Wait!!! Jody!!! I found a nameless guy that had just the gesture I was looking for!!!



http://i919.photobucket.com/albums/a...0/IMG_0363.jpg

I love it!!!!!!!!!!!!!!!! :lol:

Actually guys, I'm an engineer, so nothing you are telling me is shocking my world. Funny enough, thermodynamics is something I am quite good at.

I guess where I am having the issue is I understand how a fuel system is laid out, but if the Comp tech guy tells me I need a vacuum referenced regulator, but don't need to hook up the vacuum line, then why exactly do I need it as I am already regulated back at the tank.

Greg, you said that I can set the injectors to the higher pressure rate...I understand that but if the EZ EFI knows that it is going to have 58psi in the line and that is what it is set for, then why have the additional regulator if that is what it is looking for. In the video I posted the 572 that had the EZ EFI on it look like it was dead headed. The pressure in the line will actually drop a bit as you get into it, which is why I figured you would need a vacuum referenced regulator to boost fuel pressure. Once the tech told me I didn't need to hook up the vacuum line I was a little puzzled.

There in lies my problem. I overthink everything. If I need to have the regulator in line that is fine. I will put it in just after the throttle body as recommended and run a return back to the tank...not a big deal.

My question then goes back to the 4th gen fbody set-up. I was able to run the deadheaded configuration with a simple line from the tank, to a Vette regulator and back to the tank - with a single line to the front...no vacuum reference at the regulator. My assumption then is that the computer handled the adjustments at the rails...is that a correct assumption?

Thanks guys,
Dave

I have run rear-bypassed systems with and without a vacuum reference to the regulator. Both ways worked fine for me. With a forced induction setup I like the reference line so I can get additional fuel pressure under boost.

I think you're fine running without it, and just having a static (unchanging) fuel pressure.

Jody

You're over thinking it.

The COMPUTER doesn't control the pump. Except to turn it on and off via a relay.

Fueling is controlled by the computer with inputs from the MAP sensor - the ECT - and the biggie -- the wide band O2

What it is doing is first building a VE table -- using your set up inputs - ie., cubic inches - how many injectors - what they're rated at - and the fuel pressure setting. It then can build the VE tables in a basic set up using that... and then modifies the tables as it tunes itself as load conditions vary - and the O2 readings in order to get to the desired (set in set up mode) A/F ratios for,
Idle, Cruise, and WOT.

I would (and do) run a vacuum referenced regulator and actually run vacuum to it. I know they say you don't have to - and the reason for that is the system will tune itself to whatever it reads and needs. But the system is built to run a Vac reference so why not use it as it was intended. Personally - I always figure the engineers know more than I do about the intricacies of their stuff and if THEY say to use it - who am I to second guess them. Just MHO.

I don't think the length of the vacuum run would make any difference - vacuum is vacuum and once there is a vacuum signal (upon start up) and there are no leaks - it should work perfectly.

Your job now is to find out what your injectors are rated at (not sure I know what motor you're trying to set up - or what injection system)... and use that as your start point for set up. The EZ EFI system is based off Corvette injectors I think (memory isn't what it used to be anymore... LOL) but regardless == the set up is going to ask you for a part number (normally they use the FAST supplied injectors so that's easy to find and input) but you'll most likely have to choose "OTHER" when you get to that point in the set up dialog. Again this info all just helps the ECU build a base table to then begin to modify (self tune). The better the base input info - the quicker it will tune itself and the fewer issues you'll have in case you have problems. It', like most things, the details that will make or break EFI. Do it right - do it the way the INSTRUCTIONS tell you to -- and it's EZ.

I wish I could attach the email I just got from a buddy that took my advice and bought an 8 stack EFI and the EZ EFI system ---- then took it to an old school hot rod shop for install. THEY, of course, figure they know more about everything and he's spent many many hours trying to get it sorted out. They're R&R'd the harness - the ECU - the fuel pump... still same problem... until the FAST tech was brought out - and HE input the right injector pressure (not the default number) and it fired right up and ran like a champ. In the meantime, as I've told him several times, READ THE INSTRUCTIONS - this is a ONE WEEKEND JOB... for the AVERAGE GUY. Seriously. These dipwads made it hell week... and probably tripled his cost! UGH! :cheers:

Jody - Ditto this.

