7M-GTE Engine Response

MDCmotorsports

Offical SM Expert: Turbochargers
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Mar 31, 2005
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Another thing to think about is having a dry sump vs a wet sump, and the diameter of the flywheel/clutch.

Having a small racing 6" clutch and flywheel would rev much faster than stock....
 

Poodles

I play with fire
Jul 22, 2006
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I'd be curious to put on a lightweight front pulley with only a belt to the alternator, and take the clutch out (just the flywheel) and then start the motor and see if it was that snappy...
 

Supraholics

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Apr 1, 2006
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Ry - Thanks for the info. I did read the N/A ITB thread. What I was trying to state was that the FXX motor was in fact close to that rotary while being a piston engine.

Doward - You're full of knowledge. Come on, spill the beans already. What's the diference between the 60º and 65º?

MDC - Yesss, that should help plenty by keeping the crank free from excess oil splashing around the pan correct? Also, can you give me more info on this 6" clutch/flywheel combo? Can it handle my HP Goals?

Poodles - I've noticed better response from the 7M motor without the PS on...
I guess someone who's replacing their clutch can have this done?
 
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buldozr

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Jan 9, 2007
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rotary is a different beast, now for apples and apples, comparing a ferrari motor to a 7m..... their rod to stroke ratio is critical in a high revving motor, Dont think its JUST THE STROKE cause its not, it comes down the rod/stroke ratio, rb26 like to rev, b16 honda motors like to rev(actually they have the closest to perfect rod/stroke ratio, still not a honda fan though) The biggest reason I see is the fact that the actual speed of the piston is slower on these motors at certain critical points of the combustion process, if you research it a little more, someone can explain it alot better than me. Throttle responce would come from efficiency(lightweight, low friction materials, hi compression, etc...)

EDIT: just buy a lotus or an s2000 and call it done.
 
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bwest

Drafting, not tailgating
May 18, 2005
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Rod ratio has huge implications on the dwell of piston at TDC as well as a method of changing piston speed based on RPM (read as shifting the powerband). look at the Ford 2.3 4cyls (that are used in SCCA) there are a number of different piston/rod kits that fool with exactly that (rod ratio) to help with building a motor that works in conjunction with head/cam/turbo/etc as a package.
 

MDCmotorsports

Offical SM Expert: Turbochargers
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Supraholics said:
MDC - Yesss, that should help plenty by keeping the crank free from excess oil splashing around the pan correct? Also, can you give me more info on this 6" clutch/flywheel combo? Can it handle my HP Goals?

Unless you're willing to spend the big bucks, and you are or know a machinest.... like my uncle Gueedo says... "Fogg-tta bout it."

The indy cars and alot of speedway (nascar trucks when qualifying) use a small 6" diameter clutch with 3 or more plates.

I think it will handle your horsepower goals....
 

Supraholics

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MDCmotorsports said:
Unless you're willing to spend the big bucks, and you are or know a machinest.... like my uncle Gueedo says... "Fogg-tta bout it."

The indy cars and alot of speedway (nascar trucks when qualifying) use a small 6" diameter clutch with 3 or more plates.

I think it will handle your horsepower goals....

I'm willing to invest, but not on a race team level :biglaugh: