Is multiport injection worth the extra cost??

[twobjshelbys]

Originally Posted by bobcowan

To say that EFI is just an expensive carb is just... I don't know... silly? Ignorant? Simplistic?

Silly??? No.

Ignorant? Well, I don't profess to know everything, but this I do know.

Simplistic? There, you've got it. Absolutely.

Even a primitive hammer and chisel can be used by a skilled artisan to produce masterpieces in stone.

Bob, you are an artisan. But that puts you in the top 10%.

Ed's and my comments are directed at the 90% that this simple EFI is going to solve a problem they have struggled with, only to find that in most cases they spent a lot of money and still have the same problem.

The "FAST" and other systems seem to be reasonably robust. Their self-learning systems will get you going, but are only a start. I know one person that is happy with it, another that ended up spending the money on the dyno tune.

The Rosuh 427IR started with an Accel DFI system that could run either mode but was configured for MAF but didn't actually operate above 5000' due to an incomplete configuration of the altitude adjustment table coupled with a lack of understanding of fuel/air flow through the faux 8-stack trumpets. Fixing this had the benefit of me learning alot about fuel injection systems that I will never use again (see earlier discussions about kits and learning skills that you'll only use once, but I wasn't going to let a computer get the better of me). Roush has since changed to one of the FAST-like systems (don't know which one).

What you describe with your laptop adjusting for different conditions is an electronic re-jet. But where did those tunes come from??? Maybe you actually spent the time in the different conditions to arrive at them. Great. Maybe those "tunes" are "open source" and can be downloaded from the internet. Great. But it's still a manual intervention, and admittedly less intervention than a physical re-jet. The whole point of this discussion is about using speed-density vs. a MAF system. If your conditions are static, then the single solution will work. If you go through changes the MAF system will take care of those adjustments automatically.

To the OP: I think you're getting the gist of the pros and cons. It's your car and your money. Personally, I'd just get the carbs set up properly. The problem you describe seems fairly basic. Of course the problem even here in the US is finding a mechanic that can even identify a carb let alone know how to really "manage" one (you said you're in Scotland, right). For that reason alone the EFI system might be your best solution.

Good luck!