so i was reading maximum boost by corky bell and it was saying



"in any catalytic-converter equipped car, the wastegate discharge must be put back into the tailpipe before the converter, because all the exhaust gas must pass through the converter."

but then goes to say

" where no converter is required, the opportunity exists to make a completely separate tailpipe soley for the waste gate. a simple muffler may prove necessary to keep noise withing limits when the system is at maximum boost. the value in creating a separate tailpipe here is that it effectively increases the exhaust systems's total flow area. in general, a wastegate will be more positive in response and somewhat more eeffective in controlling boost pressure when accompanied by its own tailpipe"


so would it be more benificial for me to run a separate tail pipe for the wastegate then to plumb it back into the Y pipe? i know it states it in the book but is anyone running

would it be overkill or not? i don't have to run emissions and i am going to keep the duals so should i just make the second muffler just for the wastegate. is anyone running this set up???

 

there are people w/ muffled vented wastegates


and he just states that since if you have a cat, you generally want everything to be up to snuff and emissionsified. theres no reason why you can't

lotsa people on the forum run vented wastegates. I personally think they are too loud for driving around every day. They sound awesome, but are ungodly loud. Muffler would definately help on a rotary.

Then again, you can always just re-route the w/g line to the main exhaust if you don't like the chainsaw on steroids vented wastegate approach


I'm rerouting mine
1) I live in cali and run a cat
2) I don't want to catch any trees/grass/etc on fire because I live in a heavily wooded area.
3) Don't want to have any more attention to my car while boosting than it will already attract.

This is a daily driver in cali mind you.

-Ben Martin

 

well i know those cali emissions are strict. i think that it would probably be loud still if i plumbed it back into the exhaust running 3 inches back to a Y pipe. i think that the exhause routing would be easier imo if i just ran a single muffler off the hot side and then another strech of piping to run for the wastegate venting. im not too sure. does anyone have any pics of their set ups like this???

my friend just put a t3/t4 on his 7 and he doesn't even have a dump pipe on his waste gate and imo i think that strait off the wastegate is too loud also.

 

see i was thinking some thing like this would help with the noise. i just scanned this out of the book but it gives a general idea of what i am thinking about doing.

 

anyone running pics of this kind of set up???

 

that diagram makes it look like the turbo has 2 exhaust outlets, or maybe a twin setup? if your car is a DD then route the w/g dump tube back into the exhaust. if it is a weekend car and you dont care about noise under boost(alot of noise!) then just run a seprate tube out the w/g and have it turn and dump behind the front passenger wheel. good luck with the cops!!

 

Porsche (non US Spec ones that is) runs a system exactly like that for the turbo carrera's they have a little tiny muffler off to one side that is for the wastegate and it works fine for them,

but you really have to consider your power to weeight ratio..... is the extra horsepower going to overcome the extra piping and mufflers weight? I sincerely doubt it..... that why most people just run the re-route back after about 12~ 16"s after the turbine flange. it weighs less than a seperate muffler system, and actually gains more in the overall picture over the seperate muffler system.

kenn

 

should the pipe be dumped back in before or after the o2 sensor bung?

 

i dont think it will matter with such a modified engine

 

Does'nt really matter. If your running the stock o2 then it's most likely going to be plumbed in After the sensor.
Some people run an aftermarket Wideband towards the end of their Downpipe or ever the first part of the Midpipe. The reason for this is to keep the sensor away from the high heat that the rotary puts out in turn keeping the Sensor in good working temps/condition.
With this setup, the wastegate is normally plumbed back into the DP before the Sensor.

 

my WB is going right before the midpipe, just like you said, to get it away from the high heat. i was just wondering if it would affect the accuracy of the WB having the dump pipe before or after?