Hi all

i have a question about spark tables...

when you look at a stock bin, the spark adavance is real mild, sometimes not mor than 20° in upper rpm VE regions..

on "tuned" bins, the spark adv is much more aggressive..

why ?

just octane purposes?

who is right? the maker of the stock bin, oder the maker of the tuned bin?

thank you

 

Lots of fuel and lots of spark tends to make people think it feels really good :-)

This isnt true most of the time.

Never, ever trust what you find on someone elses bin will even be remotely close or even work for your application.

What your real end goal is if tuning it properly is the least amount of timing coinciding with the best performance.

Like Grumpy beats into people here, give it what it wants not what you think it wants.

U also need to look at whether the modified bins use the PE adder functions or not and what type of fuels and whether the app is now NA or boosted

later
Jeremy

 

Hi Jeremy!!

thank you for your reply....

im running now a near pefect VE table, and about 30°@WOT + 3.9° PE SA makes a total of 34°

this is, what most consider as "normal" spark table, not too mild, not too radical...

i´ve also seen, good Chambers need less timing, bigger chambers a bit more...

sound 34° reasonable for 72cc comp port AFR heads?

regards

 

One thing about timing is that its not about having the most timing, the least ammount of timing, but the right ammount of timing. Ideally, you want the mixture to be fully burned by the time the piston has just passed TDC to make peak power. Is some cases, though, the engine may go into detontion before this point, so you may have to run less, which is probably why the factory tables look the way they do, as the car has to both run well in all climates, and not go into detonation. The stock timing tables are usually very conservitave. Most engines will run like crap (drink gas, lack performance) on the stock timing tables.

On the other hand, too much timing will cause the motor to also lack power, and overheat as your compressing a hot, burned mixture, which dumps a lot of heat into the pistons and chambers.