TIMING....... IS EVERYTHING !

[dynaglide]

Winston,
I'm interested in some more detail on your build.  Is it at 9.5:1 CR, or have the heads been decked to bring CR up?  If so, how much?
Do you have the cam specs?  I'm interrested in the cam timing/lift that's making 100/100 from 95" at 9.5:1 (if that's what it is) compression.  Not skeptical; curious.

[Winston Wolf]

Dynaglide,

The cam is a custom Cyclerama 575 cam grind, specs are

Cycle Rama 575 cams

Intake Open 15 Close 35 .575 lift 230 duration 100LC 22 degree overlap 105.5 LSA
Ex. Open 49 Close 7 .560 lift 236 duration 111LC

I do not believe the heads are decked, but you could call them and see if they deck them for the package.  They did a nice port job on the heads and intake, and I am using their 95" flat top pistons also. The rest is pretty simple. HSR42 carb and open air cleaner, Rinehart staggered duals, Daytona ignition with custom curve, S&S gears with S&S adj pushrods.  I can't remember the head gasket thickness, but I used the ones they supplied in the 100/100 kit. (I think they were Comtek?)

If you send me your email address I can shoot you my timing curve.  I did have to dial it back quite a bit to get rid of all the detonation.  I credit that to my having an overdrive trans though.  I wanted to be able to twist on it in 6th from lower rpms and not worry. With a 5 speed you could probably add a few degrees to the midrange. I didn't, however take anything out of the WOT, so it retains the HP. I am really happy with everything so far.  This trip to Sturgis I got 45-53 mpg, depending on how fast I drove that tank. (between 60-85)

The Wolf.

[Winston Wolf]

I don't know how to post the map. I don't have an FTP. I would gladly email it to you if you would post it up for me. PM me your email.
[/quote]

Please post the map
[/quote]

[Winston Wolf]

In the TTS manual it gives a procedure for tuning your advance curve by adding two degrees to the cells in the timing maps, doing runs, watching for knock detection, removing timing from the cells where knock is detected, and repeating the process until all the cells in the timing maps are three or four degrees below the knock threshold.

Anyone have any real success doing this?

I did this with my DTT, took me 6 maps to get it right.  I did not go down 3-4 degrees below detonation though, maybe 2 deg.  It works.  I would wear earplugs and put my left hand in front of my ear so I didnt' get any wind noise, then test at various throttle positions and rpms.  I could hear the detonation with my plugs in as clear as day.

[wurk_truk]

In the TTS manual it gives a procedure for tuning your advance curve by adding two degrees to the cells in the timing maps, doing runs, watching for knock detection, removing timing from the cells where knock is detected, and repeating the process until all the cells in the timing maps are three or four degrees below the knock threshold.

Anyone have any real success doing this?

Yes, but only went down 1/2 point or one point below knock detection.  It is very time consuming, but bike doesn't ping.  The time taken was worth every minute as far as 'rideability'.  I did not ADD timing in most areas, just removed 'ping' points.  But actually the best way may be to pinpoint problem areas, add a small amount of fuel and see what THAT does first, THEN mess with timing if VEs get too far whacked out of shape from what the TTS or TS seems appropriate.  Every timing change has the ability to screw with the VE,s... so new VE runs are needed to correct fuel for timing changes......  back and forth.

Here's my thought, though, just altering a timing map for 'maximum timing' that the engine can withstand... doesn't really cut it.  One may move beyond where power is made.

Timing is tough... a dyno SHOWS power gains with timing changes.

I have a low power build (105hp/118tq) that is very forgiving build (grooved heads, 10:1, andrews 54s), and feel the TTS way is pretty good.  But for bigger power, or more finicky builds, a dyno would be needed.

This is all IMHO...

[Sonny S.]

>>>Here's my thought, though, just altering a timing map for 'maximum timing' that the engine can withstand... doesn't really cut it.  One may move beyond where power is made.<<<

     ... completely

thanks for the update wurk_truk !   
it would be interesring to see how much advance you are running 

[Don D]

Timing is tough... a dyno SHOWS power gains with timing changes
Yep at 90-100 MAP

Might find on the dyno that when the high map areas are fixed and timing is massaged the grooved head builds like a leaner AFR set in the 14 range and less timing for maximum power. They will make more power and torque midrange below the ping threshold and using closed loop AFRs

[wurk_truk]

I have to get the bike on a dyno this winter.

I had it dynoed in the past, but that didn't work out all that well in the timing dept.

v-tuning is great, as far as it goes, but timing is key (as Don says I have groovy heads), and I need a GOOD tuner to look for power on the dyno and get the timing right.  I have just guessed at timing right now with the 'max it and back off a couple' kinda thing.  This isn't the way to do it AFAIK.  IMHO.

I plan on having Jim--Strokerjlk-- do the dyno thing, eventually.

When I do this....  I will surely post the timing maps then.

[Don D]

Good tuner! he will get er done

[Heatwave3]

Here's the timing tables on my 2010 110" with Hillside Heads (10.3:1), SE 58mmTB, SE 5.3 injectors, roller rockers, Woods 408-6 cams, stock pistons/cyl, D&D Fatcat, Ventilator A/C, SEPST. Latest Dyno shows 111hp/115Tq. 93 octane fuel at sea level. Thoughts on the timing are appreciated.

