I can't seem to remember, but are there any side affects of doing this other then how loud it is?

global warming


jk lol. i dont think so. :)

actually, I'VE HEARD,..... up to like 5-10whp gains.

actually, I'VE HEARD,..... up to like 5-10whp gains.

humm... ?

humm... ?

any turbulence you can leave out of the exhaust system is a good thing. Additionally, there's less back pressure at the end of the wastegate than there would be if it were tied back in. It is not uncommon to pick up hp by not tying it in.

plus it sounds monstorous when it opens up

plus it sounds monstorous when it opens up

Aka - It will scare kids that are around.... So do it. :evil2

just remember to dump it out of the engine bay via a dumptube

some people experience a little boost creep up top w/ open wastegate, other than that, all i see are benefits ( more flow, sound, etc :devillook )

It's loud and sounds very angry, DO IT!!1!:evil2

http://i3.photobucket.com/albums/y83/lisaotis/IMG_0450.jpg

routing the WG back in to the exhaust will help with boost consistency. You will also need less total WG flow in many cases.

I have been running an open wastegate for the past 1500 miles of my build with no issues! I will warn you, it is very loud, scaring people out of your way is not uncommon. As soon as I get to the dyno I wll be able to see what numbers I'm putting down.

some people experience a little boost creep up top w/ open wastegate, other than that, all i see are benefits ( more flow, sound, etc :devillook )
???? Wouldn't more flow cause less boost creep? Ive always heard and experienced less boost creep with my other cars when venting to atmosphere. Seems logical that putting back into exhaust would cause more backpressure in both systems and would cause boost creep. I may be wrong, but it seems more likely those people would be having more boost creep issues with it redirected back to exhaust and probably needed a larger wastegate to begin with. Am I wrong on this, but everything Ive seen in the past points to open WG=less boost creep but now theres 2 people on this thread saying differently. what are your guy's explainations for your conclusions?

P.S. not trying to be argumentative, just wanted to know your logic behind the argument... I could be wrong I supposed.

I'll tell you right up front that I don't have actual experience with this question, but I've given it a lot of thought. :rolleyes :D

Anyway, to get myself subscribed to the thread and such, the one way I can see it (atmo dump) causing boost creep is that the lack of the wastegated exhaust volume in the exhaust system down stream of the turbine creates a larger pressure differential across the turbine wheel, which has to cause it to spin faster (creating more boost).

On the other side of the issue, obviously the greater flow potential of the atmospheric dumped WG should help hold the boost down. . . . So who knows? (and that's not just a rhetorical question, I'm hoping to learn something here! :cool ).

I'll tell you right up front that I don't have actual experience with this question, but I've given it a lot of thought. :rolleyes :D

Anyway, to get myself subscribed to the thread and such, the one way I can see it (atmo dump) causing boost creep is that the lack of the wastegated exhaust volume in the exhaust system down stream of the turbine creates a larger pressure differential across the turbine wheel, which has to cause it to spin faster (creating more boost).

On the other side of the issue, obviously the greater flow potential of the atmospheric dumped WG should help hold the boost down. . . . So who knows? (and that's not just a rhetorical question, I'm hoping to learn something here! :cool ).
boost creep is ussually an issue of not enought flow on the wastegate side (Like your 2nd idea). either the WG plumbing is not large enough to flow what is needed or the gate itself is not large enough (or if it is rerouted to exhaust the pressures could slow the gated gasses down). if the turbo spools more boost is still regulated by the WG in the end. If it has enough flow, it will vent what is needed to achieve the proper amount of boost. if there is not enoug flow through the WG then the pressure in the manifold will grow and cause boost to rise. This factoid is why I say that open WG will flow more than a close routed through the exhaust (UNLESS THE EXHAUST PIPING IS LARGE ENOUGH NOT TO INCREASE BACKPRESSURE OR SLOW WASTEGATED GASSES ENOUGH TO CAUSE HIGHER MANIFOLD PRESSURE.)

