FI Conversion

[76124]

Anyone have experience using a redline FI conversion kit? Seems like using the OEM IDF manifold with one of these kits using IDF throttle bodies would be the best of both worlds, looks cool, sounds cool, and so reliable. Maybe it's more work than worth, but something to think about.

[vandor]

Is that a throttle body kit, or a full FI kit with computer, harness, etc? I built a car for a friend with IDF style throttle bodies and programmable FI. It was a nightmare. The high performance cams have little and inconsistent vacuum signal, which the FI needs to calculate fuel requirements. One can set the FI up without it and only use throttle position and rpm to calculate the fuel needed, but it's a compromise at best. Driveability would not be great, so what's the point of using FI?
The FI would work better with mild cams, but then the stock FI can deal with those just fine, no need to go to the programmable FI route.

[grrrdot]

Its a bummer to hear it was such a pain.
I was thinking of going down a route like this because I like that it could maintain a stock look.
I've seen a few forums where folks had success with adding a vacuum reservoir plumed to every cylinder, its still a compromise because a larger reservoir smooths the signal but also makes the signal lag the engine.
The other alternative I have seen is synchro map: http://www.synchromap.com/ you have a map sensor per cylinder that are sampled.

-G

[76124]

I guess I don't know that much about it to know all the ins and outs, but if it works for others I can't imagine our TC engines are so different that it would not work. Again, ignorance is bliss!

[vandor]

I've seen a few forums where folks had success with adding a vacuum reservoir plumed to every cylinder, its still a compromise because a larger reservoir smooths the signal but also makes the signal lag the engine. -G

We were able to smooth the signal, but the problem was that with the cams the vaccum signal band is a lot narrower (it idles at 8-10 in-Hg instead of ~17), and does not change smoothly or consistently. For example one can add just a little throttle and it will go from 7 inHg to 3.
So there was just not enough variation in the signal to use it as an indication of engine load.
The car had good power, but the driveability was not as smooth as FI should be and as soon as I solved one problem, those changes caused another.

[VAS]

Dear Kraig-

Here is information you may not have been previously privy to on this forum: My own Spider uses VAS Programmable Fuel Injection and it works great. This is available in kit form has been sold to enthusiasts for over 5 years .

In addition, the car utilizes our individual throttle bodies and runs like a champ. If you've heard ITBs don't work, you are welcome to drop by VAS and take it for a spin and see for yourself. If that is not practical, please give me a ring.

-Jerry Phillips
Vick Autosports
817 483-9933

[klweimer]

The other approach is to find a donor vehicle and swipe the Fiat factory FI set-up. Granted, it will no longer look like a stock carb set-up, but is well tuned to the twin cam engines.
Kirk

[VAS]

Dear Kirk-

In my post above I was talking about Programmable Fuel Injection (PFI) which may be used as a performance substitute for the Bosch System and is necessary if one wishes to install Individual Throttle Bodies (ITBs).

You are correct that if one has a carb. Spider, you can harvest a used Bosch system from a FI donor car. I have done this on swap on a carb 2 litr Spider, as well as 1800 & 1608. We have also done it a number of times in our shop. Note most replacement components (fuel injectors, for example) are available. The result is an engine with the advantage of a more advanced fuel delivery system.