My Mustang friend came across a thread where a Turbo Mustang guy switched from rerouting his atmosphere to the downpipe to venting it directly to the atmosphere. He said the extra noise wasn't THAT bad, and he gained HP and the wastegate could vent pressure more efficiently. Is there any truth to this? Should I do this for the sake of performance rather than for the sake of being retardedly loud?

 

Its retardedly loud on a rotary. Mine will make your ears bleed. But hey people know when you're on it.

Not sure about the HP gains or losses, I let you know when I plumb it back into the exhaust.

 

does venting your wastegate to atmosphere change your a/f reading when using a wideband since alot of the exhaust gas isnt making it to the sensor?

well, i guess the gasses that actually do make it there are at the same ratio...

 

I went from atmosphere to DP, no discernable change in either HP, or AFR. The noise from a rotary will get you arrrested, for that matter even my Supra was~122db, so I would say it's a matter of where you live, and if you want evryone staring at you, or running off the road every time your on boost You want to merge at the bottom of the DP, no closer as a general rule.

 

Vent it to the atmosphere; Boost comes on smoother, no hiccups/ issues, Car feels stronger vented to atmosphere. It is loud but keep in mind it will only be open while venting to control boost, AKA WOT which you car will already be drawing some attention to itself so who cares.

i had it dumped into the Dp, switched it to atmosphere and won’t ever think about putting it back it

 

my personal preference is to vent to atmosphere but it can be loud!

 

mine is vented and its damn loud.

 

Mine is vented as well, its is very loud, but man does it sound awesome. If you pass someone on your passenger side at WOT and they have their windows down, they will be hurting.

 

Those of you that don't live in Cali can do that. A vented wastegate in Cali will draw the wrong kind of attention. And the SMOG ****'s out here don't play!! Snub, I'd keep it plumbed into the DP if I were you bro.

Zach

 

I have two 38mm wastegates vented to the atmosphere and they sound like 2 Buells or baby Harleys screaming from under the car. If you search some of Maxcooper's posts, I believe he made the transition from vented to plumbed and may even have the before and after dyno sheets. I'm not 100% sure though.

 

Carl what if you were to plumb the wg a bit back further like the begining of the mid pipe?

 

From what I've read plumbing it back into the exhaust can cause some unwanted turbulence in the gas flow, as well as some exhaust velocity loss. I doubt you'd actually see or feel any real difference on a dyno though, so who cares.

 

Mine is vented to the atmosphere and my car is loud as hell, especially with 3" all the way and no cats. It does break ear drums, but you are going so fast at that point no one can catch you!

 

Venting the wastegate is the best way to go for power... I seen as much as
30-40 whp loss/gain by replumbing it... Although it is rather loud but the good thing its only when you are at full boost.. And it really doesnt affect the afr's at all... The sensor only needs a very small ammount of exh. to read it..

 

I made an old lady jump and grab her husband waiting at a bus stop...1st gear is sick! I bet they thought someone was gunning them down.

 

Steve do you see that big of a loss in HP with it back in the exhaust from all the cars you have worked on?

 

Wow - I just drove for the first time with a closed WG, and my car is much more enjoyable!! Maybe it doesn't pull as hard @ 8k (ear piercing), but man does it rock at max boost mid range!!

my new mod, so thought I'd drop $0.02

 

Hmm...I'm seriously considering doing it for the performance advantages. If it's too loud, couldn't I just have a muffler shop add a little mini-muffler to the wastegate dump tube?

 

I have 2 35mm tials and a 4" DP and 3" open exhaust and it is loud as hell. I like it going under overpasses and bridges and going WOT. It sounds like the end of the world.

 

Now imagine running just a downpipe, with your wg going off, and you backfiring at the same time.

I did that once and a van beside me swerved and almost crashed from it scaring the driver so badly.

 

^^

haha thats great

 

I remember someone posted about his FD being too damned loud, and he couldn't figure out why. He had a Greddy SP exhaust, and a resonated midpipe, and he just couldn't figure out why whenever he got on it, people in other cars would freak out and small children would start to cry. Then he saw that his wastegate was dumping under the car...hahahahaha.

I still don't know if I should do it. I don't live in an area where there's a huge crackdown on modified cars, but I still wouldn't want my car to be ear-splittingly loud.

 

It wont be, as long as you are not at full boost.... it also depends on what turbo and how much you are boosting... For example, im at 15psi on a t70... If my wastegate is open, it means that I have passed the speed limit a while ago, and either way, im breaking the fukin law..

but if you have a smaller turbo, and are boosting pretty low, then I dont think open WG is what you would wanna run.

 

i am venting my HKS GT gate and its bit loud, but not that bad

 

External wastegates are the sheeeeeeeeeat son! I wouldn't trade mine for gold!