From the Evolve thread:
Evolve 4-1 Step Design Headers Dyno Tests
Dyno used - MAHA LPS 3000
Two sets
The Test Car:
The standard car was a 1999 LHD E39 M5 with 86,000 miles. Very good healthy engine making 403hp.
Already fitted with brand new 100 Cell high Flow cats, H Pipe and Rear Exhausts (so that these are taken out of the equation and we are testing headers only)
Standard ECU with speed limiter in place.
Tested in 5th gear
Speed limiter came in at around 6600rpm so this is the max RPM we could test to and this is ok because the stock car makes it peak power at around here.
Graph 1: (Uncorrected Test 1 - std vs run A)
Graph 2: (Corrected test Std vs run B)
Notes and brief discussion:
Why two sets of graphs? Just to show that results can very from test to test with the same upgrades.
This allows us to give you a maxima and minima of the increases in power rather than just one graph.
We did this last time on the RHD headers and it was very welcomed as it shows a bigger picture rather than just a definitive increase which simply doesn't happen with ever changing variables.
You get the general idea of how the graph changes shape and that's what we need to get accross to you.
Yes, it does make it more confusing but again it's important for us to show different tests.
We could just post one graph, say that's it but knowing how the ignition advance changes we cannot do this.
On run A the ignition advance was higher in the mid range than the higher rpms.
On run B it was the opposite.
The ignition advance goes up and down in different places during a run based on lots of variables.
The dip @ 3500rpm is also present with our 4-2-1 RHD header design.
The scaling on the Torque graphs is very small but the average gain is around 30lb.ft (40Nm) upto 4000rpm which is almost exactly the same as our 4-2-1 RHD versions.
Overall, we are looking at around 30-40hp and 35-50Nm (29-37lb.ft) through the rpm range with the peak gains being approx +40hp and 45Nm torque.
The minimum gains will be around 30hp and 30lb.ft torque.
I hope that's enough information to digest and make your head spin a little.