doubt about mufflers

[absolutepressure]

Originally posted by VFR750R:
Do you think the judges would notice if you cut two cylinders (4 cylinder engines only)at the point of MAP and RPM you see during sound test? It is pretty far out on the map, you would almost never see that on the track...and if you did, you obviously had your foot at something less then WOT.

Can you hear the difference between a V8 and a V6? Between a V6 and a four banger? Now the difference between a four banger and a 2cyl? I'd hope so, especially if you're the "engine and turbo guy" at cornell. You know what? Go out to your car, unplug 2 spark plug wires, and tell me you can't hear a difference.

Everything sounds like a V8, the only difference is the number of beats it's either missing or adding.

[absolutepressure]

Better yet, you might as well put injectors in your exhaust manifold and run your engine backwards. That would quiet down your muffler.

[Bryan Hagenauer]

Of course the judges would notice- but so what? If the rules only require the noise test at that rpm with that throttle position, and every single time they retest you, you pass with the same thing, whats the problem? It is no different than tuning the exhaust for the test rpm, but more extreme.

Do you meet the rule? Yes. Do you meet the intent of the rule? No. Don't be too suprised when you don't get to run.

[drivetrainUW-Platt]

why does Cornel care, they have the turbo muffler going on, plus the smallest muffler in fsae....lets not discuss cheating, children....

[Bryan Hagenauer]

Who's discussing cheating? I'm talking about meeting the rules perfectly. They could just as easily do the noise test from a certain distance away at a certain point on track, like other forms of racing.

[Bill Kunst]

OKay, if you have a big bang 4-cylinder firing only two cylinders, would you notice that? If it didn't significantly change the tone, you could easily get away with it. Or you could make it like DOD, shut off the injector and ignition on two cylinders at low load (idle) for "better gas mileage". Just some thoughts-
Bill

[BeaverGuy]

Its not cheating in any way, and if you look he is a Cornell alum. And there was an explicit change to the sound rules this year, if you are above the sound limit at any RPM below the check RPM you will fail. As far as circumventing the rules, disabling the two cylinders isn't any different than adjusting the fuel and spark in those regions to meet sound only a much more extreme version of it.

[VFR750R]

Settle down guys, I'm not advocating cheating. As far as I'm concerned, it's something everyone can do, and it innovative thinking. I would count it as cheating if you were going to change it back to run on the track. But in this case, it's a design intent that you could run successfully all weekend.

Absolute Pressure...I didn't mean that they couldn't tell the difference, just-would they care. Would they look at it as design intent to work the rules, or as 'cheating'. Either way, they have obviously changed the rules to reflect they don't want to see things that are quiet only at the test rpm.

[mario_rbr]

How exactly do they measure the engine speed at competition?, just by looking at the tach? or do they attach something to the coils or something, to measure real speed, beacuse if it's just by looking at the tach, you can set it up to lower than real values, son when it shows 11000 rpm, the engine it's only at 9000 rpm

[B Lewis @ PE Engine Management]

In the past, they have allowed you to show them your ECU tuning software to get RPM. We usually have one or two teams asking to borrow a laptop for just this reason during the noise tests.