Benefits Of Advancing Timing?
 

What are the benefits of advancing your timing? I keep seeing people do this, and I am curious. Also, what is the procedure for doing this? I have a 91 n/a, pretty well stock except Weapon R intake, wired open VDI and ports, no air pump, and soon to have Bonez Racepipe and Racing A SS exhaust, if that helps.

I know it is a stupid question, but any comments?

more power, but need to use higher octane if advancing

My timing is advanced through the roof and i use 87. Seems to make my car feel a little better and I noticed a small power difference right away. My vary thou from car to car.

That is what I thought, but how does one do this? Any ideas. And I already run 91 octane, so I got that under control!

advance timing, by looking in the manual on how to do it, u really can only do this perfectly on a dyno, but u can drive it and see teh diffrence, also make sure u dotn advance it too much so it doesnt start knocking on u

SO the Hayne's manual tells ya how to do this? Wel, I guess I had better get to reading! Thanks all!


How far is safe to advance the timing?

Hows your top end? Does your power start to fall off close to redline?

Well, yeah, a little. But the VDI and ports helped that, as well as the gutted cats. Why?

Don’t flame me for this but I’m going to explain it in terms of a piston engine because it’s easier to visualise, but the theory is exactly the same for a rotary.
You want the ignited fuel/air mix to reach peak explosive pressure just after the piston has passed top dead centre (TDC) and started to travel downwards. This will impart the maximum downwards force on the piston for the longest time. If that peak pressure is reached a bit later, you’ve wasted some of the piston’s stroke, resulting in less power. If it reaches peak pressure to early, i.e. before the piston has reached TDC and is still travelling upwards, the pressure actually slows the piston down and wastes some of the charge’s energy (because it’s not pushing the engine in the right direction), plus this places massive stresses on the engine resulting in wear and damage.
The reason the spark is fired before TDC is because it takes time for the spark to ignite the mixture and for the mixture to burn. Obviously it’s only a few fractions of a second but as the cycle duration gets shorter as revs climb (60ms @ 1000rpm, 8.57ms @ 7000rpm) you need to fire the spark earlier at higher rpm.
So there is a “sweet spot” for your timing that produces max power. Retard it form there and you will lose efficiency and power, advance it and you’ll lose power and do mucho damage to your engine. The stock timing setting will be slightly retarded in the interests of safety.
Sorry for the long-winded post but I hope that answers the original question. :)

WOW, that is awesome info! So how far should I advance it?

Man, that is one of the most informative answers to one of my questions I have ever received! (Mental note:Add NZConvertable to Rico's List Of Heros...)

If anybody is having their top end fall off after advancing your timing, use higher octane. Thats preignition causing power to drop off. It wont kill your n/a engine, but isnt good for it either.

I have not yet done this, I am just researching the "Why's" and "How's". So, how far should I go?

hey how much is it u are trying ot advance your timign again? :)
"advance it and you’ll lose power and do mucho damage to your engine"
this is not true u will gain power not throughout the powerband though

Oh. So is it a good idea to mess w/ this, or just leave it alone?

If your engine is ported the whole timming stuff changes. Remember... Porting is the equivalent of performance cams. It all depends on who's hand the grinding tool is on :D

Kahren, reread the post. I was referring to advancing it further than the point that produces max power, not from the stock setting. The reason you advance it from stock is to try and find that point.
Sorry Rico I have no experience with advanced ignition timing on rotaries, I've always just left it stock (I've only had turbos).

Just keep on advancing it, until the power starts to drop off. Once it does, back it off a couple degrees. CJ

sorry didnt understand u right
but now i see this, "Retard it form there and you will lose efficiency and power, advance it and you’ll lose power and do mucho damage to your engine." u mean the other way around right

No, I mean exactly what I said. There is a point where maximum power will be achieved. Retarded from there you will lose power, advanced from there you will also lose power but you'll do damage because you're trying to push the piston down while it's still coming up.

Quoted from Angel Guard Racing Team
Man- I'd hate to be the guy with the tool... I wouldn't want any grinding tool ON my hand!! :)
Just kidding man... anyways...
In terms of porting- it still doesn't change how far you can advance the timing- because combustion can still happen before the optimal point- not to the point to too much combustion is happening while the chamber is still in compression

Porting is the equivalent of valve timing on a piston engine. Ignition timing is STILL ignition timing on a rotary or piston.
Maybe I am missing something, but I don't see how porting could modify the desired ignition timing unless you are WAAYYY retarded (the timing of course!!!! :)), because the exhaust port is uncovered a bit sooner- interupting full combustion...
I don't know why anyone would have timing that retarded that extreme amount though.

If I am wrong here... someone please correct me!

My 2 cents- I have the timing advanced about 10 degrees (1 cm on the wheel) before the stock pin... I noticed an immediate improvement in smoothness and power.. Runs better- But I have a ported engine... which by what I said shouldn't change anything anyways..?

How exactly do you advance the timing ? Like where in the engine is it since there are no pistons?? I mean is there a special tool.. because i have a really bad acceleration problem... any ideas ? I think the timing needs to be advanced.. i am running 97 octane and it solves the problem of the top end fall off but, i wanna know how and where to adjust it at... and degrees as in ? like turn clockwise or counter clock ? HELP !!..... AAAHhhhhhhhhhhhhhhhhhhhhhhhh

I think you better learn how a rotary works before you start messing about with timing! :eek:

I am saying i will have someone do it but, i want to know for future refrence

You adjust it by turning that distributor looking thing behind the alternator. It's got a flat black round cover over it and you just gotta loosen the 10mm nut so you can turn that thing clockwise by the above mentioned 1cm. I think it's is called the crank angle sensor. I noticed a slight increase in power on my previous motor with no apparent detrimental effect. Though members mentioned that the timing was self-adjusting after a certain rpm?