waste gate feeding atmo

Riverside · Apr 12, 2014

Going to throwing on a good ol set of High Powers very soon.
Going to utilize the atmo feed with a gate......that's where my questions start.

For now, at least, it will be stk fuel.
At what BP psi should the gate be set to begin feeding the atmo.

Is sooner better : or later - or don't even bother cause stk fuel doest have enough ass to push the atmo any harder with a feed line then running it all thru the vgt.

I remember reading somewhere that there was the idea that one could close down the vgt (how much....I have no clue) as the boost/rpm climbed to raise BP that could be then feed into the atmo.

True or false.......or a horrible idea.

Riverside · Apr 13, 2014

Anyone?

I don't know my ABC's on gating.

Looking for any info :

What brand of gates is preferred.

How many springs to start with

Are some easier to adj then others.

Do I need to have 2 gates.....one feeding the atmo another to relieve BP to the DP?

Sorry guys if im asking to many questions or if this is basic 101 stuff that I should know

jdgleason · Apr 13, 2014

Hey buddy. Give me a bit to get to a spot where I can sit down and actually put some time into a response.

Dzchey21 · Apr 13, 2014

dont gate between stages, the turbin in the low pressure is too small and not really effective
you are better off to just trim total back pressure with a gate that dumps to atmo or in the downpipe. Back pressure should be around 70 psi with boost in the 55 psi range.

start off with about 1.2 bar of springs or around 16-18 psi depending on the gate

Lots of guys have switched to water cooled gates on max/high powers due to heat in the engine compartment, also i feel that turbosmart gates are good as well as turbonetics also makes a good gate. You are going to want a gate in the 44mm range

also let the vgt go all the way open. Dont try to close it down your back pressure on one bank will be too high

ncollins64 · Apr 13, 2014

I was gonna run 2 gates but since I'm not running nitrous yet I'm just gonna run 1 gate dumping in the dp and I have the port between the chargers blocked. We felt confident with this set up and im running big fuel and max powers. When I do run dual gates, both will be water cooled tial, one on top dumping between the turbos and one dumping off the driver side running to the exhaust.

jdgleason · Apr 13, 2014

Ideally, you would have a gate into the atmo and into the downpipe... Then down the road you can play with the two and see what works and what you like. I want to say Mike didn't gain anything gating into the atmosphere with his stock fuel setup, but if you add fuel down the road, it could help.

The 76 in the high powers doesn't make a whole lot of boost without driving it harder (~25 psi) and I would be willing to bet there is power to be had by driving it harder. The stock housing 76 in the high power jr's that Wayne ran would make 45psi on it's own and it worked well. I think you can drive that 76 harder is all I'm saying.

The gating itself is simple. You will be using your wastegate to alleviate back pressure. So, pick a number that you don't want to exceed and go from there.

My truck runs about 83psi absolute (which includes atmospheric pressure - 14.7 psi) or 68-69 psi gauge. It makes - about 55lbs of boost. Works well. Ideally, you'll wanna be on a dyno and see where power starts dropping off or boost starts dropping off.

For the springs - you'll wanna have 1.2 or 1.4 bar worth of springs in it. You'll figure that out when you look at the gate. I like the Tial MVR's because they seem to be a little more resistant to heat.

Back to gating into the atmosphere - Mike and Dustin had better luck gating around the atmosphere into the downpipe on a truck they built. However, Tadd's little short bed truck picked up like 180hp gating into the atmosphere... Obviously different setups and tuning, but you get the idea.

Riverside · Apr 14, 2014

Thanks guys.
That's great info....thanks

Dustin.
If I were to have both up pipes piped into one gate that would be feeding the atmo would there be any potential benefit......stk fuel, or with duals......to closing down the vgt?

Just curious.

Dzchey21 · Apr 14, 2014

it might work that way, i havent had the opportunity to try it but i feel that the turbine on the 76 is just too small to do any re-routing into. I would be curious to know what the 180hp gains were on tadds truck with high powers. mainly before and after and boost numbers ect. Mike and I have never really been able to make the gate between stages work that well.

Riverside · Apr 24, 2014

With dual fuel on High Powers will I have to run 2 gates?
Is it unsafe for the that atmo having only 1 gate that dumps into it.

Or should I skip dumping into the atmo and go straight to the DP.

sootie · Apr 24, 2014

dumping to the atmo is not a safety thing it is to not waste the built up drive pressure when you could be using it to drive the atmo harder which in turn makes more power.

mike@haller's · Apr 24, 2014

Making the gating into the atmosphere work is tricky. You wanna drive the low pressure turbine hard but not lose all the drive pressure spinning the high pressure turbine when you open it. Ive been tuning on a max power truck the last few days. The truck has two gates one feeding the low pressure turbine, one going to atmosphere. On the street tune it normally runs I open the gate to the low pressure around 2500rpm. And also command higher bp to close the vanes and keep the high pressure spinning good. Then open the atmosphere gate around 2600rpm. Doing this nets 29psi out of the low pressure, 65psi total and drive ends up 3psi lower than total boost at 62psi. If I crank the atmosphere gate down one turn, leave the gate between stages alone and limit the vgt close point. Boost jumps to 32psi atmosphere, 74psi total and drive jumps to 79psi. The truck also gains over 100hp. In my opinion though that's a race or dyno setup. If you set yours up with just an atmosphere gate and an aggressive bp file you will do fine. There is power in gating between chargers, but its alot of effort to get it all.

Dzchey21 · Apr 24, 2014

plus you need to be able to spend hours on end on the dyno

mike@haller's · Apr 24, 2014

That too.

Fast-6.0 · Apr 25, 2014

Dzchey21 said:
it might work that way, i havent had the opportunity to try it but i feel that the turbine on the 76 is just too small to do any re-routing into. I would be curious to know what the 180hp gains were on tadds truck with high powers. mainly before and after and boost numbers ect. Mike and I have never really been able to make the gate between stages work that well.

My trucked picked up that kind of power with Max-Power X's. I tightened the minimum VGT duty cycle to run the VGT harder and then drove everything to the atmosphere through the wastegate port.