turn FI to carbs

[stephanspider2000]

hello all
last weekend i helped a guy here who was stranded with his spider aside the road with his spider.In return for the favour he gave me a intake manifold he says is from a 131 abarth.now i can put double carbs in my spider, only mine is 2.0 FI.
Now i already have an 1800 head that needs work.Does it make sense to get rid of the FI ,put on the 1800 head with the intake and double carbs? i know i must also have to do something on the gas pressure and the ignition.But do i get more hp than the 105 from the FI? I think this can be a nice winter project
ps.What size of carbs do i need (weber 40 idf??)

[So Cal Mark]

if you're willing to trade driveability for more power, then consider the swap. It just depends on what you want from your car

[stephanspider2000]

since im not driving it mostly for short distances , drivability is not so important for me.I had a fiat 500 wich i tuned from standard 18 hp, to 45 hp , it wasn't drivable at all but i had so much fun with it.
can you tel me how much more hp this setup is
and what sort of carb should i use, i can get my hands on weber idf 80 og from a volkswagen beetle 2.0
are they usable?

[MIGHTY 8]

http://images.google.com/imgres?imgurl= ... S%26sa%3DN

This might help!

Good luck,

Gabriel

[sptcoupe]

Guess I will never understand why dual carbs, power and driveability are incompatible. Done properly, you should never be aware that you have dual carbs unitl you put your foot in it and feel and hear your engine turn inot the fire breather it can be. The proper cams, CR, ignition, fuel regulation, exhaust and carteful jetting and tuning will result in a motor as smooth as my FI 81 spider, with immediate throttle response and ability to pull to redline anyday you want to.

[stephanspider2000]

hello
thank you gabriel thats a great site with lots of info
i understand from it that the VW idf's are also usable especially whit a electronic ignition, they are much more common over here. I still like to know from someone who has done the conversion if there is a noticable difference in performance??
my favorite part of the hobby is working and figuring things out on the car, but it has to be worth the effort and the money

[So Cal Mark]

the reason that carbs will never give the precise driveability of FI is that a carb is a very crude device for mixing fuel and air and dependent on a perfect manifold design to deliver it evenly to all cylinders

[stephanspider2000]

I agree with you marc, but when i want to put in different cams, raise the compression, put in other pistons etc i must use a very very expensive programmable injection system on it, wich i cant program myself, so i must go to a very expensive shop to do it for me. Or put on carbs and other parts that are reletivly cheap here(the netherlands)and easy to get an i can do all the work myself, wich I enjoy.the spider is not my daily driver and mostly i take a spin around town or go to meetings or shows, and sometimes take it to the tracks.
I think a carbed engine is easier to tuneup , or am i wrong??

[So Cal Mark]

I was mostly answering sptcoupe, but I agree with you about perf mods and stock fi. I was merely comparing stock driveability with FI to perf mods to carbs

[sptcoupe]

Mark - I agree that carbs are crude compared to FI, but the point is that even those crude carbs can be, and have been for decades, properly tuned and set up to be perfectly streetable and yield significant performance gains, on many cars. The key is doing all that you have to do to properly set up a carb'd motor. My carb'd 1800 is just as tractable as my FI 2.0L spider, but puts outs more HP per liter than the (mostly stock) FI spider. I will agree that an equally modified and properly set up FI engine will get more HP/liter, and will also be a reliable and streetable motor. If you are satisfied with a FI 2.0L putting out 100 or so HP, as I am in my spider, then you are better off doing that than trying to get the same perfomance by simply bolting on two IDFs on an otherwise stock 1800 or carb'd 2.0L motor. My point is that dual carb'd engines with the proper mods are perfectly streetable and reliable power conversions.

[So Cal Mark]

I don't dispute anything you say. My point was that for the average owner/driver, the FI system offers great driveability compared to carbs.

[sptcoupe]

And I agree. I always recommend going all the way with dual carbs, or going with FI or a single carb upgrade. BTW, this killer 2.0L I am building will be ready for the dyno in another month or so, and I will likely be crying for help when we get down to mapping it. Your header will on it, having been closely ported to the head. Stand by! I'll try to post some progress photos as it goes together. Denise - can you post the photos I sent today?

[thechadzone]

I'm almost done with my IDF conversion on my Spider. I'm using IDFs that were previously for VW application that I got a good deal on. (I believe I paide $266 for both). However, the cost of the Fiat calibrated parts for these carbs that were recommended on this forum have costed me almost three hundred dollars from Pierce Manifolds. Still, that lady who answers the order desk phone is so nice...

If you enjoy the planning and problem solving stages of engine upgrades, this is the project for you! There are countless ways to link IDFs to the accelerator linkage, and I'm still shaking my head at what I've come up with. It works well, but...

While wating for the Fiat specific IDF parts to come in the mail, I afixed the IDFs to the newly installed manifold with the VW specific parts still in them just to see what'd happen. The car runs, but not particularly well. The plugs are all still a good color, but the idle is erratic, and the carbs sneeze more than they should. Still, the power is very much there, and the torque is fantastic! It's also pretty impressive on the top end.

I've never driven or been driven in a FI Spider, so I don't have a comparisn there, but my engine is a two liter with the 1.8 head The addition of the dual IDFs is already fantastic by comparisn to the DFEV I had previously. The increased induction sound and fortified exhaust sound is a symphony in my garage, but until I get the Fiat specific parts in the carbs, I haven't bothered taking it out of my neighborhood.

I do have a pair of perfectly prepared side drafting webers on my Alfa Spider, and I agree with Mark that dual carbs drive a bit more rough than FI engines, but I think that you get a lot more personality from dual carbs than from FI, and that's what sets my Spider apart from my Civic EX. Fuel injectinon, electronic ignition, and 100 HP sounds a bit like a Nissan Sentra to me...

BTW, that guy gave you one hell of a gift!

[stephanspider2000]

the vw carbs are very common around here , i see prices from 150-200 euro for a overhauled pair to 400-500 euro for a new pair, the specific fiat ones(13-15??) i haven't seen them yet.Can you tell me what specific fiat parts are needed

[sptcoupe]

There are no parts needed to use the newer IDFs on your FIAT. Of course, you will need a manifold, either the originail waffle style from FIAT, or one of the variants available form a number of vendors. You will also need to rejet them if they have been set up for a VW, and possibly put new chokes in them as well, depending on what else you have done to the engine (the mst common size for most FIAT applications is 32mm) . Finally, you will have to cut the throttle plate shaft on the inside of the carbs to make them fit on the FIAT manifold. This takes a vice, a hacksaw, and about two minutes to do.