To me that still looks like a lot of advance in the middle.
To me that still looks like a lot of advance in the middle.
The combination of port and pipe is firmly set at 12,000 so this is what I would use as a baseline.
Its initial drop off is to get it to idle well from the big static, plenty of mid advance for throttle response and then enough for a good peak ( assuming correct com cc ) but falling further to help revon.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
That`s a bugger TZ, still seems a lot of advance in the curve you are using.
My fiddlings with the Mota programme show a lot of heat and temp with those adv. numbers ( for my engine at least )
I have settled on 11* @ 11000
8* @ 12000
6* @ 12500 and up
Any more than that shows temps and press. way above where a Honda RS 125 is happy living (according to the Mota example files)
But then I could be miles away too ???
@ Farmaken
Never mind the Mota temp indications.. I was very concerned a couple of years back, as you are.
Mota's peak cyl temp of 2400C for RS is far away from the 2650-2700C that EngMod2T predicts. And the latter seems to be a far better simulator.
I get about 2800 if I set 15* ADV at max torque RPM (with air-booming.. sorry -cooling).
I am not sure what's the deal with this measure, but I think I remember Wob telling us not to care much about it, rather look at the max unburnt zone temp (target: >900C). But Mota doesn't calculate it..
@TZ
Yes, why use so much advance in the overrev? I assume you got better results that way, eh? Can't you try leanning the mixture, instead of rising -decreasing in overrev- the timing ?
By the way, do you have a wideband/lambda meter? It would be very interesting to monitor the AFR during testing.
In general though, it's not bad at all. Ok, it's a new setup and you're starting already almost at the top of the previous one!
So, don't worry, you'll get it figured out and it shall reach the figures you espere!
just as a question Rob, have you recently used a timing strobe to check that what you ask for is what you get?
Don't you look at my accountant.
He's the only one I've got.
This is how we setup the Ignitecs ....
We use a timing light and the Ignitech base advance to match the initial ignition firing point (strobe flash) with the engines timing marks.
The initial setup is a little approximate but optimized on the dyno later. So we never know for absolutely sure if 15 deg BTDC is actually 15, it could be 13 or 17 as the accuracy is only as good as ones eye, a little inaccuracy in the initial setup will be reflected throughout the whole curve but doesn't matter that much.
As knowing the actual true advance to the last few minutes of a degree doesn't really matter, as its all about the bike enjoying the advance curve as seen by the dyno and track results and we only need a general idea of where its at.
Because the Ignitech display is only a visual aid to help with manipulating the ignition curve to suit the engine we are working with. It makes no real difference to the engine whether we know what the real numbers are or not.
The motor only sees the reality of the curve and accuracy between the displayed curve and reality is only as good as the initial timing light setup and the accuracy of that is only useful for visualizing the curve and discussing it with friends.
Wow. Wobblies timing is even more advanced, but it does pull the advance out sooner and has surprisingly little advance at 12,000 considering his comment.
I take from this that the danger area is where the timing starts being taken out and not where it's at 28deg.
I can't see how you will be able to set up a safe ignition with no brake on the dyno and not listening for knock. Or as mentioned a wide band lambda.
Could be reving over a potential engine killer. Could be wrong but seams thats what has killed a few engines lately.
I will be there myself soon my ignition arrived yesterday.
Yes, I had forgotten, TeeZee got one of those knock sensor things that Wobbly pointed out on Ebay. Its on TZ's desk, I will have to see if I can get it to work. Anyone tried one with an IgniTec and can give us a few tips. The Lambda sensor will have to wait until we can get away from leaded race gas I guess.
Bucketracer, why don't you use Ignitech's method of finding the base advance? Or even making your own, super accurate measures and welding a new lobe band at those exact measures??
I believe that a +-1 error is not to be neglected. At 8k or 11k it might not be a problem, but at max power it can cost either power or pistons. So, why leave it 'inaccurate'? Factories -probably- tune at 0.1 accuracy!
..No, I disagree with your opinion on this.
edit
Now that I mentioned factory ADV curves, here's the ADV-PJ tuning tables from two season TZ250 I once found over the web:
edit yet again
General tip for the wideband lambda sensors; they are unfortunately quite quickly damaged by the oil in mixture. Reading around says that the way to go is with an EGT and a CHT gauge, along with the Knock sensor.
Thanks for the curves and I agree tuning the curve accurately is important, if you look at the video and post you can see I am checking the timing and adjusting it using the IgniTec base advance.
But only the motor knows the real advance to an accuracy of 0.1 and sure its important to get it right but that can only be done by testing.
My point was, that, the motor doesn't care what we think we know about the shape of the ignition curve, its only our friends who do and that gets us into a whole different world of accuracy of measurement and reporting.
Andrew down here has some head phones that run through a little amp. You just attach a little alligator lip to the head and listen at different rpm under load. You can hear it det loud and clear. You can run A wide band lambda with 2 stroke's on Ave gas apparently. The main thing is to let it heat up to operating temp before starting the bike. Also if the bike is silly rich it will kill it fast.
Thanks for the tips.
Yes we need a brake on the dyno, to load the motor at constant rpm and to also slow the drum after a run.
Headphone amp is easy, its the alligator clip I dont understand, how does that generate a signal that can be amplified? does it have some sort of mike attached? I would like to know more so I can make one.
I've got a link somewhere (I'll dig it out) that shows one being built from Jaycar bits; but yes its a mic attached to the Alligator clip (on the ones I seen; not Andrew's one).
Here's a good link:
http://www.youtube.com/watch?v=L57fnOlWdaI
Would you mean one of these?
http://www.d-series.org/forums/diy-f...5-dollars.html
http://www.autospeed.com/cms/article.html?&A=0353
I though you guys purchased one of the LED indicators that Wob has suggested some time ago.![]()
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