If you search for HT60 on this board you get a lot of info about the thing, and most of it contradicts other bits of info posted, even people with a lot of useful info on turbos in this size range like rotoryota and a few of the other 'big dogs' have posted different subjective info in different threads, so I'm trying to consolidate and clarify.

First, as far as I can tell, the only difference between an HT60 and an HX60 is that the HT rotates in the opposite direction, correct (as far as holsets go, of course you'll find a few different layouts of every designation anyway)?

Now as compared to the TV8101, 8102 and 75xx'¦ Most threads seem to start with how big, heavy and slow spooling the HT60 is, but then when you comare it to the rest of these, at least the TV81xx the HX spools faster, right? So is it that the HT60 is just physically bigger/heavier and spools slower then say something like a T76 that it's getting a 'it's slow spooling' or what?

Inducer sizes'¦ the HT60 is 74mm, the TV8102 and 75xx are about in the same range while the TV8101 is larger but I can't seem to figure out how much larger. While I'm at it, the GT42, 45'¦ turbos are basically the TV's little brother's, they get into that size range but the shaft/'frame' size is smaller making them not as durable when pushed really hard. I'd imagine that they are also smaller, lighter and spool faster then the TV series. For that matter, I'm not clear, are there actually any GT series turbos between the 42 and 60 from Garrett or are the 45, 50'¦ just other pieces slapped together to get something in that range or turbonetics bastard designations or something?

Exducer/down pipe flange: Correct me if I'm wrong but the TV series, and even the Garrett GT42 and larger (T06 style, the T04 ones are just turbonetics and others confusing things again, I think) all use a 5' flange. The HT60 uses roughly a 4.5' flange and they all have actually exhaust exducers in the 3.5' and larger range, right?

OK, so lets make some noise here'¦ these are the details that _I think_ I've figured out so far, if they're incorrect someone please correct me, if you have more info, please add it.

 

The TV8102 has a 77.5mm inducer and a ~108 exducer on the compressor wheel, the TV7511 I have has a 72mm inducer and I'm not sure of the compressor wheel exducer, I think the TV7512 is closer to 75mm in the compressor wheel inducer. TV8101 is 85mm on the inducer and ~108 on the exducer of the compressor wheel also.

THe TV8102 has a turbine wheel exducer in closer to 4", the TV7511 is right at 3.5"

-Brian

 

The HT60 is very similar to the turbo I used to have... A HT3B. The size of the exhaust housing is stamped on the inside of the inlet side of it. Should range from about 22 to 36. Hopefully you have a 22cm housing or close to it. With a fairly stock 383 big block 3.55 gears, auto trans @ 4000lbs I couldn't get 8 psi any sooner than about 4000 RPM. They are slow spooling compared to my GT42 by a long shot.

 

I havn't had the pleasure of trying a GT42...but I will say that my HT60(22cm exhaust) spooled about twice as fast as yours. I could hit about 18psi on the brake at 42-4400rpm after my timing was sorted.......and this was with 358cid. On the other hand....my 8101 spooled alot slower. Maybe 11-12 psi by 4400.

 

Difference between a race and street engine I suppose. Still spooled at similar RPM mine would build fairly fast after that with a stuck wastegate that is. Basicly not much action below 4000 in my case. That is with no trans brake or high stall TC, just throttle.