Why EFI?, maybe excellence was expected and they came as close as they could.. |
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Why EFI?, maybe excellence was expected and they came as close as they could.. |
Gunn1 |
Jun 11 2016, 03:59 PM
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#1
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Senior Member Group: Members Posts: 1,021 Joined: 14-February 16 From: Minnesota Member No.: 19,670 Region Association: None |
Did Porsche eff up?
No they didn't eff up, they did the best they could with the new technology they had. It seems as though the technology was purchased by the folks at Bosch from the aviation component of Bendix. That said most Injection systems were originally good at idle and full open throttle, so primarily racing applications. So in there infancy not well suited for automobile applications. Been reading on different types of fuel delivery systems and their pro and cons. There are very few con's to todays EFI systems, there were however performance and reliability issues with the original designs. Even today Claims of increased HP, Fuel economy, drivability, reliability and so on....some still dispute how much these differences really mean. It appears the main thing EFI does extremely well over Carbs is in the pollution factor, or in this case the ability to pollute less. Carbs are a some what open system allowing hydro carbons to escape/vent in to our atmosphere even when the engine is at rest, where as the EFI is essentially a closed system releasing no vapors or gases unless the engine is running and those gases are then coming out of the tailpipe from the exhaust cycle. Many of the Guru's (about 5 to 1) prefer carburation. The above Statement isn't correct, although what confuses this OP is the sheer amount of photographic evidence on this site and others including evilbay and CL showing most engine compartments with Carbs installed. Many here have spent thousands on their cars, and what do you see when the lid is lifted? a Carburated engine..... So while my intentions will be keeping my cars in their stock or near stock form, with EFI, I cannot understand why so many Carburated cars. (Because its easy isn't an answer, because its simple isn't an answer and because its cheap isn't an answer) With this being the case, Did Porsche mess up when they went the EFI route with the 914? I do not believe they messed up, I believe they did the best they could with the available technology they had. Granted they did sort of use the end user as of a kind of a guinea pig/test bed, but what manufacturer doesn't in some way. WHY DID THEY DO IT????? I think that just as much as seeing the Ljet and Djet as a performance and platform to develop future EFI systems off of, Porsche and others also incorporated EFI into there products to show they were progressive company's in design and practicality. EFI, Unibody, Targa, Mid engine, four wheel disc, and many more attributes can be cited as Porsches View into the future. I would like to keep my car stock with the factory EFI, but increasingly getting more difficult to do with so little information backing it up. Above statement is also incorrect. In my case I think I am fortunate because I believe I have most the parts needed to reinstall the factory EFI's on all three of my cars. There is a plethora of info on both sides, but for now.... just for originalities sake, EFI will be the way I go. To those that added constructive comments and or facts to this thread... it is much appreciated...to those that took this thread as some sort of attack on their beliefs, or way to "clutter" the site, I can appreciate how you feel, but I just see those arguments as shutting down the free flow of ideas and the give and take of facts that get each of us to arrive at our own understanding of the information. |
gereed75 |
Jun 13 2016, 11:13 AM
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Senior Member Group: Members Posts: 1,244 Joined: 19-March 13 From: Pittsburgh PA Member No.: 15,674 Region Association: North East States |
Thanks Darren for the post. Wish it had been started in a separate thread for open discussion about carb tuning.
I have a wide band O2 sensor and gauge on my 6. After much research and consultation with very experienced folks to get jetting right, I see very solid 12.3 - 13.5 AFR's under pretty much the entire RPM range under driving loads (heavy throttle and acceleration and pulling hills etc). However under partial throttle steady state cruising, I see AFR's in the 10's - way too rich for economy. There may be ways to correct this, but they will require some carb mods not easily done (changing of idle air correction jets, that in the IDA 3C are not changable). My point is, the triple throat Weber is a pretty sophisticated carb (PMO's are a bit better). Mine are tuned relatively well. They are fun and make good power when being romped on - otherwise they pretty much stink. They just don't carburate cleanly everywhere and probably never will..... short of doctorate level fiddling. Am currently putting together an EFI system based on MFI throttle bodies. Really looking forward to seeing how well this engine can run!! |
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