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RE: [T3] Pollute less with more gas? (was: Dual carb versus EFI ? )

On 16 Nov 2001, at 7:54, Erkson, Toby wrote:

> Okay, so you're statement is focused mostly to that time period, right?  I
> understand where you're coming from.  I think that if we were to take our
> air-cooled engine back to the engineers and say "Make it FI, run clean and
> more power" the FI system would be different and we'd see combustion
> chamber/intake/exhaust changes as well.  Like what Porsche had to do before they
> finally threw up their hands and went water-cooled :)

Right. I just don't know if it could actually be done with the air cooled 
pancake foundation that we already have. The big question in my mind is 
why does it matter that we are air cooled. It seems to me that the intake and 
combustion happens so fast that there should be little heat transfer into the 
fuel/air from the hotter air cooled engine. Yet emissions regs clearly put the 
end to air cooled engines.

> My '95 Jetta GL is a 2.0L stock.  I get just over 30mpg on the highway and
> about 100hp @ the wheels now that I've customized her (new engine management
> chip...technology has come far!) whereas stock it was about 12hp less.  My
> Squareback is 2.0L bored and stroked, carb'd, and gets a top mileage of 28-29mpg
> on the highway (Gene Berg Memorial Cruise 2000).  Estimated hp @ the wheels w/a
> 20% drivetrain loss is 112hp.  Stock condition her hp was about half as less and
> for a '72 y'all know the mileage for FI better than I.

You don't mention your emissions, and I doubt if your car would pass today. 
I don't think any of the aftermarket chip sellers guarantee EPA compliance, 
that's why these are all sold "for off-road use only." So I think it's pretty clear 
that they have traded emissions for power and mileage.

> I think engineers have become much better at the game but for back in "our" day,
> yes, things weren't as good.

Clearly we were just starting up the learning curve.

> So, do you think an after-market FI set up would be a better system, in
> terms of power, emissions and mileage?  For argument sake, I'm assuming a
> complete system, like an engine management system, that includes ignition
> control.  As you know, today's engines just aren't FI like back when, they
> are engine management systems because the fuel is manipulated by many
> factors, including the ignition system.

I think 2 things are clear: 

1) A well financed engineering push using modern engine management 
techniques could produce a much better (more power/better gas 
mileage/lower emissions) type 3 engine today.

2) No one's gonna do this because they would never earn back their 
investment. What we will get will be aimed at the "off road use only" 
aftermarket, with rule of thumb guesswork instead of real research and 
engineering. It will probably give good power, medium efficiency, and 
unknown, untested (meaning poor) emissions. Long term reliability (does it 
burn valves, pull head studs, or break cranks?) will also be unknown because 
it will be sold before any test engine sees more than 5k miles on it.

Jim Adney
Madison, WI 53711-3054

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