SD With CL

[Sid447]

Any particular disadvantages,

to running SD with Closed Loop?

I've been running like this since 2005 but on a COS V3.

But would it work okay with an LS1-B single spark tune and also E38?

[WeathermanShawn]

It will work on the LS1-B. Like you said you lose dual-spark and the Adaptive Spark Control.

I never found much difference over MAF closed-loop. The Trims distribution is a little different, though overall comparable. If your MAF is restrictive you may see some MAP gain on WOT. I saw a 1.5 kPa difference.

But, yes it works just fine on the LS1-B..

[joecar]

Doesn't the COS give dual spark tables (and adaptive spark)...?

[Sid447]

Hi Joecar,

Yes it does. Though just asking about a normal LS1-B OS and for E40, E38 etc.
I'd in the meantime forgotten that HSV validated the GTS models through to MY2004 with single-spark SD and Closed Loop operation.
In fact there's three GTS files with just that in the holdencrazy "store." :angel_innocent:

Hi Shawn,
yes I found a MAP difference without the original 75mm Maf-sensor and even tried the later type 85mm type which was fitted on the Holdens from 2005.
But a back-to-back dyno session where everything was closely monitored (same dyno, same day, same tune, etc, etc) showed SD to be giving a fair bit more average power (more than 2 Kpa's worth anyway!) and better throttle response so decided to stay SD (& CL). :)