Wastegate Poll

[KPowerEP3]

Alright, This is an easy one. Do you guys think I should do an external wastegate dump or route it back into the exhaust? I plan on fabbing up a tubular o2 housing for my car, and can't decide which route I want to go.

[josh green]

external dump sounds better. Dumping back in actually affects the flow of exhaust as well.

[drmcivicsi]

why do u post so many dumb threads ?

[81911SC]

Shut your ****ing mouth.

[Big J]

Recirculate it. It's more fab work, but it'll sound 100Xs better. Recirculating it will affect exhaust flow, but not nearly as much as people make it out to be. Just plumb it in as far from the turbine outlet as possible and you'll never miss the 2hp you might gain by going with an open dump. Open dump sounds like sh!t

[patrick4588]

i personally like the open dump and how loud it is, but if you are against noise then re route it. its not like you hear it all day long or anything, only when you really get on it and hit maximum boost; which i would think at that point how loud you are shouldnt matter.

[Maniaç]

External dump /thread.

[Big J]

i personally like the open dump and how loud it is, but if you are against noise then re route it. its not like you hear it all day long or anything, only when you really get on it and hit maximum boost; which i would think at that point how loud you are shouldnt matter.

It'll start to crack before max boost, so if you run 12 you'll probably start to hear it around 6-8 PSI. I just think it sounds like sh!t, I do exhaust work so it just sounds like a huge horrible exhaust leak to me, Im not aganist noise, just sh!t that sounds bad. There are enough loud and crappy sounding imports on the road as it is.

I like to be able to hear my motor when I'm beating on my car, the best gauges you can have are your ears and eyes if you know what to look and listen for $.02. Turbo motors usually don't blow up while crusing.

I've run an open dump, and I've run recirc, I'll take recirc anyday. Open dump is just easier to do, your production tollerances can be less percise, it doesn't take any extra time, tools or skills to do an open dump, so you see open dump a lot more.

When I hit max boost, my car is actually quieter than at part throttle.

[Danny]

external dump if u want max power, recirculate if want less noise.

most will see a bigger than 2hp increase. it does sound shatty on small, lower power motors.

[Big J]

external dump if u want max power, recirculate if want less noise.

most will see a bigger than 2hp increase. it does sound shatty on small, lower power motors.



You're not going to see a real benifit, other than a small amount of hp if your exhaust is effecient to begin with, (more than 2 whp, but not a whole lot). Untill you get to the point you are really pushing the flow limits of your exhaust system there isn't much benifit. If you lose effenctiy, in the form of increased back pressure, around 500whp on a 3" exhaust you'll see a lot more gains going open dump then if you're nowhere near outflowing your exhaust and you dump, you'll mainly just get noise.

On a 1000whp Supra w/ a 3.5" or 4" exhaust, an open dump is goin to make way more difference than on a 300whp 1.8L **insert car make here** w/ a 3" exhaust. You'll have more than enough flow left in your exhaust to handle what the WG dumps back in. If you running a 2.25" or 2.5" and 300ish WHP, an open dump will make more diffrence than with a 3" exhaust.

There's more to it than preference, unless you're dead set on feeling the need to anounce to the whole world you're in boost.

[blackshine007]

You're not going to see a real benifit, other than a small amount of hp if your exhaust is effecient to begin with, (more than 2 whp, but not a whole lot). Untill you get to the point you are really pushing the flow limits of your exhaust system there isn't much benifit. If you lose effenctiy, in the form of increased back pressure, around 500whp on a 3" exhaust you'll see a lot more gains going open dump then if you're nowhere near outflowing your exhaust and you dump, you'll mainly just get noise.

On a 1000whp Supra w/ a 3.5" or 4" exhaust, an open dump is goin to make way more difference than on a 300whp 1.8L **insert car make here** w/ a 3" exhaust. You'll have more than enough flow left in your exhaust to handle what the WG dumps back in. If you running a 2.25" or 2.5" and 300ish WHP, an open dump will make more diffrence than with a 3" exhaust.

