2BAD4U

iTrader: (1)

Anyone running a twin waste gate set up on a big single turbo? I have some questions reguarding boost numbers with the spring setup i have. I'm not seeing what i thought i would. And i know everyones first reply is BOOST leak. But already got the fog machine on it and no issues there. I'm running twin 38mm tials. The springs that were in there were large yellows. And i'm only seeing 5psi. I wonder if 4,500ft elevation has anything to do with it? Or the fact that it's some what normal because i'm running through good size intercooler and dumping out twis as much with the twin waste gate set up. I know it would be a bit higher if i ran boost referance off intake manifold vs turbo housing.

What do you guys think?

Anyone run twin waste gate set ups?

TiAL

probably a combination of: back pressure, pressure drop and altitude.

where are the gates getting their signal from?

2BAD4U

iTrader: (1)

That what i was wondering. I bought two large greens and put them in. Boost went up to 6lbs. I put in 1 small red with one large green. Boost is about 7lbs. I just bought 1 small green and about to but in with the other large green. I'm guessing that might get me another two or maybe 3lbs. But like i mentioned above. It might help if i have my boost reference point come from the manifold vs the turbo housing. (So off of turbo)

SATAN

iTrader: (2)

You could potentially have too much waste gate. Let me explain.

You have cracking pressure and full boost pressure. Your cracking pressure is typically 50% of whatever the full boost pressure would be. This means if your full boost pressure is 10psi, your waste gate will start to crack open at 5psi.

Now, lets just ASSUME you have too much waste gate (not saying you do). The wastegates will both crack open at 50% of full boost. If you have too much exhaust flowing through them, you may not be able to boost any higher due to too much exhaust bypassing the turbine. This would also explain why putting stiffer springs in gets you more boost, but still not the desired level. It keeps cracking open at a higher psi, but once it does, it just flows too much and can't build any more.

This is just a theory though and I could very well be wrong.

My suggestion is to make a block off plate for one of the waste gates. Try again paying VERY close attention to your boost levels. One waste gate MAY be enough for what you are doing.

2BAD4U

iTrader: (1)

I think you might be right. And I thought about blocking off one myself. But its good to here other peoples thoughts. Especially when they are along to back up my exact thought.

skinnies

iTrader: (33)

Run a vacuum hose to the top port on one(nothing to the bottom on that one), that will slam it shut, so will be only running off one WG then and see what it does.

2BAD4U

iTrader: (1)

Great idea... Thanks!!!!!!!!!!!