Now, I almost forgot about this, if you slow down the exhaust after the turbo, or create more backpresure, the turbo will not be able to spool as much and can slow boost creep that way. On Rx7's with full exhaust and intake are notorious for boost creep. One such remedy is a restricter on the downpipe which causes such backpressure and slows the spool, but as you would guess, robs power. The other remedy is to port the stock wastegate opening. some port larger than the stock gate door and use a turboII wastegate door which is slightly larger. This works well. Other people port it a couple mm then remake the downpipe so it has a separate wastegate pipe and vent it to atmosphere like an external style. This by far works the best. I remember many GT35R single Rx7's having creep issues with 46mm gates rerouted back into the DP and then remedying it with just a simple dump.

just remember to dump it out of the engine bay via a dumptube

so basically try and make the dump pipe as short as possible then is what you're saying...

It sounds badass! I had to dump mine for design reasons and i'm glad i did. It sounds like a hissing type of growl. You'll love it. The good thing is it only makes that noise when you're really flogging it.

I am interested to learn how loud the dump is when made to atmosphere. Can someone grab a short video or sound bite and post this scary noise?

I am considering changing from a log manifold to a tubular header design and it would really simply my life to not have to route the waste gate back into the down tube.

Does the waste gate dumping to atmosphere provide a flame thrower effect at night? If I direct it out the top of my hood would it make my car look like a top fuel dragster or roman candle launcher?

It's too loud....:eyecrazy

It drove me crazy while I had it open... I like loud but not this type of load is just a loud shusssssssss.

my 2c.

We're also going to run a 3" straight exhaust back into a magnaflow :rofl this thing is going to be loud as hell..

We're also going to run a 3" straight exhaust back into a magnaflow :rofl this thing is going to be loud as hell..


See that is a good example... My exhaust has no muffler and I love it.... But the WG is like a bad example of loud.

here is to the atmosphere: http://video.google.com/videoplay?docid=-2553866101753160350

here is not: http://video.google.com/videoplay?docid=1532865219329789436

Good luck anyway.

We're also going to run a 3" straight exhaust back into a magnaflow :rofl this thing is going to be loud as hell..
same here except I have a 3inch vibrant resonator. still strait through though.:D

wow... and it's a Pontiac GTo :D

what are you doing for tuning?

wow... and it's a Pontiac GTo :D

what are you doing for tuning?

I know, I know I always get my domestics mix up, mustang camaro gto all the same to me...:stickoutt

It's a TRM kit so it comes with tuning. Techno550's tune.

Makes it crappy to tune with an open dump :( Tougher to hear knock.

Also dyno facilities usually do not appreciate it, as some dump tubes can melt sensors and wiring in the dyno.

I know, I know I always get my domestics mix up, mustang camaro gto all the same to me...:stickoutt

It's a TRM kit so it comes with tuning. Techno550's tune.

BOV with DME tuning?

I don't care for the way it sounds either, it's not so much that its loud it just has a raspy sound to it.

Makes it crappy to tune with an open dump :( Tougher to hear knock.

Also dyno facilities usually do not appreciate it, as some dump tubes can melt sensors and wiring in the dyno.
Good points.

BOV with DME tuning?

yes sir.

yes sir.

humm... do you have issues when shifting with AFRs going buck nutty?

It's too loud....:eyecrazy

It drove me crazy while I had it open... I like loud but not this type of load is just a loud shusssssssss.

my 2c.

x2

Makes it crappy to tune with an open dump :( Tougher to hear knock.


Yup, completely. I can't hear my engine at all when the w/g opens up. It's just "brrrrrrrrrrrrraaaaaarrrrrrrr." Quite annoying actually. I want to hear the engine, turbo and the exhaust, not just the w/g and exhaust.

