I decided to start a new thread on this because I'm not sure if the dealership dynoed by bike in the right gear.

I searched the forum on this topic trying to find out which is the correct gear to run a bike during a dyno run. You'd think that the answer would be simple and straight foward but it doesn't seem so. Here's the different answers my search uncovered:

1) Always dyno a 5 speed bike in 4th gear
2) The standard used to be to always dyno a 5 speed bike in 4th gear but the new standard is to dyno in 5th gear
3) Dyno 5 speed and OD 6 speed bikes in 4th gear. Dyno DD 6 speed bikes in 5th gear.
4) Dyno bike in whatever gear yields a 1:1 gear ratio

So, my bike has a Baker OD 6 speed. In what gear should the bike be dynoed - 4th gear or 5th gear?

Thanks.

 

I thought it was to be dyno'd in the 1:1 gear ratio gear.....BUT, I'm not an expert.

 

The "standard" to dyno tune 5 spds in 4th, was a huge pile of BS.
That would be like pulling a Shovel in 3rd!!!!!!!! Ludicrous.
Who, in the Wide World of Sports, came up with that notion??
The way Dynojet trained us over 15 years ago, was to tune 'em in whatever gear did not use the mechanical leverage of the gearbox in either direction. 1:1 ratio.
Once on the dyno, a 43-47 spark count, will show what gear is correct.
Scott

 

The guy who worked on my bike initially gave me dyno results that I'm fairly certain were based on a pull in 5th gear (106 HP, 108 TQ). However, he never actually provided me with the dyno sheets and based on other bad experiences with him, I was skeptical about the results.

Late yesterday afternoon, my engine builder was talking to the technician at the dealership who dynoed my bike (backup baseline) and found out that the pull which yielded the results they provided to me was done in 4th gear (95 HP, 104 TQ).

That's the reason I started this thread. My engine builder and I had a lengthy discussion yesterday and neither of us could understand why you would dyno in 4th gear. We both believed that the bike should have been dynoed in 5th gear where you get the 1:1 ratio. I'm glad that we're not the only ones who believe that is correct.

Thanks for the reply. In the future, I guess I need to be more specific in my instructions to the dyno technician with regards to which gear I want for the final pull.

 

Clark,
You, should not need to "school" the dyno tech.
He should be showing you the way.
Might want to consider a different outfit for your dyno needs.
Scott

 

You're absolutely right. That's also something my engine builder and I discussed at length. I need to find a tuner with a lot of experience. In my immediate area that's a little difficult. That's why I'm leaning toward taking the bike back to Kendall Johnson Customs. I had a great experience with them when they fixed my tranny problems. And, they dyno about 5-6 bikes a day. So they have plenty of experience. In fact, I've already talked to the shop manager there and he was all over the dip in my torque curve. KJC is about and hour and fifteen minutes from me (all interstate) so it's not to bad to get to them.

Even though he's further away, I really wanted to try Clark Hemrick. It's my understanding that he's an incredible tuner. He comes highly recommended in this area. However, due to very serious health issues (battling cancer), he isn't able to take on any work right now.

I think the biggest problem now days is finding a tuner that has a lot of experience with carbureted bikes. With all of the new bikes being fuel injected, that's where most of the tuners experience lies. Carbureted bikes are more and more becoming a thing of the past and I fear that tuning them will soon become a lost art.

 

Give Kevin a shout over at www.protwin.com he may be a little out of the way but will get it right.

 

Mr. Kevin Baxter, in Lawerenceville, GA.
Him and I, were on the phone this past week.
Very nice guy.
Scott

 

Some interesting info and data about Dyno's and gearing: http://www.bishopsperformance.com/dynoinfo.htm

 

As I posted on Fletch's other thread, I have a hard time accepting that a 5th gear pull will yield higher numbers than a 4th gear pull.
I called my local dyno tuner today, and made an appointment to test and tune my 96" Evo next week.
To expand a little on what I posted, my local guy explained that he normally tests in 4th gear because it's easier on the engine (less time at WOT), and for safety reasons, i.e.wheel speed, and he is generally testing for tuning purposes, to monitor A/F ratio, rather than max output.
He has never done a 4th to 5th gear comparison, but agreed to do one for me.

Edited for spelling and to add that I am talking about a 5 speed where 5th is 1-1.