Do It Yourself cheap 'Dyno' tune

[Wrightturn]

Hey Vonkas,

Where are you located ? Can you still get real gas ? In Orlando it is all 90/10.
What cam did you use ? What pistons ? Head gasket ?

I have found the stock ignition to work fine until you raise compression. Pipes, breather and rejet still provide stock reliability. I have used the Crane Ignition with higher compression. I have no use for the Screaming Eagle ignitions.

I have a 99Dyna with a SE breather, AR100 pipes and a 26g cam with the stock ignition. Now has 42k trouble free miles.

[frisco-rigid]

Von---
The 85/15 will have less HP and mileage because of less BTU energy in the Alc..
Todays gas has about 120,000 BTU's, alc has, if I remember correct about 78,000 BTU's.. A mix of 85/15 is about 113,000 BTU's..

Timing and jetting for Low-Octane gas will never give as much power or mileage in a motor made for higher octane.. Also----
I dis-agree with tuning with Low-Octane gas for exactly the reason you mentioned, Timing..
Timing should always be final before Jetting and timing for Low-Octane will be diff than timing for High-Octane.. If forced to use Low-Octane gas the rider will just have to compensate until the gas of choice is available..
However---
This is an experiment we all may be forced to do in the near future if the Commies that will take over in a month have their way..
They want us on Bicycles..

Interesting that you say the stock HD ign is useless..
I must dis-agree again..
Obviously you think it is useless from your experience..
There are many of us with contrary experience,, for instance I use the most stock HD ign of all,,,, points,,, in my 120" with 10.5-1 and I get every ounce of power that I got using a Compu-fire, HI-4, Dyna-S and a couple others.. I prefer points..
I must also dis-agree that any mods to an HD require an ignition change.. Utterly Preposteous..
Perhaps that's based on Your Strong Opinion but please refrain from making such broad statements cuz it's simply mis-leading..
There are many folk that just simply don't know enough to realize they're being mis-lead or exposed to One Mans opinion..
If I may, with all due respect,, let your Opinion be known, based on your experience of course, then let the reader make up their own mind..
The way you state things in such a definitive manner, I get the feelling you think that we know next to nothing, careful now..!!

I set up the edelbrock 4bbl on the 390 in just the same way you describe..
Lean, about 15-1 for cruising and fatter with any load..
Jetting that way is not as easy with carbs like the Holley (autos) or butterfly Keihin, Bendix or any S&S,, but easier with some carbs like the edelbrock (autos) and the Mik.. Miks are my fav, I guess you like them too..

I have done many 1/4 and 1/2 throttle and also gentle and firm acceleration dyno runs to confirm that my jetting is correct but the HP and TQ readings are usually very low and unreliable because those are un-loaded RPM's..