Ignition advancers - which one...2 or 4 degrees?......

[knight]

Aparrently there are 2 types of ignition advancers for the bird - 2 degrees and 4 degrees.....which one is most commonly used and what will it give me interms of performance and power?....how different does the bike feel to ride when a certain type is fitter (2 or 4 deg?)......

:sad:

my base mods are on a 98 carbed motor, a new full stainless exhaust system with single silencer, dynojet kit and K&N filter, ram air ducts installed - aparrently worth 3bhp when at speed! - on the dyno currently gives 144Bhp at the rear wheel.

[Mikey]

Remember the more you change, the harder it will be to start and idle rough. May help out while moving, but it's a fine balance.

[CALCXX]

I've thought about getting the 2 degree advancer for my XX.

I put a 4 degree advancer on my previous bike (ZX-10) after

the pipe and jet-kit. I never had the Kawasaki on a dyno but,

it really helped in the mid-range.

Had to use Premium fuel only. It didn't like regular.

Anyone got one on their XX?

my .02 cents,

Cal

[SwampNut]

I'd guess the horsepower change would be slight between them. You'd probably gain 0.2 HP with the 4 degree and 0.1 with the 2 degree. :roll:

[CALCXX]

I'd guess the horsepower change would be slight between them.  You'd probably gain 0.2 HP with the 4 degree and 0.1 with the 2 degree.   :roll:

LOL, Carlos, by the "seat of the pants" I'm sure the advancer on

my Kawasaki made at least 40 horsepower differance.

10 horsepower for every degree of advance! yuk-yuk

[pace]

The one I saw was adjustable across a range of ignition advance. I'll try to find the link..

-Pace

[Edit] Adjustable ignition rotor for carb'd 'bird here: http://www.factorypro.com/Prod_Pages/prodh75.html

[SwampNut]

My sarcasm was due to being tired of debunking the ignition advancer bullshit. It doesn't do shit. If you're lucky, you'll just not blow up the motor or lose some HP. The XX already sets timing automatically to get as much as possible out of the motor. An ignition advancer does nothing on a modern bike without other mods.

[knight]

thanks swampnut......thats the answer I was looking for!.....I think your right with regard to being lucky not to blow the motor, as advancing the ignition more than the factory unit sounds risky to me.....there are bigger fish to fry me thinks :grin:

[pace]

When tuning cars, we can see significant gains in horsepower from modest advances in ignition timing. Essentially you are trying to achieve an ignition curve that nets you as close to mean best torque (MBT) as possible. Often you are limited by octane and you will not get anywhere close to MBT timing without detonating and many factors impact the tendency of a particular motor to detonate. Bear in mind that even motors with ECMs that implement adaptive ignition timing, do have a limited range of authority to advance or retard timing.

That said, I don't know much about the Blackbird's dynamic timing algorithm or methodology, so I really can't comment on the usefulness of an advanced ignition rotor. My bird runs fine on 85 octane, which tells me that both the fueling and particularly the timing are in a conservative state of tune. If I was willing to move to 91 octane, I could probably significantly advance timing and realize tangible gains in horsepower. This is pretty much as you would expect for a machine that is designed to run safely under a wide range of conditions, loads, and fuels.

Personally I'm considering spraying nitrous on the bike next year, and in that case I may actually want to retard timing a few degrees.

-Pace

[BIG BOY]

I think sometimes when you install ignition advancers, you loose power???

[pace]

In theory that is possible, but for example I know that with forced induction motors your fuel octane is generally the limiting factor that prevents you from attaining MBT timing, let alone passing that point. This is also true of high compression motors, and motorcycles engines would probably fall into that category. It's true that normally aspirated motors can get good results with flatter timing 'curves', but my guess is that our crappy US gasoline will still be the constraining factor.

Essentially what you are trying to achieve when adjusting timing, is to attain peak cylinder pressures at some point ATDC that maximizes net work. ie. MBT. Too much advance, and the motor is fighting rising cylinder pressures on the last 90 degrees of the downward piston stroke (because the piston will be decelerating at that part of the stroke). A general rule of thumb is that timing retardation from MBT results in a significant loss of torque, whereas advancing past MBT results in torque falling off more slowly.

Hence I think the biggest problem with over-advancing your timing is going to be the practical limits of your gasoline, evident as detonation. That can certainly rob you of power, as well as your piston crowns.

-Pace