82 Fiat Fuel Injected Spider - How to more speed

[Fiatracertracer]

How can I improve performance out my 1982 Fuel Injected Spider.

[narfire]

Head work and cams with adjustable cam wheels to benefit the work and cams.. Lightened flywheel will help acceleration(a bit). More bucks available... rebore cylinders and install oversize pistons with better compression and balance the whole works. Might get you another 20-25 or so HP is my guess. A lot of money for a little extra HP. Perhaps headers but the 4-2-1 exhaust manifold is not that bad.
I found the head work, cams and degreed in properly made the most noticeable difference.
Chris

[2500diesel]

This was my recipe from my old SCCA racer;
Ditch the fuel injection for a dual Weber setup ( I had 40IDF's, but YMMV), port the heads, add the heavier springs, 40/80 cams. Bore the block .030 over, don't use anything higher than 10.5/1 compression if you want to be able to use pump gas, don't use anything higher than 9.5/1 if you're a cheap, er, ah frugal person and want to use anything lower than super. Balancing is not that important in an inline engine, but why cheap out, right? Add an MSD box, I suggest the MSD 6AL with a 7000rpm chip. If you do the work yourself, (except the machine work), and eBay the Weber setup, you're in for about $1k on the block, about $2k-2500 in the head and Webers, $200 for the MSD box. It dynoed out at 166hp.
And then you can work on the suspension. Cut the springs, 1" front, 2" rear. Konis all around, bigger front sway bar, rear sway bar if yours is missing. Weight is your enemy. Pull the back seat, use a motorcycle battery, and get the spare tire out, jack too.

[2500diesel]

Forgot to mention the headers into a 2.5" straight pipe. The only muffler you can use with this setup is the Supertrapp. It allows you to tune the back pressure.

[So Cal Mark]

back pressure is a bad, bad thing. First, make sure the engine is running at peak efficiency, then consider performance parts

[vandor]

Really depends on your budget. Let us know your budget and we can give you better answers.
The two cheapest ways to get a few more HP (assuming everything is in good working order) is to get a better flowing air cleaner that gets cool outside air and getting rid of the converter.
Even drilling holes in the stock lower airbox and near it in the inner fender will show improvements.

[divace73]

nobody has mentioned to remove the bumpers.....and maybe diet all up it could be 50kg's or so....I find when you chase more power it kind of never stops, there is always the next step to do, I have read in places that that there is a possible bigger AFM swap but don't know how true that is. Having a car that handles extremely well is just as much fun as increasing horsepower
Keep us posted

[2500diesel]

back pressure is a necessary thing. First, make sure the engine is running at peak efficiency, then consider performance parts

Fixed it for ya.



Too much back pressure is a bad bad thing, but so is too little.

[vandor]

> I have read in places that that there is a possible bigger AFM swap

The 2.5 liter Alfa V6 made 154 hp and use the same size AFM, so I doubt the Spider needs a larger one.

[divace73]

> I have read in places that that there is a possible bigger AFM swap

The 2.5 liter Alfa V6 made 154 hp and use the same size AFM, so I doubt the Spider needs a larger one.

Ironically I read it on a GTV6 forum as I just bought a 1983 GTV6, knowing it came out with 154hp is a bonus, such a gem of a motor.
I guess it depends on driving style but in the upper rpms my spider 'appears' to be suffocating?? Earlier this year at the Fiat Nationals here in Sydney I'd keep up with the other 124's but down the straight they all passes me and they all had smaller capacity engines but bigger carbs. I do have higher flow injectors in and realise there may be many factors involved, but it felt like it was restricted, click on the image below to see the you tube clip if interested

[vandor]

I used to have a GTV6, that is an amazing engine.

You are correct, the injected Spider falls on it's face at higher revs, but it's not necessarily because of the AFM's size. I think having such a long intake with so many bends, plus a restrictive airbox is what kills flow at high rpm.

[So Cal Mark]

don't edit what I wrote. The only thing backpressure does is quiet the exhaust and prevent popping on decel. Backpressure increases dilution in the cylinder during overlap. Backpressure in NOT necessary

[divace73]

I used to have a GTV6, that is an amazing engine.

You are correct, the injected Spider falls on it's face at higher revs, but it's not necessarily because of the AFM's size. I think having such a long intake with so many bends, plus a restrictive airbox is what kills flow at high rpm.

Could be.., I do have one of those cone filters so we can eliminate that??
Would be good if I had a larger AFM to do back to back tests on a dyno with a wide band sensor in to know for sure...
It could be a cam timing thing for all i know?? I do have plans (however long they may be??) to replace the L-Jet with Megasquirt, wasted spark and then individual throttle bodies, then after that I have a regata head (with the bigger valves) and some cams to go in...it may take me 10 years but I will get there eventually....

[narfire]

Another point in getting more power from these engines.... consider sourcing a 2L engine, put it on a stand, tear it down and build it over a year say, to what you are looking for. Top of my head guess....$2-3000 would be a good budget over the year. I did it that way and the $$$ I spent was a little bit easier to deal with as it trickled out over a year.

[vandor]

Also remember that the 2000 Spider used the same cams as the 1600/1800. But a 2L will flow 25% more air (theoretically) than a 1600 at the same revs, so likely the cams restric high-rpm flow as well. You can put mild cams into a stock FI engine and it will improve high rpm power.

Your filter looks fine, as long as it can get outside air. In my previous Spider I had a 2L with stock injection, a much better air cleaner (from a 2.3 liter turbo Ford, so it had plenty of flow), 9.8:1 compression and 40-80 cams. It ran very well.