On the normal XFI etc style ECU's -- it's an either or game... and where I've seen people run into problems is they tune WITHOUT a vac reference then later someone trying to fix and issue decides to run WITH one... DO THAT and the system needs to be re-tuned.

On a big motor - like I think he's running (a 502?) - going WOT will maybe save a lean spot using a vac referenced regulator? Since you can't TUNE this out like you would on XFI etc. Just wondering out loud here.

I have the same Engineering affliction as you Dave and also tend to over analyze things. I will be running the same pump module and regulator as you with our EZ system. Everything these guys are telling you is correct. I will help them out with some more details of the system as supplied by FAST. I have also talked to the tech guys there and received very similar feedback as you. If you are asking anything out of the ordinary they tend to be vague. Anyway this should help some.

The throttle body as supplied has 4-88#/hr @ 60psi injectors. They have the system set out of the box at 43psi. At 43psi that is 298#/hr which should be 608hp or so at 100% duty cycle. Since you don't want to run at 100% duty cycle which is when the injector is open all the time, that is why the system is "rated" at 550hp. Which is around 90% duty cycle. Depending on your combination BSFC or efficiency these numbers can very slightly.

Now take what I just posted and forget about it. The system is set up to be EZ! The fuel module you are using with the 4th gen regulator is a bypass system. It just bypasses internal to the module. This helps reduce temperature and aeration. That fpr is set at 58psi. Just type that pressure into the hand held controller and let the computer do the rest. At 58psi those injectors will flow about 362#/hr which would be around 700hp give or take at 100% duty cycle. I would think you will be fine.

The only issue left then would be the vacuum reference. This Vaporwox set-up does not use one and it seems to be fine from the research I have done. I will find out for sure when we are up running. Sounds like you will get there first. Let me know if you don't mind.

I would say, install the Vaporworx set-up, install the EZ-EFI dead headed, set the fuel pressure in the hand held @ 58psi and hit the key. You can use the hand held to monitor the afr at tip in when you hit the throttle to see if the lack of Vacuum ref is an issue.

I hope this helps. :cheers:

Greg, Jody and Chad, thank you very very much!!!

You guys confirmed what I was thinking. Sorry I did not mention my set-up:

6.0L LY6 in a '69 442.
GM Performance Parts intake
Setting it up to look like a W-30

http://i908.photobucket.com/albums/a...1/IMG_8905.jpg

Project Red Rocket off this page: https://lateral-g.net/forums/showthread.php4?t=27033

Chad, special thanks to you as you have the exact same deal as I. I am planning on eventually going boosted with the Vaporworx set-up and need to give Carl a call to talk to him about the controller he is working on that is vacuum referenced.

Anyways, thanks a lot guys!!! I will let you know of my progress!

Fuel Regulator Air Pressure Reference vs Injector Spray Location
 

The first statement is for you "engineers".

The "placement" of the Fuel Injector outlet in reference to the Throttle Butterfly will effect Regulator Air Pressure reference location.

In most cases (non-turbo), when the Fuel Injector spray is ABOVE the "air-door", the regulator is referenced to atmosphere.
When outlet is below the Air Door (manifold), the Regulator is referenced to MANIFOLD "below" the air door.

Thus, Delta-Pressure is equal.

The ECU-882-x also uses BOTH a MAP sensor AND a BARO sensor (internal) 100% of the running time.

We have found a difference (NPC vs PPC) with Regulator Pressure Air Reference.

Lance

I'm in the beginning stages of having a local engine builder assemble a Dart-based 565 BBC for a street/autoX 70 chevelle. Original plan was to install the FAST XFI 1000HP MPFI system on the engine. The builder just called me today and said that FAST sent him an email today along the lines of they are now offering a multi-port version of the EZ EFI system that will support the 700+ hp I am looking for. Anyone else heard about this development? Should I go with this if it's true (can't find in on the FAST website yet) or should I go stick with the XFI system? I guess part of me wants to know "whats the catch?" - what compromises does the EZ EFI system make over the XFI set-up?

Rob