PM-Performance

does it really make you lose hp from routing the dumptube back into the exhaust with the downpipe?
is it better to just have an aope atmosphere dump tube?
thanks./

MiraiZ

Yeah...you can lose up to about 15% of the total HP by using a dump tube...open WG is best if you want optimum power...personally, I would sacrafice the power (on a daily driver) for a quieter ride...


[Modified by MiraiZ, 1:08 PM 10/14/2002]

sutrusu

you can get a dumptube that doesn't route into the exhaust
but if you dont run a dumptube, you risk blowing your a/c lines... someone posted here a few weeks ago that they blew their ac lines... so no more ac for them

Ri5e

You can get a 90 degree elbo welded with flanges on both ends to make the waste gate shooting down. But it still won't be as "quiet" as closed loop.

PM-Performance

i dont have ac anyhow
yea i was gonna just run it stright down via dump tube if i didnt make it closed loop / i wouldnt want to just keep the bottom of the wastegate open / like to keep things neat.

ezark

just route it pointing towards the ground

Flamenco-T

it depends on where you dumped the tube in the dopwnpipe....

I believe if you dump it 25-30" from the turbine, you lose very very minimal HP versus, closer spot from the turbine..

stan

mos

Damn 25 inches is far. I think like 14 is enough. But ya the furthur the better, I guess.

Ash J. Williams

per corky bell, it is 18"
stan

dustin

On the dyno, I didn't lose any power one way or the other... I had 3" exhaust/dp though.

Flamenco-T

yeah, that sounds about right...I knew for sure there is a certain distance to have a minimal lose off power, but again, like dustin's for example, some don;t lose power at all...

PreIudeSI

you're more prone to boost creep with a closed loop too. Unless the transition into the dp is at a shallow angle, you'll probably experience some boost creep as the wg exhaust gases have to push against the fast flow of dp gases.

EG6owner-T

what if I'm running the revhard stage 2 kit? and use a flexpipe to connect to my existing exhaust? Will I lose power?
The exhaust is a 2 1/4" straight with a 3" muffler universal. LMK
I mean my car is pretty loud, but like to keep it cause of daily driver and cops will give me noise pollutions citation.

EG6owner-T

????

craesq

It depends on whether your DP is a cause of too much backpressure. If you have a 3" DP, then I doubt there would be any increase in power going to open loop. However, FMAX has a 2 1/4" DP and they dynoed a Prelude turbo at 9psi and got 40 more HP when they went open loop!!! Go see their website http://www.f-max.com .

Also, remember, your car will only be louder when the wastegate is open. At that point, your exhaust should be really loud anyway and noise should not be a concern if you are flooring it. My car is closed loop, but I drove an open loop car and did not really notice much difference in noise.

But, make sure you have a long dump tube or else you will get black exhaust in your engine bay!

- Chris

P.S. I will be switching to open loop when I find a way to seal my FMAX downpipe.

EG6owner-T

First off im not into the noise but more in the power, but like to keep the noise to a minimum, cause cops love to hate.
so did you feel a difference in open and close loop?
i will get the rev hard kit, its not on btw.

if there's no difference in noise then how can i keep my exhaust to low volume and still not lose any power.