R-1303

why is that people say you loose horse power from dumping back excess boost back into the down pipe if it is not located 10 inches after the turbo???

accorracer

:i would like to know also


[Modified by accorracer, 3:24 PM 12/30/2002]

johnisenglish

the rule of thumb is that you won't loose power if it's at least 18 inches after the turbo. You'll also want to try to make it a smooth intersection, like a 45 degree angle as opposed to a 90

Overblown-Teg

I think it has something to do with the exhaust being very turbulant leaving the turbo.. you need to give it time and room to smooth out the flow. Also most down pipes have hard bends and lots of angles right away.. This hurts flow, so buy taking a chunk of exhaust gas out of the beginning of the dp its like having a bigger dp. Then you add it back in once things have calmed down some. I hope that helps.

R-1303

so i will loose power?? or will the dumping of excess boost just be more turbulant because of exhaust flow? will there be so much turbulance that the wastegate might not even open??

DeepSi

i think the answer might be if you reenter the gas back into the exhaust flow early it can create exhaust backup and you will not get as much horsepower. so if you reenter later it will less chance of exhaust backup and the exhaust will enter more smoothly and cause less turbulance.

If that did not make any sense, sorry, get over it

R-1303

any other peopel routing their dump tube back to their dp??

JeremyL

what about internal wastegates? aslo why would you even bother having a dumptube?

I Like Boost

i have no dumptube, it just shots out the wastegate. kinda loud at times but daily driveable. with no dumptube make sure your not runnin to rich, you wouldn't want to shot flames at your ac lines, but i dont't have those anyways so i dont worry.

R-1303

can anybody explain why having dump tube to close to the turbo causes loss of power??

BudaKai

He hit it right on the head. Backpressure = BAD

crxhybrid1320

Run it open!
No need to run into the exhaust system except to quite it down.

BlueShadow

well if you are environmentally friendly you would run the WG dump back into the exhaust. Because the WG gasses haven't had a chance to go through the catalyst yet.

crxhybrid1320

Who runs a cat with a turbo application.
Mine is no cat, no resinator, 3' exhaust with a small muffler.

BlueShadow

lots of people do, they just go with a 2.5" or 3" cat.

EDIT: at least those that are law abiding do, did you know it's a federal offense to remove the cat? some states are really strict when it comes to enforcing it and others aren't.


[Modified by BlueShadow, 1:56 PM 1/1/2003]


[Modified by BlueShadow, 1:56 PM 1/1/2003]

Elite Hatch

Whats a catalyst...

OHHH YAH...thats the thing they have on those all motor cars.

Come on now no turbo cars run cats...unless they dont have anything in them, or they want to lose a lot of HP

b18CT

a to loud exaust or dump tube will not give you a chance to ear detonation if it occur!

BlueShadow

That's why you have all those fancy gadgets and doo-dads to monitor your engine and adjust timing so that you dont detonate.

VerbalKint

Someone needs to add a spelling and grammar checker into these forums

MotorMatrix.com

catalyst full exhaust 2.5 inch dump

3inch downpipe out the side of the front bumper


[Modified by MotorMatrix.com, 11:36 PM 1/1/2003]

crxhybrid1320

3" turbo back is good for the street or strip

I'm sorry if the cops read this forum then yes I have a cat

BudaKai

You don't need a cat if you run with a higher ring package and never see high intake temps. Otherwise I don't use a cat either.

R-1303

thats my point i live in cali were it is very strict on smog and plus i hate that lawnmower sound when hitting boost, so what happens if i run it lets say 5in pass the turbo??

blkDOHCsol

whats a catalyst?? im running open, its not loud at all

blkDOHCsol

how you gonna pass emissions with an external wastegate in cali??