This is deliberate, you have to remember the car is not moving so there is no ram-air effect, if you were to look at the AFR on the road at actual speed, the AFR would be perfect. This is something we have seen tuners often screw up, they set the top end too lean, when the race car is pulling on the track in the high speed sections, they run dangerously lean and we have seen engine failures. Any decent tuner knows this.
Any half decent engine management system has no problem at all compensating for a miniscule increase in air density due to "ram-air effect". Any decent tuner knows this.
Not when these cars were made, nowadays yes, back then no. I'll connect the gear up and do some runs on the road to prove it, happy to do that.
I'd suggest keeping an open mind, it is a real thing, I have seen it with my own eyes on gear I trust. What you are suggesting is the air pressure through the intake system, and in the case of the 348, one which is part of the car's aerodynamics at speed is no different than the car standing still with a fan in front of it? I just hope I dont get caught speeding and lose my license...lol....
This is a silly video and perhaps not perfectly scientific, but if you watch it you’ll see that it takes A LOT of forced air to effect the performance of an engine. What you get at 80mph is inconsequential.
It is a known thing, I don't think thats a good example, you need to actually drive the car on the road. For example, why do you supposed during the evolution of F1 cars, there have been occasions where the governing body changes the rules to reduce the area and height of the air intakes, which have always been around reducing the ram air affect? Its happened numerous times....in the interest of reducing horsepower, forcing more air in, means you can put more fuel in.....more power. But at the end of the day, you can believe what you choose, and all good, we dont having to get into a pissing contest, but in my case after being around a guy most of my adult life who tunes race/rally cars, I have seen how this can affect things at speed, on the track/road. You can lean the car out in the top end if you want, but I wouldn't..... We can agree to disagree and we can be okay with that.
They use a MAF sensor the same as most new cars sold these days. The situation you're talking about could arise in a setup that used Throttle Position vs RPM for load sensing without any pressure compensation. This is very bad practice as it wouldn't even compensate for changes in altitude.
[Q MAF is not in use on WOT, its using the fuel map. If you did a dyno run using light to medium throttle then yes, the MAF's in conjunction with readings from the O2 sensors in closed loop will compensate and you'll see a leaner AFR for economy and keeping the greenies happy, since we are doing the runs with WOT, then this is a different story... Newer cars are now using wide band O2 sensors with far more advanced control over the fuel system than what the dirty old 80's Motronics were capable of with the narrow band O2 sensors the 348 is using. But the old Motronics still do a pretty good job, and I was pleased to see it running 12-12.5:1...Last thing you want to see is the engine running lean...
Not sure what you mean by "axes". All ecu's have ignition timing and fuel maps. Which is a table consisting pre determined values for the injector pulse cycles at different RPM vs Throttle position and possibly map sensor, and the same for the ignition table. They would have developed this on their engine dyno. The reason the engine is not using this below WOT is simply for fuel economy and to meet emission standards....this is the "max power" function, "screw the emissions" type thing. You can look up how the ECU works in the workshop manual, I haven't gone into it in much detail, I'm recalling from years of fitting and tuning engines with aftermarket ECU's...
To save you the effort of looking it up, here is a couple of quotes taken directly from the F355 2.7 manual. I assume 348 is the same: Hot wire air flow sensor • Engine load, and hence the volume of air intake, is detected through the signal generated by the air flow sensor (necessary to meter the quantity of fuel). • In other words, the ECU completely ignores the potentiometer signal and it is not used for any regulation. Note: if the air flow meter malfunctions and provides information which is incorrect or recognized by the E.C.U. as implausible, the "recovery" procedure is activated. Under this, the signal from the potentiometers on the throttles is analyzed to establish when the throttles open and thus the amount of air taken in by the engine. In this case the regulation is less precise than that obtained using the flow meter, but it is however sufficient to keep the car running efficiently and prevent it stopping.
Because teh F1 guys can run enough tests to get it right, and the average car guy cannot. Ram air enters the system fast, fast air has low pressure (Bernoulli) so you need a large box into which this air can flow so it can slow down before it reaches the engine intake. most cars do not have a big enough volume to put this box, so most car add-ons fail to deliver any power improvements at all. Cooler air is often achieved, but converting ram intakes to power takes considerable effort. While this is true in theory (when theory is properly applied), if fails in practice most of the time. You have to get the fast moving air to slow to nearly no movement at all to achieve a pressure increase--which is what puts more air into the cylinders. I agree that the theory works, but is more difficult in practice than in theory.
So your saying all those 60's muscle cars with "ram air" didn't add 50 whp due to that. I know a bunch of former hippies who swear the ram air makes a ton of power. Especially if it's got a hemi in it! [emoji14] Sent from my SM-G990U using FerrariChat.com mobile app
I plan to add "ram air" (well, through the firewall/cowl) on my 60's hemi musclecar but more so for the purpose of cold air. I've read a good system is around .2psi at 100mph so not much but better than nothing
