Contour Enthusiasts Group Archives Forums Modifications Duratec Performance 70 MM Throttle body.

so... anything happening on the dyno?

Okay, I saw something really wrong in here. Someone (not mentioning names) said that they were going to swap in a 4.6 stang maf and use 4.6 stang injectors. That is wrong. Ford control's injector sizing inside the computer. Us Tauri peeps have tried this going from our stock 14# up to the flex fuel 24# by swapping maf/injectors with NO luck. Custom burned chip is needed for that swap. I'm sure you could get away with 19# since its only a little bit larger then stock but its not optimum. I did a maf mod (not recommended by RARA so I won't go into detail about it) and increased my fuel pressure to compensate for the extra air.

I'm probably the guy you are calling wrong. I've been running the 19# injectors with the 80mm MAF and 70mm TB for several months now and the whole setup works just fine. Needs tuning for WOT, but doesn't for "normal" driving. Dunno what's going on with the Taurus 24# issue, but I do know that the transfer function used in the MAF for the Cobra(which uses 24# injectors) is not compatible with the stock contique pcm program.

dan

Yes, it will work, but is not the right way to go about it. Its patch work.

This coming from a guy drag racing a taurus?

You funny man. I never claimed that this was the right or best way to do things. Merely correcting an invalid assertation you made.

dan

Ford does not control injector size through maf size. They do it all in the pcm. The aftermarket tries to adjust by changing the size of the sample tube in order to work with the factory programing FOOLING the computer. Larger sample tube, more cooling on the maf wires, shorter injector pulses. You installed a larger diameter maf (leaning out mixture) and larger injectors (richining out the mixture) and some how came out CLOSE to where you should be. You can throw a larger set of injectors on any car and it will run somewhat good, maybe even better in some cases, but with the talk of everyone running rich at wot you might want to consider something like a SAFC.

As for the shot at me drag racing a Taurus that was a cheap shot.

However the MAF IS calibrated to a specific Injector size. They are NOT a one size fits all electronics...

Therefore he used a MAF calibrated for the larger 19lbs injectors so the PCM would basically see nothing changed. (Just would dump a lot more fuel)

The PCM may control fuel enrichment, but it's based on the signal from the MAF and the PCM's preset tables. (Why an MAF optimizer or S-AFC works!)

...don't worry about the Taurus shot. He's just jealous you have more doors than he does...

Demon,

The MAF DOES NOT HANDLE INJECTOR SIZE all the MAF does is send a signal to the PCM indicating how much air is flowing through it. "Re-calibrating" a MAF for different injectors, and MAF "optimizers" alter the signal from the MAF to the PCM, to trick the PCM into thinking a DIFFERENT amount of air is flowing through it. This is used to compensate for injectors that are the wrong size. Regardless, this method is a half-arsed way of tuning, the injector size should be changed at the PCM either via a re-flash, or a custom "chip"

furthermore, wtf is "fuel enrichment" ???? The A/F ratio is either correct or it isn't. The term "fuel enrichment" historically implies a dump of an indiscriminant amount of fuel; this is dumb.

Been following this thread a while. Interested in knowing what the "best" setup for MAF and TB is for our cars. Taking into consideration daily driving vs. WOT. I know there are a bungh of other variables such as air filter, exhaust and chipped. Just interested in what the general consensus is with all the bolt on's but no internal mods.

Getting a 75 and an 80mm on Mondayish. I need to order a 65mm tb and I'll let you know. The guys at the dyno are just as curious so I think that they are going to cut me a break on $$$$. By the way I have an afc to tune these parts