Make a donation

Author Topic: Why peak bhp numbers dont matter....  (Read 625 times)

Offline PDT

  • Just look at my post count
  • ******
  • Thank You
  • -Given: 3
  • -Receive: 142
  • Posts: 2010
    • Email
Why peak bhp numbers dont matter....
« on: March 03, 2013, 05:39:55 pm »
I often come across customers that are only interested in peak BHP, we often lose these customers because cheap amateur tuners i.e we 'r' remaps.com down the road in their mobile tuning van promise more horespowers  :confused:

You hear tuners talikng about 'area under the curve and average power gains' and I think this illustrates this perfectly.

 Today I was tuning a BMW 325d which was a perfect example of why peak BHP numbers are just pub talk. I flashed on a stage 1 test map (pink line in this graph below) and although the peak power was good, the entire mid range and low torque/power was missing something.... I had missed the in gear torque limiter maps  :ashamed:

so back to the map editing software and 30 mins later we had found the missing power and torque (red line). So although both maps made within 5bhp of eachother, they would have been very very different on the road. Another big reason why dyno tuning is so important during software mapping.


Offline PDT

  • Just look at my post count
  • ******
  • Thank You
  • -Given: 3
  • -Receive: 142
  • Posts: 2010
    • Email
Re: Why peak bhp numbers dont matter....
« Reply #1 on: March 03, 2013, 05:40:25 pm »
left hand axis is ft/lb of torque.

Offline Hedge

  • Just look at my post count
  • ******
  • Thank You
  • -Given: 484
  • -Receive: 304
  • Posts: 6621
Re: Why peak bhp numbers dont matter....
« Reply #2 on: March 03, 2013, 05:48:18 pm »
Absolutely right peak numbers are for oub talk and it's all about the area under the curve.

It's all about how long you torque for.  :wink:

Offline Hurdy

  • Just look at my post count
  • ******
  • Thank You
  • -Given: 52
  • -Receive: 137
  • Posts: 7683
Re: Why peak bhp numbers dont matter....
« Reply #3 on: March 03, 2013, 06:39:22 pm »
This is what I keep banging on about too, I couldn't agree more.

Previously to having wmi fitted my car felt really strong on the GIAC stage 2 map and the times reflected it, but after fitting wmi the power comes in lower down the rpm range and the torque is held for longer. The car now feels much stronger than before in every gear and at all rpm's.

It is also one of the reasons why I still have the K04 on the car as BT conversions often are great for peak figures and on track, but for day to day driving can simply feel "flat" as the area under the graph doesn't even impact till half way through the rev range.
Golf R gone.