Did you spend a lot time sorting the system after installation?

I asked a very knowledgable Shelby dealer/builder. I was considering taking my dual quad off for an injection system. I was told not to do it. Too much hassle and problematic. Thats what I was told.

I'm staying with my dual quads. They offer the WOW! factor with meat and potato reliability.

I was told the same thing by the owner of the shop that dyno tuned my car. Considering he could have made some money on the deal, I was surprised.

Well it's documented here on CC where either David or Tom Kirkham said they run carbs on their engines because they could never figure out how to get FI cars to run right.

Love it!

It took me a while to tune it in. The biggest hump was to understand what wasn't working, speed density mode. These manifolds simply do not have enough vacuum. I see all kinds of postings out there from people who claim they work well. They build all kinds of over-sized vacuum accumulators. The FACT is, you cannot get more vacuum then you have by increasing the accumulator in size. You just buffer the fact of quick changing from the map sensor.

When I finally made the jump to Alpha N my problems all went away.

A good friend and I spent a lot of time rebuilding the tables. That included a lot of time in the seat with a laptop logging what was going on. It has been a really great learning experience.

So yes, I'm very happy and satisfied. I don't mind the extra time figuring it all out.

len

Actually, you might ask Tom again. Last time I was down with my Cobra I let Tom take my car for a spin. He was impressed with how well it ran.

I think they like carbs from a simplicity standpoint. If you breakdown somewhere you can fix nearly anything with a screwdriver, wrench, and hammer... %/

Tom is an engineer who builds for elegant simplicity, much to be admired about that philosophy!

len

The past 9 months or so I've been working on an FE with an aftermarket FI system installed. In the FWIW column I've observed the following.
If the engine was originally designed with a FI there are a lot of tuners and information on tuning the system available and dealing with it can be RELATIVELY easy.
If the engine wasn't originally designed for FI it can run the gamut from a real can of worms to relative ease. Tuners and information on the system become much more rare. Finding a tuner who's knowledgeable about the system can be a major undertaking but if you find one he or she is worth his or her weight in gold. Tuning a "non standard" system yourself requires an extremely steep learning curve. It can be done but it can be a struggle.
Unlike a carb an FI system is incorporating several different disciplines which, in general, aren't commonly known.
On the plus side a well tuned FI engine is a real pleasure to drive. Most of the systems have enough latitude in their make up to correct for minor anomalies that come up in day to day operation and are seamless in their corrections. They will compensate for differences in atmospheric pressure and temperatures without missing a beat and remain running at their most efficient level. The ability to have multiple tunes that you can switch to on demand is also a plus.
All in all the FI hasn't really eliminated the old "shade tree mechanic" but it has forced him to move to a different tree.
Both camps have their champions and their detractors. What I've found is that, as with anything else, knowledge is king both in deciding if you want to go to an FI system in the first place and working with it after you've got it.
If you do decide to go with a FI system REALLY do your homework. Find someone with the system that you're looking at and really pick their brains about the care and feeding of it. Going in without a solid foundation can lead to a lot of disappointment and unnecessary expense. If you have someone else tune for you it can be expensive up front but if you opt to do it yourself dust off your reading glasses and be prepared to burn some midnight oil.
Modern FI systems have come a really long way in their capabilities but, relatively speaking, it's still a very young discipline. Before you start make sure the engine is as mechanically sound as possible. While a something as simple as a vacuum leak isn't a big deal is a normally aspirated engine it can have you chasing your tail with a FI system if you don't know it's there.
Not taking sides pro or con on the FI, just observations from where I'm sitting.
DonC

Well, I started my own business about 6 years ago and we have been growing like a weed, without much time to enjoy my car. Over the winter I had a new gas tank built so the car did not run, but I have not been in any hurry to get the car running.

Once the DynaTek guy went to KCMS in Plano and tuned my engine I have had no issue with the system or the engine. I just wish they would have told me about fuel delivery so I could have researched and bought/built a gas tank/surge area while the car was being assembled.

But frankly the system/engine runs without a problem, even though I would rather have FAST and a wideband O2 sensor.

E

Moral of the story seems to be the FI system can be great if you really know what you are doing and prepared to deal with potentially complicated issues.

For those without the understanding or access to someone who has the understanding your best to stick with the ol' four barrel.

http://www.twminduction.com/v8_kits/...pecial_fr.html
TWM, they are easy to install and setup. The hardest part is welding on the bung for the O2 sensor. The best way to set it up is have someone sit shotgun and make Alpha N adjustments on the fly as you put the engine thru the paces (not a job for most wifes)

:rolleyes:

Thanks oh wiseman...

E

Your welcome. ;)

You could always do your own and run megasquirt. Mine is a small block but the principal is the same. Once you get it set up you will be happy with it.

So did you build your own controller? How does the features and software compare to commercial controllers?

I saw the movie Megasquirt. Death by water gun is never pretty. :eek:

E

Let me be clear that I did not design or build my system, that being said after looking at it and working on it im pretty sure I could. The controller can be bought from any number of sources customized to your preferences, the whole ecu set up can be done for about 300 dollars. The new version of megasquirt 2.2 can do just about anything the other controllers can do and probably more. Here is a link to a site that I found helpful for the various systems out there.

http://fordfuelinjection.com/?p=65

I have no doubt I could tune a decent EFI system and would do my homework before buying. I also have no doubt a well tuned carb system can come very close to the performance level of EFI. Seriously, I believe that, I suspect the vast majority of carb systems are not optimally dialed in, that could be said for EFI as well! :) In either case, to get them to work at their highest level you really do have to know what your doing.

Why I prefer a carb over EFI is simple, the "wow" factor of dual fours is equal to the "wow" factor of EFI, in my opinion, at a fraction of the cost!

Tom K's comment, as I recall, about EFI was about the same time he was getting ready to run Bonneville with the K car. He wanted to spend the time DRIVING it, not working on it! Tom could certainly work out the bugs, given enough time. :)