I was wondering if anyone had experience with advancing the timing, then retarding per pound of boost, say 18 degrees at idle then retard 1 degree per pound for example...

 

if you got standalone you can leave it at stock timing of 16 if you dont retard like .33-1 for 1lb of psi

 

well I was wonding (with a standalone) if it's a good idea to advance timing off boost to get better low end.

 

using too much advance in vacuum/lower boost (1-4ish psi) can slow the spool of the turbo... there is a point where you get too little timing, cause high egts and crappy responce off boost.... but i will usually give up a slight ammount of responce off boost in order to spool up faster.

 

Yes and no.

Too much advance off throttle can slow down the onset of boost (in terms of the time to boost), but that's not the whole story.

While timing retard may shorten the time to which boost is reached, the car will be an absolute pig until then. In this case, the car would actually be faster with more timing, because even though it does not have boost, it still has more power under the curve.

The stock maps are generally pretty good... I like to run an extra degree or two in the cruise range for better response and economy, and then you may want to pull a little bit of timing out in order to keep knock out at boost onset.

It would be interesting to compare the timing map from a good turbocharged car to the map from a turbo Honda.

 

kpt.. i think we are talking about the same thing.... under cruise conditions i generally leave it stock or in the case of lower compression engines ill add a few degrees... but in the area of hte timing map around 0 boost i will pull a couple of degrees to quicken the spool.

stock turbo'd cars generally runs WAY less timing than hondas do..

example, dsm's run about 10 degrees or less under boost

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">kpt.. i think we are talking about the same thing.... under cruise conditions i generally leave it stock or in the case of lower compression engines ill add a few degrees... but in the area of hte timing map around 0 boost i will pull a couple of degrees to quicken the spool.</TD></TR></TABLE>

Yeah, I think we are too. Just wanted to add my 2 cents, and wanted to point out that retarding it more and more for faster spool won't work.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
stock turbo'd cars generally runs WAY less timing than hondas do..</TD></TR></TABLE>

I may disagree. Turbo Hondas often have quite a bit higher compression than stock turbo cars, which limits the advance they can run.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">example, dsm's run about 10 degrees or less under boost</TD></TR></TABLE>

Oops. WAAAAAYYYY off.

Here is a picture of the stock map from a 91+ DSM. Those are the 5 highest load levels (in grams per revolution). As you can see, the stock map peaks at almost 25 degrees at the highest load.



I'm running slightly modified timing maps in my 93, with a tad less timing overall and a MUCH flatter curve up top. It's basically just 22 degrees or so, which holds until redline.

 

where did you find that??

i know the dsm's we have done with the ems dont like alot of timing at all...

my base maps have around 16deg at 10 psi and 9 deg at 20 psi

 

It came out of stock DSM ECU code.

I have fuel and timing maps, I'd be more than happy to send them to you, or post them up. I also have alittle bit of 2g stuff as well.

Most of it came from the guys at the DSM-ECU e-mail list, and some of the custom maps are my own stuff.

At 9 degrees of advance, those thigs must be *** slow, unless you're running so much airflow that you can't go any higher (more than 500 whp, I'd say).