Stock horsepower

[duggy72]

I have been reading on other forums that Audi were conservative in their figures when they stated that the B8 S4 had 333bhp and in fact it was quite often the case that they had produced a fair bit more.

I have also read that due to some software update the B8.5 did not produce such higher figures.

Does anyone know if this is correct? Dont get me wrong, I'm more than happy with mine and to be honest i would not even remap mine as it is adequste for my needs as it is.

It is just a nice to know fact to know that the car is possibly even more powerful than stated.

Anyone else on here noticed that it is a bit quiet on this forum? Perhaps people also post elsewhere?

[Chiefbadger]

Hi Duggy,

No ideas on the power although I've also read similar. Worth signing up to audi-sport if you're not already though as the S4 forum seems to be pretty active.

Ols

[duggy72]

Thanks. When does your arrive?

[duggy72]

[duggy72]

A couple of pics of mine debadged. The dealer removed the rear tailgate and wing badges but could not remove the grille as they did not want to risk damaging it. I have covered it up since with black tape.

[Skiptowncat]

APR claimed that their s4 made 330 at the wheels when stock. I don't think anyone else has come across this though, so I can only deduce that their dyno reads high.
Mine made 330 @ flywheel at MRC before on was tuned.

[S4_V6T]

Although I have my car tuned at stage 2 along with a Milltek non-res exhaust, I have had my car dynoed at each stage of modifications for comparisons (all on V-Power).

Stock - 365 bhp
Stock + Milltek - 375 bhp
Stage 1 + Milltek - 430 bhp
Stage 2 + Milltek - 475 bhp

I was pleasantly surprised with the stock output

[duggy72]

Thanks for the further replies. S4_V6T, is yours a B8 or 8.5? You're stock figure is great.

[S4_V6T]

It's a B8 6MT version.

Thanks

[duggy72]

Thanks. Would be nice to know if the B8.5 is similar.

[Yoof]

When a vehicle is approved for sale, the country of sales authority (for us in the UK, it’s the VCA) will witness various tests on the vehicle, for engines this will be a powercurve with it rigged to an engine dyno, with all production components fitted.

Engine will be run in as per manufacturer’s handbook, and all hardware will be as per vehicle, any substitutions due to test cell restraints (cooling pack, vehicle exhaust) must be approved as having the same performance as vehicle, including temperature set points. I.e. you can force cool plant water over a charge cooler at 10°C if vehicle hardware would run at 55°C.

With all this setup the OEM declares figures, these are published figures they are allowed to sell the car with. Both torque and power, at a speed. Torque is traditionally given a band (say 2400rpm to 4500rpm) and power a set point with speed tolerance.

Critically the tolerance on these is ±4% for torque, and ±2% for power, on an ISO1585 corrected figure. This correction factor takes into account ambient conditions; pressure, temperature and humidity etc.

So for Audi their declaration in the UK is 333bhp, VCA will witness and accept 326bhp to 339bhp.

It is often the case that an engine with more hours on it, will make more power, especially when compared to a relatively green engine, as used in witness testing.

This coupled with the flywheel calculation error that rolling roads use, it’s no surprise that the cars appear to be very healthy.

However, this is not because Audi lied, or undersold the book figures, they are approved figures.

Hope this helps,

Pete

[duggy72]

When a vehicle is approved for sale, the country of sales authority (for us in the UK, it’s the VCA) will witness various tests on the vehicle, for engines this will be a powercurve with it rigged to an engine dyno, with all production components fitted.

Engine will be run in as per manufacturer’s handbook, and all hardware will be as per vehicle, any substitutions due to test cell restraints (cooling pack, vehicle exhaust) must be approved as having the same performance as vehicle, including temperature set points. I.e. you can force cool plant water over a charge cooler at 10°C if vehicle hardware would run at 55°C.

With all this setup the OEM declares figures, these are published figures they are allowed to sell the car with. Both torque and power, at a speed. Torque is traditionally given a band (say 2400rpm to 4500rpm) and power a set point with speed tolerance.

Critically the tolerance on these is ±4% for torque, and ±2% for power, on an ISO1585 corrected figure. This correction factor takes into account ambient conditions; pressure, temperature and humidity etc.

So for Audi their declaration in the UK is 333bhp, VCA will witness and accept 326bhp to 339bhp.

It is often the case that an engine with more hours on it, will make more power, especially when compared to a relatively green engine, as used in witness testing.

This coupled with the flywheel calculation error that rolling roads use, it’s no surprise that the cars appear to be very healthy.

However, this is not because Audi lied, or undersold the book figures, they are approved figures.

Hope this helps,

Pete

Thanks for such a comprehensive reply. Much appreciated.

[jp-berwick]

At a guess after having turbo cars (and tuning them for a while) for a long time (so not a perfect fit) mine is around 340BHP that's stock.

I have a few 'run' around local roads, really it's over 90+ mph where it feels like it's torque dives compared to other car's I've had, again all turbo.

edit mine is 2011

[Ducatikid]

Hi, I had my B8.5 on the dyno with just over 4000 miles on the clock. Showed 333.5 bhp, around 261 bhp at the wheels. It's just passed 30000 miles this weekend so may have a little more. I'm thinking about remapping so will have it dyno'd prior to the remap to see what I've gained after.

[Ian_C]

Manuals (ie prefacelift only) will make the most power as the engine redline is higher. Automatics change up at a considerably lower rpm. Facelift autos the shift up point was lowered further still.