Buidling boost with open WG
 

For baseline tune purposes left the wastegate arm unhooked.... no boost till like 5k... then 5.8k or 6k or so boost suddenly builds really fast... this is a h1e/c holset on a 2.5l.... is this just because the internal gate is too small or what? just curious. I'm worried then that it will build like 30# when I only wanted 17 if the gate is too small... but I dont get how it could be! They run 17-23 stock.

Re: Buidling boost with open WG
 

does the flapper move freely and open all the way without hitting anything?

Re: Buidling boost with open WG
 

are you using a bellmouth downpipe? the flapper will hit a standard exhaust flange. Search the diesel forums there have been guys opening the hole to 38mm.

Re: Buidling boost with open WG
 

I am using the stock 3" vband exhaust. So it should not hit ----. flapper seems to move freely.

Re: Buidling boost with open WG
 

The wastegate on the holset turbo is not meant to regulate boost pressure like normal gasoline t3's are. The holset flapper is small and doesnt open very far because its used more or less to keep egt's in line on the cummins engine. It will work for regulating boost pressure but only so much. Thats why all the holsets you'll see on honda's either run external wg's or use the bullseye power turbine housing.

Re: Buidling boost with open WG
 

Ding ding!

Re: Buidling boost with open WG
 

LOL does that mean my ---- is going to have to see 20+ psi at redline? I'm running this fucker with just that gate regardless, I was just hoping to have it stay in one piece!

Re: Buidling boost with open WG
 

port that wastegate hole out... since its designed to regulate at 20+psi, its not gonna have to flow as much as if you wanted it to regulate it to 10psi, port that ---- out as much as possible... IIRC on my HY-35 the hole for the internal gate was tiny as ----.