Do you loose any hp whith a closed loop setup? Does it matter where it ties back into the exhaust? Could you weld the dump tube right into the top of the DP?

 

I dont think you can acutally lose horsepower with a closed loop setup. And it shouldnt matter where you weld the dump pipe to the down pipe.

 

Does it affect anything then? Why arn't more people using it? Or are they, and Im just blind?

 

actually you might wanna ask arturbo about it, the way you routing the closed loop in the downpie can affect HP..prolly not by much, but I'd ask him first...

 

If you weld it to the top of the DP it has to fight the exhaust exiting the turbine and you will lose horsepower as well as have possible boost creep problems. If you plumb it back into the exhaust well after the turbo it is fine.

 

exactly... basically u will lose more power the closer it is to the turbo where u plumb it back... farther away u will lose power... either way u will lose power... but not much when running low boost... i dont know about high boost as normally people running high boost run open loop

 

I was thinking I could make a testpipe with the dumptube welded to that. Then I will put a flex pipe somewhere between the waitgate and the test pipe. Will that work?

 

Uhm.. no.. dont listen to what Tom just said. You wont lose HP if you plumb the pipe down, far from the turbo, and with an agle at the connection to the exhaust. Dont have it plumbed straight to the exhaust like a "T". Have it like a "V". The reason F-MAX lost so much hp with a closed loop system is 1.) they had it plumb'd real close to the turbo. 2.) cuz they actually routed the pipe in the direction TOWARDS the turbo..

 

<------dummy... dont listen to me

 

Im understanding it alot better now. I think when the times comes, I just weld it in "v" to the very end onf the DP like Rob92SC said.

 

oh... just so io may be allowwed to clarify... any power loss isnt going to be really noticable... maybe ull notice it if u have it vented back into the exhaust right after the turbo (once again for low boost)

 

What size pipping should be used from the waist gate to the DP?

 

I would say probably the same diameter as the output of the wastegate. Then go all the way down by where a flex pipe would be and weld it into that dp in the y shape. I will have to experience this first hand in a couple of weeks when I fabricate my downpipe. Ofcourse I will post pics. Unfortunately I will be going with a 2.5" dp cause I dont feel like upgrading my catback from 2.25 to 3".
Stay posted!

 

Is the closed loop waist gate alot quieter that a open waist gate? Iv never heard a open waist gate, or cloosed loop waist gate for that mater, but can someone explain the 2 different sounds for me?

 

Just look at Dustin's "My car is alive again" thread. You can see how he welded tubing to his DP and used mandrel bent tubing out of his wastegate. When I talked to him, he said that he used flexpipe as well...probably in between the two pipes.

 

Yep. Closed loop owns heheh.

 

A closed loop wastegate should be very quiet. With an open wastegate, first you hear the turbo starting to spool, then as you reach maximum boost, you hear the wastegate let off that crazy hot rod sound. It's freaking loud in my opinion, especially if it goes off in a tunnel or under a bridge. It is intimidating to unsuspecting ricers.

 

open wastegate sounds like an exhaust leak, closed wastegate is basically silent. And like tom said, no matter where you put it you will lose power, placement just depends on how much you lose. btw im not talking about big numbers here, you plumb it correctly and you will lose less then 10hp

 

I honestly do not think you lose much power. I did not notice a difference... the car actually feels faster after (I lost my A/C too though).

Dustin

 

hmm...i dunno about gaining power. maybe you should trust something more accurate then the butt-dyno

 

Oh I know you don't gain any power... I'm just saying the difference was negligible.

Dustin

 

i think the best spot to route the dump tube on a closed loop system is 18 inches after the turbo, or so i have heard.

 

So says corky bell.

 

another option to think about is just welding a muffler of some sort onto your dump tube. Figure out what to use, and how you are going to mount it. I used to ride moto-x bikes, and i think a 125-250cc race muffler would work quite well. They are small, and not terribly expensive. It would look pretty cool too !

 

I will run open loop to start with, then later if it is too loud I MAY go closed loop. I do not mind extra noise, so I will probably stay open loop. I like any extra intimidating sounds, esp since I have a little SOHC!!! Then I may get some of the "big boys" to chicken out so I will not have to run them! YEAH RIGHT!!!!