The ED Sprint, EB and EL GT and AU V8's all cam with a 65mm TB and a 70mm MAF, thats the basic Ford performance combination.

Thank you.

I know that the AU MAF has a different plug to my E-series setup.
So what is the solution here?

If I change the AU MAF with my stock MAF then I lose the calibration already built into the AU TB setup as well as the benefit of the larger MAF. That doesn't sound good. Is the only other solution to add an adjustable fuel pressure regulator? Is there no other way of retaining the AU MAF / TB setup as it is with its calibration, like perhaps changing my E-series plug to match it?

The E-series and AU electronics are calibrated almost the same. With E-series electronics it does tend to lean out a bit up high but that cam be combated by running an adjustable fuel pressure reg and upping the fp a bit. The other option is to change the plug on your wiring loom over to the AU type, I run a 90mm Lightning MAF which comes with the AU style plug so just converted the wiring harness over. Don't know if anyone sells the plugs over here in australia though.

the MAF calibration is matched with the injectors not the TB ,so using an AU TB will not make any miscalculations in the ecu, correct me if I am wrong ,but the maf is just a hotwire that heats up to 200deg C ,and when air passes over it, it requires more voltage to retain the heat, therefore by using a bigger TB the maf will have more air to pass over it requiring more Volts, as long as the maf has enough "headroom" to monitor the extra flow.
the 65mm is all I currently run (now) and I believe it has plenty of potential for the engine that you described. You would benefit much more by upgrading you're cam, the stocko leaves a lot to be desired!
thats just my opinion, but I am speaking from experience with the same combo.

I thought I'd read here that MAF's are calibrated to their respective TB's, no matter what size. I know that when my original MAF failed, the reconditioned unit I received came complete with it's own TB and I just handed over my original MAF / TB for them to take away in exchange. I think they said it's important to have them calibrated to eachother - hence my concern. Is that not the case?

Last edited by Vic on Thu May 19, 2005 11:58 pm, edited 1 time in total.

EDXR8 you run a forced induction, am I correct?
is you're maf a blow thru or draw thru?
90mm is just such a big unit, and its common to sacrafice low flow accuracy with a draw thru type setup.
I have researched these bloody things so deep lately, and finally can relate to them being simmilar to power valve circuits on holley carbs which aren't that complicated when you think bout it.
I am not critacising your setup, just curious???

I may have misunderstood, do you mean the body that the sensor screws onto? if so s**t yeah ,very important!!
when I stated TB I meant the body with the butterfly valve that regulates airflow to the manifold.

Yes.

have you changed you're injectors at all, as I believe AU injectors are no longer the EV1 pintle type, they used EV6, which can run more accurately with less fuel pressure, maybe it would be a good idea to use the AU type injectors as the mafs would already suit them?
I run BA XR6 turbo injectors and have found them to be much more accurate with fuel flow, only had to raise fuel pressure 4psi once everything was tuned together.

I've never pulled these injectors since I've owned this car so I assume they are the stock 19# injectors. The TB will not be fitted just by itself, it will only go on when the intake manifold is replaced as well and at which time it will be worth me pulling these injectors for a good cleaning.

Yeah thats right, the MAF and TB don't have to be technically matched, what we are talking about here is matching flow. Usually a MAF will flow more than a throttle body of the same size, because of the blade etc, so as long as the MAF is at least the same size as the TB you are fine. Also unlike a TB, you can't really go too big with the MAF.

That's interesting! Are you saying that AU or BA fuel injectors can actually be more fuel efficient and precise and just plug straight into a HO or Explorer intake?

Ok Kenny,

With the exception of some terminolgy that's sort of correct.
The hotwire requires more current to maintain temp with greater airflow.
The MAF electronics sense this current and output a resultant voltage ranging from zero to 5Volts. This is the airmass vs the voltage out and is known as the MAF transfer function.
The MAF transfer function is therefore a 2 dimensional map programmed into the EEC. The axes are airmass(in KG/hr) vs Volts. The MAF itself is not programmed to suit any particular injector size. The EEC is programmed for injector size. The injector size for the HO engine is 19lbs/hr.
The MAF electronics and hotwire assembly are very similar in their calibration between each other. This is one reason why you can get away with using the early electronics on a later and larger MAF housing and only experience slight inaccuracies in fueling.
Aftermarket MAF's like the C&L/Vortech take the concept a step further.
They use the stock electronics on a larger MAF housing. Normally this would result in a dangerously lean condition. They fix this by changing the size of the sampling tube. By making the sample tube larger they effectively measure more of the total airflow through the MAF. This brings it closer to the original MAF transfer programmed into the EEC. If larger injectors are required the sample tube is sized so that when the injectors are opened they happen to flow the correct(well close to) amount of fuel for the actual mass of air entering. The problem with these MAF's is that it's possible to actually hit a maximum output of 5Volts before the MAF has actually hit maximum mass flow. They've also been known to require "clocking"(rotating) in the tube to account for their questionable flow characteristics and are inherrently "noisy" in signal terms.
Other aftermarket MAF's(Pro-M,Granatelli,Ford racing) are actually calibrated electronically for the desired transfer function. Once again this can be a skewed transfer function to compensate for larger injectors. This of course means that they do not suffer from a maxing out of actual mass flow before maximum output voltage is reached.
All the while the EEC(in the case of the 5.0HO) still thinks it has 19's and a 55mm MAF.
This means that load calculation by the EEC is thrown out which, can result in detonation. Many modified engines can actually benefit from increased spark but an across the board spark advance increase can result in problem areas.
Many of the aftermarket MAF manufacturers provide the actual MAF transfer function for entry into the EEC. For EECIV and V this can only be done via a chip,TwEECer or EEC-Tuner, EECV can also be reflashed.
This is the only way for correct load calculation.

Cheers,
Pete.

they can..providing u use the correct impedance ( high) but u must use the correct length,i believe they are the EV6 long nose,also dont forget u must use a mafs 2 suit if u r going away from standard flow rates.
the xr6 turbo are rated at 28.8 lb/hr and flow best @ 40-45psi and can be purchased on ebay every now n then for $300 starting bid for a set of 8.
they also have 4 holes in the bottom allowing better fuel atomization.