emulator question

David A. Cooley n5xmt at bellsouth.net
Tue Oct 13 04:25:25 GMT 1998


At 11:53 PM 10/12/98 -0400, you wrote:
>
>-----Original Message-----
>From: David A. Cooley <n5xmt at bellsouth.net>
>To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
>Date: Monday, October 12, 1998 11:22 PM
>Subject: Re: emulator question
>
>
>>
>>Well,
>>It's a proven fact that Gas engines make more power the cooler they are...
>
>Nope, I've done back to back testing and when optimized the
>performance is the same, or within my level of driving being the
>same.    Less blow-by do to tighter piston+ring sealing.  Maybe
>on a carbed engine, where the fuel sits around heat soaking in the float
>bowl.  Maybe do to lower under hood temp., but when these
>are eliminated in testing I'll stand by what I say.


My opinion was based on testing with 2 vehicles... 1969 Mustang 302, 4bbl
headers etc.
192 thermostat car ran 13.90's at 91MPh
160 thermostat under similar weather conditions (Within 5 degrees ambient
and humidity/press also within a couple percent) times dropped to 13.40's
at 95MPh

2nd car was a 1985 Buick Regal T-Type with multiple mods... Same chip for
both tests and again, same weather (2 back to back weekends) 14.10's at
88MPh with the factory 180 thermostat and with the 160 stat, 13.42 @100.5MPh.

On both the SyTy and GN list, with identical chips and identical weather
conditions, the cooler the coolant, the more HP and better the times are.  

Now if you could totally isolate the intake manifold from engine heat, the
differences would probably be negligible, but as the air heats up on the
way to the cylinders it becomes less dense, so less air gets into the
cylinder.  Less air means either the mixture richens, or the ECM leans it,
but richer or less fuel/air both mean less HP.
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           David Cooley N5XMT           Internet: N5XMT at bellsouth.net
     Packet: N5XMT at KQ4LO.#INT.NC.USA.NA   T.A.P.R. Member #7068
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