MSD 6530 with throttle postion sensor

[Tom Kirkham]

Stuart,

The MSD 6530 has a nice feature in that it will average the manifold air pressure signal over 2, 4 or six engine revolutions. This should help in smoothing out an erratic manifold air pressure signal. If this does not help enough, then I would suggest trying a TPS.

Another thing to notice is that at 1,000 RPMs I have a little v-notch in the timing curve. This notch also helps stabilize the idle, as well as help off idle drivability. This notch BTW is not possible with most non electronic distributors.

If the centrifugal advance springs are too light, they can lead to surging ...

[A98Coupe]

Originally Posted by Tom Kirkham

Stuart,

The MSD 6530 has a nice feature in that it will average the manifold air pressure signal over 2, 4 or six engine revolutions. This should help in smoothing out an erratic manifold air pressure signal. If this does not help enough, then I would suggest trying a TPS.

Another thing to notice is that at 1,000 RPMs I have a little v-notch in the timing curve. This notch also helps stabilize the idle, as well as help off idle drivability. This notch BTW is not possible with most non electronic distributors.

If the centrifugal advance springs are too light, they can lead to surging ...

Hi Tom,
I'm using the 'blue' springs in my MSD distributor - not the lightest, but stability of the advance from idle up to max has crossed my mind. A tell tale sign is the fact I cannot determine the advance at idle with the strobe. The line dances around a lot. Beyond 3k rpm it's fine and stays bang on 36 degrees. I think the 6AL-2 + MAP sensor will give many benefits.
I have 2x4 600CFM Quickfuel carbs sitting on a Blue Thunder dual plane inlet manifold. There is a 1/2" NPT plug in the back of the manifold which is not used and seems the ideal position to install the MAP sensor. Can you recommend a sensor that would fit and not look too out of place in period looking Cobra 427 engine bay?
I can lock out my MSD distributor so should be no problem upgrading my MSD 6AL box to the 6AL-2?
I'm also planning to get an Innovate LM-2 for the carb tuning so that I can get the A/F correct (or as near it can be), for all or most driving conditions.
Thanks
Stuart

[Tom Kirkham]

The blue springs have typically not been a problem. However they don't let the advance come in as fast as I would like it.

The MAP sensor can be hidden out of sight. Just run a vacuum hose over to it.
The MAP sensor is just a generic GM sensor. Due to emissions laws, all of them seem to be good. The connectors are Weatherpack. You will want a MAP sensor that is rated for 1 atmosphere.

With the O2 sensors you should be able to dial your system in very quickly.

[A98Coupe]

Originally Posted by Tom Kirkham

The blue springs have typically not been a problem. However they don't let the advance come in as fast as I would like it.

The MAP sensor can be hidden out of sight. Just run a vacuum hose over to it.
The MAP sensor is just a generic GM sensor. Due to emissions laws, all of them seem to be good. The connectors are Weatherpack. You will want a MAP sensor that is rated for 1 atmosphere.

With the O2 sensors you should be able to dial your system in very quickly.

Thanks Tom,
Great information & advice. Really helpful!
Regards
Stuart

[Tom Kirkham]

Choosing between MAP or TPS - Autosport Labs