Supercharger Types and Prices

[DJThom]

Gentlemen, a couple of questions on superchargers:

1) Has anyone ever compared this MG supercharger to the one available from Moss:

https://www.hi-flow.com/HP2MGSuper.htm

2) Do any of the Moss distributors offer the supercharger kit for less than the retail price in ther catalogue?

 

[Steve_S]

Hi-Flow is supposedly capable of a higher level of performance because the Moss unit is designed to be safe on a stock engine. But the Hi-Flow unit is not going to be a simple bolt-on procedure like the Moss blower kit. You will spend more time fitting, fabricating, tuning, etc than you would with the Moss kit. You can also buy a high boost pulley for the Moss kit to increase its performance.

 

[Hap Waldrop]

Yep as Steve said the Hiflow unit is more designed for a specific force induction built engine, this uniut has the reputation of blowing up stockish engines. The Moss unit with the suppiled pully puts about 5 pounds of boost, that about right for a stockish engine. If you're going with the higher boost pulley, it produces about 9 psi of boost, so this approach needs a engine more designed for forced induction, use of the hi boost pulley also voids any warranty Moss gives. Steve has a APT built forced inducton engine putting out about 9 pounds of boost, I done a similar engine for customer, we both use custom pistons that lower the compression ratio for the higher boost levels, both used camshaft that favored the blower and many more tweaks. Dyno result for Steve's motor look quite impressive, I'm still waiting on my cusotmer to get his engine installed so we can chassis dyno.

 

[vagt6]

Hap, what kind of HP/torque numbers will 9lbs. of supercharger boost with the purpose-built engine produce?

I'm guessin' about $10K to build that engine with the blower and get it tuned correctly, is that fairly accurate?

 

[Steve_S]

Actually Hap, my engine has the low boost pulley on it because the high boost (smaller) pulley kept slipping under load. Since that was on an engine dyno, I plan to try it again in the car and see if it will grab in real world conditions.

So, the numbers you've seen for my engine are with the low boost pulley. I have no idea how much more power the high boost pulley will produce but I suspect no more than 10 at most. Just a semi-educated guess, really.

Mark, my engine is putting out 150 hp / 150 lbs-ft at the flywheel, with the low boost pulley.

 

[DJThom]

Thanks guys. I rebuilt the engine 17+ years ago with my dad and am a bit sketchy on details (I was 18 and not high on documentation). It has a Brown and Gammons fast road cam and higher compression pistons. I believe my ratio is around 9.5:1 but never have done an exact measurement.

Is this engine a good candidate for supercharging, or will the higher compression put it at risk? Should I be looking at other goodies like roller rockers, weber carbs etc instead?

 

[Grantura_MKI]

Too high of comp. I am a Shorrock runner. No Weber with a blower. A single carb is the ticket.
Cheers,
D.

 

[Steve_S]

I lowered my compression from about 9:1 to 8.5:1 for supercharging. Custom pistons were needed to accomplish this.

 

[Hap Waldrop]

We used custom JE pistons I had made with a 8.0 to 1 CR. We're also using the Hans Peterson/Hi flow sepentine pulley/Harmonic blancer set up. I'm still waitng on Frank to sort out his new wiring harness to get the car going, and get it to the chassis dyno. It's got some wild goodies on it including Yella Terra stud mounted 1.5 roller rocker arms on it.