New A/C compressor!

[Lonnie]

Based on the pumping volume & boost level desired, this charger would need to be run significantly slower than it would be on the Cobra engine.

The Duramax pumping volume at 4000rpm has about 80% of the pumping volume of a 281CI 4.6L at 7000rpm.

Couple this with the lower boost (4#) vs. the stock Cobra at 8#. Your blower drive ratio would likely be about 40% of what it is on the Cobra (based on a stock charger).

I would strongly consider the low speed efficiency of the blower, meaning how well the rotors seal (leakdown) at lower speeds, determining at what rpm the blower can make effective boost, as well as the ability of the seals inside the supercharger to hold up against the positive inlet pressure provided from the charger. Whatever the rpm/boost lag is on a Cobra, it would be roughly double on the Duramax. This is about the only instance where a large charger turning slower, is not potentially as good as a smaller unit driven at a higher speed for the same equivalent boost level. Another consideration is the strength of the rotors, as they must be designed to withstand the maximum boost pressure, otherwise they can deflect & self destruct.

 

[McRat]

Heck, it was $300! I can use it grind coffee with if it don't work!

 

[Turbo Buick 6]

Heck, it was $300! I can use it grind coffee with if it don't work!

Was this a one time deal or can you get more of them? Also was it just the blower or did it come with onything else, ie. lowerintake and intercooler and so on.

 

[LB7Diesel]

Was this a one time deal or can you get more of them? Also was it just the blower or did it come with onything else, ie. lowerintake and intercooler and so on.

The million dollar question..:rofl:

 

[McRat]

It is a very low hour take-off unit that I found on Ebay. I suppose there are others floating around.

No manifolds or intercoolers, but it does have a boost-actuated bypass valve to cap the boost. It is not a blow-off, but instead regurgitates air.

Making the manifold will be the real challenge.

 

[mick]

It is a very low hour take-off unit that I found on Ebay. I suppose there are others floating around.

No manifolds or intercoolers, but it does have a boost-actuated bypass valve to cap the boost. It is not a blow-off, but instead regurgitates air.

Making the manifold will be the real challenge.

Buy a Banks Big Hoss Manifold and axe the top

 

[Turbo Buick 6]

it does have a boost-actuated bypass valve to cap the boost. It is not a blow-off, but instead regurgitates air.

QUOTE]


I could be wrong, that but if I remember correctly, on the Lightnings at least, that bypass is vacuum opperated and used to allow air to bypass the blower under no boost conditions (high vacuum) . An old trick on the Lightnings was to unplug the vacuum line to this and it would give you quicker throtle responce (forcing the air to go through the blower all the time). I don't think that it controles boost because I can remember putting blower pullies on Terminators and not having to do anything with this bypass but still getting a boost increase. Hope this helps :hug:

 

[McRat]

First thing I need to find out is how much power is lost without intercooling. Hopefully I get those tests done soon. If the intercooler does not gain more than 5% HP, then I will not run one. This affects the plumbing and position alot.