DragLS1

I have a 68 mm holset turbo. What kind of power can I expect to make with 20 psi and the usual mods(heads:315 cfm cam: 242, 244@.050 50-60lb injectors and intake)?

Any info would really help. I dont have turbo experience just yet.

Thanks

y2khawk

iTrader: (5)

you'll be hard pressed to make 20 psi with that size compressor on a stock cube motor. Even worse on a larger motor.

usually a mid to high 60's mm compressor is good for between 700 and 800 flywheel. Depends on who's turbo and what wheel.

DragLS1

The wheel is too small?

sb427f-car

That's a desiel turbo isn't it? Holset makes great turbos, tough to break, but they usually don't flow what a gasoline apps turbo will. Where'd you get it and off of what? Look at the map and think about using two of them if you can source another.

DragLS1

Yeah...it's a diesel turbo but I got it for a good price and it is in great shape. If I can make it work until I can get my hands on an 88 I will be happy. I love the turbo as a power adder and if I can make this work for now that would be great.

DragLS1

I got it from a 10 litre diesel. Holset wont let go of their maps but I did the math on a few guesses. A 10 litre diesel @4000 rpm flows roughly the same cfm as a 5.7 litre at around 6500 rpm at a pressure ratio of around 2.5 which equals roughly 20 psi. If nothing else I know that it will work at around 4500- 7000 rpm. If anyone has ideas on this setup please let me know.

y2khawk

iTrader: (5)

having run 2 66's on a stock cube motor, the most the pair would flow bearly got me to a pressure ratio of 3.

20 psi or not, I don't think you'll get enough air from that sized compressor to make much more than 800 at the crank.

DragLS1

HAHAHA.....800 hp. I think that I can be happy with 800 hp for quite some time! 800 hp on the street should quench my fire until I can do a single 88 or 91. Anyone know of a reputable manufacturer of welup headers for the ls1?

sb427f-car

You must understand something though, I too have research Holset turbos, as they are common on Dodge Cummins Desiels, that they do NOT needed to flow the same amount of air as gasoline applications. What model turbocharge is it? Have you checked http://www.holset.co.uk/files/ for a compressor map? Have you posted for info off of the desiel forums? Desiels will standup to a higher boost pressure with less airflow, mainly because they use the turbo to cool the EGTs and help to keep them in an optimal op. temp than make BIG HP, of course they help with that too. Who's your sourse on these? Did you get it new or used? Like I said, Holsets will LAST. Good luck cooking them.

DragLS1

The model that I have is an older H2D that has been rebuilt. I looked all over the holset website for maps and don't list them. I then called the techies at holset and they wouldn't give me a map for anything. They just said that the H2D is a massive turbo and that it might not spool. Well we all know here that 68 mm is borderline too small for what we need them for. Anyway...I hope that I can make some power with this one.

sb427f-car

I know when i was looking @ stealing a turbo from a cummins dodge truck, I posted over on the desiel boards and someone told me they are basically corks. (the particular models I was looking @). They suggested running two. The problem is that they start to flow in the upper portions of the compressor maps, when they get outside the center island. Try contacting Gale Banks engineering. www.bankspower.com I know they've built some mean deisel applications with holset products, maybe they'll give you a resource? It's worth a shot.

DragLS1

This turbo didn't come from a fullsize truck, it came from a BIG truck. I have done some researc on this particular model and it is much bigger than the ones found on the cummins trucks. The deisel that this one came from was 600ci. I'm not sure which truck because the engine was already pulled. Physically the turbo is quite large but to the best of my measurements the inducer(smallest portion of the inlet) measured at 68mm. The exducer (where the wheel is the largest) is 93mm. The actual intake housing is petty big. The exhaust housing is 19mm (they dont rate in A/R). I hope it's not a cork...

sb427f-car

No, that's not, and I know of the motor you speak of, It's a cummins B series is it not? I knew you were not refering to a dodge pickup. . If you ever get a chance...check out their site and their version of the Varriable Geometery turbo, pretty neat stuff.

DragLS1

The motor it came from was an L-10. Yeah I saw that turbo on their website and that is a pretty cool turbo...