Okay another question for the pros- i have been planning on getting the powerjection III or FAST EZ EFI, what would be the best intake manifold?? I have the 396 bored to 408, mild cam with Edelbrock 750 on a holly single pane mainfold now dyno at 425 hp. I really like the EFI kits, and understand they are a great upgrade for my weekend driver. I have read most of the theads about dual over single and came to the conclussion that the dual would be what I want- still deciding over the RPM or the AIRGAP. Would the EFI effect that choice? I look forward to your help, thanks.
Joe:popcorn:

The RPM and the Airgap are essentially (but not exactly) the same manifold with the Airgap having the....well.... air gap....to seperate the intake runners from the hot oil in the lifter valley. This helps during some conditions, but not as much in others. There was an article in some magazine where the went into the detrimental effects at certain temperatures. The Airgap also has a cutout in the plenum divider that the RPM doesn't that is supposed to add a little additional power in the upper RPM band. I've got a book that shows the Airgap was worth 10 lbft and 5-10hp peak over the regular RPM. That said, I'd buy an Airgap if I didn't already have a regular RPM. I got my Powerjection III finished yesterday and the base tune loaded but didn't have a chance to drive it.

With a big block and the addition of EFI, you may not even need to change intakes. EFI adds a good bit of of under-the-curve torque and throttle response. I don't think EFI is going the change the overall characteristics of either style of intake. Save a couple hundred bucks on the front end and see how it does with what you've got. It'll be easy enough to try another intake down the road.

Hey Steiner, knock it off!
Leave something for the rest of us.:D

Thanks Steiner that is good to know, I thought from my reading that the dual panes will help atomitize the fuel air better? Okay, will the EFI system help my low end HP or torque? If you dont mind why did you chose the Powerjection over FAST EZEFI?
Fred do you have any thing to add, I am all ears???
Thanks Joe:thumbsup:

Well, just a picture or two. Both systems are similar, tuning is different. Powerjection, I believe, is stilled tuned with a laptop. FAST uses a hand held input. (My system, Boss EFI is an earlier Powerjection) Understand too that I'm kinda overboard with mine. It's 1200 cfm. And I run the regulator at the intake because it vents air from the sump quicker. The air gets in when slowing after a drag run because of the sump. As far as hot oil, I've run a shield under the intake since building the engine in the mid '70's. (L88 stuff) The heads are off road. They have no heat passage for the carb. Here ya go;
The heat shield. (FI LOVES NO-HEAT)
http://epitomesrebuild.com/images/189.JPG

Mock up of the regulator move from the tank; (Note the throttle body twist. Hard to run fuel rails huh? Not to mention a ducted hood air cleaner.)
http://epitomesrebuild.com/images/313.JPG

Fred, every time I see a picture of your engine I'm jealous of all the fun you got to have planning and routing your fuel system. Well, not really.... I spent a full day drawing mine out and making up the parts list and STILL had to make another order from Summit for one friggin' hose end.

Joe,
I think either of the systems is a good choice if you want want to retain a traditional intake and carb look while still getting the benefits of EFI with fairly easy installation and tuning even if it's not multiport. It was a toss up for me between the two systems. Here's what it came down to:
1. Price. The Powerjection III came in a few hundred dollars under the FAST system once everything was tallied up.
2. I liked that the EMS is integrated into the throttle body on the Powerjection and doesn't have to be mounted. Also the fuel pump relay is internal to the unit so it's a simple one wire run back to the fuel pump. The Powerjection also looks more like a carb.
3. The Powerjection has a lot more tunability. While you can just leave adaptive learning on, it does give you the ability to go in and tune specific items like fuel delivery at a certain point, idle tuning (can set a fixed pulse width for a nasty cam), accel/decel delivery, fuel pump priming, etc. etc. (you can download the instruction manuals for both systems and compare). Also you can run boost or nitrous with the Powerjection whereas you can't with the EZ-EFI, mostly because you can't tune for it. You can also save multiple configurations (maps). While there may never be an issue with just letting the system make its own map, it's nice to know that if something did come up you can go in and adjust for it. The unit also lets you do datalogging.

As far as customer service, I'm sure FAST has a great reputation. Since Fred has one of the earlier units, he can probably tell you about any dealings he's had with Retrotek. Personally, I just called them this morning since I had an issue with my regulator. I simply told them the issue and they said they'd send me a new one right out and to just send the old one back.

One other note. Retrotek names their unit so that carb guys identify with it more, hence the "750 cfm". The unit will flow 950 cfm.


Getting back to the question of manifolds, the typical general argument for one or the other usually comes down to dual planes offer better torque at low RPM's at the cost of upper RPM horsepower (more torque at higher RPM) when compared to single planes, especially if it is one with short runners. With EFI, you're not going to rely so much on vacuum to pull fuel at lower RPM's or part throttle so response is going to be better. You're running a big block and 3.70 gears so you most likely have plenty of torque down low anyway. I'd think that if you were running a smaller ci smallblock with a street gear you might benefit more from a dual plane and if it were me I'd try what I had first considering that it would be easy to change out later. But don't let me sway you one way or the other....I know how much fun it is to spend money.

Eventually, there will be more and more people running either or these two systems so there will be more feedback. Or you can just be a guinea pig like some of us. You may actually want to wait a little bit...Retrotek just debuted their Powerjection IV at SEMA and it has timing control.

Fred, every time I see a picture of your engine I'm jealous of all the fun you got to have planning and routing your fuel system. Well, not really.... I spent a full day drawing mine out and making up the parts list and STILL had to make another order from Summit for one friggin' hose end.

Me too.:yes: Steiner, did you get that off of my web site? Here's the hose end I forgot. It's to the middle-left. (Steiner! Maybe you use someone like Jegs too much. I called Summit and cried! They looked at their computer and saw my order history and sent the fitting red lable for free.:beers:)
http://epitomesrebuild.com/images/292.JPG


As far as customer service, I'm sure FAST has a great reputation. Since Fred has one of the earlier units, he can probably tell you about any dealings he's had with Retrotek. Personally, I just called them this morning since I had an issue with my regulator. I simply told them the issue and they said they'd send me a new one right out and to just send the old one back.


X2:thumbsup:

Thanks Steiner for the input sounds like as if you and Fred are good friends?? I feel that the powerjection III with my set up would be best for now, like you said spend money later. I will begin the plan for powerjection after the holidays. See what this new kit you mention comes out is all about. I look forward to this event, since I am conferting my rear drums to disk this weekend, it never ends:yes: Thanks again guys-Joe

Thanks Steiner for the input sounds like as if you and Fred are good friends?? I feel that the powerjection III with my set up would be best for now, like you said spend money later. I will begin the plan for powerjection after the holidays. See what this new kit you mention comes out is all about. I look forward to this event, since I am conferting my rear drums to disk this weekend, it never ends:yes: Thanks again guys-Joe


Nah, we don't know each other besides board camaraderie and similar tastes although he seems to have the time and money to actually pursue his.

You're right: It never ends. I've found you pretty much just have to pick a place to stop.

Steiner! Stop?!! How? Every month a new goodie comes to mind, or a new tune, whew.