Alternate History

Guys,

I thought I'd throw a theoretical topic out onto the table for those more technically-minded than myself to chew on, and one that is related, in a way, to the still unresolved presidential election.

It’s my understanding that it was Ralph Nader and the Swiss who were largely responsible for the Bosch Jetronic fuel injection systems. I don't mean to offend the owners of CIS 911's, for I still am one, that is until I can sell my old 76' 2.7, but it's the widely held view that the K-Jetronic system, strictly in terms of engine performance, is inferior to the early carburettor and MFI systems due to its creation being a direct response to the enforcement of stricter vehicle emission regulations in the 70's.

So my question is, if manufacturers like Porsche weren't forced to adopt a more measured, and consequently, a more restrictive fuel injection system like K-Jetronic, what road would Porsche have gone down beyond MFI? Would they have further enhanced and refined the MFI system, or would they have come up with, as far as engine performance goes, a totally new and superior system?

Do you think EFI would have been in their minds, and therefore a distant dream before the advent of CIS? It's clear that EFI is quite malleable in terms of extracting and sharpening performance, etc, but I'm not sure if CIS was actually a stopgap before EFI.

Well, let’s go around the room, starting with…

Hmmmmm.

I guess the question is what, if anything, would have filled the gap between MFI and.... what.... when is the next evolution - EFI like you say? In terms of EFI, I understand the most power these days can be had from fuel injection on individual throttle bodies and a fully mapped aftermarket computer, albeit that Porsche do not offer this - rather they had (in the 993) VarioRam (or whatever).

So that indicates there is still a desire for accessible torque etc rather than outright power (torque being the one thing that CIS did provide).

I don't think we should forget about the oil crisis either. My CIS gets a crappy 18-20mpg around town, much higher on the open road, but I have read the contemporary reports which praised the CIS for significantly enhancing fuel economy, particularly over the 'S'. So torque and economy are additional benefits over emissions.

I do remember reading about the 911 SCRS - a very limited edition homologated (sp?) car for Group B rallying. It managed, I think, 255hp from 3.0 litres and featured Bosch/Kugelfisher (sp?) mechanical injection. It came out in about 1983.

Here is a picture of the engine:


So I guess that, technically speaking, represents a development of MFI. I don't think they did much though (beyond what was in the '74).

I guess I need to reiterate Matt, are you trying to guess what would have bridged the gap to EFI? Or how mechanical injection would have developed for the "RS" type models if emissions weren't a problem?

End of my big, uneducated ramble...

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Cameron Baudinet
1975 911S

Gosh, So much comes into play in this topic. Pollution,fuel economy,financial feasibility... I think Pollution laws kind of just accellerated the process,no pun intended.
New technology cost bucks. But in a situation where every one must comply your competition can't under cut you by selling older technology ie carbs. I think the progression was a natural one that followed the rules. There's no doubt that the new technology works. ie. racing. I must say though I really dig MFI. It's unique. And it looks so cool. I'm facsinated with it not unlike the way I was facsinated by erector kits as a kid.

Bobby 72' TE Coupe
72' Targa (project)

To distil my point, I guess, my feeling is that K-Jetronic was a retrograde step strictly in terms of performance, and its advantages, i.e., cold starting, fuel economy, and a more even torque curve, are compensatory to the degradation of sheer performance and throttle response inherent in the design.

Considering that the K-Jetronic system is essentially a compromise between performance and environmental concerns, it's still a pretty darn good system, in fact, it's brilliant, but from a harsh, performance-biased and environmentally insensitive viewpoint, carbs and MFI are both superior methods of delivering fuel.

But the point of this topic is not to beat up on the CIS system, but rather, to canvass ideas on what would have been, in a hypothetically ideal world immune to pollutants, and with an unlimited supply of fuel, Porsche’s evolution of the MFI system before EFI, assuming EFI was always on the cards irrespective of the development of K-Jetronic.