131mirafiori forum

Hi,

Does anybody have any experience/knowledge of using mechanical (electronically controlled) fuel injection systems as alternative for carbs.

I am told that such modern system can significantly (by 20%) increase power output and unlike Kugel Fischer, be easily (and not very often) adjusted, as well as practically immune to humidity, temperature and atmospheric pressure changes.

Miro
     

I'm not clear - do you mean Mechanical fuel injection where fuel flow is controlled mechanically by throttle position and engine rpm by some system of control valves and/or an engine drive fuel pump.

OR
do you mean a programmable electronic fuel injection system where the fuel is controlled by a computer taking imputs such as throttle position, engine vacuum and RPM ?

Well my knowledge on this is very limited , but it looks like Kugel Fischer ( tubes going into the inlet  and ijnectors attached to it).

The Americans use this for alcohol fueled hot rods.  But I also understand that unlike purely mechanical initiation of injector ( doseage and timing)  there is some sort of electronic control.

 

you mean something like hilborn injection?

The american systems hillborn/enderle etc. often are nickednamed the "drip feed"

they do not actually turn off, fuel is always flowing and is just dribbling out of the injectors at idle/low speed (not great for fuel consumption or driveability) the fuel flow is controlled by an engine driven pump (so its proportional to rpm) and a valve attached to the throttle linkage. tuning of the system is done by changing orifice restrictions in the fuel supply to the "injectors" (although they are really just nozzles)

this type of system is really just for pure racecars, especially dragracing where wide open throttle is all that really matters.

BUT

what you are talking about, an increase in power and being able to cope with atmospheric pressure changes etc. - this sounds like an electron injection system like any modern car.

Ultimately the question is what are you trying to acheive? assuming this is on a fiat twincam engine - any of the induction systems carbs/mech. injection/electronic injection can all be made to work 

 That said, I would be leaning towards carbs or electronic injection - the mechanical system is going to be an experiment very much as its going to be custom and somewhat experimental - I have never heard of anyone running mech. injection on the fiat twin cam apart from the works race/rally cars of which next to no detailed information is available, and even if it was it would be difficult to build a replica injection system.

I used to have works kugelfisher complete injection but it was actually usless due to very limited setting up. The car run fine up to about 3/4 of throttle opening and after that it flooded the engine no matter how i have set up the linkage. The best will be to use some electronic EFI(Megasquirt or any other standalone system). This is quite easy to set up and works very nice.

I am hoping to wire my megasquirt system into my x1/9 turbo over the crimbo...

If you need any help with MS then let me know. I have made few installs so know a bit about that.

Tomek,

I will ...

PS : is your Kugelfisher for sale ?

M

 

Walezy thanks for that as it is coming with a base map and then I get to have fun tuning her up on the road but do you do any will extensions for 124's thanks

Kugelfisher is sold.

As for setting up the megasquirt email me at walezy at proaxer dot com

I had a '71 US spec 1750 Alfa Spider rated "130" hp "Pre-SAE". Compared to a 124; it's suspension was antiquated (late '50's?). You had to lift off the GREAT BRAKES for dips/debris. I really liked the brakes!

What I liked better about it than any other car I have ever driven was the throttle response. The mechanical Spica injection was timed for 70 degrees before intake opening.

With 4 throttle plates open; you didn't wait for MAP/MAF sensors telling an ECM to send more fuel. Fuel was there before the air.

Thanks ,

Based on your tip I found an interesting site for Spica systems :

http://015cb80.netsolhost.com/hp.htm

I have contacted them for availibuility and will report what I find.

Miro 

With 4 throttles you do not use MAP sensor as it's readings do not change too much with throttle opened more than about 1/3 as you do not get enough resolution to tune the engine properly. The only good option is to use Alpha-N fuelling that is based on TPS readings and this has instant response.

With the complications IN GETTING AND THAN INSTALLING AND TUNING such system on one hand and my serious attempt to keep my 131 as original as possible (or at least in accordance with the tuning standards of the day the car was being produced and used for serious sports) I fell it will be safest and simplest to stick to my Weber 45 IDF?s ....