Redoing VP setup..

[zfaylor]

So I guess I should pressurize the system to see when the gate opens? What would be the correct pressure for the gate to open? And could a 12cm housing cause drive pressure issues? Or would I just have to reset the gate if I switched housings to control drive pressure?

My he351cw (9cm housing) didn't have any drive pressure issues with the wastegate hole hogged out to 1" if that tells you anything. If you know overall boost and the boost from your primary there is a formula floating around here to calculate the pressure from your secondary.

 

[diesel_importer]

I hook up pressure hose to wastegate actuator with a regulator in line. Increase pressure on regulator and see where gate begins opening and is fully open. 12cm shouldn't be too small @ 600-650 hp.

 

[Chrisd91]

So I guess I should pressurize the system to see when the gate opens? What would be the correct pressure for the gate to open? And could a 12cm housing cause drive pressure issues? Or would I just have to reset the gate if I switched housings to control drive pressure?

Drive pressure also pushes on the puck, opening the gate earlier than it would open on shop air alone. There is plenty of info on tuning twins in this forum, search and read. Try your gate at different settings and record your results

 

[Smokem]

Primary turbine is simply too large.

 

[B N S slammer]

Primary turbine is simply too large.

This is what i believe, good for top end, not so much for bottom. I also wonder how big of a difference switching to a 1.10 housing while keeping the 96 turbine would make spoolwise...

 

[Chrisd91]

Primary turbine is simply too large.

I agree that it's not ideal, but it can work ok for a budget charger. He's complaining of poor low end spool, which I would think would be due mostly to the secondary. If anything, a large turbine and housing on the primary should very slightly help secondary spool up vs. a smaller turbine and housing.

I would advocate the OP at least spend some time trying different wastegate settings before throwing more money at it.

 

[12vriviera]

My he351cw (9cm housing) didn't have any drive pressure issues with the wastegate hole hogged out to 1" if that tells you anything. If you know overall boost and the boost from your primary there is a formula floating around here to calculate the pressure from your secondary.

you must not have been pushing it that hard then?

 

[zfaylor]

you must not have been pushing it that hard then?

Not all that hard no. 60+ psi out of my ht3b and he351cw twins setup. My point was a 12cm may not mean high drive pressure. Turbine wheel has to be taken into account as well.


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