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[jluvs2ride]

2008 Fat Bob, Mostly stock, J.E.T. AirStack, D&D Fat Cat. I run premium no ethanol.


[attachment removed after 60 days by system]

[djl]

Here's some explanation of why higher timing numbers (in the right areas) help.  This is a carburated module example, but the same timing suggestions apply to injection.
More timing at idle (up to reasonable levels) will smooth out the idle and let the engine run cooler idling.  Very helpful when you're stuck in traffic.  That's one spot the available maps using the module dip switches fall short.  When you use the switches to come up with a map that doesn't ping and gives good wide open power, it is lazy and retarded at the low end.  That's where a custom map can help.  If you hook up a scanalyzer and look at the timing a big twin idles at with stock ignition, it's around 26-30 degrees (earlier Twin Cams, anyway).  No reason you can't do that with adjustable modules too.  It's not going to ping when it's idling.

I've seen late model injected bikes idling at 12 degrees on a canned tuner map.  What are these programmers thinking?  Must be for emission reasons.  Less timing = less emissions.  These motors are way happier idling at timing numbers in the 20s.

The other area that benefits from higher timing is when coasting down from higher rpm (where some motors will pop & backfire).  More timing there will usually lessen the popping in the exhaust.  Again, you're not going to ping when you're decelerating.  Carbed or injected both benefit.

When a tuner says "timing is maxed at 26 degrees wide open" he means that at the lowest manifold vacuum (when the throttle is wide open)  (see the bottom of the attached graph), the timing goes no higher than 26 degrees.

The "roll-on" throttle area is where most pinging issues occur.  It's sometimes helpful to drop the timing there to stop pinging when you roll into it (say around 60 mph in 5th gear to pass someone).

Ken,
Would you mind posting the ignition table for that graph?  Still learningand it would help me to see both.  Particularly interested in the coast timing and what timing issue might cause a "burp" at level cruise, say 70-80mph.  More likely jetting but curious if timing could contribute.

[Ken R]

Upper right = looks like a well developed ignition map.
Upper right = looks like a large, general swipe at timing by basically removing all the agressive timing, possibly due to high compression.
Lower left = looks like the engineer who wrote the map forgot to set timing for low MAP, upper rpms. LOL! (not too important)
Lower right = looks like a map for a high torque, high CCP engine.

And the survey says?

Looks to me that three of the four have timing of approximately 12 degrees at idle and the fourth (lower left) very close to that.    Am I reading this wrong?

[chrisroadking]

The factory sends the bikes out advanced for emission standards so taking timing out will infact  reduce emissions but improve power 

[mayor]

The factory sends the bikes out advanced for emission standards so taking timing out will infact  reduce emissions but improve power

really, got any examples to share? what ranges are you talking about? 

[FLTRI]

The factory sends the bikes out advanced for emission standards so taking timing out will infact  reduce emissions but improve power

really, got any examples to share? what ranges are you talking about? 

I have yet to see examples of this timing strategy. Maybe heard it through the grapevine?
Bob

[blusmbl]

Timing is usually retarded at cold idle to aid with catalyst lightoff & maintain exhaust heat.

[mayor]

Timing is usually retarded at cold idle to aid with catalyst lightoff & maintain exhaust heat.

now this I have seen.   

[Steve Cole]

As a general rule of thumb the more retarded the timing is the higher the EGT's are going to be. The more advanced (to a point) the cooler the EGT's will be, but it will also raise cylinder pressure and produce more NOx emissions. So using this to there advantage the factory typically sets the idle timing retarded to aid in catalyst light off and lower NOx then when the engine heat gets too hot will advance the idle timing to aid in cooling the engine and loose the reduction in NOx.

[Ken R]

Sounds cut and dried, same timing for all of us? 

So where should idle timing be set (cool engine, warm engine).

[Steve Cole]

With Mastertune the default values are very close to what is needed. Each combination can take a slightly different value but about 18 - 20 degrees in the closed throttle tables at normal temperature and 23 -25 at cold temperatures is a good starting point. Also make sure to set the main spark tables at the idle area to whatever your final values are in the normal temperature closed throttle tables.

[CTCVOrider]

Acknowledging that no generalization is true in all cases...  Is there a general coorelation between more or less timing that yields the best fuel economy?  In other words, decrease until mileage decreases than add 1 or just the reverse?

[Overcamber]

I just read every single thread on this post and it ends like this???

[Jackal]

Finally, a post dedicated to ignition timing! ...about 3 years ago.

I am looking for advice on initial ignition timing on an EFI Sportster 1250 10.5:1 with lots of cam overlap and a sluggish off idle throttle response once warmed up, and off idle acceleration issues till about 10 MPH. Commanding 14.6:1 and I think the cams bleed off compression down to about 180 psi cranking comp. Would the best column to make changes to be the 50 KPa column from say...1000-1750 RPM or??? Currently I am at about 12-13 deg advanced in these cells. Thanks!!! I also made a detailed post in this section if that interested.

ETA: Here is a shot of my fantastic running 2006 (carb) timing MAP (top table) provided by XLF member Rico, with conversion tables to KPa (middle two) for comparison purposes with the 2008 (EFI) timing MAP in the bottom table labeled "PV1 MAP".

[skypilot_one]

An interesting old thread.