EZ EFI throttle body

[Orange65]

A little more bench racing EFI as I try to decide which direction to go-

The FAST EZ EFI system is rated up to 600 HP. Has anyone here used one on a high HP engine (up to 600 HP)? I was reading some old threads where someone built a throttle body with 8 injectors in the TB and it did not run well. Dieselgeek said he had the same problems with a similar design at AEM (if I remember correctly). Is the EZ EFI system stable at 600 HP?

I am weighing my options right now. I have decided to use my Air Gap RPM intake, but I don't think that there is enough room on the runners to install both the injectors and a N2O fogger (should I choose to do that). Note that N2O on a dual plane is limited to about 200 HP due to distribution issues, so that is not something I really want to try to disprove.

I found the EZ EFI throttle body with the built in injectors and thought it might be a possibility. Should I chose to go this route, I would use it with my MS controller.

[SpiderGearsMan]

why not use the fast controller ?

[Bamfster]

How about an under manifold port injected N2O setup? Then put the fuel injectors on the top of the runner ....

[Orange65]

I was thinking of the MS since I have one. FAST controller is a possibility.

Under manifold nitrous is not possible- without machining big holes in the lower part of the manifold to get to the runners. The air gap between the runners and the base of the manifold is a problem.

This is the one I have:

http://www.summitracing.com/parts/EDL-7562/?rtype=10

[Matt Cramer]

I was there at one event where Dieselgeek tried to tune an aftermarket TBI with the injectors below the throttle blades. It wasn't a FAST setup or AEM; this one used eight nearly vertical injectors. I didn't see the dyno pull or the numbers, just saw the hardware. Hopefully DG can fill you in on just what numbers it got; all I know is the distribution was really bad. FAST claims they spent over a year trying to get the fuel distribution OK with that throttle body; I don't know how close they got it, though. I'd also suspect that any manifold with fuel distribution issues in a plate nitrous system would also be likely to have issues with a TBI. You might be able to get the injectors set up in a port system higher up the manifold runners.

[CDMBill]

IIRC Hot Rod or Car Craft did a dual plane manifold test with N2O and didn't see the distribution issues everyone talks about.

If you plan to run a big fogger system I don't know that the manifold will really matter especially if you sneak up on the tune and use the right plugs. I was wirth buddy last week who was dynoing his N2O motor. He uses NGK 11's as his plugs becuase the ground electrode is seen as sacrifical in the event a cylinder runs lean instead of killing a piston.

BTW his 531" BBC made 938 on nuts and 1440 with a "500" shot. he runs the 275 Drag Radial class in several different West Coast organizations. And yes he does run run a single plane with a carb no EFI.

I'm not excited about the Easy EFI for a real performance application. Simple street car stuff maybe but not in anengine that's gonna see substantial spray. I think you could build a Mega-squirt PI set-up for the same money and get better results. You could also run a dry shot then simplifying the N2O plumbing.

[Orange65]

I agree that the EZ EFI is more for street only performance. I am concerned about it limiting performance.

As for plate systems on a dual plane, the experts on YB- Monte Smith of NOS and Steve Johnson- have posted that not all dual planes have distribution problems and to sneak up on the tune. Edelbrock posts not to exceed 200 HP on a plate with the Air Gap intake.

I made my own fuel injector bungs for the intake here at work and took them home yesterday. Using them and the injector drawings on the net, I believe I can make them fit up stream of the fogger nozzles and get them both to fit on the intake. I will try to get a fogger nozzle this weekend and mock it up. If they will both fit, then I will go with some other throttle body.

[CDMBill]

One note on the fogger nozzles and EFI. When I had my dual quad tunnel ram set-up done by Wilson Manifolds for both the EFI and the a wet fogger set-up (so I could use a progressive controller) they placed the EFI nozzles in more or less the conventional location with new bungs that aim the injectors more at the back of the intake valve. They then put the fogger nozzles up stream.

The thinking is that the injector flow will be less disrupted with that configuration. Optimal injector location for N/A would be higher on the runner. The lower point makes for better drivability and part throttle tuning however, so the trade off was OK by me.

This N2O set up has jets for 150-500. Haven't used it yt.

[Orange65]

That intake looks nice! It looks like the N2O nozzles are turned- not facing down the runners. Is this an optical illusion?

[CDMBill]

The nozzles discharge straight down into the runner intersecting it at about a 30* angle.

[dieselgeek]

A little more bench racing EFI as I try to decide which direction to go-

The FAST EZ EFI system is rated up to 600 HP. Has anyone here used one on a high HP engine (up to 600 HP)? I was reading some old threads where someone built a throttle body with 8 injectors in the TB and it did not run well. Dieselgeek said he had the same problems with a similar design at AEM (if I remember correctly). Is the EZ EFI system stable at 600 HP?

I am weighing my options right now. I have decided to use my Air Gap RPM intake, but I don't think that there is enough room on the runners to install both the injectors and a N2O fogger (should I choose to do that). Note that N2O on a dual plane is limited to about 200 HP due to distribution issues, so that is not something I really want to try to disprove.

I found the EZ EFI throttle body with the built in injectors and thought it might be a possibility. Should I chose to go this route, I would use it with my MS controller.

I think on a dual plane manifold you'll have a bit of an easier time with TBI fuel distribution, but be aware - in my experience, carburetors work better at fuel distribution / atomization on a 550+hp aggressively cammed engine. I think this is because the carburetor creates an immediate low pressure area that "kicks" the atomization process (at the cost of airflow restriction at WOT).

Anyhow, if you have the choice to save money I'd go with the MS for the control of whatever you use, if you have the TBI already then use it, and perhaps upgrade later on. What sucks about distribution problems is, you might not be able to tell exactly what the problem is, whether it's tuning or debugging electrical issues, or actual misfires due to distribution- so it may get a little confusing trying to sort out the tune on an engine making that kind of power.

MPI really makes tuning aggresively cammed engines a no brainer and might be the better choice if your first DIY EFI experience is going to be running an engine that's making your kind of power...

[BKBridges]

According to FAST, no nitrous with the EZ system... The O2 sensor is in the loop 100% of the time and cant read the Nitrous mixture properly... nitrous= loss of control.
BKB