FAST has run the EZ-EFI on the dyno successfully at 650 HP with no issues. The tech said they boosted the fuel pressure on the system.

With the wideband O2 sensor and the learning ECU, I should be running optimally AFR at most all times, which is the main reason I am changing. My cam is too radical for me to tune effectively for all situations.

One of the guys on the FAST tech forum is running a C3 with a tunnel ram and dual throttle bodys with dual ZEX nitrous plates.

 

Some good reading here for those who want to tune their carb correctly and get EFI mileage. I did this years before this article was written and got 24mpg out of a 550HP 406ci

http://www.innovatemotorsports.com/r...FI_mileage.php

 

I think you hit a possible issue on the head. All of the efi systems use closed loop correction and rely completely on the O2 signal being exactly what is coming out of the motor. If you have any leak around the sensor or closer to the motor, you will find your motor will always be rich. I've seen this with header gasket leaks alot on peoples cars. Just my preference, but on the sidepipes I installed my O2 bung in the collector before it gets to the side tube part, just to eliminate one more possible leak.

As far as being slower with fuel injection that a carb, in only 1 instance have we seen that one of these systems made less than 5 to 10 hp more than the carb. This doesn't have anything to do with fuel injection really, just how stable a carb can retain a perfect tune. In drag racing or on a dyno if you tuned a carb perfectly and the fuel injection to the same airfuel ratio, they usually make the same power. The same fuel and air, the same power. The difference shows up when the temperature, humidity, density altitude or just altitude changes. Then yes, the fuel injection always makes more power since it is still tuned perfectly hundreds of times a second.

 

What is the difference between the Powerjection III/EZ-EFI systems and compare them with Edelbrock Pro-Flo II
Will you get more value for the $ if you buy Edelbrock Pro-Flo II?

 

I considered having EFI on my original '71 BB months ago and I had both the Powerjection II and the EZ-EFI systems into my consideration, I was leaning towards the EZ-EFI for few reasons, 1st, it had so many success stories and been used and tested by many car guys with very good results (and so is the Powerjection III but I saw more people talking about the EZ-EFI), next thing is I didnt like having the computer module in the same throttle body, I felt it would be better having it in some other "Cooler" location, and last thing is the size, the EZ-EFI is smaller and would use just any kind of air cleaner base.

For the time being, I suspended all these ideas because of some $$$ problems in my side

 

Hard to say. It looks like the Edelbrock System is running about $2900 on Summit. I got my Powerjection III for $1900.

There kit looks pretty complete though. I believe that with injection right into the runners that performance would improve (or so I heard). My intake was fine and I like the semi-stock look with the drop-base aircleaner on.

Other than that, I can't believe that the basic operation is too much different. O2 sensor, water temp, TPS, MAP, MAF and spark inputs. It controls the fuel and airflow from there...

 

what do those look like? I need something to couple the small return-line input in the gas tank to the 3/8 stock hard fuel line.

 

PJ,

If I understand your question right, then you are using the stock supply line for your return line and want to have that go up to the return to your tank. Is that a connect understanding?

In my situation I went ahead and plumbed new supply and return lines so I was going from a -06 hose to a tube and just found the right size fitting at Smiley's.

For your situation I would look at possibly finding a 3/8" to 1/4" hose adapter and just connect a 3/8" hose to your supply line, clamp it and go into the adapter. Then step down on the other side and clamp it up to the stock return nipple on the tank. Probably easier than trying to flare anything on the end of the stock line.

 

Pro-Flo II doesn't have wideband in the base kit does it?
I does have sequential injection, which neither the projection/fast ez have.

Prolly outta the scope of this conversation, as the carb replacement auto-tune EFI kits aren't aimed at people who want things like sequential injection.

 

Yes, that is what I am doing, plumbing the return line via the stock 3/8 hard line. I figured it would be hard to cut and flare the stock hard line ... there is just not enough space, but I wanted to see whether you had found a way to do it.
I'll see if I can find that 3/8 to 1/4 barbed reducer.

thanks

 

Hey Dave, Looking for some updates. How is the car running? Is there any regrets
in buying the Powerjection setup? How did your clearance's turn out for an air
cleaner to clear the hood? And last but most important, Do you have more photo's
of your setup at the engine and maybe some of the work under the car?

Thanks,
Riggs.

 

 

Sorry it took a while to respond. I will try and take some pics tomorrow or this weekend.

