Does anyone have reference to the exact facory specs of our turbo? I am looking for inducer/exducer size and trim for compresssor as well as wheel size and trim for the turbine section. Also the A/R for the comp and turbine would be great. I want to use my original turbo for a different application so I need to know the exact sizes. Thanks.

 

I did a net search for Holset turbos a while back and found something like you are needing. You might try that. I couldnt get any responses now though.

 

You might want to try this site

http://www.holset.co.uk/files/4_4_1-...%20manuals.php

You will have to allow pop ups if you block them.

It is a zipped pdf of 3.89mb for the H1C

Hope this helps

Michael

 

That is a great rebuild manual but unfortunately no turbo specs. Anyone else got any more info?

 

I think the turbos on all 1st gens use the same turbine wheel. I'm not sure on the inducer size, but I believe the exducer is 57mm. The inducer is probably around 65mm. The 18cm and 21cm exhaust housings are a pretty big A/R. Unfortunately Holset doesn't give an A/R for their compressor or turbine housings.

Non-IC trucks have the "baby H1C" with 3" compressor inlet and 2" outlet. The compressor wheel should have a 50mm inducer and an 83mm exducer (I think).
IC trucks have a 54mm inducer/83mm exducer compressor wheel.