[guccieng]

hello all! i never thought i would end up in this section of the forums, but here goes: is the holley 2d pro-jection worth the time and effort and $1k? i'm considering it for my 68 bird with a 7.6 compression ratio, 400 ci engine. it's low horsepower with highway gears and i thought that system might work well with my setup. i don't want to spend a million dollars, and at the same time want to get as much from this low compression engine as possible. it seems pretty easy to install and tune, which i like. it would make me put in a return fuel line and fix my vapor lock issues as well. i'm trying real hard not to hotrod this car and keep it friendly enough for the girlfriend to drive as well (she's too scared of the camaro, and i'm just fine with that!). would people consider this fuel injection an improvement to the car, as in resale value? any opinions, please!

[camcojb]

I think it'd work fine for what you're looking for. I prefer the 4 barrel multiport system as it can grow with future mods, but the 2D would definitely work.

Jody

[guccieng]

thanks jody. one more thing: this unit doesn't control timing, right? is there any specific way to set it up the timing curve, mechanical and vacuum, to use it? or would a good curve with a carb be the best for the injection, too?

[JimM]

The only thing I came up with searching for "projection 2d" is Holley part number 502-20s

This is a 2 bbl system with a standalone controller. It is NOT a commander 950 based system. "closed loop" (narrowband o2 sensor) is NOT included, it's an option. It does not have a variable Idle Air control motor, but rather an on/off fast idle solenoid.

This system has a few selectable preprogramed maps, with fine tuning done via dials on the front of the computer (idle / main / power enrichment)

I would say you DO NOT want this one, I wouldn't even use it in a non performance grocery getter application. It would probably work pretty well in a boat, on a mercruiser V6.

Instead, I'd recommend a commander 950 based TBI system.

# 950-20s is the 670 cfm 2bbl system, $1275 at summit
#950-22s is the 700 cfm 4bbl system, $1570
#950-24s 900 cfm 4 bbl $1570

The commander 950 based system use the exact SAME computer as the port injection and stealth ram systems. Narrow band O2 is standard, as is a real Idle Air Control motor. Timing control is standard too. Wideband O2 is optional. They even have a "turnon" wire for your electical fans.

These systems are fully programable from a laptop, and include datalogging if you get a copy of the Pro software (ask and you shall recieve, c950 firmware must be v3.x to use the pro s/w)

You can also find these used. They are a great "starter" system, and lots of people who bought them upgrade to a port system or stealth eventually. Look on ebay, as well as here on Team Camaro.

I found a 950-24s 900 cfm system for a very small fraction of new cost, and will be installing it in my 68 this winter.

[guccieng]

yes jim, that's the one. it does seem like a really simple system, but that's kinda what i like about it. i don't own a laptop and really have no desire to. but, for the cost of the total install, i would rather run out and get a new top end for the motor. as for the tuning, i'm a 'set it and forget it' type of guy, which is hilarious when you realize i'm a flight engineer on a jumbo jet, where you don't set and forget anything, ever! i guess i appreciate the simplicity of my old cars that way. all this led the question 'is it worth it?'. i'm leaning toward no... anyone else?

[Rodder]

Set-it-and-forget-it is one of the reasons I like modern fuel injection... once it's tuned right, it runs great at any altitude and any temperature.

That said, the Pro-Jection 2D isn't what I'd call a modern EFI. There are three basic ways an EFI system can figure out how much fuel to inject:
1) Speed Density - the computer uses MAP, RPM, and temperature to look up in volumetric efficiency tables to calculate the amount of fuel required. The downside is the work required to create those tables.

2) Mass Air - the computer uses a Mass Airflow Sensor (MAF) to directly measure the mass of the air entering the engine and divides by the desired air/fuel ratio to determine the amount of fuel to injection. The downside is that the MAF creates some amount of restriction in the intake.

3) N-Alpha - the computer uses throttle position and RPM to look up fuel requirements from a table. The downside is that it's very inaccurate except at WOT, and can't compensate for altitude. The Holley 2D system doesn't even look at air temp either.

All of these systems use throttle position for Acceleration Enrichment tables, basically the EFI equivalent of an accelerator pump.

Good systems will have an Idle Air Control motor, the rapidly adjusts the idle airflow to maintain a steady idle. Some systems (like my stock GM LS1 PCM) also tweak timing to maintain a steady idle. IAC can even smooth out the idle of a fairly big cam.

Personally, I think you can make a carb run better than an N-Alpha EFI system...

[guccieng]

thanks, reverend! looks like i'll stick with the carb till i can afford a ramjet 502... i should start buying lottery tickets, then!

[ldrisner]

This Section makes me feel stupid as I am very EFI illiterate. I have a lot to learn!