External Wastegate open or re-route into exhaust

[Thumper]

With my new turbo I might have to go with an external wastegate so i'm contemplating how to install it. I will most likely run a 38mm tial off of the stock manifold located at the no. 5 or 6 cylinder.

My question is should I re-route the exhaust port into my downpipe or just leave it open? I'm worried about performance, sound, and reliability. Thanks

[Sparky]

I run mine open and wouldnt have it any other way, the sound when the WG opens is INCREDIBLE, like my engine is shooting out a jet propelled swarm of angry bees.

I'm running a 1.5 foot length of 1 1/4 inch tubing that dumps one slightly lower than the cross member just forward of the drivers side footwell. (this may change) I've noticed no performance or reliability issues...yet. im running a deltagate now but will switch to a tial when I upgrade to the T66.

Thumper,

No you are talking! You have started down the path of no return. Larger Turbo, external wastegate, next will be the turbo header! Performance with proper exhaust and tuning both open and closed will work. Did you put cards in your bicycle wheels for the noise? If so open, if not closed.

Pete

<http://www.cardomain.com/ride/2116389>

[Moridin]

It drowns out a lot of your exhaust noise. My friend had his wastegate running open on his single turbo Supra (yes, I know, everyone has a friend with a Supra) and personally, it sounded pretty crappy. I'd much rather hear the melodious sound of one's exhaust compared to that.

[Brad-ManQ45]

Or you could have a complete exhaust to the back for the wastegate only, w/small muffler.

This is the best of both worlds, performance and sound-wise, to anyone that doesn't like loud....

[Clifton]

IMO the only thing that sounds worse than an open WG is a Harley. The power loss from rerouting it back into the exhaust is nothing, unless it's an all out, no comprosmises race car. If you have any knock you won't hear it either. I like my exhaust as quite as I can get it, I don't need officer A-hole hearing me before he sees me. It's still plenty loud when I get into it.

[thehelix112]

Hey,


I have a 2.5" screamer pipe on my setup. Can hardly hear it at 11psi. It might make more noise at higher boost, but I love it.

Dave

[Z-Gad]

I run my wastegate open as well. It makes no difference in sound until you are building enough boost to open it and then it just sounds NASTY (in a good way). If someone offered to route it back into the exhaust for me for free and give me $50, I would say no. I like the sound of the open wastegate. It is all business.
BTW, I ran the 2JZ wastegate open as well, even if i haven't been able to use it yet (another gremlin story).

[Thumper]

So performance wise keeping it open is slightly better. No one has responded to reliablility so I assume there is no difference. On the sound issue it seems we have two completely opposite opinions. Either you love it or hate it.

I think the sound is going to sway me either one way or another. When I was a kid I did put baseball cards in my spokes but lately i'm getting tired of loud cars. My z was running with just a downpipe for a month. Then I put a muffler right after the downpipe and now i'm planning to put a full exhaust 3" exhaust with muffler on it. Something I just thought of is during normal driving or highway driving it won't matter since it won't open. So the only difference will be under full throttle.

So my question has now become what sounds best open or re-circulated? Thanks

[Chris240zTurbo]

I vote for open, VVVVVVVVVVVVRRRRRRRRRRRROOOOOOOOOMMMMMMMMM


actually rerouted might sound better, and surely not nearly as loud, mine is LOUD, but I like it, and I don't think I'll change it... you're right, it's only nasty when it's open.

oh what do i hear!!!! Chris saying he LIKES it open.
didnt you give me crap because i told ya you need to make yours open.. ha told ya you would like it!

mike

[PrOxLaMuS©]

running it open is also called a "screamer pipe" very popular in the U.K with Nissan Skylines and such...




Not my car.. but you get the idea

[spork]

I run mine open, but my exhaust is loud enough you don't ever hear the wastegate dumping anyway...

[slownrusty]

Does this help?



