[JimmieD]

The page at the Link is an info page from HTT, High Tech Turbo:

http://www.htturbo.com/Service.htm

I purchased [but haven't installed] their Stage II Upgrade for my Holset H1C on the Cummins 4BT engine. I went with a minor upgrade because at time of purchase it looked like I would be doing some extensive heavy towing, and didn't want monster EGT's to smoke the little spinning & pumping parts!

Now the towing issue doesn't apply, so I thought, Hey, maybe I need a big old honkin' compressor upgrade instead of that puny Stage II. After reading the info on their site I'm going to install what I have. [Good, 'cause I'm broke anyway hah!]

Living in a mountainous area and using an NV4500 in a full size Dodge I need power down on the bottom, in addition to an increase thruout the power range. Turns out the Stage II is still the correct choice for my application from what I see on HTT's site. Hopefully their info page [and they have other info] will help someone else make the right decision on compressor/turbine or turbo upgrades.

Some folks will want to check their 'Specials' page too. HTT has a very good reputation on several Dodge Cummins sites.

 

[JimmieD]

More info at this link, it's a .PDF file

http://www.htturbo.com/MatchingHighTechTurbos.pdf

Their site is full of info, but not the easiest site to FIND the info!

 

[JimmieD]

Sorry to keep posting to my own thread!

Something to remember: the info on HTT's site, say under the Dodge section where I look, is relevant to a Cummins 6BT. So for example, the Stage II might seem like a pretty puny upgrade, not worth the money & bother. However I have a 4BT, 2 less cylinders to fill, so that's a direct 33% gain in turbo oomph for my application, compared to a 6BT!

I spoke extensively with HTT's main tech guy about my planned upgrades so my choice wasn't only based on my own head scratching, but upon his professional, hands-on, real world experience with their offerings.

The parts I received were not some backroom mfg or funky hombrew looking stuff, but were genuine Holset parts. I like that....

 

[Dougal]

Have you run it yet?

 

[Elbonk]

Good info

thanks for the link, I am still not up to speed but am getting there.

 

[Ggg]

I can say from first hand experience that HTT does some nice work. I am running a modified H2e from them in a Ford with a PSD engine.

 

[Carl Donica]

Hope Im not raining on your parade but there will also be 2 less cylinders of hot gas (exhaust) being pumped through the turbine. And besides that, like oh my gosh Jimmie, JUST DO IT ALREADY! Im going crazy here! If youll come down here to texas Ill help you.:rasta:
Carl

 

[JB Custom Fab.]

I have nothin' but good things to say about HTT.
They made sure that I not only got what I needed, but understood why.
They asked a lot of questions about the motor, gearing, and the application.
They nailed it!

 

[LincTex]

like oh my gosh Jimmie, JUST DO IT ALREADY! I'm going crazy here! If you'll come down here to Texas Ill help you.

LOL!

Has anyone had any experiences with compressor surge? Compressor surge happens when you are trying to get big PSI numbers but the flow isn't there (4 cyls versus 6 cyl). I know that there has been one person having surge problems with a HX35 on a 4bt. I wonder how easily some of the upgrades designed for a 6 will surge when running on a 4.

 

[Dougal]

LOL!

Has anyone had any experiences with compressor surge? Compressor surge happens when you are trying to get big PSI numbers but the flow isn't there (4 cyls versus 6 cyl). I know that there has been one person having surge problems with a HX35 on a 4bt. I wonder how easily some of the upgrades designed for a 6 will surge when running on a 4.

This is my concern too. It's one reason I have to keep dissuading diesel owners from bolting on turbos for petrol cars.

 

[JimmieD]

Sorry to ignore everybody, but replies to my onw thread didn't show up under 'New Posts'!! Wonder what all else I've been missing...?

Not installed yet, but VERY soon. I talked to HTT 3 times and they gave a pretty good idea of what I was looking at. I feel they would have suggested something else if surge was a potential problem, as I had very specific needs. At the time money was no big deal, and this is still what was suggested for my described requirements! That told me a lot about the company right there: honest.

Sorry I can't remember precisely, but I think the guy said that in effect this upgrade would end up the same as either an HY35 or HX35, I think it was the HY. I'll holler, good or bad, soon as it's in kids! Thanks...

 

[JimmieD]

Boy, what a jerk! Sorry for never getting back here guys! I had some pretty heavy duty stuff come down on my life way back then, also had to move, things were complicated, lost track. So I've had the HTT Stage II installed for a few years. Don't think HTT offers it anymore, at least not the last time I looked.

As I recall I lost a little bottom end, gained a little up top. Also added a 3,200 rpm spring, rotated fuel pin, turned the screws a bit, still using 16cm exhaust housing. Stock timing. Overall pretty happy with it.

I now live in the mountains, a few steep grades, some long and steep. Engine has good power and easily pulls the grades. EGT's could hit 1,100-1,300 to ??? Bill gave me an air-air intercooler out of a '91-92 and that solved the EGT's. Thanks to him I could then drive as I wanted, not always feathering the throttle on hills.

All in all it worked pretty good I guess. Just wish I could remember more of what the bottom end and overall power was like before the turbo compressor swap....

 

[LincTex]

LOL! Yeah, I have swapped pumps since my last post! But still driving it with the same set-up. Need to get the main shaft seal replaced in my old pump still.