I'm building a big block chevrolet engine that will be over 500 horsepower and I am looking for a good port injection system. I would like one that uses a 4 bbl throttle body. From what I know, Edelbrock and Holley have been very good but I have never used either. Any suggestions or information would be great. Thanks.
As far as I know, the Edelbrock can't be tuned via a laptop. It uses a chip that is programed by Edelbrock, then it can be fine tuned through the included tuning console.
The Holley is laptop tunable. This is what I went with, I also wanted a 4-barrel style. I think Accel also makes one.
I had an Accel DFI Gen 7 system on my engine and currently have a Holley Commander 950 Pro. The Accel system is more sophisticated and can be run seqential injection whereas the Holley can only run in bank to bank mode. Not a bid deal really. However, one nice feature that DFI has is individual injector trim where you can modify the pulse width of each injector seperately. I could really use that because my Holley oval port manifold is showing some pretty uneven air distribution. They can both control spark with the correct distributor.
Which brings me back to the subject of manifolds. If you have oval port heads, I'd recommend the DFI manifold. The Holley oval port EFI manifold has the peanut port sized oval ports which required a LOT of grinding to match my oval port heads. This is most likely the biggest cause of the poor air distribution I'm seeing. Judging by my spark plug coloring, I'd say I have a range of 13.0 to 10.0 AFR at WOT between some of my cylinders. That's a lot. That's where the individual injector trim would be nice. You could compensate for some of that.
Bill is correct, the current Edelbrock Pro-Flo system requires a pre-programmed chip. It uses technology that is outdated IMO. Addtionally, it is only available in an oval port version. Edelbrock is coming out with a completely tunable system late this year. It will utilize variable flow rate injectors, which are pretty cool. You can see it on Edelbrock's website. The Accel system is nice, but it is pretty tall. The notes say that it requires a minimum of 12" of hood clearance due to the use of a high rise intake.
I ended up going with the Holley Commander 950 universal kit, the Edelbrock EFI Victor Jr. manifold for rectangular port heads, and Accel 48LB. injectors. I need it to support around 650 HP. The total cost was about $2,150 through Summit.
We just dyno'd a 427 small block and we installed a FAST EFI system. One of the best I've ever seen, and made an easy 538HP. It also has individual cylinder time/fuel adjustments, which we didn't bother with...
i have oval port heads, and i definately want a 4bbl throttle body and tuned port injection, so it looks like its between FAST, Accel, Holley, and Edelbrock so could anyone just tell me the pros and cons or just the differences of each one?