pgm02002

So ive been building my set of twins (hx35 & bht3b) and i'm trying to figure out the right wastegate setup in order to spool as fast as possible. From what i've gathered, an external wastegate around the hx35 and piped into the bht3b is the best way....if this is true, can anyone recommend a particluar wastegate?


....With this setup I dont understand how the total boost is controlled...it would seem this would only control the boost from the smaller turbo, which is not the best way to keep my headgasket intact (even w/ arp studs)....

RowJ

Easier to plumb if you open up your HX-35. But if going with an external WG...get a Tial 38mm. Worked very well for me and others.
Opening up your HX-35, good read HERE
Tial Wastegates HERE

Fastest spool up is to set your HX-35 at near max boost...say 35 psi. Wastegate on your primary (bottom) can be adjusted to give whatever total boost you want! Should be a great set up!

The WG on the primary is important, IMO. Many adjust total boost by adjusting the 35, but I believe this is not best way to get spoolup and lowest EGT's.... based on my conversations with a turbo design engineer.
If you have two adjustable WG's...you can play with them and come up with your own research. That would be fun, IMO.

RJ

pgm02002

thanks, however my primary is non wastegated, so really the only wastegate i would have would be the one on the hx35 (either external or internal).....would that be alright?....also if you wanted 50 psi of boost w/ that tial, would you jsut stack the springs shown on the website to equal 50 psi?....i appreciate the help.

RonA

No. You would need To add a measured amount of boost pressure to the spring side. 50 psi on the secondary is a bit much though.

RowJ

Nope! It helps to get the Tial WG in your hand before it's clear how they work... but all you need is the one spring...21 psi I think.
You run boost air to top & bottom of the Ext WG. Full boost in the bottom fighting the spring and regulated boost on top of the spring to help it keep the gate closed off. The difference you set into the regulator determines your total boost #.

Regulator mounted on wheel well...


RJ

pgm02002

thanks....there are good piping diagrams on the website....where did you get the pressure regulator?

RowJ

From Grainger -It's a Wilkerson Flow Regulator; something like 0-100 psi?? - PN #R08-02-F000.... $19.95 in 03! Worked perfectly! (Not sure if that's a Grainger # but think it's Wilkerson's PN)

Good Luck

RJ