[Art_NJr]

Originally Posted by AFNurse

Not sure if this plays into the equation or not.....when I owned metric, one thing that I noticed was that I could reach top speed faster if, when shifting grears, I got the RPMs UP, but when actually shifting, the shorter the arch in the tack the better for continued speed..... going from 11,500 RPM (my redline at the time) would then drop RPM to 6K or so......almost sluggish acceleration from there..... but shifting at 9K would only drop to 7k or something.....resulting in a much more snappy response.....is this what you are talking about???

Yes. We typically use the simple formula HP = (Torque x rpm) / 5252 since it applies to most American-made engines, but you can also measure torque & power in Newton-meters, kilograms-force, joules, Watts, etc. with other formulas. Those apply to engines that run @ much higher rpms & where peak torque can be MUCH higher than 5252 rpm. But the same basic rule still applies - keep the engine in it's peak torque range as you go up thru the gears & you'll accellerate quicker.

If you watch racing on TV such as the Pro road-race bikes, Formula I cars, etc., you can sometimes see it when there's been a camera mounted to show the instruments during a race or if the telemetry is shown - coming off a slow corner, the driver will not hit the engine's redline as he accelerates & will only "wind out" the engine in top gear on a long straight. They shift so fast the bike (or car) sounds like it has an automatic transmission, but watch the rpm range they stay in while accelerating - that's the peak torque range for that particular engine.

Simple rule - he who comes off the corner the best wins & torque is what gets you going, not top-end HP. Same thing applies in drag racing, where how quick you get to the finish line is far more important than how fast you're going when you get there. Same thing also applies in Land-Speed-Record runs, where your top speed is the only thing that matters - but you only have a certain distance to get to top speed, so you better get going as quick as you can.

[voodoo1]

some fellas on HDs tend to go right on past the "Torque zone" and are on the chip long before they need be. Love it when some fellas do that and I go right on past em,they tend to go right past it and I am still pulling leaving third alot of times,by the time I get to 4th start going past/around them they wonder what happened. plain ol' out-torqued them. We know alot about torque and HP from our Automotive Machine shop and drag racing/tractor motors and baja engines,school bus' dump trucks,you name it,etc. Just use it to my benefit on the bike, never read anything about where I am supposed to shift in a book. I look at the HP and Torque curves and ride by ear and feel. We change our shift point by 200rpms 7400 intstead 7600 in our small block chevy duece and picked up time even quicker.,we stayed in the "range" longer to get all the pull before shifting instead of going by it.. just last year while dialing it in.

Later
Voo1

[fxdxriderleo]

I, as most everyone else, shifts as the engine tells me too. I try to keep the rpm's up above 2200. Any lower and the engine lugs, not good.

[HellBoy]

Good to see you posting again Art, I knew it was you before reading your byline!
OK, so my Dyna doesn't seem to have as much pull as it did before all sorts of sh*t went wrong. Had exhaust and baffles removed twice, new lifters, one new head. Clutch adjusted 3X. The HD mechanic said it needs some break in time. Is this true? Grip has been getting a little better, but I still don't get as smooth a first gear as I did before. Slight deadspots that only I might notice, having ridden before all the work. I'm currently trying Shell gas for two tanks, just in case their cleaning the engine gunk commercials is true. Forgot to mention the change from dino to synthetic and back to dino in my engine.

So, do I understand correctly, for faster 0-60, stay in gear a little longer, but not quite to the top? (no tach on my 07 Dyna)

[Art_NJr]

Originally Posted by HellBoy

Good to see you posting again Art, I knew it was you before reading your byline!
OK, so my Dyna doesn't seem to have as much pull as it did before all sorts of sh*t went wrong. Had exhaust and baffles removed twice, new lifters, one new head. Clutch adjusted 3X. The HD mechanic said it needs some break in time. Is this true?

To a certain extent, yes. New parts will take a little while to "take a set" & while it varies quite a bit from one change to another, even the best-fitted parts don't necessarily work together right away.

