turbo2256b

iTrader: (1)

Can think of a lot of carbed cars that had tuned length systems like all of them some were just better thought out than others like my cross ram 413 wedge dodge

buck35

I'm sure carbs are the cats azz... for people who like to play with them, but if you want to go boating with the little free time you have how could you not love efi.i have plenty of old temperamental farm vehicles to fill my need of tinkering on chit so it will start and run when needed.

BUP

iTrader: (9)

Here is the story I wanted to post but could not from web as I had to find my magazine first to be able to pull it up off the web to post the link to it. Read it please as back in 2010 I thought it was a good tech story. So here it is, the web version. The other stories all come to my email, it gets very cluttered everyday. Link below and read it if you like. I went thru a little work & time to find it.

http://www.hotrod.com/how-to/engine/...6-l-mod-motor/

turbo2256b

iTrader: (1)

You wouldnt believe how much time can be spent with a pigyback tuner and a factory ECM on a modified engine compaired to a carb. There are over 500 functions in a factory ECM. I remember staying up all night caculating injector timing based on my aftermarket cam, Staying up late to all night tweeking A/F CHARTS , CHANGING TIMING CHARTS, load charts, WOT timing, A/F ratios, speed of advance, hours of data loging turned into months of tuning. I taught friends what I HAD LEARNED, they helped me data log and were amazed woh well mine was dialed in compaired to thiers.
Then I went further than the factory fuel lines could handle. Put my dual quads on took less time to tune them a couple jet changes and a couple air bleed changes and was all done. Have been giving thought about a coil pack set up and ditching the dizz would improve it more than anything at this point.

BUP

iTrader: (9)

^^^ auto ECMs & fuel injection yes, marine ECM's & injection no. I am in favor of fuel injected in boats but OEM marine fuel injection in the 1990's really nothing special nor ran any better than carb marine engines back then. Also there was no fuel savings running an EFI marine engine in the 1990's from the OEM's compared to carb engines. OEM Marine fuel injection currently is finally catching up with the auto side but still has some distance and a long shoot away for tuning / remapping the ecms compared to auto's. I will say at least marine fuel injected engines are not 15 years behind the times compared to auto's like they use to be, they have closed the gap but not completely.

About 5 to 10 years from now it will be huge common known issues publically about marine catalyst engine problems from the ones that have been currently produced. 3 way catalyst systems in the marine environment has no longevity.

beaver 3

maybe there was resistance to the ecm causing the ecm to recieve the wrong inputs, there for sending out the wrong outputs. fuel injection is so easy to diag its rediculous. just think of the ecm as a voltmeter. thats just the day to day tech coming out in me. when im out on the river where **** can go wrong when something breaks. i want the ability to poor gas down the carb out of my beer can to get home when the fuel pump ****s out.

CNC

Interesting....I switched from carb to EFI expecting BIG hp gains. Was disappointed, identical peak hp. What I did gain was better starting, great idling around docks, stronger mid-range and vastly improved fuel economy (economy..kinda of a funny word to use on 1150hp motors). Mine was a direct swap out 850 Pro-systems carb for a Fast throttle body and 8 injectors off fuel rail into intake port. Everything else was the same (intake manifold, massive intercooler,M4 Procharger)

MILD THUNDER

iTrader: (3)

In a blow thru deal like yours, I would say you definitely made the right move. I fooled with my buddy's M4 blown engine with a carb setup. I just didnt like it, and I am more of a old school carb guy. Besides all the obvious negatives, the fuel distribution sucked as well.

14 apache

iTrader: (1)

You have some pictures to share of the engines? Thanks

BUP

iTrader: (9)

With EFI and speed density systems basically has the calibration program for every rpm thru out so once the internal vacuum and or intake air changes within the engine in any shape or volume form - the ecm can not adjust outside of the parameters the sensors are imputing / feeding the ECM for the corrected outputs.

Basically the ECM can not adjust for parameters that are outside of its calibration / tune.