Reply With QuoteYou advance until peak torque does not get any higher, I think? That's what motec say anyway... and before it begins to detonate obviously...
Hope that is remotely helpful
Ignition Timing
Is there like an optimum guide to ignition advancing per RPM points based on fuel rated octane and load?
for a 4A-GE silvertop for example.
at stock: it's about 15degrees on idling at 850-900rpms
what about when it reaches RPM points like 1k then 1.5k...2k...2.5k
on say 93-96octane fuel.
Re: Ignition Timing
You advance until peak torque does not get any higher, I think? That's what motec say anyway... and before it begins to detonate obviously...
Hope that is remotely helpful
Re: Ignition Timing
Originally Posted by Ryley
ive only had my eyes and ears on the "before it detonates". but does that timing really bring out the best output?
with what motec says regarding peak torque, i'd really have to get it up to a dyno tester. sadly, it'd cost much just to know your engine only. was hoping to get a more general rule to this.
was wanting to see if an ITC would really bring out a definite advantage over stock ESA in terms of output ofcourse and by how far an advantage.
Re: Ignition Timing
ive only had my eyes and ears on the "before it detonates". but does that timing really bring out the best output?
with what motec says regarding peak torque, i'd really have to get it up to a dyno tester. sadly, it'd cost much just to know your engine only. was hoping to get a more general rule to this.
was wanting to see if an ITC would really bring out a definite advantage over stock ESA in terms of output ofcourse and by how far an advantage.
What's 'ITC & ESA'?
Thanks.
Re: Ignition Timing
ignition timing control
electronic spark advance
Re: Ignition Timing
From what i've found there isn't a lot to be had over the standard computers on 20 valves. Every motor is different and then using lower octane fuel isn't the best either. Some engines will reach peak torque before they detonate and others wont and the most torque you can get at all engine rpms is better than the most power. Tuning for peak power at all rpm can make some motors hard to drive.
Re: Ignition Timing
good tip regarding the torque vs HP.
regarding higher octane rating, i know it has it's effects on not detonating compared to lower octane. but what about burn time? is it still the same or would higher octane gas burn or consume longer?
typically as ive read, it takes about 0.003 secs to burn all a/f mix in chamber.
by computation ive found 15.3deg BTDC to TDC is .003secs on 850rpm
a lot of factors are to be considered however after idle like load, temp and i dont know what else..
Re: Ignition Timing
Can you explain this to me???
I'm reading a contradiction here. How can you achieve peak torque at a given rev/load point or peak power at the same rev/load point?
Tuning for peak torque at a given rev/load point will also give peak power at the same point.
"Don't worry what people think, they don't do it very often."
Daily: Glorified Taxi (F6 Typhoon). Out Of Action: Twin-charged Adub. Ongoing Nightmare: Over re-engineered (not) Alfa Romeo 75.
Re: Ignition Timing
I've only found a couple of motors that you can get more power than torque at the same point. The car i had on the dyno actually picked up torque at the same point with no change in power when the ignition timing was retarded slightly.
Re: Ignition Timing
Power = (Torque x Engine Speed)/5250
If you increase the torque, then the power must also go up.
If you're using a dyno that can show an increase in torque with no increase in power, then I'd sugest using another dyno
"Don't worry what people think, they don't do it very often."
Daily: Glorified Taxi (F6 Typhoon). Out Of Action: Twin-charged Adub. Ongoing Nightmare: Over re-engineered (not) Alfa Romeo 75.
Re: Ignition Timing
Sorry. When i say no change in power the couple of kilowatts it did change over the 15 or so nm it gained i considered nothing.
Posting Permissions
Bookmarks