How important is trailing spark?
 

I got a wolf3d and i dont have my trailing hooked up yet because im waiting on the bosch ignitor. I was reading the manual and it says that 95% of the power is made from the leading spark, but the trailing has to help out in other areas other than power right? For example I think it would for starting, because mine doesnt start very good on a cold engine and ive flooded it out a couple times because of it. Well that partly because its not tuned but I think the trailing plugs have something to do with it also. Whats do you think?

Combustion efficiency. Better performance, more complete combustion and less emissions.
Wanted to add. I had a '88 TII I purchased new and because of a design flaw, the trailing plugs wouldn't fire after about 100 miles. Noticed a decrease in performance. FYI-Mazda bought the car back because of the problem which they, nor NGK had any answer for....Except to redesigned the S5 housings.

Yea but im trying to figure out if it affects starting much?

well one time I changed my pluges and forget to plug in the trailings and I didnt even tell the differnce at all.

I would think so, you need 4 things for starting an engine.

1)air
2)fuel
3)spark
4)compression

Since its cold, compression will be shittier resulting in hard starting. You also have the one spark plug not firing at all, lessening the chances now of getting your car started.

Both are needed like stated above, it improves combustion effieciency. The more fuel you can ignite in the compression stroke, the more power you can make, its simple.

Your EMS may not be tuned properly for cold start.

Yea ive been messing with that by turning off the coolant temp correction and using the hand controller to increase overal trim while cranking til the car fires up. Ive gotten it to start up like that, but other times it wants to just flood out even though ive set it.

I just went out and pulled my trailling wires and it started up and ran fine

UMMMmmmmmmmm

There have been many discussions about trailing spark........ and thats about all i'm going to get into... you can sniif around on your own about that.

I think your starting problems lie in your tuning.... not the lack of trailings... I had problems starting my car in the cold with my haltech untill i monkeyed around with the primer and cold start maps.

HOWEVER... you'd better wait to get your coil in and get your car tuned right... if your are going to run with trailings, best to set it up to run with them... bad things can happen if you leave dead plugs in the holes.