I must punish mine then. I am getting between 25-35 around town. I have a spool 3.9 diff, Shift kitted auto in a EF Mont Ghia. That is about 200 per 72l, and on the highway it isnt much better, looking at 420 from a full tank, but the EMS is still to be tuned properly. I have a similar setup to yours, but am running 24lb injectors, and aftermarket intake. At 110kph, it is revving at 2900rpm, so that hurts economy on the highway
Brett

the tune is o.k. has been on the dyno bout 4 times as i've been trying to get on top of a cold start issue(which i finally have) and each time he altered settings for that he'd give it another run to make sure nothing else changed.

i was actually hoping when i bought it that it would be around the 14 - 15l/100km range but like people have said. hard to drive it economically when it sounds that way and gives you a nice shove when you stick the boot in.

the one thing i have noticed though is it doesn't roll very well. is this to do with the fact it has a minispool. tyre pressures are o.k. when you try to push it though its a lump of lead. my ba wagon is easier to move. handbrake is not on as that needs adjusting up. i reckon this would be causing a bit of thirstiness as when cruising you have to be on the gas otherwise it slows down.

so if anyone has a 3.7/3.9 lsd they don't want they could throw it my way.

i'm still running e7 heads and eb intake manifold although it does have larger throttle body. i guess in the future if i go down the gt40p path the economy isn't going to get any better. no point worrying about fuel if you want to enjoy your v8 but it does reach a point where enough is enough.

whats your tyre wear like? if your front tyres are wearing very fast you may have some alignment issues im just guessing this from you saying that its hard to push around

Replacing those heads and the intake manifold would definitely be a good thing, but like you said, everyone has their limits. I'm planning on setting my limits to what the auto and the standard block can handle

Explorer manifolds off AU Falcons are cheap these days, and much less effort is needed compared to taking the heads off as well (regarding a full top-end swap). Combining one of these with your E7s should see some more improvement over your existing HO/E7 combo.

Brett - 2900rpm @ 110? Are you sure your auto doesn't have a lockup problem? I'd seriously check out what's going on there...

xr8ute - lol

-Dave-

2900, i dont have a lockup prob, but i do have a 2700 stall. And with regard to the car being hard to push, that is definitely related to the spool, mine went exactly the same way
Brett

I can't understand why your car would be sitting on 2900@110...

I'm at a total loss! I could understand 2700 *if* your stally unlocked under minimal throttle, but 2900... stumped!

Maybe he's got 13" wheels
But seriously.... is this microtech running closed loop control?

Pete.

No Pete 17's all round. Car originally had 16's and 3.45, and that was about 2300 from memory at 110
Joe installed the EMS8860, not sure on open or closed loop, but i was going to set it up as sequential injection, til i heard that it made little if any difference. Also, be aware that i do have 3.93 diff gears, which is why it is singing along at 2900 at 110. When i step on it at 110, if flares a little to about 3000 then takes off like a rocket
Brett

what is closed loop. i wouldn't know. i think it is running o.k. i was just interested to hear what other people with similar mods were getting. there will always be variations though as no two cars are the same.

as far as revs at a give speed. i think terroristGHIA's is a lot closer to the mark than ghia5L. with a 3.23 diff these things are revving at around 1900 at 100kph. a 3.45 will be around 2100rpm therefore a 3.9 will be up around 2400rpm.

even with my setup i don't win a lot of drags (at the strip of course) as even with a minispool traction is no good in first and pretty ordinary half way through second so by the time i make decent power most people would be backing off. new tyres and decent shocks would prolly help.

Let me put it this way. how well do you know your computers? I'll try and explain closed loop control in plain english for you.

Computer has a few target parameters, such as AFR (air fuel ratio) and ignition timing.

Now during light throttle the computer will run closed loop control. But as soon as you nail the throttle the computer goes into open loop control and fuels and fires the engine as per the maps input into its memory.

Back to light throttle and idle, because the changes to fuelling and timing are so small the computer can self adjust to reach a pre determined target. It does it in the following manner.

1. Cylnder fuel and fire

2. Computer looks at AFR (via HEGO), and also air temp, coolant temp and a few other sensors.

3. Computer asks itself, Does AFR look right for the conditions?

4. If yes then computer repeats steps 1 and 2 all over again.
If no then computer makes a minor change to fuel, timing and/or isc position then repeats steps 1 and 2. Computer keeps adjusting till the AFR's match the target value and even then the computer constantly monitors everything and is always making tiniy adjustments.

A human tune can only store target values in maps and DOES NOT allow for any on the go adjustments like closed loop control.

Now can you see why closed loop control is such an important feature on an aftermarket computer. With the cost of fuel these days a computer with closed loop control will pay for itself by the end of the year if you do a lot of country driving in a modified car.

Actually I was talking to prydey Brett but, no matter.
It makes little difference in outright power but it does make a difference everywhere else. Seeing as you already had sequential injection it would have been easy to stay that way I would have thought?
Another advantage the EEC has is the adaptive strategy. Over time the calibration is adapted via a table with cells that are updated which give an offset to the base fuel maps and this helps maximise the fueling accuracy.

Pete.

Diff ratio vs revs.

1) Note RPM@100kph with old diff, ie 1800rpm with 4 speed auto in overdrive & 3.27 diff
2) Divide RPM by old diff ratio, ie 1800/3.27 = 550.4587 etc
3) Multiply this by new diff ratio, ie 550.4587 x 4.11

New RPM@100kph = 2262rpm.