Grip has been getting a little better, but I still don't get as smooth a first gear as I did before. Slight deadspots that only I might notice, having ridden before all the work. I'm currently trying Shell gas for two tanks, just in case their cleaning the engine gunk commercials is true. Forgot to mention the change from dino to synthetic and back to dino in my engine.

I've switched back & forth from conventional to synthetic & have had no problems - BUT - I always use the same SAE grade & no multi-grade - SAE 50 Valvoline Racing Oil (conventional) to SAE 50 Red Line (synthetic) or vice-versa (60 weight too - weather depending). I will ONLY use Red Line in the race engine, but it's so expensive that changing more often with conventional on the street bikes actually costs less.

So, do I understand correctly, for faster 0-60, stay in gear a little longer, but not quite to the top? (no tach on my 07 Dyna)

Nope - got it backwards. You should get a tach, but "winding out" in each gear actually slows you down. You certainly don't want to "lug" the engine by staying down in the very low rpm range all the time & the Dyna has a lower torque range than the Sportster you had before, but it's still a "mid-range" engine.

Check out this great "Speed Calc" program:
SpeedCalc

Click on "Setup" then choose the bike - by playing with the program a little bit you can see what the engine rpm is in any gear @ any speed. I would think your Dyna pulls best in the 3000-4500 rpm range - but I'm a Sportster guy - what do I know ?

[HellBoy]

Thanks Art, that very interesting. I get it now. I usually go past those speeds when shifting, but when I'm in the mood for a slightly quieter, more comfortable ride, I shift near those speeds. I'll try that next chance I get.

*My first gear "mini dead spots" are most noticeable when trying to take off very smoothly at slow or medium speeds. I'm guessing it's something to do with the clutch, but the engine does seem to rumble a bit more if memory serves, so I'm not sure.

[Art_NJr]

Originally Posted by HellBoy

*My first gear "mini dead spots" are most noticeable when trying to take off very smoothly at slow or medium speeds. I'm guessing it's something to do with the clutch, but the engine does seem to rumble a bit more if memory serves, so I'm not sure.

I'd be looking @ carb (or EFI) issues, as if you had a clutch problem, it'd show up in all gears.

[HellBoy]

I would have thought EFI also Art, but having ridden before the work was done, I know the map on my V&H Fuel Pack works nicely, I checked the settings and they are the same. Something on the bike's changed a little. Can the throttle adjustment affect first gear's smoothness?

Still haven't had much chance to try the suggestions here, I'd love to know the quickest possible places to shift for maximum take off, uhhh you know... just in case

[Art_NJr]

Originally Posted by HellBoy

I would have thought EFI also Art, but having ridden before the work was done, I know the map on my V&H Fuel Pack works nicely, I checked the settings and they are the same. Something on the bike's changed a little. Can the throttle adjustment affect first gear's smoothness?

Still haven't had much chance to try the suggestions here, I'd love to know the quickest possible places to shift for maximum take off, uhhh you know... just in case

I don't know enough about H-D's EFI setup to be of any help - but I do know that if you've got a clutch problem, it'll show up in every gear, not just sometimes in 1st gear. Sounds to me like you have the EFI version of the "carb farts".

[HellBoy]

Could removing the exhaust twice cause issues like this? When I asked HD to put back my original baffles in my V&H Big Shots, one of the original baffles had been damaged in the process, so they gave me a new one. So, now I have one baffle with 4,000 miles of use more than the other. Still, I don't think it should make a difference.
This thread reminded me that I want my grip back, not mini EFI "farts"!

[Art_NJr]

Originally Posted by HellBoy

Could removing the exhaust twice cause issues like this?

Yes. The exhaust gaskets you can often re-use, but they "crush" when you tighten the pipes to the heads & the SE gaskets are far better than the stock ones. If the same gaskets were used, there is a very good possiblity you've got an exhaust leak & especially with an EFI engine, that will mess the tuning up.

[HellBoy]

hmmm, that's interesting Art, thanks. Any easy test for an exhaust leak?

[chucktx]

soapy water,,,,mix it up in a spray bottle..........

[cardboard]

Didn't read all the post, but if you don't have a ear for it. You need a tach. Always keep the rpms over 2000 when shifting gears so you don't lug the motor. Bike will also ride smoother.