External wastegate question

[RonA]

I think I may need to put a wastegate in my hotpipe for my primary charger. I am running a 16cmss housing on top and I've been thinking about mounting the second gate either in a new thicker wastegate cover plate in place of the stock cover plate or in the angled external surface where the gated gas goes from the chamber where the flappers are to join up with the flow that has gone through the turbine. If the second gate vents to atmosphere, it seems like that would lower the pressure in the top chargers wastgate channel allowing even more gas to flow through it and reduce the total flow going to the primary.

 

[Highfinance97]

Contact Chris at Engineered diesel

 

[RonA]

I'm pretty sure they will recommend 2 external gates. I hate to have to run 1, 2 would be very difficult to keep set at the right level. It would be nice if someone made one that was adjustable with spring tension instead of relying on air pressure regulators.

 

[carfichris]

A 50mm gate in a system with 70 psi of drive puts 70lbs of force PER square inch of valve. Thats over 200lbs of pressure trying to shove that valve open. Thats where your cheap/ricer/gasser gates with 6-12lb springs cannot handle our drive pressures. We use spring and air to overcome this and still control the gate where we need too. Now as far as difficult to keep set, even if its two of them, doesnt have to be the case. You dial in each one (if your using two) they work independently. Unless your set up is ever changing it would be there time after time. If your set up is changing then its simple to adjust and move the opening point where you need it to keep the chargers happy.

 

[RonA]

213.04 lbs assuming the exposed face is exactly 50mm. My problem has always been day to day and week to week fluctuations in the opening pressure. Like the regulator isn't consistant.

 

[zstroken]

What about using a pressure switch and a solenoid? Set the gate mechanically to open at a low pressure, but don't provide air to it. You hit the pressure switch and then it opens the solenoid. This would probably be ok if you did a lot of on and off(like sled pulling, drag racing) but if you were at a point where you just needed to open the gate a little, it might not work as well.

 

[carfichris]

Ron, We have an in cab adjustable pressure switch you could use. If your still concerned with the regulator. This holds pressure until it reaches the point you want it to open then release's. Its an all mechanical spring seat set up so nothing electronic. You still have to tune it in and be familiar with your individual trucks performance and set up. Another thing to consider when we are talking about regulated pressure. The required pressure to open the wastegate valve is alot less than the drive pressure or total system boost. There is an imbalance created by the spring and applied pressure to the top of the wastegate cylinder. The amount of regulated pressure applied to the bottom is only to assist the drive pressure that exists on the valve face in opening the valve when you need it.