Whats my hp?

[coltspeed]

Asked this on rs246, but seems nobody can be rs'd giving answer.

Had my rs4 carbon cleaned, deflapped and remapped. Before and after dyno runs done going from 202kw to 227kw at the wheels. I was wanting to know how you guys would calculate the hp? I see most of the US claiming up to 450hp after remapping etc.. But i can't figure out how you come to those numbers.

I figure there is nothing wrong with the car as i have done a few 3000-8000rpm pulls in 3rd and the times (although not exact) are consistently in the 8.3-8.7sec mark.

Any help would be great cheers

[LINDW4LL]

We go by wheel horsepower, as reported by the dyno. We generally don't guess/extrapolate to crank HP as they do across the pond in UK/EU. A stock RS with carbon cleaning will do ~300-330whp depending on the type of dyno.


202k2 = 270 wheel hp
227kw = 308 wheel hp


Sounds about right to me. Carbon buildup must have been quite bad I assume?

[gautam]

http://www.rapidtables.com/convert/power/kw-to-bhp.htm

http://www.mk5cortinaestate.co.uk/calculator4.php

Figure a 20% loss and you're at around 360 bhp at the crank. You sure about the 227 kw at the wheels? Seems very low.

[Velox]

http://www.rapidtables.com/convert/power/kw-to-bhp.htm

http://www.mk5cortinaestate.co.uk/calculator4.php

Figure a 20% loss and you're at around 360 bhp at the crank. You sure about the 227 kw at the wheels? Seems very low.

huh 20% loss on 360 crank would mean 288 at the wheels, not 306

[q_dubz]

use this:

https://www.google.com/url?sa=t&rct=...39782543,d.eWE

[coltspeed]

Definitely 227kw at the wheels after remap.

[coltspeed]

We go by wheel horsepower, as reported by the dyno. We generally don't guess/extrapolate to crank HP as they do across the pond in UK/EU. A stock RS with carbon cleaning will do ~300-330whp depending on the type of dyno.


202k2 = 270 wheel hp
227kw = 308 wheel hp


Sounds about right to me. Carbon buildup must have been quite bad I assume?

My understanding was it was one of the worst they had seen...

[coltspeed]

Will going back into the shop tomorrow to get video and graphs of the dyno runs. I will post if i can figure out how

[gautam]

huh 20% loss on 360 crank would mean 288 at the wheels, not 306

It was a rough estimate, using the 2 links I posted, 227 kW equals 304.4 bhp at the wheels which equals 365 bhp at the crank for an all wheel drive car with a manual transmission. Still seems low to me...

[coltspeed]

Car had a small vacuum leak. Now making 231kw at the wheels which is 310hp which is 314ps which is 427hp corrected like the UK do. Pretty happy.

[Hooblah]

Assuming you have a 20% loss, 310bhp at the wheels would equal 387bhp at the crank.

[coltspeed]

Assuming you have a 20% loss, 310bhp at the wheels would equal 387bhp at the crank.

I have looked at many of the mrc dyno runs and they are running the same numbers. I just used the same corrected hp as they did with the same actual at the wheels kw/hp