Ignition timing by vacuum guage

[S1000RR]

I set the timing on my Triumph TR6 with a vacuum guage, which seems to work as well or better than the timing light. If you are not familiar with this method, which admittedly I only learned recently, it's very simple: you hook a guage up, advance the timing to the maximum vacuum reading, then retard down by a reading of 2. On my TR, a reading of 17 really seems to be a sweet spot.

Does anyone do this on the 930?

[puddy]

Is this even possible on a 930? I"m curious to know!

[1979-930]

You could and have the best ignition setting for idle and pre boost. A low compression engine like these is probably going to make the best vacuum around 18* advance and you would end up around 15*-16* at idle.
I'm just guesstamating here, but I'm sure you would be too high for the advance canceling/boost retard system and detonate on boost.

[S1000RR]

Ok thanks. I figured the 930 was too complex for this. ;(

[mark houghton]

Hmmm....cool approach I've never heard of. On my old MGB and MGA I used the standard timing light method.
On my 930, I run around 10-12 advanced at idle. This my second 930, they can handle quite a bit more advance than most realize. All the spec'd retard was for emissions reasons and just cripple the performance gain you can have.

[puddy]

May be a super dumb question but i'm not afraid to ask it,. How do you adjust timing on a 930? I have no distributor, its an old electromotive TEC1 twin plug ignition system. Would the previous owner have done timing that thru computer programing when he originally installed the TEC1 unit back in 1998 or so? I think he gave me a floppy disc with the car...

[jpnovak]

Yes. This works. I use it all the time with EFI to set idle advance and fuel AFR. I use the built-in manifold pressure sensor. Though you have to be careful that your rpm stays the same at your maximum vacuum reading.

[Speedy Squirrel]

If you have the vacuum limiter in place it most certainly will not work. It is the large zinc plated, disk shaped canister connected between the upper and lower intake.