Any reasons not to?

my friend took a turbo from a volvo, took off the exhaust housing and had a cap and shaft machined on the back. he put on a small honda alt pulley and now has what seems to be a Centrifugal Supercharger.

what im tring to figure out is if it will spin up enough to create any boost, i know real Centrifugal Superchargers are gear and chain driven.

turbos are exhaust driven and im afraid the exhaust that passes through is flowing a lot more than equivilent average 5000-7000 RPM.


Am i right or worng? will it work? im just looking for 6-8 LBS of boost cheap and custom. im not looking for a big vortech of drag kit gain.


Thanks

~Hybrid

 

yeah I think turbos run over 15,000 rpm. Ask Mr. Fatbooty, he knows all about it.

 

I think those turbines spin more like 50,000 to 100,000 rpm... could be wrong though. :a:

 

heh, some spin at like 68,000rpm.

 

yep:thumbup:

 

Turbos spin at tens of thousands of RPMs so it won't be quite as simple as smacking a pulley on it and driving it with your accessory belt.

The best thing to do is to see if you can get your hands on the compressor map for that trim turbo and use the affinity laws and engine size and RPM range to figure the proper speed to run the turbo.

If you can't find a compressor map for your specific turbo measure your impeller diameter and use a compressor map for a turbo with the same impeller size and similar design. I'm pretty sure Turbonetics has compressor maps for all the Garretts on their web site.

Next step is to find the RPM range of your accessory drive which can be figured pretty easily using the crank pulley diameter, accessory pulley diameter, and engine speed. Compare that with he compressor RPM you need to run and pick up a gear box with the proper ratio. I doubt you'll be able to go with a belt or chain drive due to how steep the gear ratio will most likely be. You'll probably need the power requirements of the compressor to properly size the drive. This can be figured from the work for adiabatic compression at the desired boost, required air flow of the engine, and adiabatic efficiency of the compressor, which should be around 70% for a centrifugal but it should also be on the compressor MAP.

Another tip, go with helical gears, spur gears will whine like a banshee.

If you really want to do this, I could probably give you a hand with the engineering

 

Sounds like more trouble and probably more $$ than just buying a Centrifugal Compressor from vortech or powerdyne.

Thanks for all you input.

~Hybrid

 

*sigh*

And I was hoping to get my hands dirty

Honestly, this can be done for probably between 500 and 1000, maybe even cheaper depending on the gear box versus 3200, though if you want my honest opinion, if you're gonna go supercharger, go with a roots or a screw, they better fit an engines air requirements

Another way of simplifying it is to get your hands on a turbo with a larger diameter impeller, you could run it at much lower RPMs