Tuning after head replacement

[crazyfox]

Thinking about putting aluminum heads on my 86. Stock block. I have switched to mass air. Anyone know if I can get away with not dyno tuning after the heads install? Will I be leaving a lot on the table if I don't get it tuned? Anybody do a heads and mild cam swap and not alter the tuning. I imagine I'll need to step up to a 195 fuel pump and 24 pound injectors. Looking for input. Thanks

[erratic50]

Biggest thing is 19 lb injectors are at 100% duty cycle at around 320 HP.

The next challenge is injector size vs computer vs MAF. There are those who put on a "recalibrated" MAF so they can run larger injectors without tuning the computer. Recalibrated is another way of saying broken. They give up massive amounts of timing and yield an uncorrectable loss in performance.

What you need is larger injectors, a "normal calibration" MAF, and computer that knows about the larger injectors rather than being lied to by a MAF.

For a mildly modified 302 with AL heads and a slight cam you should be able to run 24 lb/hr injectors along with a EEC-IV built for the 1993 Cobra. Put a wideband O2 on it and monitor. You can improve a lean condition with additional fuel pressure but there are limits. If it turns out you need 30's your only good option is to tune the computer.

[4eyedfoxdriver]

What heads and what cam? Fact is some combos better calibrate to each other than others do. My 88 mass air car I put Trick Flow 170 Heads and 1.7 RR , 24lb injectors and pro m meter . Had it on the dyno and it was all fine. We played around with tuning a little, because I had a chip, but it didn't really help anything. If you're intention is a mild build I would leave the stock injectors and monitor either on a dyno or with a wideband.

[crazyfox]

Not sure on the cam. Maybe tfs stage 1. Probably twisted wedge heads. I'm just in the planning stage

[dynodon64]

Just changing the heads only, the stock computer will control it just fine. You may be close to maxing out the injectors, but it will be fine with the stock tune.

[rock4451]

Which way are you leaning for heads?

[srad2drag]

I ended up making 295 rwhp with some ported gt40's and a ported stock intake, 19# injectors, xe270 cam..The car made decent power but diidnit idle good at all. Converted it to maf with a 80mm meter and 24# injectors. The car finally idled good but once it was back on the dyno it lost 20hp. Fortunately tuning got the power back up to 296..