performance ignitions and the results

[ridemyEVO]

Hopefully this is in the right place.
Ok I've got to ask about programable and preset non stock ignition systems. I've been reading quite a bit on these ignitions and not so much of how or if one system is better than another but I think more about what you can actually achieve installing one of these ignitions in the average Joe's bike that has a descent motor and for now I will ask more of the ignitions that have been installed in the EVO bikes, particularly the FLH models. My buddy has an 87 FXR and I've tried his bike, it has the S&S ignition and hq-24 cam and other than that its stock motor with 30,000 miles. I found it takes off like a jack rabbit after it gets past the semi dead spot of the throttle. Now question is if these are from what I've pulled from info more REV limit adjuster systems how would they work for an average Joe like me for an 89 FLH if I ride the bike like a dresser and not like my 02 Dyna basicly not pushing the rev's high? Like is there an advantage that you've found if you've installed one of these ignitions on an EVO ( note EVO and not TC ) bike ? Haveyou's found this ignition adds to torque at all?
On my dresser I go through the gears not really even shifting higher than 3-4000 rpm because motor sounds like its screaming at me, other than that I may drop agear on the hiway to pass, that is if I'm going slow enough not to have the motor screaming.
thanks

[gryphon]

To be perfectly honest, for the type of riding you do and with your motor, it's not likely you would notice any difference at all. One of the biggest advantages to an aftermarket ignition is the ability to adjust it to suit your particular build.  If you were going to replace your's you would be best off to choose based on reliablity rather than features.

[fxr4mikey]

To be perfectly honest, for the type of riding you do and with your motor, it's not likely you would notice any difference at all. One of the biggest advantages to an aftermarket ignition is the ability to adjust it to suit your particular build.  If you were going to replace your's you would be best off to choose based on reliablity rather than features.

I'd have to agree with gryphon on this .... if you're not looking to do any other mods to your bike, and to adjust the timing to 'advance' the ignition for quicker response and the likes ..... and based on your driving style, as you've described it ...... I don't think it's worth your money to swap out your ignition system.

I have the Compu-Fire system in my FXR4 = 1340 EVO

I have it running in single fire mode.  I find the bike starts easier than it did in stock format .... one reason is the Compu-Fire ignition module delays the spark until the engine has turned over twice ... this helps to eliminate engine kickback against the starter.

it also 'seems' to me, that the engine runs smoother ... of course this could be in my head

I have the advance set to next to the earliest advance curves in the list ... which means that the timing is advance sooner in the rpm band

this module also advances the timing more than the stock module.  If I remember it correctly, the stock module max advance is 30 or 32 degrees, and begins to retard again at about 4200 or 4300 rpms.  The Compu-Fire module will advance the timing to 35 degrees max, and will hold that advance curve until you hit the rev limit, which I currently run my at 6K rpms.



again, all that is done in an effort to help with quickness .......

Other than a dyno, I don't know how a person could quantify any additional torque as a result of the ignition system

the higher you rev your bike, the sooner you need (think advance) to send the spark signal to the coil to fire the plugs
the higher you rev your bike, and the longer you stay in the higher rpm range, you want your spark advance to remain present, you don't want the module to start retarding the advance, say at 4200 rpm, when you have a cam that will make power (torque) out to 5300 rpms

you don't want to much advance, you don't want to send the spark to the plugs at a point in time that the resulting burning of the combustion mixture fights against the rising piston ......... this would result in a large loss of power, also resulting in pinging .....


I'm no expert in this area .....

[hrdtail78]

I think a single fire ignition will always outperform the stock dual fire.  This might only be seen at easier starting, and smoother idle.  You can see a rise in low end tq with a more advance timing down low.  With whole systems for under $300 I talk customers out of carbs and into new ignitions.

[Phu Cat]

I think a single fire ignition will always outperform the stock dual fire.

In what way Hrdtail?  Once the fire is lit on the compression stroke, the spark plug plays NO further role.  Allowing the other plug to fire on the exhaust stroke accomplishes zero.  It may have been an idea that came from the EPA way back, or it may have been a way for the manufacturer to save having to provide an additional coil, but what's reallyaccomplished by firing a plug on the exhaust stroke with the exhaust valve open?  It's sure not going to make any more power.

PC

[hrdtail78]

The wasted spark is just that wasted.  Back cylinder fires and crank rotates 405 degrees untill front cylinder fires, then another 315 degrees and back fires again.  With single fire both coils get an even 720.  In what way is this an advantage?  Smoother idle and easier starting.  Get into rear offset timing, and some other features single fire units have, and they are better than stock dual fire systems.  I also like the different curve you can pick from besides the stock lazy one.

I get customers coming in with basicly stock engines, stage ones and maybe a cam, wanting a new carb for more power.  I set them up with a decent single fire system, and they find what they were looking for.