So from what I can tell from everything I've read, the short and sweet regarding ignition timing is that advanced timing is good for low end and midrange power, but retarded timing is better for top end. So my question is this: would it be beneficial to advance timing at the distributor for optimum low end and use the timing retard function on the msd box to retard it at a certain rpm for optimum top end?

I was going to run nitrous and never did, so now I really have no use for the timing retard function on the 6+. I was thinking I could use it for this though. However, doesn't the ECU retard timing at the upper rpm range anyway? If so, would this setup with the msd box even be worth the trouble?

I'm going to a dyno tomorrow and I just want to see what other people thought about this idea, or see if anyone's actually tried it before.

 

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actually i think retarding = low end, advancing = top end.

 

No, I'm pretty sure you're supposed to retard timing as the rpm's increase. I was just wondering if using the MSD unit to do this would be useful since the ECU seems to do this to some degree anyway.

Anyone else?

 

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Advancing the timing helps top end. This is because as the speed of the pistons increase the timing needs to advance more (happen sooner before TDC) in order for it to combust the fuel in time for the compression stroke.

Retarding the timing would give you better low end power.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FourthGenHatch &raquo;</TD></TR><TR><TD CLASS="quote">Advancing the timing helps top end. This is because as the speed of the pistons increase the timing needs to advance more (happen sooner before TDC) in order for it to combust the fuel in time for the compression stroke.

Retarding the timing would give you better low end power.</TD></TR></TABLE>

 

Ok, I don't ming being told I'm wrong about something. I'm just repeating what I've read on other posts on the board. However, now I can base my statements on experience since I just dyno'd the car today. I started off running rich and f'ed with the fpr until I was running within 13-14 a/f ratio throughout the whole rpm range.This increased my hp by 3. The final run I advanced my timing from 18* to ~19-20* and noticed an increase of ~1 hp. Granted that's not a lot, but it made my total gains from the original 146.47hp to 151.00hp. Not bad overall, and based off the graph below it looks like it helped both low end and top end, although top end benefited more. It's nice to actually see results in person instead of reading about it on forums and basing your opinions on that.

I run 93 and there was absolutely no pinging anywhere in the rpm range, so my settings are definitely safe.

Sorry to doubt you guys. Here's a link to a graph of my first run vs my final run after the fuel pressure changes and timing advance (if anyone cares).