Is the intercooler necessary w/ m90?

eightvalver

Registered User
Is the intercooler necessary with the m90? does it really provide performance gains from cooling the discharged air? Because I mounted an m90 to my 4 banger and I havent hooked up the outlet yet but when I put my hand to feel the air coming out....well it doesnt even feel like its hot, maybe warm.
 
Yes it's completely necessary. Put your hand there whenever it's at 15psi then tell me if it's warm or not.;)
 
To run the boost numbers we do, it's needed. You could put a larger pulley (larger, right?) to lower the boost to 5-6 psi and then you could get away without an intercooler, similar to the GTP's.

-Melon
 
To Supercoupe, OR an M90 installation on something else

Originally Posted by Melon
(1) To run the boost numbers we do, it's needed. (2) You could put a larger pulley (larger, right?) to lower the boost to 5-6 psi and then you could get away without an intercooler, similar to the GTP's.

-Melon

Yes & WRONG.

Yes: The M90 on an Early SC spins @ 2.5 x crank speed. That is why SC's need an intercooler.

Wrong: It is wrong to apply Supercoupe supercharger speeds to NON-Supercoupe applications. Our stock M90's are overdrive 250% from the factory.

If you spin the M90 less than "we" do, it will produce less boost, AND it will produce less Heat! So telling the guy to run a larger SC pulley, just doesn't apply, BECAUSE you are baseing the "larger pulley" idea, on the Supercoupes 250% overdrive, which the guy Isn't using.

68COUGAR
 
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that is a good point, but the speed of the sc is not as much the issue--a fairly decent rule of thumb is to use an intercooler if you go over 5-6 lbs of boost on really anything. In either case, an IC will not hurt anything. The M90 is a fairly commonly attempted sc for rotary engines on RX7's, and to date there is only one guy I know of who ran this SC on his RX7 without an intercooler, and made it worthwhile. he was only boosting to 6 pounds. Anything over that, and the temp does start to rise.

Also, in regards to the speed, it may not be the same as ours, but keep in mind that it is based on the size of the pulley on the crank. Depending on what size you are using, you may actually find yourself in a similar position anyways.
 
Melon said:
To run the boost numbers we do, it's needed. You could put a larger pulley (larger, right?) to lower the boost to 5-6 psi and then you could get away without an intercooler, similar to the GTP's.

-Melon
post test, need to correct wrong HTML
 
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