Egt's and ignition timing

[GavinL]

Does advancing ignition timing reduce EGT's

A simple question, probably a complicated answer http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/smile.gif

[alex h]

Ususally, NO. You advance the timing low dow the revs to get the EGT's up and help the turbo's get up and running....then you retard the ignition gradually to keep the EGT's at a safe limit.

Well that's my understanding.

[Nathan]

It is reasonably complicated, yes http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/wink.gif

You don't advance the ignition timing to get EGT's up. You do it to get more power- high EGT's do nothing to get the turbos working any better. The basic idea is to run as much ignition advance as possible, at all times. The main problem pushing you back is det, not EGT, and they are not as related as many think.

Advancing ignition timing CAN reduce EGT's, but it normally only happens to cars that are close to the edge. An example would be a fairly stock Mk4 running say 1.5 bar. You would be well on your way to det but trying to knock back the ignition enough to stop it would more than likely send your EGT's through the roof. So much so that the scenario really wouldn't be possible even with the fanciest of ECU's. The only option would be to run less boost, and bring your advance back (and would also reduce EGT). Which would give you the same power output as running more boost but with loads of retard anyway.

In general, advancing ignition timing doesn't reduce EGT though. It usually means the car makes more power, and providing the fueling is there the EGT's should always stabilise. A 1000bhp car, set up right, should have EGT's no higher than a BPU Supra. It may even be lower.

Is that complicated enough?
http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/biggrin.gif

Cheers

Nathan.

[GavinL]

I understand that no problem, thanks.

I believe that advancing ignition timing helps with engine response. Is that your understanding/experiance?

[Nathan]

Yes.

Am aiming to be a one-liner person like you now http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/laugh.gif

[GavinL]

Quote[/b] (Nathan @ Sep. 12 2003,09:15)]Yes.

Am aiming to be a one-liner person like you now http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/laugh.gif
even better than me that's a one word reply http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/tounge.gif

[Nathan]

Indeed.

You strike me as a very logical carbon based life form. Whats with your avatar?

[Gaz Walker]

Wise words.

Very nice to see a high quality of posts on here.

Anyway ?http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/buttrock.gif rock on!

Gaz.

http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/smile.gif

[THOR Racing]

Quote[/b] ]The basic idea is to run as much ignition advance as possible, at all times

This is my take on it....

Advanced Ignition Timing

Pros...
Moves peak cylinder pressure close to top dead center.
Puts more energy to the piston and less to the exhaust, water, and oil.

Cons...
Can build peak cylinder pressure beyond the threshold of detonation.



Retarded Ignition Timing

Pros...
Can help prevent detonation by moving peak cylinder pressure further past top dead center.

Cons...
Can cause high exhaust and water temperatures.
Power will be lost.

Regards
Pete

[Mark Kindell]

But if your running NOS retarding the timing is allways good it can give you a longer burn time thus getting more power from the mixture as well as all the above http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/rock.gif Just to confuse things even more http://www.mkivsupra.co.uk/iB_html/non-cgi/emoticons/devil.gif