???? Wouldn't more flow cause less boost creep? Ive always heard and experienced less boost creep with my other cars when venting to atmosphere. Seems logical that putting back into exhaust would cause more backpressure in both systems and would cause boost creep. I may be wrong, but it seems more likely those people would be having more boost creep issues with it redirected back to exhaust and probably needed a larger wastegate to begin with. Am I wrong on this, but everything Ive seen in the past points to open WG=less boost creep but now theres 2 people on this thread saying differently. what are your guy's explainations for your conclusions?

P.S. not trying to be argumentative, just wanted to know your logic behind the argument... I could be wrong I supposed.
I get a little creep, not sure how to explain it- or what your looking for.

FWIW I was driving next to multiplex and went WOT - he txt'd me saying "open wg sounds ridiculous".

I may tie it in, though I am thinking not. I dunno... crap.

humm... do you have issues when shifting with AFRs going buck nutty?

No at all. The only thing I had to do is adjust my driving technique since is hard to do a PT while accelerating in a turn. I

I can't hear my engine at all when the w/g opens up. It's just "brrrrrrrrrrrrraaaaaarrrrrrrr." Quite annoying actually. I want to hear the engine, turbo and the exhaust, not just the w/g and exhaust.

Good point my fellow FI member, when I'm racing I need to be able to hear $ feel my engine reving, sometimes or most of the times I can feel/hear it before anything goes wrong, like a boost leak; you will not be able to hear it if your WG goes to the asmosphere...

I think it sounds horrible, i would suggest riding in a car with an open wastegate first. A friend of mine had a big turbo vw 1.8T with an open gate, and i thought it was awefull. Gotta be worse on a big hp straight six

i do not like open wastegates. way too loud. i will eventually route it back into the exhaust.

No at all. The only thing I had to do is adjust my driving technique since is hard to do a PT while accelerating in a turn. I



Good point my fellow FI member, when I'm racing I need to be able to hear $ feel my engine reving, sometimes or most of the times I can feel/hear it before anything goes wrong, like a boost leak; you will not be able to hear it if your WG goes to the asmosphere...

Definitely agree. I recently ran a modified auto-x (higher speeds) for the first time since being FI and almost all I heard was open wastegate every second I was wot.

Oh and for the people who do dump to atmosphere, make sure you route it as far to the rear of the car as possible. The smell is nauseating after a while.

open gate on a bit turbo big port rotary is kinda scary.
You get this loud rotary exhaust note, some turbo spool noises - then things just explode, your shoved in the back, punched in the eardrums and can smell unburnt fuel and burning rubber :D

However, an open gate on a piston car just sounds like an exhaust leak. Dunno about you, but i dont like exhaust leaks.

Enough said. Thanks for the advice I will keep my waste gate tied into the down tube.

I wonder how far down the exhaust system you would need to go to optimize the trade-off between additional tubing weight and back-side turbulence.

I read once that a separate waste gate tube all the way to the rear of the vehicle is preferred, but that seems a little ridiculous for a front engine vehicle.

I would assume that after both approximately 90 degree bends that get a down tube to the tranny tunnel, the turbulence impact of a merging waste gate pulse would be almost negligible.

just remember that the dump tube is going to be thermal cycling much more than your dump.
Either give the wg return a flexi, the dump a flexi, or build a bit of room into the two of them for the wg return to expand and contract - otherwise you will always be cracking the front half of your exhaust.

As for where to join?
Before the cat is usually the best way to do it.

Oh, i have seen someone put a muffler on their open wastegate before ....

I like this. Someone gotta try it on a bimmer :D

I like this. Someone gotta try it on a bimmer :D

That's what I am doing out the passenger side behind the fog light

That's what I am doing out the passenger side behind the fog light

Yeah I want to make a plate like that for my rear bumper. I am fed up with cleaning the black soot at every gas station. It shows up really easy on a white car.

Yeah I want to make a plate like that for my rear bumper. I am fed up with cleaning the black soot at every gas station. It shows up really easy on a white car.

Nice tune.

Nice tune.

:confused What's your lambda on boost?

Hmmmm need better sound clips :devillook

:confused What's your lambda on boost?

