Weber IDF for Fiat application:

[thechadzone]

I know that there are a handful of differences between an IDF for air cooled VW application and IDF for Fiat application, and I have these diffferences bookmarked somewhere, (but I can't seem to access the page) I'm wondering if there is a company that I can contact and buy the needed conversion components in kit form.

I already have the shafts & hardware to link the two carbs in the center, it's the jets & the like that I'm after. One stop shopping for such things is nice...

Thanks as always for the help I get from this site.


Useless chatter:

I just recieved a very nice set of IDFs from eBay from New Zealand. $266.00 US. Yea me! They took a while to get to me, as did the factory IDF/Solex manifold that I bought from Italy, but I don't mind the wait since my car is running great with the Single Plain manifold & Weber DFEV combo atop the 1.8 head over the 2.0 block. It's running so well that it's hard to stay on campus and study while my car is visible to me from where I'm at now...

I see that how to link IDFs to the throttle is a hot topic on this board, and since I have the early "A.S" Spider, I think I'll go for a cable pull system made from a motorcycle accelerator cable actuated by the (now former) choke arm found on the early throttle linkage. That is unless I could re-ignite this topic/issue with further insight... If it were available and reasonably priced, I'd go with the solid factory linkage in spite of itself just for ease of installation...

It's currently hailing wildly on my Spider that's parked on the University of Oregon campus. It better bring May flowers dammit!

[mdrburchette]

I get all my IDF parts at Pierce Manifold. Do you know what jetting you want to start with? We may be able to help you muddle through a few scenarios if you don't have a clue. As for the linkage, I've got my 72 Spider with a rod linkage and my 71 has a cable. Both with the original pedal.

[manoa matt]

Chad,

I sent you differences between the fiat and vw carbs several weeks ago, check your private messages inbox. Send me an email and I can send you pictures of several linkage setups that I've seen. One cable pull setup is extreemly easy to fabricate and should work well.

If the center inkage from the Solexes don't fit the Weber throttle shafts to link them up in the center, Pierce sells a kit that links up two VW IDF carbs in the center for Fiat applications. http://www.piercemanifolds.com/linkage.htm scroll down the page, part number: PM3717

Jets: http://www.piercemanifolds.com/calpart.pdf

Main site: http://www.piercemanifolds.com/products.htm

[thechadzone]

Thank you both for chiming in on this one, I really don't know where to start with the jetting of these carbs for my 2 liter engine. I don't plan on racing it, but without abusing it, I enjoy driving the shit out of it on the rural stretches on the way to the local yacht club. I'm not sure if my driving habits will make a difference in the jetting of my IDF's, but this describes most of my Spider driving, which is rarely more than 50 miles round trip.

The cable linkage install that I like so far is shown here:

http://www.kendickson.com/car/idf/idf/index.html

If there's an easier one than this, I'm all ears! (Thanks again for your guidance on this Matt)

I'd love to know what y'all have done with your IDFs to optimize them for Fiat Spider application.

[manoa matt]

Your driving style/habits will not dictate the jetting. Your motor configuration will. We know you got a 2 liter, but what else? Stock/performance cams? Stock/high compression pistons, 2L/1.8L head, 4 to 1 exhaust or 4-2-1 exhaust, What type of ignition system? All these parameters will determine the "ball park" figures for jet sizes. You will need either a colortune kit, dyno runs, wide band O2 sensor(on each exhaust port), careful reading of your plugs, or a combination of several to determine the final jetting and fine tuning/mix.

There are a couple of gurus on Mirafiori.com that can give you the ball park figures to start off with, if you give them all the aforementioned engine information.

Optimization comes from porting, polishing, and gasket matching the intake manifold to cylinder head ports. A bit more can come from velocity stacks and air cleaner selection.

Send me an email for pictures of several throttle linkage setups. matt.scarton@gmail.com

[thechadzone]

That makes sense. I have the 1.8 head on my 2.0 motor, which is a great upgrade. I've heard the CR increase is worth a half a point, and you can sure feel it! I have the 1.8 exhaust manifold on it. I have stock cams, stock components within the head, and I'm currently running a single set of points for ignition. I don't have a catalytic converter, exhaust comes out the manifold, down the pipe, and out of a Monza Twin Tip muffler.

I do have fantasies about a pair of autocross cams from IAP, but I'll see what I think of the performance gained by the IDFs first.

[stefhahn]

Howdy,

I had a very similar question some months ago re the jetting of 40 IDFs for my slightly upgraded 2.0 - this is what came out:

Code: Select all

	Mike	Jeff	1600(Fiat)
Chokes	32	32	32
Aux Venturi	4.5	4.5
Idles	55	55	55
Mains	135	130	125
Airs	225	210	210
Emulsions	F11 	F11	F11
pumps	40	50	40
bleedbacks50	35	50
needles	175	200	175

The advice was given by Jeff Schefferman (IDF-pope at the Fiatforum) and a german chap called Mike who's got the same engine that you have.
Well, at least this should give you a good starting point.

ciao,
Stefan

[thechadzone]

Thanks so much stefhahn! This dual carb rpoject is & has been a big undertaking, and I haven't even twisted a wrench yet... I keep meaning to email matt about the linkage ideas, but my girlfriend is almost as high maintenence as my Spider... (she just got home...)