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Porschefile Porschefile is offline
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Join Date: Jun 2004
Location: Austin, TX
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Originally posted by DDDD

EFI will make your engine run cleaner and optimize throttle response, but it won't do a hell of a lot until you are actually on the boost except make sure your timing is advanced the way you want it.

Sorry but, that's not accurate. A good aftermarket engine management can still provide substantial improvements (not necessarily peak power wise) even off boost. With older turbocharged cars from the '80s and '70s that have older injection setups and turbo systems, usually stock stuff is much more focused on the powerband on boost, and usually not so much so on off the off boost powerband. Even smaller displacement cars like 944's can benefit from a good modern EFI. Rather then defaulting to the typical "emotional" terms such as it's magic, or it's a PITA, etc etc, lets talk some actual facts. Compared to old factory EFI systems, CIS, etc etc, modern EFI systems generally have faster processors, larger number of tuning load sites, ability to fine tune a larger number of parameters, some systems give you the ability to use advanced ignition or injection systems (coil on plug, sequential injection, etc). How do these things make any improvement? Well, with a larger number of available load sites for tuning, you can more finely tune at smaller rpm intervals over a broader rpm range. How does that help? Well, you can actually focus on tuning below 2000rpm and achieve much better torque and response below 2000rpm, which can have a substantial improvement on off boost performance, lugging the motor through traffic, etc. Don't believe me, go ride in a well setup EFI'd older car (preferrably something nice like a Motec setup) and you'll see what I mean. In addition to that, there are plenty of improvements to be made in "tip in"/partial throttle response, maximizing torque throughout the rpm band, etc. Anyone that doesn't think so either has never been able to successfully setup an aftermarket EFI, or has never experienced a properly setup one. TUNING is everything with any EFI setup, and unfortunately that is the easiest part to screw up as it truly is some sort of art form.

For the do-it-yourself'ers out there, there is no real reason a typical EFI setup should have to cost more than $5-7k for the EFI components + tuning. I realize with 930's there are other things such as injector blocks and intake manifolds to consider, but I'm just talking about the EFI setup itself and not turbo/cam/head/etc upgrades. Much over $10-20k as some 930 setups are advertised and well over 50% of the cost can usually be attributed to labor rates IMO. There are a few companies out there with plug and play setups like DTA, Tec3, etc for less than $5k so it can be done relatively inexpensively. Regardless of anything else, just don't skimp on the tuning. There's no real point doing an aftermarket EFI if you don't have the tuning to actually take advantage of it. For sub 500whp levels, the CIS has been made to work just fine for quite a few years, so technically, yes, there are better areas to spend the money than an EFI setup. For anyone considering over 500whp though, I wouldn't exactly say starting with an EFI setup is necessarily a "bad" route per se. True, there are more initially effective ways to spend the money, but you could also think of it as starting out with better components in the first place. This is the same as the age old EFI vs. carbs argument.
Old 07-17-2007, 12:34 PM
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