06-05-12, 04:30 PM
Hi Ian
Yup, I'm here ... they can't get rid of me.
Typical stock power is 121 - 123bhp at the rear wheel. A typical post-Full Monty reading is around 135 - 137bhp. However, as T-mation pointed out, there can be significant variations in dyno results depending on many factors; environmental, operator-related and condition of the bike. A tight, worn or poorly-lubed chain can rob 4-5bhp alone.
You still have my e-mail address, I hope. If so, please send me a copy of the dyno chart. I'd like to see it because the advice to go up 3 - 5 sizes on the main jets is hopelessly wrong. Seriously, I will put my hat and overcoat on that statement. If the mains were undersized by that degree you'd be getting nowhere near 130bhp and you'd have very obvious lean running indications.
Just so as you know, stock mains are a size larger than Ivan's mains. Ivan uses the smaller main jets because his needle profile is more tapered towards the tip, allowing more fuel past the needle at 3/4 to full throttle. The stock main jet/needle combination actually runs rich at full throttle, so increasing main jets by 3 - 5 sizes with Ivan's needles simply will not work.
Based on the advice to supersize the mains alone, I suspect that the dyno results are skewed for one reason or another. If I can have sight of the dyno chart it will help me diagnose why.
On the silencer question, I understand Simmi are a small local concern in the NE who enjoy a good reputation. If you're running one of their cans with a dB killer insert that could account for the lower than expected peak power output. When all is said and done, though, a less restrictive can is exactly that ... it doesn't make a great deal of difference whether it's a top-spec Akrapovic or a well-made budget item. At most, I'd expect a difference of 2 - 3 bhp at most between best and worst of breed.
One final question. Was the dyno run a 'dyno day special' ... ie, the sort of offer dealers/tuners do without appointment? Essentially, a quick strap down and single run for whoever fancies it on the day?
Please get in touch direct and I'll do what I can to interpret the results you have and we can talk it through between us.
Mike
Yup, I'm here ... they can't get rid of me.
Typical stock power is 121 - 123bhp at the rear wheel. A typical post-Full Monty reading is around 135 - 137bhp. However, as T-mation pointed out, there can be significant variations in dyno results depending on many factors; environmental, operator-related and condition of the bike. A tight, worn or poorly-lubed chain can rob 4-5bhp alone.
You still have my e-mail address, I hope. If so, please send me a copy of the dyno chart. I'd like to see it because the advice to go up 3 - 5 sizes on the main jets is hopelessly wrong. Seriously, I will put my hat and overcoat on that statement. If the mains were undersized by that degree you'd be getting nowhere near 130bhp and you'd have very obvious lean running indications.
Just so as you know, stock mains are a size larger than Ivan's mains. Ivan uses the smaller main jets because his needle profile is more tapered towards the tip, allowing more fuel past the needle at 3/4 to full throttle. The stock main jet/needle combination actually runs rich at full throttle, so increasing main jets by 3 - 5 sizes with Ivan's needles simply will not work.
Based on the advice to supersize the mains alone, I suspect that the dyno results are skewed for one reason or another. If I can have sight of the dyno chart it will help me diagnose why.
On the silencer question, I understand Simmi are a small local concern in the NE who enjoy a good reputation. If you're running one of their cans with a dB killer insert that could account for the lower than expected peak power output. When all is said and done, though, a less restrictive can is exactly that ... it doesn't make a great deal of difference whether it's a top-spec Akrapovic or a well-made budget item. At most, I'd expect a difference of 2 - 3 bhp at most between best and worst of breed.
One final question. Was the dyno run a 'dyno day special' ... ie, the sort of offer dealers/tuners do without appointment? Essentially, a quick strap down and single run for whoever fancies it on the day?
Please get in touch direct and I'll do what I can to interpret the results you have and we can talk it through between us.
Mike