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I was looking at an SLP hp dyno graph between stock and their pipe and found a couple things that were interesting. First off the motor pulls extremely hard between 7000 and 7600 rpm and then the power gain fades off and slowly rises up to 8200. Is this the reason for the hard hitting mid range and lack luster top end? That we can't fix, but my second observation we can. I noticed that after 7200 rpm the power drops like a rock. It looks like by 7400 rpm the hp is down to the low 130's to 130 hp. Betwween 7800 and 8000 rpm it only loses 5 at the most. IMO, shooting for a peak rpm of 8000( 8100 at the most) is where we should be to ensure not going over 8200. Just my $.02!
 

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When I bought my XCR 800 I also bought a HTG 180 kit. I also asked them to send a dyno sheet, which they did. Funny thing was the rpm where it made the most hp was lower than where it ran best. The motor made good hp at 8600 rpm, yet the dyno sheet indicated significantly less. (Can't remember how much less tho).
 

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The difficulty with a dyno chart/run is that it is really only a simulation. That's why field testing still rules.

The dyno gives you very valuable information, but it can vary considerably depending on how the run is conducted. For example, what's the intake air temp and pipe temp? the latter will impact what RPM the HP peak occurs at. The longer the dyno run takes and the slower the operator moves up the rpm the hotter the pipe would get and the higher the rpm that the peak hp would occur at.

So again, field testing of what you are actually trying to accomplish is the way to go (1/8 mile? 1/4 mile? flying mile top speed run?)
 
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