Dyno tuning 20V Silvertop w/ SDS ECU in Savannah, GA Saturday...

[sporqster]

So if anyone in the area knows a thing or ten about these motors, I'm taking my 20V silvertop-powered Lotus 7 knock-off to "Asian Automotive" on Abercorn in Savannah, GA for some dyno tuning time Saturday morning. I'm going to be sharing tuning time with my wife's 911 running a Megasquirt system.

As is, the car (the Lotus) makes PLENTY power on the top end (4250+RPM) - espically for a 1300lb car, but the power curve is really 'peaky'. It feels almost like the car has a turbo (it does not). Is that just the nature of the silvertop beast? (really peaky power curve) I have a wideband hooked up to it - and watching it under load it is always just on the 'rich' side 12-14:1- which is a good thing I suppose.

Also - I have 0 electronic vacuum advance set currently on the SDS computer. Think I should be doing something here? If I'm cruising at low RPM, downshift and nail it there's a slight miss and hesitation before it goes plaid speed. It used to do this if I kinda pumped the throttle from idle, and I retarded the timing a bit under 1250RPM which seemed to fix that issue. Rev's quite freely now.

I don't see any 'acceleration enrichment' on the SDS controller like on the Megasquirt - but I'm new to both controllers, so I could just be missing it. I've got short little individual throttle bodies - I wouldn't think the TPS would tell you much the MAP wouldn't, anyway.

I'm not exactly an engine tuning guru or anything- and I've got very little experience making fine tuning tweaks 'by the seat of my pants'. Anyone with some knowhow want to come lend me a hand? There may be a free dyno pull in it for you given the time ;-)

[Rapid Roy]

I haven't tuned any "modern" type engines, but all my tweaking on old carburated cars w/o any type of ECU, included vacuum advance on the timing. You just had to keep a careful ear out for detonation. The more advance, the better spool up. Hope this helps or even applies to your setup.