Flubyux2

I've been browsing around and the general consensus is that a 76mm turbo is an ideal size for a rear mount. The smaller ones like 70mm and under will choke up top.

I noticed the holset hx/ht60 are 76mm turbos and cheap, even when new. I'm a firm believer in holset quality based on my experience with them thru diesels. I'm full aware they are "old". But so are Garrett t-series. even the gt series aren't exactly new either. For my budget rear mount, newest and best isn't something I'm concerned with.

I'm just curious if the ht60 will be able to spool reasonably well on a stock long block. I believe the hot sides are 23cm and 28cm depending on luck. Obviously, on a stock motor, I don't anticipate going beyond 8psi.

If this turbo isn't a good match, I could always hunt down an hx55 if that would give more linear response and still not choke off before redline.

NemeSS

iTrader: (127)

ive used a holset h1e on a remote mount and did quite well, spooled pretty quick for a diesel turbo on a stock lt1. car could only handle bout 7psi though. safely. ran for years. good strong relaible turbos.
a hx60 IS A HUGE BITCH!

5.3-on-steroids

iTrader: (3)

Everyone on here is gonna tell you you need to run a t67 or some tiny **** equivalent to it and tiny 2.5" pipes or you're gonna have tons of lag, most people don't know how to properly set up a rear mount for big power. Just run what you have the key is to wrap the hell out of the exhaust with header wrap. The main problem with rear mounts is the loss if heat between the manifolds and turbo due to the extra piping. I'm not joking when I say one layer of header wrap alone took my home made tc78 rear mount from being almost unable to create boost to making a lightning fast 15 psi by 3k rpm, and the more layers you do the better it gets. Be sure to use stock manifolds and a quick spool valve will be beneficial for a turbo of that size, maybe even consider having the exhaust ceramic coated.

ericwilloughby

I started with a wh2d and an hx50 and its not just the a/r that's too big, the turbine itself is massive. I only got#4 boost max. No Wastegate needed. Wrapping the pipe helps a little bit but unless #4 is your goal spend $400 on a 76mm on3 performance or $700 on a masterpower turbo

The only way those big diesel turbos make numbers is mounted up front. And there isn't much room for a #50 turbo

95bowtie

Not to be a dick but I honestly wouldn't follow any advice from this guy.

I had a 76mm comp. With a 86mm turbine exducer on a t6 frame .96 a/r and it spooled 10 lbs by 3500 rpm. With 2.5 mid pipes y'd into a single 3 inch pipe. ....that being said its all in the setup.

It's all about keeping the exhaust gas velocity up and keeping the heat in.

Use stock manifolds like others said, whatever id the exits are on those run pipe the same size as that all the way to the y pipe. Y it into a single 2.5 all the way to the turbo.

My rearmount I had performed flawlessly. I put a 7# wg spring in and it produced right at 5.5 to 6#s of boost by 3500-3800 rpm. That's with a pretty large turbine wheel like I said.

Car was a stock 347 cam only with stock manifolds. Made 610/540 at 10# and 15* of timing. Through a 6 speed.

ericwilloughby

Wow. U called it. You were being a dick

Flubyux2

Lol. Ok thanks for the input guys.

I was trying to find an old hks t51r spl or a greddy t88h-38gk. Both 76mm turbos with 1.01+ turbine housings. I just didn't want to spend $800+ for a turbo. Apparently old jdm turbos went up in price over the last year: I couldn't GIVE my old t88 away for more than $400.

I want to avoid a Chinese turbo so that means my selection is limited given my price range. That's why I'm looking at old diesel turbos. I'd love a gt4202 but can't find one for under $800.

I did see that heat energy was a big variable. It's also an issue with my Subaru. So I understand the reason for stock manifolds and wrapping. I figure I can keep my ory and slp lm1. I'll just use that stuff.

I did have a crazy idea: use a divided turbine housing. Split the mid pipe in two. Plumb a wg into one runner. One side of the turbine housing gets all the exhaust flow. When the boost is reached, the wg opens up and passes exhaust to the other volute.

If the housing is big, it simply won't reach the upper boost levels and maybe I won't actually need a wg to bypass exhaust around the turbine.

Oh, and the h1c or wh1c are on the small side. Those are only like 60mm compressor. I was originally looking at an ht3b. That's what a lot of us cummins folk use for cheap compound twins setups. They are the perfect size for the top turbo, over the stock hx35. 60+psi is no problem with that setup. Maybe I'll Hun down an ht3b

LilJohn

Your quickspool valve idea would work... might need a 2nd gate to control overall boost as well.

Also stepping down the diameter of the pipe as you go back helps. This will keep the fps of the exhaust up as it cools. Big gains here. Double layer wrap minimum... Cam with extra overlap to help keep drive pressure up.

Put alot of miles behind an N14 with an Ht60 on it... that turbo made 52 psi rolling coal with a Pittsburgh box set on 7 and full 6 inch exhaust turbo back. 630/2280 to the ground..

Just dont tell anyone it spins backwards... they look at ya funny.

95bowtie

Lmfao I forgot about that

Bazman

Wow. Let me tell you guys something from real world testing:

1 - stock manifolds do NOT make more power than proper headers

2 - Wrapping your exhaust does NOT make more power. It might spool 200rpm earlier, if you could notice that

3 - What works for NA works for boost as a general rule.

If that makes someone laugh hysterically, you need a white coat.

95bowtie

1 and 2 are wrongo....real world testing with proof of results have been done saying exactly the opposite of what you just said....

Wrapping will make it spool very noticeably faster. Plenty of guys have gone that route with no wrap and suffered from a laggy setup. Turbine doesn't just work by blowing wind on it. It needs heat too, more heat energy and high velocity of the exhaust gas is proven fact to hell spool in a front mount or rear.

Aka stock manifolds and wrapped small primary pipes and y pipe.