Yasin

I say do NOT run it open... it's going to be VERY loud. I remember when I ran my car with just the open DP for a week... man it was horrible... way too loud. Though my car is as much a sleeper as a Z can get, it still get's too noticed when I get on it, and yeah that's gotten me in trouble already once, $400 worth. I agree that the performance gain would be so little that it's also not worth even thinking about. You may think there's times when it would be cool to have it loud like that but remember, you sometimes hit boost even when not going all out, like climbing a hill, or other times... where you would not want that sound.

I'd rather do an exhaust cutout with electronic control in the cabin that I could open only when at the track or something. Though with a proper 3" mandrel exhaust and good muffler even this would probably make so little difference in performance.

[Thumper]

Originally Posted by bastaad525

I say do NOT run it open... it's going to be VERY loud. I remember when I ran my car with just the open DP for a week... man it was horrible... way too loud. Though my car is as much a sleeper as a Z can get, it still get's too noticed when I get on it, and yeah that's gotten me in trouble already once, $400 worth. I agree that the performance gain would be so little that it's also not worth even thinking about. You may think there's times when it would be cool to have it loud like that but remember, you sometimes hit boost even when not going all out, like climbing a hill, or other times... where you would not want that sound.

I'd rather do an exhaust cutout with electronic control in the cabin that I could open only when at the track or something. Though with a proper 3" mandrel exhaust and good muffler even this would probably make so little difference in performance.

I think you are confused. We are not talking about the exhaust system just the exhaust coming out of the external wastegate. I too have run with just the dp and its very loud. Not going to do that again. I think i'm going to run it open and then if its too loud I will re-route it in. Although its only going to be loud during full acceleration so I don't have to worry to much. Thanks

[Scottie-GNZ]

The w/g dumping to the atmo can be loud and the shorter the dump pipe, the louder it will be. However, it should only be dumping at full boost when the w/g is diverting exhaust from the turbine housing/wheel. If it is "loud" any other time, then there is something wrong with it. As for loud, that is relative. You get used to the hushed sound of a turbo exhaust then switch to the "angry pack of bees" sound and you will notice it. As for using the electric cutout, that is definitely another option but what is the difference? Actually, the cutout will be louder since you are dumping out of a 3" pipe vs 1.5" or slightly larger. As for the benefits, it depends on the HP and DP/exhaust diameter. If you are running closer to stock levels and have a decent DP and exhaust, then it is probably not worth it. If you are running a T04 then it is assumed you will be making enough HP to see a gain. It is all about reducing back pressure in the exhaust and the better function of the external w/g.

I just modified mine to dump to the atmo because I am at the point where I should see a gain over my 3" DP.

[Pyro]

I like it to dump back into the exhaust system.

Lately having been working on a friends turbo Z that has an atmosphere venting wastegate and I don't like it at all. It is makes a loud obnoxious noise under the car that always seems to startle me since I never really know exactly when it will go off. It distracts me from driving and prevents listening for detonation. Plus it sounds like driving a car with stock exhaust manifolds without a muffler (barf).

I also have my bypass valve plumbed back into the intake. But I'm not trying to impress anyone.

nope I understand the difference, I've seen the high hp turbo cars with WG dump pipe open but still having a full 'proper' exhuast.

Still, I think even if it's only going to be loud during WOT... it's still going to be too loud, IMO.

I guess for me... I just drive around WOT way too much so I still think it'd be too loud... and the last thing I need driving around in a big, heavily-cop-populated area, is to hit WOT and some cop two blocks down hears me coming and nails me.

The less attention I garner from the police, the better.

This, coming from a guy who just bought a bright red SRT-4 with huge wing on it (taking that thing OFF soon as I find some good plugs for the bolt holes!)

[Scottie-GNZ]

Originally Posted by bastaad525

... and the last thing I need driving around in a big, heavily-cop-populated area, is to hit WOT and some cop two blocks down hears me coming and nails me.

The less attention I garner from the police, the better.

What you should have said:
"... and the last thing I need driving around in a big, heavily-cop-populated area, is to hit WOT.

The less attention I garner from the police, the better."