this should eb an easy one: i got an Accel DFI gen 6 stand alone system from a friend that will be going into my heavily modded 89 iroc along with its new motor, fuel system, ignition setup, etc. i just got it and havent had much time to look into it...but will this system be a speed density system? i imagine it would be and if it is, will it come with everything needed to swap over my existing MAF setup to SD??

can anyone using Accel DFI give me some insight?

thanks for the help

Damien

 

gen vii and the fast unit are speed density, so id make an educated guess (not an assumption--that would just be dangerous) that the gen 6 is s/d also.

since you're getting it from a friend, you should ask him if it comes w/ everything u need to convert from a maf setup. im pretty sure the main sensors that are diff from a maf setup are an iat (intake air temp sensor), they both have a map, but not sure if they're the same part #, probably are, and... im either having a brain fart right now or thats all... i think its just iat, map, and rpm.. and also the ve tables, but theres no sensor for that.

 

Yes. The gen 6 system is speed density as it operates off of engine load (via a MAP sensor) and engine speed. It most likely came with all the sensors that it needs to run -- MAP, ECT, TPS...etc. Make sure you get them from your friend.

The difference between the Gen 6 and newer systems is that the Gen 6 is Pulse Width based. This means that your base fuel map is simply a programmable matrix of target injector pulse width values vs. engine speed and engine load.

Newer systems like the Gen 7 are volumetric efficiency based, meaning that you use the calibration software to model the air pumping efficiency of your engine vs. speed and load. The ECM then mathematically determines a pulse width value based on your speed, load, target a:f ratio, ve values, sensor readings, and other influences. Since there are more variables used to determine the pulse width value, the ve based systems are more complex, but also offer much better control over an engine than pulse width based systems.

 

i see...

thats some great info. i hasnt checked out the main differences between gen 6 and gen 7 dfi. that makes sense though. and despite wanting the gen7, all i can afford is to buy his used gen 6 setup so ill have to work with what ive got...for now.

but thats great that i can swap over. i was thinking that was probably the case, but wanted to be sure. and as far as the sensors go, shouldnt i be replacing the sensors with new ones anyway? i mean he's has this system a couple years running 2 different motors....plus sensors arent too expensive...wouldnt it be worth it to replacew them all now?

 

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