I am still learning about superchargers, so please keep the flaming to a minimum. My question is basically this:

Say one was to swap up to say, an M90 Eaton blower (roots type). The blower is bigger, yes, but I am wondering where the gains would be. Are the gains in:

A. higher boost capability?
B. say you run 15psi out of the big one..can you get the 15psi at a lower blower rpm, thus, less parasitic power loss?
C. lower heatsoak..big blower produces less heat at 15psi compared to the smaller one?

If one was to swap up to an M90, all supporting hardware good to go, and if you could get the pulley sized to making 15psi, just like stage 2 GMPP, could you in theory run the stage 2 gmpp tune and gain any power from less parasitic loss? any estimates?

 

I just sold my whipple and am working on the adapter plates for this swap. How much power will it make? Your guess is as good as mine but it should produce enough cfm to reach 300whp.

 

good post, im gonna keep an eye on this

 

gains would be minimal. the M90 is too big for the LSJ.. you'd be gaining power due to Cubic feet per minute of air flow, but losing more than you would with a different blower type all together (just trying to spin it. Gigantic parasite)
you need a smaller s/c with a better volumetric effiency

 

Here we go again. It's not too big for the LSJ.

 

would it be that much harder to spin than the stocker due to its larger size?

if psi is measured in the manifold, does higher cfm = higher psi?

 

no psi is directly related to pressure inside the blower or maniflod, with the larger blower, holding more litres of air, you can make more power and have a higher cfm, yet be making less boost than with the M62.

i believe psi is measured by vacuum lines attached to the blower, not the manifold

 

i thought pushing more air didn't make more power? sorry had to bust your ***** there man

and the parasitic loss on an M90 would be more than a M62 and the pully you would have to use to make it work well would be enormous... you would more than likely be better off swapping it out for something else... there's a reason that gm didn't put the M90 in the lsj platform ... it's on a 3.8L pontiac gtp comp g car... the difference between those two cars is night and day...

 

oh wow... let me make this simple cause everyone is waaayy off base here


The only way the M90 would make more power at a certain boost level is if its more efficient in the operating range. (all else equal)

First, we are exceeding the limits of the M62 already with a stock heat exchanger and cylinder head/valvetrain.

Now, if the valvetrain, cylinder head,exhaust manifold, and intake manifold was optimsed to flow better and now can utilize extra air then the M90 will make more power becuase the unit is more efficient at higher flow than the M62.. assuming pressure ratio remains constant before and after (thanks to more supercharger flow and better flowing engine)

at the end of the day, its all about increasing air density in your intake manifold for the least amount of energy.

 

if you are going to use a m90.. please look at the 2004 + grand prix blowers... they have a gen 5 m90.. the 97-03 GTP's have a gen 3... the gen v is more efficient.

 

I gess I am a lil confused. I have read many threads about this issue and they all say that the M90 is too big because it takes more hp% to make HP. On paper the the M90 outflows the M62 at similar rpms for the same VE. I gess it boils down to is over 200 CFM at 14,000rpms worth 20 HP in loss.

 

I would like to see someone do a TVS R900 or R1050 swap. It's that Twin Vortice Series from Eaton.

http://www.eatonperformance.com/superchargers/TVS.html

 

Before people start doing all these crazy blower swaps, they need to do a rebuild on their engine to flow better. Otherwise, your just trying to jam more air into an engine that is already at its flow limit.

 

The M90's adiabatic efficiency is lower at the high pressure ratios needed to force additional air into a small displacement engine such as ours. Parasitic loss MAY be less but heat produced would be much greater than the m62 is at the peak pressure level. You would probably end up with less available horsepower due to a hotter intake charge being susceptible to detonation among other things.

Eaton publishes gen5 efficiency maps on their website, anyone can compare the m62 with the m90.

 

Seems like we have run out of blower but have yet to max out our topend. I know that opening up the ports and a valve job will ease the stress on the blower. It just seems like the blower is more of a weak link.

 

max effiency of the m62 is 7 psi.

stock boost levels from gm is 10 psi, give or take a few.

some of us are pushing over 17 psi.

the after cooler helps with keeping temps down, but only so much. this is why gm has the dual pass, to help it even farther. because they know it's out of range.

the m90 pushes more air, yes. it's a larger positive displacement supercharger. thats a given, BUT. it is not as efficient for our application as the m62, or a twin screw is.