flamin-roids

I'm thinking about putting the car on a dyno later this month but I want to know what to expect. I've looked at other similar dyno's and they are pretty vague. So thats why I'm asking what would be a good estimate so I don't get dissapointed. Here's the setup.
S5 N/A motor with consistant 105 p.s.i compression
ACT prolite TII flywheel w/ TII clutch and tranny
3.90 (auto) rear end
K&N cone filter
Stock exhaust manifold w/ straight 2.5" exhaust with a single high flow muffler
Accel 8mm wires
Royal Purple Max gear 75w90 synthetic gear oil

The car runs excellent and definitly can feel the power. Everything else is stock. And there are no issues with anything. I believe the factory FWHP was 160-165hp (depending on where you get your numbers) so would that be maybe 120ish RWHP? Anything over 120 RWHP will be fine for me. What are some estimates?

buzz

I have an s4 6port in my 1st gen. I made 96 or 98rwkw, so about 128/131rwhp - I was happy enough as it is nothing special. I had a 48ida weber with only 37 or 38mm chokes and a K&N filter... it actually dropped power without the filter.... exhaust was truly ordinary press bent extractors (around 2" od) with short primaries to a 2.5" pipe with resonator then offset straight through muffler. I don't know what he revved it to but the power did really drop off just over 7k, but have now fitted 42mm chokes on an inlet that actually matches the ports (!!) (note no port actuators), less-bad quality extractors with long primaries and large dog leg muffler (really large) and I'll be on the dyno with the boys in a couple of weeks. I don't know if it makes more power (certainly laps faster), but the extra 1k rpm before the power dies enalbes me to hold it just that much longer.

On paper the s4 has less power than the s5 with its lighter rotors and higher compresion.

Your expectation seems to be pretty realistic. The biggest power adder for you is the exhaust, though the driveline upgrades might minimise power losses.

87cncnu

Think you'll do better than that. My S4 87NA with a cone filter, single hi flow cat and custom exhaust pulled 130.05 and 129.08 RWH with about 85K mi. on the motor. Torque drops like a stone on the S4 at about 6KRPM, but (I'm told) your S5 doesn't, so I'd expect a solid 140 RWH if the motor is tight.