Dual Wastegates
Thread Starter
Haltech E6K
Joined: Feb 2001
Posts: 420
Likes: 0
From: Northern California (USA)
Dual Wastegates
I am interested in anyone running a dual wastegate setup. Why did you do it, do you have graphs from before and after? How much did spool-up improve?
Yes, I know why you would do it, just looking for info from peeps that have done it.
Anyone?
Yes, I know why you would do it, just looking for info from peeps that have done it.
Anyone?
a couple have just look at some peoples build threads.... after 8 yrs you havent done this? lol must not have been important. but seriously just cause your running dual wastegates dosent improve spool up.... UNLESS it was part of swapping a divided manifold and turbine setup's single wastegate to duals, so it would completely divide the exhaust pulses to the turbine. with the single wastegate setup it would have bled the pulse into the other runner via the wastegate piping killing the effectivness of the pulse to spool the turbo. hope that answers some of your question cant say how much it would improve spool though i havent done it
z
z
Thread Starter
Haltech E6K
Joined: Feb 2001
Posts: 420
Likes: 0
From: Northern California (USA)
No, I became side tracked with my car. It is all cozy in my garage. I am back to working on it though. Trying to decide if I want to sell my one big wastegate and put on two smaller ones.
Yes, this thread is old. I did a search for all the threads I started and this one didn't have any information in it
Yes, this thread is old. I did a search for all the threads I started and this one didn't have any information in it
Trending Topics
I went from a divided 60-1 with single wastegate to a divided GT35R with dual wastegates and my spool improved dramatically. With both setups the runners were very short. The original setup didn't reach full boost (14 PSIg) until nearly 5K on dyno pulls, and the new setup is all in by just over 3K (12 PSIg).
Can't say how much of the difference is due to the turbo and how much to the manifold. Pretty sure the boost level didn't make much of a difference.
Can't say how much of the difference is due to the turbo and how much to the manifold. Pretty sure the boost level didn't make much of a difference.
Zilla Killer
Joined: Mar 2001
Posts: 333
Likes: 0
From: New Zealand
what size wg are you using elwood? and what diameter are you runners?
im looking to use 2 of th enew tial 38s with 42mm runners with TO4z, was suggested to use 2x 44 but I think its well overkill and far more expensive
im looking to use 2 of th enew tial 38s with 42mm runners with TO4z, was suggested to use 2x 44 but I think its well overkill and far more expensive
I went from a divided 60-1 with single wastegate to a divided GT35R with dual wastegates and my spool improved dramatically. With both setups the runners were very short. The original setup didn't reach full boost (14 PSIg) until nearly 5K on dyno pulls, and the new setup is all in by just over 3K (12 PSIg).
Can't say how much of the difference is due to the turbo and how much to the manifold. Pretty sure the boost level didn't make much of a difference.
Can't say how much of the difference is due to the turbo and how much to the manifold. Pretty sure the boost level didn't make much of a difference.
Joined: May 2004
Posts: 2,988
Likes: 0
From: Home of the 305 Boyz(miami)
i run on bigs single. its a little cheaper running 2 small wastegates if you dont have the money.
BTW this thread has to be in the hall of fame as the oldest thread in history
kinda sad 8 years & no response
2x 38 mm wastegates and a long equal length manifold and I'm never looking back.
As what Enzo said, the dual wastegates help considerably when managing boost. But a proper manifold is the way to go. I'll never cheap out on a mani ever again in life. BIG difference.
As what Enzo said, the dual wastegates help considerably when managing boost. But a proper manifold is the way to go. I'll never cheap out on a mani ever again in life. BIG difference.
WG Sizes
The single WG was a TiAL 46mm; the duals are TiAL 44mm. When I went dual, I used the 44mm WGs because they are much smaller and use V-bands. These attributes combine to make them package better.
Spool wouldn't change. The wastegate is still closed during spool up. Since dual gates would typically flow better you might gain a very small amount near target boost by holding them closed longer, but it would hardly be noticeable.
Regardless of the cause, I'm happy as a clam.
Wouldn't a fully divided manifold with dual wastegates completely separate the exhaust pulses and help with spoolup and possibly peak power since the flow of the exhaust path is smoother?
thewird
thewird
On some of the bigger turbo setups( 42R+) and Half bridge motors running under 18psi the dual waste-gate setup is the way to go for boost control...
In theory it might. I am almost done building a turbo manifold that has a divider between both waste-gate runners all the way up valve on a single wastegate. I am going to see how it compares to a standard collected waste-gate runner setup.
