Optioning out a roller

[eschaider]

The choice depends entirely on you and your skill set, along with what you are willing to pay for the skills you don't have. Neither route is cheap; each has its advantages. If you go to the Holley site and select 850 cfm, vacuum secondaries, and an electric choke, the site will present you with a single solution. It is a Holley Speed Demon carburetor with a price tag of $731. Add about $250 to the price tag if you want one of the whizzy double throw down carbs.

To that price tag, you will need to add dyno time, the cost of a competent Holley carb tuner (the real McCoy, not an imposter), and perhaps a hundred bucks or so in toys to bring the carb up to where it needs to be to work properly on your engine. Figure about $1,000 for dyno time. You might get away with less but probably not. When you are done, you will be in the tank for about $2.5K to $3K. The bulk of the money will be spent on services for dyno time and the right carb guru.

If you go the EFI route, while many paths are available, I recommend the DIYAutotune MS3Pro PnP ECU. You can buy it for $1,499, but that is not the end of the road. The Fuel pumps and associated lines are another $1K in round numbers, and the injectors will cost $750, give or take a hundred dollars, depending on where you buy them. Add another $350 for fuel rails. The engine wiring harness the MS3Pro PnP uses is a stock Ford harness, so that saves you some money because you can source it out of Ford, eBay, or a salvage yard. Let's say $350 (or less) for your harness.

Like virtually all aftermarket EFI systems, the MS3Pro comes with both tuning and data logging software, and in the case of the MS3Pro PnP it also has a base tune to get you out of the blocks. If you do not know how to tune and have the current social media imbued, but not useful, tuning skills, you will need to get back to the dyno. This time it should be less expensive than the carburetor stop, but you will still be in the tank for $500 to $700.

A Mass Air Flow based EFI system will start in any weather, and at any altitude with the flick of the key. It will provide you with OEM quality, reliability, repeatability, and driving satisfaction — but all that, not surprisingly, comes at a higher price point than a carburetor-based system.

Relative cost differences: Carb, somewhere between $2,500 and $3,000; EFI, somewhere between $4,500 and $5,000. If you decide to add whistles and bells to either system, the price of poker goes up.

A couple of parting thoughts. The old idea of recurving your ignition advance with springs, weights, and assorted black magic is caveman crude compared to what you can do with EFI. Your ability to specify timing in fractional degrees and precise rpm increments using EFI is simply impossible to reproduce in the old style distributor systems. This comparative difference is pretty much the case across every aspect of tuning the two different systems.

For example, the ability to control your AFR across the entire engine operating range and hold it to your target AFR within a decimal fraction of one AFR is impossible to do with a carb. Additionally, the ability to build into your tune a highway cruising mode where you get 23 to 25 mpg possibly higher without hurting your wide open throttle power production (or the engine) is absolutely impossible to build into the carburetor fueled engine.

In short, the reliability, predictability, drivability, fuel mileage, and horsepower you will be able to produce will be more in line with what you intuitively expect with EFI than with a carb.

There is one final consideration. Today it is becoming increasingly difficult to find knowledgeable carburetor tuners/modifiers. They tend to be old guys at or near end of life. When the few that are left pass on, you will be hard-pressed to find someone to care for the carb — because they will all be dead and buried.

Not so with the EFI service crowd. You might even discover you can learn how to do it yourself with a bit of reading and curiosity — it is far from hard to do and has a much more visible cause-and-effect relationship with what you do and how the engine responds than the carburetted alternative.

The EFI alternative will be more expensive initially and less expensive over the life of your car — and you will discover if you should choose to, that you can easily maintain it yourself. The ante at the poker table will initially be higher for the EFI, and the cost of ownership will be lower in the long term. The driving and ownership experience will be superior but initially more expensive with an EFI election.

[patrickt]

Originally Posted by eschaider

There is one final consideration. Today it is becoming increasingly difficult to find knowledgeable carburetor tuners/modifiers. They tend to be old guys at or near end of life. When the few that are left pass on, you will be hard-pressed to find someone to care for the carb — because they will all be dead and buried.

This is unfortunately the case. Here's my recommendation, buy two of the exact same vacuum secondary carburetor, one nice and new from Summit or Jegs and the other a cheaply priced used version off of Ebay. Then watch YouTube videos on taking it apart, cleaning and adjusting it, how to change jets, power valves, how to adjust the A/F ratio, how to get it to idle off the secondaries instead of the primaries, the importance of the transfer slot, vacuum and so on and so on. Do all of that as you practice on the used one there at your kitchen table until you start to feel pretty good about your skills when it comes to monkeying with it at the table and then have one of the old guys at your local club show you how he likes to tune and adjust your carb. If you lived across the street from me I could have you up to speed on tuning your Holley is one summer and the knowledge will last you a lifetime. A properly tuned Holley is an absolute joy to drive in a Cobra whether you're driving hard or just puttering over to the car show.