There's more to it than preference, unless you're dead set on feeling the need to anounce to the whole world you're in boost.
It's the ricer in them that makes them want to hear the noise :yes:

I definately agree with you. There's really gonna be mimimal gains with and external vs. an internal. I personally would recirculate it. Whooptie doo that you have boost, why annoy the whole world with it? Just like I would recirculate the BOV as well. Either way with a cone filter, it's gonna be heard. :2cents:

[nextelbuddy]

route the WG dump back into teh down pipe or exhaust.

i left it open on ym first turbo build on the m3 and it sounded like ****. and way too loud.

if you route it back into the exhaust at a direct 90 degree angle you will cause turbulance in the exhaust flow.

always route your dump pipe back into the exhaust at a angle so tha the dumped exhaust merges into teh exhaust flow smoother and also teh exhaust acts as a vacuum helping to pull the exhaust fromthe dump pipe as well.

[Big J]

always route your dump pipe back into the exhaust at a angle so tha the dumped exhaust merges into teh exhaust flow smoother and also teh exhaust acts as a vacuum helping to pull the exhaust fromthe dump pipe as well.

ding ding ding, we have a winner. You can actually use the recirc to increase velocity in the air mass of either the dump tube or the main exhaust depending on which has the higher velocity at any given time and the angles you use. That's part of the reason my exhaust starts at 2.5" goes up to 3" and then I run a 2.5" muffler. By the time the exhaust has reached the 2.5" muffler it has lost a good bit of heat, and because of that volume, so the restriction acts to speed up the air mass, help retain velocity, and create an area of lower pressure at the end of the exhaust via the venturi effect, or I'm completly full of ****.

nothing about this downpipe cost me power. It's idealy recirculated 16 or so inches away from the turbine outlet and is merged smoothly back into the main pipe just before the next pipe. Once I step the next pipe up to 3" it should work even better.


http://treadstoneintercoolers.com/specdp2.JPG

Open dump is somtimes, to some people, just turbo car rice.

[Danny]

thats a nice setup you got there. many people dont spend the time to fab something like that, thus it causes a measurable loss in power. But i would still like to see your downpipe vs a dump to atmosphere on a high power car, that could be interesting.

[KPowerEP3]

Well, it's an internally gated turbo [mitsu], and like I said in the OP, I want to fab up a tubular O2 housing, and I know some people claim gains with an external, and others say it's just for noise. I was mainly looking for the fluid dynamics aspects of it like Big J posted, from some one with more knowlege than I. The noise doesn't bother me, but it isn't necessarily a plus for me either.

oh and just FYI[blackshine and big j]...my BOV is recirculated....I'm not one of those 'look at me, my car is turbocharged' guys, I don't want too much unnecessary attention.

[Benefit]

route the WG dump back into teh down pipe or exhaust.

i left it open on ym first turbo build on the m3 and it sounded like ****. and way too loud.

if you route it back into the exhaust at a direct 90 degree angle you will cause turbulance in the exhaust flow.

always route your dump pipe back into the exhaust at a angle so tha the dumped exhaust merges into teh exhaust flow smoother and also teh exhaust acts as a vacuum helping to pull the exhaust fromthe dump pipe as well.

x2 , it sounds like ass...:no:

why are people saying leave it open?

[turbosx©]

caus thats what they were told by there buddies

[Big J]

thats a nice setup you got there. many people dont spend the time to fab something like that, thus it causes a measurable loss in power. But i would still like to see your downpipe vs a dump to atmosphere on a high power car, that could be interesting.

Lets put it like this, Turbonetics, the big turbo experts, made 275 at 8psi with a BB 50 trim t3/t4 on a Spec V, their recirc and manifold are anything but ideal.

I made 271 @ 5 psi with the same turbo, except I used a journal bearing unit, 8-8.5 PSI I made 304 whp and spooled just as quick.

Open dump on these cars are good for about 10whp, that's it. 2.5L reliving manifold pressure out of a 1.5" dump tube sounds like total ****, I've run an atmo and a recirc on my car, recirc hands down.

The more restrictive your exhaust to start with, the more power an open dump will make. If you try to optimize everything from the get go, open vs recirc won't really be a big issue of concern to start with.