On some of the bigger turbo setups( 42R+) and Half bridge motors running under 18psi the dual waste-gate setup is the way to go for boost control...
On some of the bigger turbo setups( 42R+) and Half bridge motors running under 18psi the dual waste-gate setup is the way to go for boost control...
thewird
Maybe I wasn't clear enough -- my engine is a streetported 13B-RE with -REW rotor housings.
The original setup:
- divided short runner T4 flange exh manifold
- collected wastegate runners that led to a single 46mm TiAL wastegate
- 60-1 turbo with 1.00 A/R turbine housing
- No boost creep, but near 5K RPM to achieve full boost
Current setup:
- divided short runner T4 flange exh manifold
- completely divorced wastegate runners; each leads to a 44mm TiAL wastegate
- GT35R turbo with 1.00 A/R turbine housing
- No boost creep issues, full boost by just over 3K RPM
My current setup keeps the pulses totally separate, which is why I went to the twin wastegates. I believe the totally divided nature improved spool, which is a generally accepted design guideline. The only way to quantify exactly how much would be to swap the 60-1 back in, since I changed two variables at the same time. But I suspect the fully divorced manifold was a part of the gain, since I don't think others have seen this much of an improvement simply by changing turbos.
The original setup:
- divided short runner T4 flange exh manifold
- collected wastegate runners that led to a single 46mm TiAL wastegate
- 60-1 turbo with 1.00 A/R turbine housing
- No boost creep, but near 5K RPM to achieve full boost
Current setup:
- divided short runner T4 flange exh manifold
- completely divorced wastegate runners; each leads to a 44mm TiAL wastegate
- GT35R turbo with 1.00 A/R turbine housing
- No boost creep issues, full boost by just over 3K RPM
My current setup keeps the pulses totally separate, which is why I went to the twin wastegates. I believe the totally divided nature improved spool, which is a generally accepted design guideline. The only way to quantify exactly how much would be to swap the 60-1 back in, since I changed two variables at the same time. But I suspect the fully divorced manifold was a part of the gain, since I don't think others have seen this much of an improvement simply by changing turbos.
Maybe I wasn't clear enough -- my engine is a streetported 13B-RE with -REW rotor housings.
The original setup:
- divided short runner T4 flange exh manifold
- collected wastegate runners that led to a single 46mm TiAL wastegate
- 60-1 turbo with 1.00 A/R turbine housing
- No boost creep, but near 5K RPM to achieve full boost
Current setup:
- divided short runner T4 flange exh manifold
- completely divorced wastegate runners; each leads to a 44mm TiAL wastegate
- GT35R turbo with 1.00 A/R turbine housing
- No boost creep issues, full boost by just over 3K RPM
My current setup keeps the pulses totally separate, which is why I went to the twin wastegates. I believe the totally divided nature improved spool, which is a generally accepted design guideline. The only way to quantify exactly how much would be to swap the 60-1 back in, since I changed two variables at the same time. But I suspect the fully divorced manifold was a part of the gain, since I don't think others have seen this much of an improvement simply by changing turbos.
The original setup:
- divided short runner T4 flange exh manifold
- collected wastegate runners that led to a single 46mm TiAL wastegate
- 60-1 turbo with 1.00 A/R turbine housing
- No boost creep, but near 5K RPM to achieve full boost
Current setup:
- divided short runner T4 flange exh manifold
- completely divorced wastegate runners; each leads to a 44mm TiAL wastegate
- GT35R turbo with 1.00 A/R turbine housing
- No boost creep issues, full boost by just over 3K RPM
My current setup keeps the pulses totally separate, which is why I went to the twin wastegates. I believe the totally divided nature improved spool, which is a generally accepted design guideline. The only way to quantify exactly how much would be to swap the 60-1 back in, since I changed two variables at the same time. But I suspect the fully divorced manifold was a part of the gain, since I don't think others have seen this much of an improvement simply by changing turbos.
thewird
5000 rpm is too slow for a 60-1 i used to have one and had full boost by 3700 (15psi) my t70 sees full boost just before 5k. Something was wrong with your setup and it's not from a single gate unless it was stuck partially open.
Manifold Pics
Unfortunately, these are the only pics I have. The ones that are out of the car show the setup as it was with the single wastegate. The installed pics are of the dual wastegate arrangement. I made it out of mild steel schedule 40 tubing, which is very thick, so hopefully it will last. The rest of the exhaust is 304SS.
wow, thats sweet elwood, i like that you had a completely divided manifold, makes the twin wastegates really make sense. and i cant believe this thread is 8 years old, and no one ever replied. :O