ziggy07

ok i got a 92 civic coupe with a stock b18b motor. running a .57trim no name turbo. i have 2.5 inch exhaust from the turbo back and a little resonator at the end. now my main concern in my obx wastegate that dumps under the hood.

having such a open exhaust would i have to worry about back pressure when routing the dumb back in down stream. personally i dont like loud exhaust notes under the hood, i prefer to be able to here my turbo working.

i know the main advantage of a open dumb is less back pressure in the exhaust pipe for the turbo.

NotAJDMFanBoy

Open dump would help with boost creep. Routing it in makes it quietter and I think smoother or something, idk. On a DD it's fine routing it back in. Or you could put a little muffler on the dump or something.

Stopsign32v

iTrader: (1)

open dump sounds like ***

AlexDphoto

Routing your dump back into the exhaust shouldnt be an issue for you, but I would suggest going with a bigger exhaust, as turbo setups like to be able to breathe.

routing the dump tube back into the exhaust system will quiet things up for sure, but I dont see any benefit in being able to hear your turbo work. If something were to go wrong with your turbo you would

A. Feel a noticeable loss in power
B. See a **** ton of smoke spewing from under your hood/exhaust

Stopsign32v

iTrader: (1)

Great advice! I 2nd the bigger exhaust. Keep in mind its a single exhaust.

Some people don't like the SSSSSSSSBAAAAAAAAAAAAAAAAAAAAAAA of the open dump tube.

AlexDphoto

I do. theres nothing like hearing the sound of an open dump, run a youtube search on supras, its absolutely beautiful.

And theres nothing like being able to deafen a bastard who cut you off in the summer with their windows down with an open dump.

Stopsign32v

iTrader: (1)

LOL I do agree with that last part! I'm the complete opposite though, I like the hiss of a turbo inside the car. I had open dump tube on my Mustang and people said it sounded evil but I didn't really like it.

Now how bout this question which makes sense to me...if you are going to run it back into the exhaust wouldn't a 44mm WG do better than 38mm with boost creep?

Stopsign32v

iTrader: (1)

Oh video FTW

http://www.youtube.com/watch?v=r1wIdzrT1S0

AlexDphoto

If youre creeping, it wouldnt have anything to do with routing it back into the exhaust vs open atmosphere dump.

Most of the time youre creeping with improper wastegate placement, inadequately sized wastegate for your setup, and * turbo size vs wastegate pressure. I asterisked the last one because its one I havent researched much. I found through researching threads on clubrsx, that sidewinder customers of peakboost and full race were complaining of boost creep on their manifolds despite running 44mm wastegates, I believe the end verdict was turbo size vs wastegate pressure.

ziggy07

bigger exhaust lol its 2.5 straight pipped how much bigger do i need? i would like some power at low end ha.

sanman000719

3" or 4" what ever you can get under the car safely

darkvader0

I have always run closed-loop wastegates. With both 2.5" and 3" downpipes/exhausts. And with RevHard and DRAG cast manifolds (wastegate placement on #1). TiAL 35 and 38mm wastegate. No boost creep. Nice and quiet all the way to 28psi.

I did spike to over 40psi this morning since it was < 18*F. :-\ My 4th gear is set to something like 77% duty cycle on the boost solenoid and that spiked me pretty hard this morning lol.

sanman000719

i run an open dump, and downpipe only

BLU CIVIC

you wouldn't need to run a 3 or 4 inch exhaust on a turbo set-up that's on a stock engine i wouldn't think. i'm running a 2.5" exhaust and making good power.

sanman000719

yes it will make good power on a 2.5 but emagine what it might do on a 3"

I ran 3" under my crx

BLU CIVIC

The general consensus from what I've been reading is that unless you're going for big power, 2.5" is fine and the difference between a 2.5" and 3" was marginal. Coupled with the cost of replacing your exhaust with a mandrel bent 3", it's probably isn't worth it, IMO.

sethm

I too like my dd's on the quiet side.. Had a 3" on my last car and I couldn't stand it

Stopsign32v

iTrader: (1)

You can make a 3" just as quiet as any other size. Infact the bigger you go the quieter it gets if you use the right mufflers.

sethm

I don't know about that one. I tried a lot of different things on mine and couldn't get rid of the drone on the highway

sanman000719

my car with no exhaust on it at all is alot more quiet than most with full exhaust

sanman000719

i had a video of my car running with no exhaust to prove it to someone on here in the past but i cant find it now

AlexDphoto

you would be surprised what kind of power you are able to gain by freeing up your exhaust system just by half an inch

Unfortunately thats the game we play. With a bigger exhaust youre bound to get some drone.

Go and ride in 3 inch exhaust NA honda and come back to a 3 inch exhaust turbo honda and tell me how much more quiet it is.

Ive got full 3 inch all the way back to a magnaflow muffler and its quieter than all of my friends 2.36 inch N1 style exhaust systems.

Stopsign32v

iTrader: (1)

Its all in the muffler/mifflers/cat combination you use. If you have a round muffler at the end it wont be that quiet.

I think I'm going to run a oval magnaflow muffler at the end and maybe a round one up as close to the flex as I can. That should make it pretty quiet with a nice deep tone.

sanman000719

ok most of us dont run mufflers on full exhaust its just another restriction, and there still alot more quiet than an n/a anyday

Stopsign32v

iTrader: (1)

LOL a straight through muffler is not a restriction