Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec MAF/Injector sizing for your hybrids...must read!

Originally posted by svttour:

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...but this is on hybrids give me your input on straight 3L with SVT cams and SVT uim and lim .. should this go from 19# to 24# or no... and if u say 19# are sufficient in most cases why are 24#ers favored amongst the 3L population.

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A 3L is a 3L in so far as injector sizing is concerned. The 24# injectors are the correct size for the engine...Ford has already determined it.
People use the 24's so much because the 3L motors come with them and they don't have to pay more for them.
Then you have to figure that they are bigger and there is more room for improvement with things like nitrous.
19's are sufficient because of the high stock fuel pressure that the contours use. If I made another 3L swap or hybrid, I'd most-likely just use stock 19# injectors if it was an SVT unless I had bigger plans like a large nitrous shot.

Then again you have people that have stock duratechs with 17# injectors and a 3L. They don't have 19# injectors handy but they need something bigger than 17's.

It is no problem to throw 24's into an SVT and use an SAFC or eManage or probably a tuned MAF to control them. The 24#'rs are about 20% larger than the 19's that come with the SVT motors so that isn't too much of a stretch if you use an SAFC or tuned MAF or eManage.
It is just with the 17-24# transition that things get really fugged up.
IF you have a normal duratech and want to go with a 3L(hybrid or regular) You need to follow the same precautions!

IF YOU HAVE THE MONEY, the best way to insure that your 3L runs ok is to:

1. Send your pcm in to the chip maker to have them read the code.

2. Purchase a MAF where you KNOW the transfer function. Don't worry about tuning it to injector sizes, just ask for one that has the flow range you need!!! Don't get one that flows 700 CFM when you only need one that Flows 350-400 CFM and conversely if you are running a turbo you need a bigger one. Pro-M supplies all of this information with their MAF's so I recommend shelling the money for one of those since they work so well and give you a complete flow-sheet with it. Photocopy the flow-sheet and send a copy in with your pcm when they go to make your chip.

3. Have them input the correct injector size AND convert the MAF data from the sheet in order to put it into the new chip.

4. get your pcm and chip back and stick it in.

5. Of course don't forget to put the injectors in!