what if you did advance the timing instead of retarding it? everyone knows you should retard it to prevent detonation, but what if you advanced it 2 degrees and your sparks were still showing you rich...is it worth it to do rather then retarding?

 

Well i'd say no, unless you had a btm ignition to retard the timing as you get into boost.... advanced timing and too much boost is bad (from what i understand)

anyone explain to me why i think this way?

 

I'll take a shot at it....
Advancing your timing causes the spark to occur earlier in the combustion process, encouraging combustion to occur over a longer period of time, thus increasing cyl temps and increasing power at the same time.
The downside for turbo is that higher overall cyl. temps combined with forced air induction and the now reduced time before the spark prevents proper air/fuel mixture, leaving an uneven mixture in the cylinder during the advanced timing spark, causing hot spots. Retarding the timing would allow more time for the mixture to properly 'mingle' (air/fuel). In addition, the retarded timing used on an FI car would have the spark occur later in the compression stroke (to reduce chances of detonation), since the turbo is creating (dynamic?) compression, advancing the spark is not necessary to extract every bit of compression for power.

I tried to explain as well as I could (at work :thumbdown.

Anything missing ?? Anything wrong with it ??

X2


[Modified by X2BOARD, 12:27 PM 6/26/2002]

 

Are you trying to correct for running rich by advancing your ignition? There is no relation between the two. If you're running rich, you need to correct that by reducing fuel... messing with the ignition timing isn't going to do you any good.

 

no, i just realized.... that my car has been advance the entire time 2 degrees....the car has been running great, for the exception of spiking, when boosting 12+ psi...but now that i FINALLY realized it has benn advanced...should i go ahead and retard it? sparks look great...great as in safe, very dark...., i'm not running anywhere close to lean.

 

Do you have any type of ignition retard... like a BTM ? Otherwise I would suggest you back it to stock timing at least.... especially at 12psi.

X2

 

Consider yourself fortunate.. reduce your timing to stock asap!

Your plugs, although a pretty good source of information about your running conditions, can be misleading as well. You may be running super rich at idle, hence your blackening your plugs just before you pull then, giving you the false idea you're running rich when under boost you may be running lean as hell (although if it was lean enough to damage anything, you'd probably see it on the plugs). Get a wideband O2 on that car and see how you're running under boost.

 

yes sir!