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[VintageLambo] Re: Ignition-Fuel Maps

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You are exactly right Dennis. It was tricky to measure the actual manifold pressure since the cross (balancing) tube via small holes is connected to each of the runners where the flow turns downward and where the throttle butterfly valve lets air in first. So the static pressure gets "contaminated" by the dynamic pressure at that location. Electronically mixing the throttle position signal into this, made the input to the TEC-1 unit reasonably linear with the load. I strongly suspect that the location of these connecting holes contribute to the brake booster problems often written about, since the pressure in that tube rises sharply for a small throttle angle. A marginally running engine (high leak-down) will need the throttle opened slightly robbing at least part of the vacuum to the boosters. Fred, The numbers "in the grid" of the timing tables are then the ignition advance as a function of load and rpm [adv(load,rpm)] and the numbers in the fuel tables are relative fuel compensation numbers per event. There is obviously a load dependent proportionality that is not shown here. The timing tables have some relevance as a characteristic of the engine in how much can the timing be pushed before detonation. At maximum load it can also be compared to a 4LV12 distributor advance curve, which is composed of 3 lines: constant to one rpm breakpoint linearly increasing to another breakpoint and then constant again with no load (vacuum) modulation. The tables are only meant as "intellectual stimulation" for those who are interested in knowing more about the characteristics of the engine. Laust --- In VintageLambo@yahoogroups.com, Dennis Briddell wrote: > From: Dennis Briddell Date:Tue Nov 25, 200310:13 am Subject:Re: [VintageLambo] Re: Ignition-Fuel Maps Hi Fred, kPa is kilopascals... as in pressure. 100kpa=1bar=14.5psi=.98ATM I think Laust"s setup uses manifold pressure and throttle position to determine the load point. Then other trims are added in to deterimine final injector pulse width (ambient temp, closed loop etc..). Dennis Hi Laust, Can you explain a couple of things for me.I don"t know what "kPa" means, as in kPa/RPM.Also, I"m not sure what the numbers in the grid represent... Also, for those of us who have the original setups, does this have any relevance?You got me started on thinking about advancing my cams at some point, which is something that can actually be done on my 400gt.But I can"t see ever putting an electromotive system in my car.I know it would help, but gosh...the car runs pretty well as is. Thanks, Fred Your use of Yahoo! Groups is subject to