dreamer1uk

For the folks with the bigger TB, MAF's and bigger injectors, isnt that pointless without upgrading the heads first? Im just curious on what your guy's fuel trim levels would be at using the bigger injectors ect on a somewhat stock setup.

maritimer95gt

I see what you're saying. Why not open everything else up first on either side of the heads before you replace them though? The stock intake is crap along with the TB and exhaust manifold. Slapping on new heads doesn't necessarily mean that you'll be able to efficiently feed them in the first place. Why slap on $1400 when you're only getting $800 worth of the gains you were expecting. I do agree that heads are an important mod, but sometimes you can't pass up a great deal when you come across it.

dreamer1uk

Hi,

That makes sense. So, would you need an aftermarket tune to stop the vehicle from running excessivley rich seeing as theres bigger injectors involved?

maritimer95gt

Yes, the MAF would have to be calibrated for the injectors you're running.

Bigger injectors than calibrated = too rich
Smaller injecors than calibrated = too lean

You can buy MAFs for cheap that aren't calibrated. I just bought a brand new 80mm Ford MAF for $65 and I'll be calibrating that for 24# injectors in a bit.

dreamer1uk

Hi,

I really appreciate the answers to my questions. However, when your using a bigger MAF and injectors, how does the ECU control the pulse width modulation of the injectors so its not going to deliver too much fuel to the cylinders with there been bigger injectors in the equation? I hope that makes sense, lol.

maritimer95gt

When the MAF is calibrated for the correct injectors, the car knows what it's dealing with and releases the correct amount of fuel according to injector size. The bigger injectors will pulse for a shorter period of time to allow the same amount of fuel into the cylinders as the smaller injectors. No matter what size of injectors you have, the computer will always strive to get the best air-fuel ratio and release the same amount of fuel volume-wise per cylinder. You'll notice a difference in the higher rpm range with bigger injectors.

AYEOH5.0

id steer clear of SCT chips. me and other people have had problem with the chip randomly cutting off power. it can be fixed by unplugging the switch cable but why should i have problems with a 300 dollar switch?