[KPowerEP3]

exhaust flow isn't an issue. I'm running 3" all the way out of the turbo, catless with a maximum goal [for now] of 400whp on a 2.0

[drmcivicsi]

what turbo ^^^

[AnthonyF]

i'd vote...but i no nothing about wastegates.... good luck. i will read to learn more though. :)

[superboost]

It's the ricer in them that makes them want to hear the noise :yes:

I definately agree with you. There's really gonna be mimimal gains with and external vs. an internal. I personally would recirculate it. Whooptie doo that you have boost, why annoy the whole world with it? Just like I would recirculate the BOV as well. Either way with a cone filter, it's gonna be heard. :2cents:


This coming from the man who encourages me to ride up next to people and dump to see the looks on their faces. :lmfao:


If you want to run it external, just be advised of the additional noise it creates. If you want to run internal, then plumb it internally. Also, you should figure out what you want to do with your car. If you are driving it daily, or frequently, I'd recommend plumbing it back in. it is only fun when you hear it about the first 10,000 times. If you plan on driving the car only on weekends, leave that beyotch open.

That being said, I prefer open, but that is my preference.

[2Fast4Radar]

Well, it's an internally gated turbo [mitsu], and like I said in the OP, I want to fab up a tubular O2 housing, and I know some people claim gains with an external, and others say it's just for noise. I was mainly looking for the fluid dynamics aspects of it like Big J posted, from some one with more knowlege than I. The noise doesn't bother me, but it isn't necessarily a plus for me either.

oh and just FYI[blackshine and big j]...my BOV is recirculated....I'm not one of those 'look at me, my car is turbocharged' guys, I don't want too much unnecessary attention.On a car that came out of the factory with a recirculating BOV or any car that has a MAF sensor before the BOV outlet on pressurized intake side the car should run better. If you run open atmosphere you are dumping unmetered air that ECU will think is there. When you vent it will cause a temporary rich condition. That combined with the a slight loss of momentum of the compressor wheel will make you lose power as well as take longer to respool the turbo. If you were running speed/density then it really wouldn't matter since you wouldn't really have a way to recirculate it.

I have a few different BOVs sitting around that I've installed my car: HKS SSQV, Blitz SS, recirculating stock BOV, and Greddy Type-S. The recirculating Type-S is by far the best performing BOV after being properly adjusted properly - for now. I'm switching to speed/density soon so I'll be removing a lot of pipes and changing BOVs again.

Open atmosphere will work (although I've heard issues of cars stalling after venting while running open atmosphere after a gear pull to redline), but closed loop really is the best for most cars.

[KPowerEP3]

what turbo ^^^
big 16g

[iEvo]

external FTW

[crashtke]

Another option is find a muffler from one of the old porsche turbo cars. They had external wastegate with a dump tube and it had it's own little baby muffler on the dump tube.

[GAtegs]

Mine goes right back in. My 3 in. exhaust is loud enough, I don't need to add to it.

[kaotickaozpunk]

to much fabricting back to the exhaust...

[chituntang]

Do not do open air. We hurt the environment enough by running gasoline engines with exhaust on. Open air wastegate just release the sh*t just burn from the engine.

Beside the extra cost, I usually see people lost races because of driver mistake, faulty car, difference in performance, but never seen lost because of 10hp...

OK, maybe on a "dyno battle."

[Mdeezy]

It'll start to crack before max boost, so if you run 12 you'll probably start to hear it around 6-8 PSI. I just think it sounds like sh!t, I do exhaust work so it just sounds like a huge horrible exhaust leak to me, Im not aganist noise, just sh!t that sounds bad. There are enough loud and crappy sounding imports on the road as it is.

I like to be able to hear my motor when I'm beating on my car, the best gauges you can have are your ears and eyes if you know what to look and listen for $.02. Turbo motors usually don't blow up while crusing.

I've run an open dump, and I've run recirc, I'll take recirc anyday. Open dump is just easier to do, your production tollerances can be less percise, it doesn't take any extra time, tools or skills to do an open dump, so you see open dump a lot more.

When I hit max boost, my car is actually quieter than at part throttle.


You said it best.

I'd take the sound of the turbo spooling over the sound of the wastegate dumping.