HDLARRY
Active Member
Got my 05 Bulldog back home a couple days ago after doing a number of upgrades. I've only put 200 miles on it this past weekend but was rather impressed with the IST ignition.
I could actually feel the motor vibration smoothing out as I was putting the miles on. They claim that it takes about 500 miles to finish it's auto-mapping but things have smoothed out nicely with just 200 miles. Even at low rpm acceleration, there is no cylinder rattle (pinging) like I used to hear. This has to be better for our motors.
Another benefit is an improvement in MPG. Used to get about 26-28 mpg but after running a full tank through it I'm up to 39 mpg. No jetting has changed in my XXX carb. Maybe it was just taking it easy on the throttle that did this but a friend of mine is running 124" S&S with the IST and getting 46 mpg hiway. I would think that mine will go up a little more as things get broken in.
Can't say much about performance until I get some more miles on it and start accelerating it harder. I can say that it idles very smoothly and starts a little easier when hot.
Will not get it dyno'd for another couple months when we have another 800 miles on it and my LSR 2-1 exhaust shows up.
For those that are not familiar with the S&S IST ignition, it automatically creates a custom timing curve for your motor. This is based on the addition of an Intake Manifold Absolute Pressure (MAP) Sensor, cylinder temperature sensor, knock (ping) sensor and replacement crank sensor. It can change your timing from 26-50 degrees per my tech but will only advance as far as the knock sensor allows. This should give you better performance and mileage. Another nice feature is that if you are stuck someplace where you cannot get premium fuel it will adjust your timing curve to compensate. What it cannot do is adjust your air/fuel ratio. So if your jetting is not right it may try to adjust itself into some kind of a performance reducing mode. Another drawback is the price for parts is around $800. On the other hand I don’t think you will find a better ignition system for a carbureted bike anywhere.
S&S IST ignition - PN 55-1221
S&S 4 1/8" bore SSW+ installation kit - PN 55-1050
S&S Single Fire coil - PN 55-1571 Might be able to use the stock coil but I didn't try it.
I could actually feel the motor vibration smoothing out as I was putting the miles on. They claim that it takes about 500 miles to finish it's auto-mapping but things have smoothed out nicely with just 200 miles. Even at low rpm acceleration, there is no cylinder rattle (pinging) like I used to hear. This has to be better for our motors.
Another benefit is an improvement in MPG. Used to get about 26-28 mpg but after running a full tank through it I'm up to 39 mpg. No jetting has changed in my XXX carb. Maybe it was just taking it easy on the throttle that did this but a friend of mine is running 124" S&S with the IST and getting 46 mpg hiway. I would think that mine will go up a little more as things get broken in.
Can't say much about performance until I get some more miles on it and start accelerating it harder. I can say that it idles very smoothly and starts a little easier when hot.
Will not get it dyno'd for another couple months when we have another 800 miles on it and my LSR 2-1 exhaust shows up.
For those that are not familiar with the S&S IST ignition, it automatically creates a custom timing curve for your motor. This is based on the addition of an Intake Manifold Absolute Pressure (MAP) Sensor, cylinder temperature sensor, knock (ping) sensor and replacement crank sensor. It can change your timing from 26-50 degrees per my tech but will only advance as far as the knock sensor allows. This should give you better performance and mileage. Another nice feature is that if you are stuck someplace where you cannot get premium fuel it will adjust your timing curve to compensate. What it cannot do is adjust your air/fuel ratio. So if your jetting is not right it may try to adjust itself into some kind of a performance reducing mode. Another drawback is the price for parts is around $800. On the other hand I don’t think you will find a better ignition system for a carbureted bike anywhere.
S&S IST ignition - PN 55-1221
S&S 4 1/8" bore SSW+ installation kit - PN 55-1050
S&S Single Fire coil - PN 55-1571 Might be able to use the stock coil but I didn't try it.
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