boost going out the dump. at small amounts of boost you shouldnt have any problems.

accordfreak

more like a lot louder haha sounds like a lawn mower on crack


edit-- the tial that is..


[Modified by accordfreak, 9:27 AM 11/3/2002]

accordexchange

if it's a turbo-related noise combined with the PSSSH and all, i wouldn't mind... oh yea, stupid me... just stumbled onto this thread... https://honda-tech.com/zerothread?id=161483