A Whopping 11HP - Where it Counts

Its not often a 'RE-TUNE' delivers as big of a real world gain as this job did. This Yamaha YZF-R6 was booked in to have a Pit Lane Limiter issue resolved. The fix for that part of the work was relatively simple, then while on the dyno, we decided to do a Tune Assessment. A dyno assessment is a great way to see where a bike is at in terms of running health and tune.

This R6 has a YEC Race ECU and Loom and had either previously been tuned elsewhere or had a map sent to the ECU.

AFR Before the tune

What we found was the bike was in desperate need for a tune. In fact the 'state of tune' on big throttle loads and high RPM was so bad that you could actually feel the bike struggle around the 12,000rpm mark on the dyno run. Not only did the Dyno's data & power readings show this, but an experienced dyno operator will be able to feel and hear when a bike is struggling a little. Thus we knew what the data was telling us was in fact real.

As a RE-TUNE wasn't part of the scope of work so we raised a RE-TUNE as a variation with the customer for approval. Those who are familiar with how we report variations would know that we categories them from 'Critical' through to 'Nice To Have'. Normally Re-Tunes are put into the 'RECOMMENDED FOR PERFORMANCE / LAP TIME / IMPROVED RIDING SAFETY' category, however this one was such that we classed it as 'CRITICAL'

The Before and After graph only tells part of the story. While there is a decent 5.1Hp improvement in the bikes peak power, there is a 10 to 11hp improvement from 11.5K to 12.5K. For an R6, this is massive!!! This RPM range is a key acceleration zone for the R6. As we always say, momentum builds momentum, in this case, the real world benefit will be huge.

AFR before the tune at part throttle

AFR at Mid throttle before the tune

Interestingly the customer was not aware the tune was so bad, he thought it felt great on track. If not for the pit lane limiter issue, we would have never uncovered this untapped horsepower and potential Lap Time gain.

And that's the thing, if you don't know what a really well sorted bike is supposed to feel like, you just don't know. If lap time and performance really matter to you, it is always a great idea to have it checked properly.

How did we know it was the tune and not an underlying mechanical issue with the bike?

There were a few things:

• How consistent the AFR was behaving and the pattern of how it was behaving

• We were able to review the existing map

• Our vast experience with R6s and YEC gave us a lot of confidence as to where the issue was

  
  

Listen to this R6 sing on the dyno