No offense, but there's quite a difference between starting your pull above 2100 rpm with the curve climbing immediately, and starting it at 1800 rpm and the curve not climbing until after 3000 rpm.

The idea that you should compare numbers and not pictures is simply wrong. The reason you're showing a chart is to show how it performs across the rev range. Numbers are very dependent on conditions and test equipment. Higher barometric pressure, lower air temperature, lower humidity will yield better numbers. STD rather than SAE correction will yield better numbers (at higher barometric pressure). A dyno can be calibrated to produce better numbers. The curve, however, shows how well the engine performs in low and high rpm. This bike performs poorly in the rpms where you ride, and only picks up in the high rpms. That's not down to the tune, but to the lack of back pressure from the exhaust. I haven't looked the Supertrapp up, but my guess it's a shorty, or it has a stepped or conical muffler.

If you tune a bike and that's the result, you should be advising the customer how he can improve the low end performance. If that chart is from a Softail with exhausts that don't go past the rear axle, this would be the expected curve, but a touring bike should produce better low end numbers with the right exhaust.

 

*scratches head

 

So your saying a bike that's making 130 + ft lbs of torque as the minimum from 1700 - 6000 RPM, is 160+ from 3750 - 4500 RPM with a peak of 163 ft lbs is a poor running bike? Yes, how you run the dyno changes how things look to a person that does not understand how they work. The picture doesn't tell the whole story and that is just why I said you need to not worry about the picture, yet look at the numbers at give points to compare. If you understood that starting the pull at the higher rpm would not show the dip but it would show it being flat and then climbing the entire time doesn't change a thing with how the bike performs. As for me telling a dealer of ours, to tell his customer, the exhaust is no good and therefor we should not tune it, doesn't make any sense at all either, nor is it my job to do. Could it have been better, possibly, but to try and discredit it and say it has a horrendous dip and is a clear example of putting the wrong pipes on the bike is just flat out wrong. There could be a million reasons why it has a 10 ft lb dip and it's there and I'm not going to deny it in any way.

Why is it, the 6+ ft lb dip in the dyno chart posted just prior to my posted chart didn't get you all up in arms? It must need a different pipe as well by your logic!

 

It's not a 10 ft-lb dip. It's a 20-30 ft-lb dip over a range of 2000 to 3000 rpm. That's not a little dip in the curve like the 6 ft-lb over a range of 4100 to 4400 rpm, that's a huge drop in performance over the majority of the range where you ride the most.

I'm not saying not to tune it. Obviously you tune it. But you go over the results with your customer (or in this case the dealer should, I didn't know you were tuning for a dealer when I made my comment), explain why the torque curve is so much lower over that rev range, what that rev range represents, and what options the customer has to improve it.

If the customer's happy with the results, awesome. If he wants to improve it, now he knows how. Just saying "it is what it is", and leave it at that, is a disservice to the customer. He put a lot of money in building a high performance bike, and the cost of improving the low end performance is likely relatively low in comparison. A couple of hundred bucks investment can see major gains in that range.

 

Clearly your are looking at something different than what has been posted! The pull starts with ~138 Ft Lbs. and dips down to ~130 and then climbs up to 163. Just lay a straight edge over the chart and you will see it plain as day.. Now, since I have the raw numbers to go along with the chart, it truly starts at 138.2 and dips to 129.8 so my statement of 10 ft lbs is completely accurate!

So where are you come up with 20 -30 ft lbs is a complete mystery ? This is a prime example of not know anything about a dyno and looking at the picture only, which is just why I've said you have to compare the numbers at any given test point!

 

 

I think there are a few things being overlooked. Being that the dealer was having it tuned, there is the actual setup of the pipe for one. Did the dealer ask to have the pipe tuned as well. Doc tuned my 12 RGU, with a Supertrapp, it took a few hours of time to get the pipe where he wanted it after the initial tune, did the dealer want the extra charges or tune it as it sits. End caps, # of disks all play a roll as we all know. The cam maybe part of the equation with it’s low end performance, and of course looking at where the runs start at is rarely seen on most dyno runs. To me the closeness of all 3 runs says the tune is spot on for what was asked. Just my opinion…..

 

Looks like it’s making more tq at 1700rpms than at 3k, maybe it’s a higher rpm type of build, some people prefer that.

 

Bottom line is "it is what it is", and there is no reason to make-up false claims of things that clearly are not there, then go on to say a better pipe is what it needs. I did not post the chart to start a pissing match but it appears that is what someone wants to turn it into. If you have ever ridden a bike that has 130+ ft lbs from the time you let the clutch out to 6000 RPM, it is a handful. Could a better air clean have helped, how about running at different engine temperatures, how about better fuel, how about different amount of plates in the Supertrap muffler and yes maybe a different pipe. What I know is the dealer had the customer test ride it when they came to pick it up and it scared the $hit out of them, from what I was told. Said they had never had a bike that you could just give it throttle with the clutch already out and have it pick the front tire up into the air on a bagger to the point of having to let out of the throttle. They were more than happy, my dealer was happy so that makes me happy.

 

For what it's worth, all SE parts...

2017 FLHXS: Stage II (power cam), pro street tuner, air cleaner, tappets and Street Cannon slip ons.