If I switch my stock turbo on my 1990 to a hx35 off a second gen 12 valve what would the gains be? Would it be quicker? I'm pushing only 22 pounds of boost on mine. And I have a bd fuel pin so I have about enough fuel to push the hx 35 right?

 

hx 35 is gated to 20 - 24 lbs unless you tie it shut...

 

The spool up is much faster due to the 12 cm housing( I think it's 12 if not its 14) but you better have a pyro and boost gauge because the smaller housing makes egts rise much faster. I have a hx 35 on my ic rig and I can get 1250* and 25 psi with the gate open.

 

17-19 psi, tamatos tomatos really though. dont do a thing to the wastegate or you will blow the turbo and or loose a HG. buy a $15 boost elbow and run it at 35psi safely for the life of your truck. the hx will spool way way faster than the h1c. they move similiar amounts of air so not a huge power gain just a big bump in drivability. a very worth while mod.

 

I have to disagree with you in the hg or turbo blowing up. If you have a boost gauge just keep a close eye on it and whenever you start seeing 32-34 psi let off slowly so you don't bark the turbo

 

And what exactly does the boost elbow do?

 

it slows the reference signal to the wastegate so the gate is slower to open. um... imagine a drinking straw. the boost elbow is a kink in the middle of the straw slowing the air flow down, you are blowing as hard as you can but it will still take longer for X pressure to build up on the other side. and sure you can guess and try and get your foot out of it, but seriously who is looking at their gauges when they are getting heavy with the go pedal. it cost $15 to do it right. or thousands in broke parts to half a$$ it. drive pressures with a 12cm housing and 58mm wheel are high and way to high without being able to bleed off pressure. the same boost #'s can be attained while bleeding off excess pressures and prolonging the life of your expensive engine parts. an over sped turbo will eventually fail and a HG that is exposed to very high drive pressures all the time will fail. if you are lucky just one happens at a time or you could blow a cool hole in an expensive intercooler with granaded turbo fins.

 

Oh alright well thanks man

 

Uhm uh sorry but his 90 has that small 50mm baby H1C not the bigger 54mm like on the Ic style H1c's or the 54, 56 or 58mm hx35's. So in short yes it WILL flow more air aswell as spool faster from the small 12cm wg housing on the hx35.

Now to the OP watch you don't get yourself a WH1C off a 94-95. Some 95's came with a hx35 some came with an H1C off a ic style 1st gen with a 12CM wg housing.

 

Good info