Carb to FI conversion or FI to FI conversion ?

[alpa]

Hi,
I'm new here (and in the US). Still don't have the 124 but planning to buy soon. I don't know much about these cars.

I'd like to have a 124 Spider I can easily tune.
There are two options: modify an FI or make a carb to FI conversion.

I have few questions about both options.

CARB to FI:
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I made a search on the forum, most of people seem to like the FI to carb conversion.
I live in California. I'd do a carb to FI conversion (aftermarket ECU) on a not smog version. Then turbocharge it, 7psi would be enough, to keep the original transmission.

Did someone do that before ?
Would an FI (are they all 2L ?) intake manifold fit a carb 1600/1800 engine ?
Is it difficult to find the manifold ?
Is it difficult to add a return fuel line from engine to the tank ? Can I install it inside the car ?

I've already done a Mini 1000 carb to 1000 MPi turbo conversion. In Europe.
Could you also tell me which is the last no smog date: summer 75 or summer 76 ?

FI to aftermarket FI
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It's probably easier. But there is all the smog stuff to keep.
Do all the FI California versions feature EGR, air injection, cat, what else ?
Could I find any compressor kit that I could remove every time I'd go to smog ?
What if I install a turbo and go to smog with it ? Say with an open wastegate to prevent turbo from spinning. Would it be possible to hide it, or would its presence make me fail the smog ?

[ga.spyder]

I dont know if the Cal versions are different(I dont think they are),but with the Bosch F.I. unit the only smog equipment is the cat.The Bosch unit is very precise and didnt need pumps,EGR,etc.. to pass smog.We dont have emission testing here and I would be excempt anyway,but there are many Cal guys on this site that can answer those questions.The F.I. cars are all 2 litre displacement.Good luck in finding your car.
Craig

[miragesmack]

Ask SoCalMark (site administrator) about that California stuff. He knows what's legal and what's not. He can hook you up with parts too!

[kristoj]

Like Craig, the area in Ohio where I reside does not have smog tests, and if they did, my Spider would be exempt due to being more than 25 years old. But I can tell you that fuel injection and a turbo make a noticable difference in performance. My car is an original Turbo (Fiat sent the cars to Legend Industries for the Turbo conversion here in the U.S. where the turbo model was officially sosld through Fiat dealerships). The stock turbo only runs 6 PSI of boost and the spark advance was extremely conservative to avoid any chance of detonation. Even with this conservative setup, horsepower was increased to 120 vs. the non-turbo FI set-up which was rated at 102. But where you really appreciate the turbo is on the highway in fifth gear. Never any need to downshift -- just stop on the gas, watch the boost build, and the car really takes off.

With a modern FI system, 7-8 PSI of boost, and a modern CPU to take better advantage of spark advance, I bet you would be looking at 140+ hp conservatively.

On the other hand, I know Mark can build you a normally aspirated, Weber dual carb set-up that can get you 150-160 hp for a lot less money than the turbo route. Probably not going to be smog legal in CA though. Mark is definitely the expert on California-legal performance, as well as most other topics on this forum.

[alpa]

Thank you,
I hope Mark will have a look at this thread.
I like FI and like doing things by myself. I have my own ECU, so it's cheap.

[So Cal Mark]

you've asked a lot of questions to answer. Models that have to be smogged are 1976 and newer. The date of mfg isn't important, it's the model year designated by the mfg. I know of several people that petitioned DMV to reclassify their cars that had been built in late 1975, but were designated 76 models. DMV turned all of them down.
The FI cars had a fuel evaporative system and a catalyst, and those have to be retained to pass a smog test. Whether you could modify and hide the changes from a smog tech would depend on the thoroughness of the individual. I'd suggest getting an early model (75 and down) and working with that if you want to modify it.

[alpa]

Thank you.
Yes I have a lot of questions because it's not easy to choose. Old cars don't need smog but an FI conversion requires an additional fuel line, a fuel pump, probably another dizzy as L-Jetro uses ignition hall sensor, intake manifold, electric stuff, ...
FI is easier to convert but I have to be able to remove the turbo and put back the original exhaust and flow meter to pass the smog. L-Jetro itself, if I keep it, is not the best system: the flow meter, the cold start idle valve crap, old style injectors.

[So Cal Mark]

the carb cars have a fuel return line. One other option is to get a later model and register it as an historic vehicle. There are driving limitations with that designation though but it drops the smog inspection requirement