Air Filter

[courtenay]

I've seen several engine bay pictures posted with aftermarket conical air filters (e.g. K & N) installed. I have an '80 Fi. Am I going to notice much difference in performance going with a conical filter? How about replacing the existing flat filter with a K & N flat filter?

[manoa matt]

You will notice the sound more than the seat of the pants umph. It may add a few HP, but hardly enough to feel. Spectre makes the same types of filters for much less $$ than K&N. http://www.spectreperformance.com/

[Foster48x]

I also used a Spectre filter. http://www.fiatspider.com/f08/viewtopic.php?f=17&t=7556

No noticable HP gains but they look allot better than the stock airbox IMO.

Rick

[pooldoctorstl]

Can you guys that have the Spectre filters give me the part number to order? I went to their web site but no Fiats listed. Or do you just buy the components and build it?

Thanks,
Jeff

[Europa]

Can you guys that have the Spectre filters give me the part number to order? I went to their web site but no Fiats listed. Or do you just buy the components and build it?

Thanks,
Jeff

Jeff, I don't have the Spectre part number. Here's a link to the thread that shows my K&N filter setup. I bought the adapter and bracket from a forum member. The bracket is what sold me on the kit.

http://fiatspider.com/f08/viewtopic.php ... ter#p42184

[courtenay]

Does anyone know whether Gus still sells the K & N set up? Or whether there is any other options for attaching the filter to the AFM?

[Foster48x]

Jeff,
I'm not sure what the Spectre part number is. I picked up mine along with the mounting bracket to attach to the AFM at PepBoys. If I recall they only carry a couple of sizes. Take a look at the pick of mine in this thread and it will give you an idea of what size to use.

viewtopic.php?f=17&t=7556

Rick

[kacperix]

Could You please tell me, if there will be any problems after exchange standard filter to conical air filter?
Is there no problems with the engine idle speed?
Do I need to perform any adjust fuel (l-jetronic) the / any problems with flowmeter?

or it's just a plug and play

[azruss]

I put Airaid 6" on my car. They are made here in Phoenix and I toured the factory. They do a nice job. There is modification required for the conversion. The AFM is held in place by the stock air filter box. It also has a square flange that connects to the box. I made a custom adaptor that bolted to the innerfender and had the proper round outlet. No modification required to any tuning. Its just an air filter. One advantage to the OEM box is the intake sits low and to the front to get away from the exhaust heat. Some put a shield around the cone filter area to do the same thing. I mounted a 4" tube through the sheet metal next to the radiator to allow air in from the grill while driving down the road.

[kacperix]

can You put some pics?

[azruss]

In the 2nd picture you can see some of the air intake hole. This is connected to a 4" trumpet on the grill side.

[kacperix]

Thanks azruss, now it's clear.

I asked if there would be problems with the injection, because I read that this typ of filters delivered much more air to the system, which means that we need delivered more fuel. (need adjustment injection adjustment) In other words, more air, the same amount of fuel that is too lean, so the engine chokes and has problems at idle and under acceleration choking

[RRoller123]

These filtration systems don't change the volume of air going into the system, they change the resistance to flow of the air, and hence the rate at which the engine can respond when calling for air.

[bradartigue]

Thanks azruss, now it's clear.

I asked if there would be problems with the injection, because I read that this typ of filters delivered much more air to the system, which means that we need delivered more fuel. (need adjustment injection adjustment) In other words, more air, the same amount of fuel that is too lean, so the engine chokes and has problems at idle and under acceleration choking

Sounds like a bad read, it is absolutely wrong. In fuel injection systems the air is metered by the AFM. The AFM measures the volume and temperature, which goes to the ECU, which tells the injectors what to do. On the FIAT there is no "injection adjustment" at all, the adjustment (or adjuster) is the ECU.

[RRoller123]

Think of it this way: With less resistance to the flow of air going in, the AFM door can swing open more quickly, the engine can rev up more quickly, the ECU adjust more quickly. (Just how much is debatable). The mixture is controlled not by the air filter flow resistance, but by the ECU as Brad says.