Supercharging a flat four VW aircooled engine

[Blade2good]

My first post so thank you in advance for feedback and support.

I have read over the past few months a number of threads regarding twincharging etc and I am hoping that some one can help with a couple of points.

I have read a number of times that the Toyota superchargers (Ogura air pumps) are only suitable for intermittent use, furthermore they have bespoke bearings that are non servicable. I happen to have one that I intend to use for supercharging a type 4 VW aircooled. The original thought behind the decision was predominantly the size however my concern now is longevity. What can I expect from this type of charger if I use it constantly? I expect around 8-10 psi running 1:1 on the pulley's ie max revs on the type 4 is 4,800 and this charger works well upto this range.

Any help would be appreciated

 

[MiketheEngineer]

Me thinks the engine will melt down??

 

[140Airpower]

Blade, if it's designed for intermittent use and you run it constantly the life expectancy would be reduced. But how bad will that be? I think these are designed for the transient condition during acceleration before turbo boost can build? If so, then constant use will probably be a very big increase in wear and maybe of more than just the bearings.

 

[dgallup]

What is the use of this engine that it will be under boost constantly? If this is some industrial application I would expect short life from both the supercharger and the VW engine.

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[Blade2good]

Thanks guys, just a couple of points
Mike, no meltdown as target power is only 140 BHP at the crank so plenty of headroom there plus the 'charger should be capable of 160

140Airpower,
I understand what you are saying but I am looking for more detailed information, I can't find any tech specs on the TX12 at all. I was hoping that someone might have some experience or more details than I can find

 

[Blade2good]

dgallup

This is being used in a van for road use so not industrial. I can design the system so that the 'charger is used intermittently but I am looking for some details that might point me in the right direction. The design speed of the 'charger is around 11000 rpm and I am looking to run at less than half that speed. This should give me a target boost of 8-10psi and significantly most of this will be low down the revs to produce a very flat torque curve

 

[crerus75]

The TX12 has both intermittent and continuous-duty ratings for both RPM and pressure ratios (see below). Sorry if you have this info already, but it's all I could find in the 3 minutes I devoted to this at work:

http://www.oguraclutch.co.jp/e/product/type.html

This makes me wonder if there actually is an intermitted-duty requirement in all cases or if it is RPM and pressure ratio-dependent as the info above tends to imply. An email to Ogura might give some more details.

You might also want to see this thread:

http://nzhondas.com/forced-induction/74114-twincharging-b16b-2.html

Looks like a very nice build of a compound turbo/supercharged engine with a TX12. A couple of years old now, might want to dig around a bit and see if the owner has any empirical data on the longevity of his install.

 

[patprimmer]

TX12s are so cheap, they could be considered semi regular maintenance like replacing disc pads.


Regards
Pat
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[Blade2good]

Thanks guys appreciate the feedback, I will drop a note to Ogura