EFI-DIY,
I saw this from Vortech.
It's a supercharger kit for the Chevy 3.7 inline 5 cylinder.
http://www.bangshift.com/blog/Vortech-Blower-for-Inline-5-Cylinder-GM-Engines.html
Was wondering if it will bolt up to a 4.2?
Is so, maybe there is a bigger blower that will fit on the 4.2?

MBHD

The pieces look to be sized smaller than I would expect to be optimum for the 4200.

All those bits are available in diffent sizes.

I would actually prefer a "twin screw" type blower like Whipple, or the new one Vortech has.

The whole point of a supercharger to me is to get boost at idle or just above.

What is nice about the centrifugal superchargers is that all the boost does not come in @ once.
Great for not blowing the tires away in smoke.

Unless you have sticky/wide tires on your ride all of the time, a centrifugal supercharger is something to consider.
They can be set-up to come on soft or very hard depending on how you set-up the pulley ratios.

With the newer more efficient centrifugal blowers they should be something to consider.
They will give you boost very quickly, & you can change the pulley ratios & just how much boost you want off of idle.

My Paxton worked pretty good considering it was ball bearing drive & was limited on how fast you can spin it.

The newer gear driven centrifugal blowers comes in all different sizes & can give you more boost than most twin screw blowers can & might heat the air less in doing so.

So I would not just blow off the idea of using a centrifugal. They are easy to set-up & could give you more boost than a typical inline 6 can take.

MBHD

Mechanically it should the front of the motors are nearly identical. A longer charge air hose would be needed.

The problem area is the GM PCM, 08&09 4200 should be ok. The other years check with Vortech.

What software is used for the PCM/ECU programming?

HP tuners? & what year/s work w/HP tuner?

MBHD

You would be better to ask someone else on the PCM's - I have not used them nor any tuning s/w. Limequat would be a good person to ask.

Currently working on a 2 bar tune for the 2006 PCM. This will go up on Limeswap.com for $99 like any other reflash.
I have a feeling that it wouldn't be that hard for 2002-2005, but I'd need to experiment on someone's vehicle. 2007-2009, no problem.

So there is no HP tuner software to tune with?

MBHD

HPTuners is available for all years of the 4.2...

I suggest you contact Self Racing Engines in Durant, OK. They are the present guru's with the top performing 4200 inline sixes. I saw one in their shop lat fall that was one heck of a modified engine producing over 700HP on an engine Dyno.
Normbc9

Self's is carbureted though, these guys are needing to retain the OEM type fuel injection or aftermarket megasquirt type.

Limequat,
What is "a 2 bar tune" ?

Basically running boost pressure 14.7 PSI or less is a 2 bar tune.

MBHD

A bar being 1 atmosphere, or 14.7 psi. Naturally aspirated engines would be "1 bar" (though nobody uses that term) since we're already at 14.7 psi here on earth. Add 14.7 psi of boost on top of that and voila... A "2 bar tune."

So what kind of HP could be expected at this level?

roughly double NA...

So on a 2006 (I would not run 15# of boost on a 2002 - 2005 unless it a disposable test engine) which has better rods etc..

somewhere between 550 to 580HP

I might have to look at this engine a little more closely if Inliners creates a class division for this engine.

I was just on the Vortech website and the kit has been discontinued. I suspect it has to do with the I5, being crap, and most of the H3's are just mall crawlers anyway. It is an interesting concept though. Since my AD truck doesn't have power steering, it would fill the spot mighty well. They do show a 98hp and 65ft. lb increase on the I5. I wonder what that would equate to on the 6. 110 ponies and 80 ft. lbs?