Thin air problem F40

This is going to sound very rude and blunt, so also putting here I dont have and have not driven an F40 - but have driven other Ferraris, and have driven problematic overheating turbos.

If the problem hit half the cars, then yes - it's a common problem, but if it didn't the other half - may be a problem between the footwell and the seat. I find I can drive an automatic Toyota very calmly, but always tempted to walk a Ferrari through any corner, if needed or not because it's just too much fun. Likewise always tempted to walk an R32 Turbo around corners in a close group with other cars.

Are you guys easing the cars around or walking the cars around corners with both feet. If it's not driving - would go through the same basic checks for a Nissan turbo, that you have clean path from hole in bodywork through intercooler and such. You've not got bent mesh, build up over filters etc. etc. Also would be interesting to look at who was driving with hot-air blown on them by being in a group, and who was easing out of hills and running clean-air space for the intakes.

 

This could also be caused by fuel icing.

In the mountains even in the summer fuel systems are prone to icing when you move from sea level high temperatures and pressures to mountain low temperatures and pressures.

I would add a fuel additive that removes condensed water from fuel and see if this helps.

You might also want to install a cockpit adjustable duct that ducts hot air (Carb Heat) to the fuel injector lines.

In our P 3/4 (mechanical FI) Ferrari routed the fuel lines inside of the water lines to heat the fuel. Our 166 has cockpit controllable carb heat which makes it work a lot better in the mountains.

 

roger, i was there and sometimes close behind you

my guess is that something needed servicing on your car. o2 sensor, air filters, gas filters, etc. the altitude difference is one thing, but it should not have stopped your car dead in its tracks. did you talk to the ferrari mechanic who was tagging along?

 

I'm not sure who sells it in Europe but we found and used it in Italy. A lot of cars in Italy use it because of moisture found in fuel there.

Basically any fuel stabiliser/octane booster will do as long as it contains "dry gas" which is an alcohol with a free radical that attaches itself to H2O to form burnable fuel.

 

I think Ross didn't have any problems because when he watched us race the 24 Hours of Nurburgring I saw him filling his water bottle with race fuel and he probably added that to his F40.

 

need different Spark plugs...

 

that's what my car did or at least it sounds like the same thing.

 

i was in the red w/stripe 360cs with swiss plates. so i did not overtake you ! but i remember your car.
the de-icing product that jim speaks of is certainly a good idea, but i really doubt that you had icing or condensation in the fuel - we ran hard all day from the flat to the top, and in the run up the mountain the fuel would not have had time to either condense or ice. that kind of event might show itself if you left it outside overnight up there and then started off in the morning, but not in a constant run. it just sounds like you were nto getting enough air into the cylinders, hence my guess that you need to check the 02 sensor, and the air filters.

 

A couple of problems that usually occur with Weber IAW equiped cars are easily resolved by either changing the water temp sensor, the map sensor or the crank sensor. Each is only under £50 if you buy direct from a weber dealer rather than ferrari. Its a robust system but as these cars get older the wiring harness at each of the sensor connections can also corrode slightly and send false readings to the ecu, so thats another area worth checking as condensation at higher altitude could be getting onto the wiring points.

 

if carb icing is eliminated as a possible issue, what are the altitudes reached in the mountains ? Engines tuned at sea level will struggle as altitude is gained, especially if running toward the rich side of things at sea level. As the air gets thinner with altitude the fuel mix becomes too rich causing a loss of power as the engine struggles to breathe.
A retune to the leaner side or rejetting for less fuel flow would go a long way at altitude.
(think of what happens as the choke is applied). Give up a bit of performance at sea level and get it back at altitude

 

"Inhibitors may be added to reduce corrosion and oxidation. Anti-icing additives are also being blended to prevent fuel icing."

 

Only time I saw icing was when I ran 110 octane race gas. No problems with 100 octane at altitude; I live at 5500' and go over the mountain passes at 7500' without any problems, in 95 degree days. Not sure if it matters but my car is tuned at 5200' altitude, and I'm not running stock plugs.

 

Being tuned at altitude would help. Italian pump fuel is very bad and often contains a lot of water. Regular cars routinely use additives there. We use it in every car we've run in Italy. Jesse's 208 GTB Turbo had issues in the mountians on Italian pump gas before we ran additive.

 

It's not "free radicals" in the anti-icing additives. I am pretty sure the active ingredient is just methanol that forms an azeotrope with liquid water that is miscible with gasoline and allows it to be consumed in combustion.

As for the tune, any fuel injected car has a barometric sensor that will adjust A/F ratio for reduced air density in the intake manifold, and at cruise the O2 sensors provide feedback to fine tune the mixture.

I feel confident it is not a tune or design problem. My first guess is a fuel issue like vapor lock (more common with oxygenated/alcohol-rich fuels) or maybe an icing issue, but icing in fuel injected engines is pretty unlikely. Fiel injected aricraft don;t even have the ability to add carburetor heat, bu I check for water in the fuel before every takeoff.

Check the fuel filters and fuel system. My F40 did the same thing due to deterioration in the rubber fuel system components that clogged the fuel filters; after sitting the debris would settle enough that the car would run for a while, then it would clog again and be most noticeable under hard running and boost, when fuel demands are high.

If the cars in question have not had their fuel bladders and other soft components and filters replaced in the last 10 years or so, that is one place I'd look for sure.

 

Ferrari designed in the ability to heat the fuel in the mechanically fuel injected P 3/4 that raced the Targa Florio ( Mountains) and hill climb 206S Dino's.

 

not familiar with the range of adjustment that the sensors allow for changes in altitude, or if the sensors are functioning properly. Fuel / air mix is a function. It is carefully considered by dragsters who adjust for altitude of each track they run in. The check list for possibilities is growing, each item should be examined, like the cliche'... each item may be small or seem insignificant, left unchecked the problem becomes large.

 

makes sense, the volume / density of fuel changes with it's temperature,