Max OD For Late Model Blower?

CMac89

Registered User
I was wondering where the cut-off for performance would be, in terms of %OD or boost, for a fully ported late model blower with MP inlet.

I'm running 14-15psi right now with a custom FMIC setup and wondering what boost level would start to become just too inefficient to make a positive gain.
 
well u can up the boost more... as long as u can sufficiently cool it down... then u also have to worry about the belt slipping and u breaking the hell out of the snout... but the more boost u make... the hotter it will be... so in other words... more boost.... cool it down more.... or else POP goes ur engine.... somebody with a lil more exp. needs to chip in...
 
Add the Snow Methanol injection and crank it up... That, along with the FMIC and a good tune should let you run 20psi.
 
acually, I don't think that he meant what is the most I can run. I think the question should have read how much overdrive can I put on a ported m-90 before it looses volumetric efficency?? See at some point the blower is gonna run out of steam no matter how much boost you are actually pushing through the blower. Also, the heat generated by huge amounts of boost might actually cost more hp than the extra boost is making. I dont think I would push a s-port or mp2 much more than 15% overdrive. a mp3 is another animal all together. Someone correct me if I'm mistaken.

Rick
 
After a while wouldn't your belt slip all the time? I remember Kevin L. saying that is one thing that is holding him back.
 
Yes I was talking about volumetric efficiency as well as heat. The SNOW kit would tally out the excessive heat, in a sense, but then the question of VE comes into play.

Right now i'm at 5% OD (15psi) and I'm guessing that 10% more OD would be around the neighborhood of 18-19 psi. Then back to my question; Would it still make a positive performance difference versus 15psi?
 
CMac89 said:
Yes I was talking about volumetric efficiency as well as heat. The SNOW kit would tally out the excessive heat, in a sense, but then the question of VE comes into play.

Right now i'm at 5% OD (15psi) and I'm guessing that 10% more OD would be around the neighborhood of 18-19 psi. Then back to my question; Would it still make a positive performance difference versus 15psi?


"Cogg It"

I am running Cogged blower drive Pulleys at 15% over with JDS Ported M-90 getting 19.5lbs of boost with double IC and stock IC tubes. I had nothing but trouble with ESM quick change with my modified jackshaft pulley at 25% overdrive slipped and shedded belts like no tomarow. With a stock late model blower not ported you wont gain much going more overdrive but with MP2 or MP3 you will gain a lot
 
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Jim Demmitt Jr said:
"Cogg It"

I am running Cogged blower drive Pulleys at 15% over with JDS Ported M-90 getting 19.5lbs of boost with double IC and stock IC tubes. I had nothing but trouble with ESM quick change with my modified jackshaft pulley at 25% overdrive slipped and shedded belts like no tomarow. With a stock late model blower not ported you wont gain much going more overdrive but with MP2 or MP3 you will gain a lot
I would love to have a cog setup, but I shook the hell out of my money tree too much where it just dried up all of a sudden.:)

The blower is fully ported, but it isn't an MPII. More along the lines of an MPI. Is there much difference?
 
CMac89 said:
I would love to have a cog setup, but I shook the hell out of my money tree too much where it just dried up all of a sudden.:)

The blower is fully ported, but it isn't an MPII. More along the lines of an MPI. Is there much difference?

If your already getting 15 pounds, I wouldn't overdrive it more than another 5%, and do that with a jackshaft pulley. Anything more and your going to start losing top end power trying to spin the blower.

David
 
A cog belt setup is no good for the street. The constant on throttle off throttle will eat belts as well as wreak havok upon the blower.
 
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