I used to have that problem when I was rich in the 10's. Ever since tuning it for 11.6 - 11.7:1 i have no more issues.

:confused What's your lambda on boost?

Couldn't tell you, no boost here.

Couldn't tell you, no boost here.

lolmabeans

Oh, i have seen someone put a muffler on their open wastegate before ....

I have thought about this but where are you supposed to find a muffler that small?

I wonder if you could employ a muffler from a small motorcycle engine or ATV?

FWIW I was driving next to multiplex and went WOT - he txt'd me saying "open wg sounds ridiculous".

I may tie it in, though I am thinking not. I dunno... crap.

its ridiculous if you were next to some old lady or something.

but it does sound kinda rad. but then you can't hear the turbo spool as much . guess everything is a trade off

I wonder if you could employ a muffler from a small motorcycle engine or ATV?

http://cgi.ebay.com/ebaymotors/Chopper-Bobber-shorty-mufflers-1-1-2-1-3-4-inlet-NEW_W0QQcmdZViewItemQQcategoryZ35619QQihZ002QQitem Z120158755997QQrdZ1QQsspagenameZWDVW

Maybe something like this? I wonder how it would sound?

or something like this:
http://i51.photobucket.com/albums/f379/JeanSada/MR%20EVO-8/IMAGE_051.jpg

Its hard to tell whats going on in that pic but it looks like maybe an open down pipe?

Two wastegates and both are dumped to the atmosphere. The pipe to the right of the pic is from the wastegate on the manifold. The other is on the the dowpipe and dumping also.

http://cgi.ebay.com/ebaymotors/Chopper-Bobber-shorty-mufflers-1-1-2-1-3-4-inlet-NEW_W0QQcmdZViewItemQQcategoryZ35619QQihZ002QQitem Z120158755997QQrdZ1QQsspagenameZWDVW

Maybe something like this? I wonder how it would sound?

Funny approach but a valid idea :)

I can here my turbo over my open dump, but i am also kinda getting tired of the noise. I think over my winter revision a 3.5in exhuast with recirc dump is in order. Im just getting tired of how loud it is and how i cant hear anything.

everyone has already said it sounds crazy. but i'll just +1 it cuz it is just that crazy. It really is the only way to go.

If you are going to put a muffler on it anyway, why not just route back into the exhaust. Just plumb it far enough from the turbo.

heres a vid of me racing a sti with fpgreen turbo/race gas/29psi plus a bunch more mods. this is me on low boost and my old timing map. This just gives you an idea of how loud open dump is.

http://www.youtube.com/watch?v=2PpXHDXn8YQ

i duno, a preference thing i guess...i like it but i can see how it can be annoying to some

somebody should do the WG muffler, maybe that will turn out to be a genious idea....:devillook

somebody should do the WG muffler, maybe that will turn out to be a genious idea....:devillook

People do it a lot just not on our BMWs

People do it a lot just not on our BMWs

ohh. Do you have a link or data to share on this? I still think is a valid idea

meh, i think it tends to be more a ricer mod. lol I dont even know where id be able to fit a small muffler on my wastegate.

meh, i think it tends to be more a ricer mod. lol I dont even know where id be able to fit a small muffler on my wastegate.

Ricer.... dont think so.

Ricer means everything for show and no go... go figure. I have a 3" exhaust all the way to the back with no muffler, resonators or cats... so I have plenty of space to work with. For someone with the stock exhaust system or with a full system I dont think so.

performance > sound who cares what its sounds like when your a mile ahead:help

performance > sound who cares what its sounds like when your a mile ahead:help

Less attention from the popo

Less attention from the popo

i geuss you cant out run the radio ;) :mad

performance > sound who cares what its sounds like when your a mile ahead:help

I agree but I love my hearing, I wear ear plugs in my race car I dont want to do it in my DD car ;)

Less attention from the popo
Unless you are the Popo,:devillook:redspot:buttrock!