What we're discussing here is NO timing split BETWEEN the leading and trailing plugs, NOT overall ignition timing like what you are reffering to. The leading and trailing plugs are seperated 10 degrees away from each other in the engine. What we're discussing is firing them TOGETHER, instead of firing them seperately from each other. I hope this made sense.

 

Yeah, I figured I didn't explain myself clear enough.
If you are reducing the split to 0, the trailing fires at the same time as the leading, oh, wait, Leading is the bottom plug, isn't it? If so, NEVERMIND!

Frank

 

yes frank, leading IS the bottom plug.

paul

 

bump

 

Good thread, didn't the 4rotor lemans car have 3 plugs for each rotor? If so, where was it located?

-edit-I just found this pic.

 

OK, here's what I'm looking at. In my "criuse" areas on my PFC map ther is no split. As I drive in those areas the engine seems to run a bit rough or not smooth.
Not real bad but I can feel it and hear it.

Would adding some split smooth things out?

 

Anybody?

 

Someone please clear something up for me:

When reducing split for an existing timing map, do you leave the leading timing alone and reduce the number for trailing? Or is their more to it?

 

add some split. the pfc timing might not be precise enough to give you perfectly zero split. you could be getting some negative split if you run it that tight.

 

Bump for great info, and hopefully some more updated info on this subject.

 

Does anyone know how they split the plugs on the 4 rotor? two leading and one trailing it seems, but at what interval timing wise? and that traliing is really way up there. Or did they fire all three at the same time...If so, was this a high RPM operation only or throughout the entire power band?

 

I'm not sure the 4 rotor engine *had* a "Low RPM" operation range... All it had to do was idle, and from the videos I've seen, it didn't do that terribly well, but it would stay running.

They weren't exactly running around the track at 3000 RPM...

-=Russ=-

 

I knew that much. but there's a difference between coming out of a slow corner at 4K RPMS and the back straight at 10K RPMS.

 

they dont run a timing split.

so theres really no "leading" or "trailing" per se.

and yes, running straight with no split kills lowend power, but who cares if its a track-car..

 

Actually, they are called "Leading", "Trailing", and "Far Trailing".
There is an SAE paper that covers the R26B motor.
The literature implies there was a split between L and T; I don't remember if this was explicitly stated.
The paper does explicitly state that T and FT fired at the same time.


-Ted

 

ok so back on this old topic. One question, what/how does no or little timing split affect your motor? I even heard of someone using neg. split in vacuum areas to help with spool up and such. Something that cant be done on microtech/haltech.

Whats recommended for cruise and idle? 20-15* split? microtech current max. is 20-0.