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M90 Flow rate? psi.


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I need to know what a Stock m90 with a stock 3.8 Pulley will produce at 4,000 RPM.

 

My guess is around 5 PSI?

 

Reason for asking will be in my project thread in other cars/trucks

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pressure is dependant upon intake restriction.

 

throw a M90 with the same pulley on a LQ1 and you might see 3PSI, throw it on an iron duke, you might see 11PSI.

 

it all depends on how well the motor flows N/A.

 

to get a truly good estimate, you would need a flow chart from Eaton. i have one for a Gen 5 M90.... i think.

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well, one of the rather intelligent guys on TGO made up a MAF patch for the 94-95 trucks, that would allow boost, assuming you can find a MAF that will measure high enough for whatever level of airflow(HP) you're shooting for.

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anything better then stock, My budget is 50 bucks, for stuff i dont have (pipe) LOL! metal is stuff from the yard ill grab, i got the blower. and could probably get a maf from an ls1? if that would work

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as long as it will read as high as you're wanting to push the motor it will work.

 

the MAF patch was only for fuel; however, i'm sure i can work one up for spark as well.

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an M90 would end up spinning 10,000rpm to more with sky high IATs just to provide enough airflow to cause boost on a 350ci engine:confused:

 

And not only that, but it will be consuming 30-50hp in the process.

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I am not going to try and break any recored here. If i just got the sound of the blower id be happy lol. But, really a 3.4 or 3.8 pulley on a 350 would give it quite a good kick from stock right? I know its not going to be 500hp, But would 255hp be out of the question?

 

stock the 350 tbi is at

210 hp @ 4000 rpm

300 lb.-ft. @ 2800 rpm

 

and i want it to keep up with this

 

 

Vortec 5.7L

255hp @ 4800rpm

and 330tq @ 2800rpm

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Your gonna need a sub 2.8 pulley to actually do anything on such a large engine.

 

And if you think a L67 has crap heads/intake and is prone to KR, well you get my point:lol:

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2.8 pulley is doable. I am not expecting a beast, its an old wore out 350 i just wanna blow it, so to speak. But if i could get 5 PSI, that would get a pretty good punch from stock, I would like to see how long the old 293k mile motor would last on boost. lol

 

would it really be that hard to get 5psi out of a stock 3.8 m90 at 4k RPM (of the motor)

 

because if i get in to sub 2.8 pulleys im looking at making ALOT of heat,

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i can ASSUME the gen3 and gen5 flow maps are similar, just the gen3 having less efficiency.... i'll try and build a decent sim(and get you an idea of what will happen), but what other info can you grab about the motor?

 

i'll also need some idea of the pulley sizes available for a M90 and what size of crank pulley on the engine.

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the flow rate of fuel system

 

@ 13 PSI they flow 55 lb/hr

 

@13 psi the 454 flows 90/hr so i could find a set of them for "Upgrades"?

 

i can port the gen 3 to make it flow on par with the gen v (gen v swaps only net like 3-8hp)

 

the crank is 6.6 inches

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LOLOL, i just mapped out what it would look like at 6PSI....

 

the fact that those heads flow SOOOOOOOOOOO shittily is actually making this look pretty good!

 

results WILL be posted when i've finished boost levels from 1PSI to maybe 8 or 9 from the looks of it. :lol::lol::lol::lol::lol::lol:

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the engine itself can handle more speed, GM just marked it that way since it wheezes beyond 5K... with a blower, it MAY be better...

 

oh, and i decided to go all the way up to 14PSI. :lol:

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LOLOL

 

first, a little explanation:

 

since there weren't 14 available colors in the MSPaint pallette, i just used the same one over and over...

 

so, each black line i added and where the maroon colors top out at? that's each PSI. goes up to 14 with the engine by itself in the light red on the bottom.

 

the most efficient line SEEMS to be roughly 7 PSI., once you hit significant boost, the adibiatic efficiency never drops below 60%, which is pretty decent for a roots blower.

 

also, the dots? they end at 5K RPM, since beyond 5K didn't generate any additional airflow. now, blower speed at 5K at 7PSI is ~8600RPM. with a crank pulley diameter of 6.6 inches, the ideal blower pulley size would be 3.84". that will give the blower a 72% overdrive, so when the engine hits 5000 RPM, the blower will be at 8600.

 

 

 

 

 

NEAT!

 

 

X5l3Y.gif

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