From: "Greg Goulden" To: Subject: Re: [DTLC] Turbo Parts Help Please Date: Tue, 14 Dec 2004 17:05:25 +1100 Reply-To: dtlc@helios.net > -----Original Message----- > From: dtlc-owner@helios.net [mailto:dtlc-owner@helios.net]On Behalf Of > stwalsh@uniserve.com > > I've got a couple of 1HD-Ts in the shop.. pretty dang sure the turbos > have CT-26 cast into the aluminium housing. I will have to check again. > I was under the impression that the CT-26 came in a number of different > wheel sizes etc for different flow rates. > > Sheldon Hi Sheldon, Most definately the 1HD-T has the CT26, and so does the 1HD-FT, but as Craig said "not all CT26's are created equal". The CT26 on the 1HD-FT has a larger turbine housing apparently. (I have both here on the shelf, and they both look identical, I've never measured them) What I was eluding to was that the smaller CT26 on the 1HD's spools up faster on the low compression motors to give good response down low, but the efficiency drops off as the revs increase (and so the air mass delivered drops as the intake charge is heated). As the 1HZ has good low down torque due to the higher compression ratio, one can specify a larger turbo as low rpm boost is not as much of an issue, and then when you want max. grunt at high rpm, the intake charge is much cooler as the larger turbo is then running more efficiently. And if there's one thing that will kill the 1HZ it's high combustion temps. (The direct injected 1HD motors don't mind the heat near so much) Basically cooler intake charge means less combustion temperature, which means more room for more fuel to make more go. does that make sense? Regards, Greg Goulden 2000 HDJ105 - 1HD-FT with Garrett turbo off 1HZ ;-) Melb. AU.