Hi guys,

I am looking at a set of 60lb Dekas for my FG XR6T but I am concerned about the impact this may have on my fuel economy. Anyone put these (or any uprated injectors) in and had issues with fuel consumption?

Thanks guys

All depends how you drive the car mate, I have I.D 1000's and around town my average is about 21l/100 but on the freeway its normally less than 10L/100, normally the rule is if you cant afford the fuel you cant afford to work your car.

With Dekas the scaling needs to be set just right otherwise they run real rich at low rpm which wil make your fule usage suffer badly. Scaled correctly well tuned you won't notice a big difference in normal usage, just when you start using the extra power and response you get from a tune.

There is a good thread on here about the Dekas, great read, hope your tuner has read it.

I gave my car to my tuner on 20l/100k and he returned it on 13.3l/100k now sits on 14.8... that's with 42lb bosch injectors... Bout to throw deka 80lb's in , but You cant rely on the economy reading with bigger injectors

I agree with the above. My dash readout of economy is now way out since the 60lb Dekas were fitted. Obviously the calculations are based on the flow of the factory injectors, be nice if this can be changed, does anyone if this is possible?

I get 15-16L/100km all city/suburban driving stop/start short trips(less than 10kms trips and 50/70kph zones) average speed around 30-32kph.. Don't think I'd get much better than this on stock tune/injectors.Falls dramatically as soon as I start to do longer trips at higher average speeds.

Why will the deka's run real rich at low rpm?

Edited March 25, 201214 yr by Ralph Wiggum
Daka hehehe

60lb dekas flow twice what the factory injectors do hence their duty cycle is much smaller for any given light throttle situation and the economy software doesnt know you have bigger injectors fitted so it thinks your using way less fuel than you actually are so in general it will always show a lower economy reading,

Edited March 25, 201214 yr by bionicxr6t05

I'll clear this up. The PCM is told the flow rate of the injector via the injector tables, estimates the airflow using a speed density algorithm and the calculates the required fuel mass to be delivered. The PCM has all the necessary parameters to calculate the instant economy. Fact is the airflow model is rarely modified in these car and the injector scalars are generally understated a little bit. Datalog your injector pulsewidth with your xcal and if your returned pulsewidth value at idle is less than ~0.0008 sec then you 4bar base scaling for the deka 60's is incorrect according to the Ford Calibratiob data.

^this guy

Knows what he is talking about.

My inst consumption is within .5ltr comparing the dash read out to the actual litres required to fill the tank vs distance travelled. (with 60lb deka's)

Too add to what Toads posted, ask your tuner the values he uses for high and low slopes. If you low slope is up over 95lbs/hr the other injector tables need some work,

Yep, my dash readout is accurate with 42lb bosch. When I fill up it says 622 and I get 622. Sometimes even more because the 0km doesn't mean your tank is fully empty. I think it still has 3 or so litres in it + surgy.

Edited March 26, 201214 yr by Paulie2256