As far as the hood goes, I already had an L88 hood for use with my taller intake. I will try and measure the base to the top the best I can on both the original 750 and the Powerjection unit. I did need to find a longer stud for the air cleaner to attach, but I believe that had to do with just the deeper hole to thread it into.

The setup at the engine was pretty straightforward. The Powerjection unit comes fully tested and assembled. You need to to just add the pressure gauge and hook up the intake and return lines. The setting for the regulator was just about set dead on already.

As far as the rest of the car, there were the electricals and the fuel. Both were pretty easy and nothing special to report here. I will post some pics though.

One problem I did have was some hesitation the other weekend around 2500 RPM. The problem that I originally mentioned with the throttle bracket not being well secured I believe is biting me at this point. I need to track down a new bracket that secures to both the studs off the manifold. Once this is done I will need to reset the throttle position sensor.

I will try and post more later. Please let me know if there are other questions that come to mind.

Dave

 

Using the stock P/U- I'd be wonder how low on gas would start to cause a problem w/ fuel starvation?

I'm looking at something more like this for my P/U



Here's the thread-
http://forums.corvetteforum.com/c3-t...k-options.html

 

I am running the stock p/u but have not driven it hard enough at low fuel levels to know if I am going to have issues. If I ever drop the tank, I will go with a similar setup to that.

The only difference that I have seen done is to flip around the pick-up baffle to have the lowest part be near the end so that under acceleration the fuel will be at the lowest point.

 

If anyone is still reading...

My name is Cody. I was head tech of the EFI division of Professional Products and RetroTek Speed for 5+ years.

I was the guy that c5_droptop would have talked to. Everything except for the electronics was made in china and assembled in California by me or a guy named Bryce. Yup thats right two guys ran the whole show. This EFI will out perform ANY other EFI or carb out there period. Challenge me, I dare you, I'll make 15 more horse than you too. Go to the RetroTek website and look at the customers cars... NA motors making 700hp and boosted cars (up to 25lbs) easily making 900+. The FAST system sucks to say the least. I tried one. I blew the head of one of their "techs" up when I tried to get help and asked legit questions.

I do not work for them any longer, I quit 10/7/10, but I take pride in what I do and will not let people badmouth something I put blood and sweat into...

 

Thats why everyone is badmouthing it. Even if there was 100% perfect proof that the powerjection was better than the FAST as long as people think that every component in it was made in America it would still be a better seller. I personally dont care where something is made. If it performs like it is supposed to then that is good enough for me. There are so many things that are supposedly Made in America that actually are not that it doesnt matter anymore. The chevy camaro comes to mind.

 

Are you saying that this unit will handle 900+HP? What type of tuning will it require for this?

I've looked at the EZ system but the HP break point is right were I'm at. I would need to change the intake to jump to a dual system and I don't want to do that.

c5_droptop don't mean to hi-jack your thread, if you want I'll start another one.

Neal

 

You realize that Americans did this to themselves right??? We tried to keep everything here in the US. Back when we were still RetroTek Speed, before Pro Products bought us, the throttle bodies were billet aluminum made by Accufab Racing. They were ****in jewels!



With everything being made here, that raised the price by about $1000 and with everyone being so cheap, sales weren't high enough to sustain business. See,, YOU guys caused this to happen. Look at my name, the only reason I run our fuel injection is because they gave them to me for free because my car was the test mule for these systems. These things do perform no question, even with the shotty china parts. Trust me, I was and the one guy left over there that's worth anything is very stringent on quality control and wouldn't let any bad parts leave the door. The computer is the best part of these systems... So dont buy the TB, whatever its the computer that makes the system. I would battle any tuner out there with one of these no questions asked. Anything from a bone stock motor to the most nasty race motor you can come up with.

 

Yes I am, and yes it will. The only thing that limits the system is that there are only four injectors. The injectors that come in it are 60lb-ers. Hit them with 87 psi and they will flow 85lbs of fuel each. Then you have 75lb and 80lb injectors that can be installed for about $80 extra. Jack the pressure up on those things and imagine what you can do!

The system I described with 900+HP had an injector plate underneath it with another 4 injectors. We have done 700 horse with 4 injectors no problem.







A dual quad PIII is just badass period. But they are expensive. Now this is a GM forum but whatever. We built a '67 Mustang fastback with a boosted 347 SBF @ 15lbs. That car made 750hp at the tires with a dual quad PIII