Boost vs HP

T

THE BIRDMAN

Registered User
I know I'm missing something here but can someone explain how you can run the same psi on the same engine with 2 diff. blowers.I.E. say you have a 94/95 style blower and you are running say 19 psi and make say 250hp.Then you place a mpII or mpIII blower on the same engine and you run it at 19 psi and makr say 300hp..So basically how can you move more air at the same psi?Cause isn't the psi actually showing you the resriction in you're engine.I'm just trying to wrap my head around this.I know it's gotta be something simple I'm just not thinking of.

Jay
 
IF you're comparing the same motor say stock motor to stock motor in both instincts then the only benefit with the MP equipment will get the boost up to 19lbs of PSI without having to spin as many RPMs, so it will give you more power band to enjoy.

I beleive that is the answer to your question unless I've missed something.

-Tim
 
OK so you would be able to run less o/d with the mp stuff to reach the same psi.Which would move the same amount of air at a lower temp.So then the hp increase would really be due to cooler intake charge due to less o/d to reach said psi.


Jay
 
I mean the MP units are a better design allowing them better flow with less work involved. So yes you are right. They are designed to be over driven to give you even more than a stock M90 be it gen 1 or 2 at normal conditions.

So your correct you're able to move more air quicker with less drag/friction and or heat which in turn gives you more hp to be used.

-Tim
 
Well here's my experience. I was making 250rwhp on a 95 Blower @10%OD and 17 psi. Upgraded to MP2 non coated rotors, 50lb injectors, 15% OD, and gained 15rwhp running 19psi. I did run 10%OD with the MP2 for a week and boost was down to around 15, and would make 17 at only high RPM's, as the 95 blower would make 17 psi almost instantly. MP blowers need more OD to really become effective.

I did notice between runs that my IC was cooler after installing the MP2.

Yes, psi is just a measurement of the restrictions in the intake. The MP blowers lower air temps, and if I am not mistaken they do this by the porting that gives the ability to be spun at more RPM's lettting more air flow thru the charger.

This is a good thread to read http://www.sccoa.com/forums/showthread.php?t=70779&highlight=real+street+performance
 
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rzimmerl said:
Well here's my experience. I was making 250rwhp on a 95 Blower @10%OD and 17 psi. Upgraded to MP2 non coated rotors, 50lb injectors, 15% OD, and gained 15rwhp running 19psi. I did run 10%OD with the MP2 for a week and boost was down to around 15, and would make 17 at only high RPM's, as the 95 blower would make 17 psi almost instantly. MP blowers need more OD to really become effective.

I did notice between runs that my IC was cooler after installing the MP2.

Yes, psi is just a measurement of the restrictions in the intake. The MP blowers lower air temps, and if I am not mistaken they do this by the porting that gives the ability to be spun at more RPM's lettting more air flow thru the charger.

http://www.sccoa.com/forums/showthread.php?t=70779&highlight=real+street+performance
Click to expand...

Another thing is, that just because you lost boost doesn't mean you lost horsepower, you probably gained a little with 10% I would think or at least sustained the same power with less boost.
 
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A less efficient blower will not only create more heat at the same PSI but perhaps cost more HP to turn. Both equalling a reduction in power....Now witha turbo....
 
Boost thumb rule;

For every 1lb increase in boost, with no temp increase.
You should gain 7% increase in power.

Air temp thumb rule;
For every 10 degree decrease in air temp.
You should gain 1% in power.

Randy
 
Be interesting to run a temp probe in the IC system before and after the intercooloer. Then mount it to the dash with a large display with flashing LED lights and a big fin.....whoops...rice.

But knowing the temps would be cool
 
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