Is it only for their blown cars?
So we saw a stock S8 on the dyno - Audi says 520 bhp but the dyno said 575.
I’ve driven around in an A5 cabriolet with the 2.0T - they say 211bhp and 258 tq but it moves around pretty good for a 4150lb rock. Probably more like 250/275.
The RS5 making 450 bhp out of 4.2 naturally aspirated litres - that’s gotta be pretty much all she wrote though right? I mean 107 bhp per liter… what more can you ask for.
[quote=“thenewbruno,post:1,topic:3935”]
disregard sound and emissions limitations and there is more in the motor
[quote=“beemercer,post:2,topic:3935”]
X2 - these two are almost always the limiting factors that are somewhat easily changed.
Converting wheel dyno to crank is a bit of a toss up these days. Not sure I would bother. The S8 dyno’d 479 WHP. That implies 8% drivetrain loss vs. the claimed 520 hp, so clearly it’s underrated. How much though is debatable.
Don’t forget they are saying 520 hp at the crank…but they’re not talking about on 93 or 94 octane gas that the car dyno’d used. They are talking about 91 octane over here RON+MON/2, or around 95 octane RON over there. They base the hp rating on the lowest common denominator, and for Audi, that is 91 (they recommend 91 premium fuel RON+MON/2).
So part of the ‘underrating’ is that we dyno and test using 93-94 whenever we can, then compare it to claims made by the manufacturer which are based on worse fuel, and are already sandbagged a little (underpromise overdeliver.)
Also, hp/litre is in my mind an irrelevant measurement of a car’s worth for an end user. Interesting as an engineering exercise for engineers to do a little horn tooting, but not that relevant when you line up at the stop light against an LSX guy and he wastes you but you hold up your hp/liter calculation and tell him you technically won and are ‘better’.
107hp/litre is nice for an NA car to be sure…but when we have the RS5 dynoing 345 whp, but JHM tune/exhaust B7 RS4 guys were dynoing 365whp (without touching the rev limiter which is the main diff on the RS5), you can quickly see there is plenty of upside. Convert that back to crank however you like.
i.e. at 034 a few stock RS4s have dynod around 320 whp or 76 whp per litre . When you have a modded RS4 dynoing 365whp there, that’s 45 whp gained, or 87 whp per litre overall.
I wouldn’t be surprised to see a 380 whp B7 RS4 all motor (on a dyno where one might make 330 stock).
too bad governments can’t learn to do this rather than the opposite all the time
My manifesto would be “hoping to make things a little less shit”