Exhaust Note Change

DSPTurtle · 01-12-2002, 08:26 PM

I figured out how to use my "adjustable" timing light this evening after owning it for six months. I thought you had to flip a switch or something...but no, as long as the dial is turned it is "adjusted". Anyway, I had never touched it but once I turned it to zero I figured out that I had the timing advanced almost 30 degrees!!! Other than a high idle this did not cause any issues (i hope). Now the car idles strong and even gurgles when you back off the throttle (I did not think my 1.8L could sound so cool).
Here's the question...
Seat of the pants tells me that now that I have the timing correctly set I have lost some punch. Both in the low and especially the high end (4000 to 5500). The vac advance is working perfectly as far as I can tell. Is it possible that by backing off the timing I have given up HP????
Also, does it make sense that the exhaust note now sounds different.
I am running a pertronix so the dwell has nothing to do with it...
Please someone let me know. It sounds really good, but I would give up the music to get a few horsies back.
Thanks in advance.
JB

SteveStromberg · 01-12-2002, 09:15 PM

More advance more power but also more chance of preignition and melting the tops of the pistons. Steve

John Rogers · 01-12-2002, 11:50 PM

I guess I am confused, but with using the timming light did you actually move the distributor? If so then I would set it as per the pelican or Haynes manual as that is the only correct way to do it. Remember, the timming on 914 engines is set at full advance at whatever RPM is specified. Good luck.

DSPTurtle · 01-13-2002, 04:53 AM

The distributor is now set for 7 degrees of timing. What I am saying is that I had to retard it significantly by rotating the distributor body to get it to come down from almost 45 degrees. So now it is "correct" according to the PP tech article but it feels slower??? (sounds cooler though)

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Yes, you will give up HP by retarding the timing. I guess it could change the exhaust note, but I'm not quite sure I see the mechanism.

But you have just significantly reduced the chances of melting a hole in a piston...

If you're so inclined, you might try advancing the timing somewhat again, and seeing if you can hear any detonation (sounds like rattling when you get on the throttle hard at medium RPMs with the engine warmed up). If not, your chances of doing the whole "melt a hole in a piston" bit are much less than if you hear the rattling. Not sure if they're more than with the stock timing in any significant way or not. Might be, or might not...

--DD