MAF - Can it be calibrated like VE on the street?

[Protec]

Just wanting to see if anyone has experience tuning the MAF on the street like the VE tutorial?

Before I start burning dyno time I'd like to run through the process several times to get comfortable and educated. Same with the VE...


Am I wasting my time or is this possible to get fairly accurate readings?



Best Regards,



John

[tokymon]

you can get it close ( rough) on the street i manly do just wot on the dyno and fine tuning

[joecar]

Problem is on the street the engine spins up very quickly very easily (i.e. you don't get enough hits in enough cells to make a useful correction map).

[tokymon]

ya i use higher gears (more load) and drag the brakes (makes more load) but this will only get you in the neighbour hood
then to the dyno to get it dialed right in

[swingtan]

In the "normal" driving range, yes, you can dial in the MAF and make it highly accurate. As joecar says though, in the upper ranges it's going to be a bit hit and miss, not only from the lack of data, but also from fuel transients.

When using the MAF, I run full OL and lean cruise with the E38, as the fueling is so close.

Simon

[gmh308]

What sort of fuel consumption with lean run on cruise Simon?

[swingtan]

I'm running E85 ATM, so it's a bit confusing. To be honest, when I was running ULP, lean cruise didn't really make a big difference on a trip. I averaged 8.9L/100KM running CL and running OL Lean cruise and both of the tests run were averaged over 400KM-600KM.

With E85, I'm averaging 20L/100KM, but that's around town and not on a trip, previously it was about 14.5L/100KM for the same driving.

I only really run lean cruise with the MAF as the fueling is more accurate, so I am more confident to run OL

[ringram]

Wow cool E85 sounds like such a good idea. Not.
I can see why you would want to run lean cruise with it.

Whats it worth in extra BHP, is it worth it? Sounds like you waste any gains on fuel costs.
Might be better to have chucked some better heads on and banked the cash?

[swingtan]

Currently, E85 is around 2/3 the price of premium ULP, but as you say, you use more. On a straight price per mile measure, you may break even on costs but it's probably more likely that E85 will cost you slightly more. Ethanol also has a lower calorific value than ULP at 30,000 Kj/Kg vs 47,000 Kj/Kg, so you need more Ethanol, all else being equal.

Power wise..... When I changed from ULP, I just added 4' of timing across the high spark table. I liked that so I added another 3', it liked that to... I then added some more spark in the lower RPM areas and it's got way more torque down low than previously. I have no issues cruising in 6th gear at 1000RPM, from 1200RPM I can accelerate up hills in 6th.

I like the fuel, but to be honest, I reckon the sweet spot for a blended fuel would be around E70 or E75 as the stoich ratio is leaner and you you less fuel over all. The big ripoff is that E85 still suffers from the oil price cycle the same as normal ULP, even though it's only 15% ULP. I'm still happy with it though, I just wish it was a bit easier to get, there's only really one station near me.