5.0 Mods need help.

[Rick Parker]

I'll be the first to say I'm not up on the electronics and fuel injection system on a 91 5.0 engine. My son has one that he has begun the time honored modification process. So far stock block crank and pistons, Holley upper & lower intake 165 AFR aluminum heads, C&L 76 mm MAF, 65mm Throttle body, Bassani full exaust system and E303 Ford cam. What would be the proper chain of events to tune it properly. I hope some of you can get me pointed in the right direction.


Lean in the west!
Rick

[Wade Chamberlain]

Rick - the stock EEC-IV 'puter should be able to handle that combo easily. What size injectors is he running? He'll probably want at least 24's. If he ever plans more upgrades, I go straight to 30's.

I'd also recommend ditching that C&L in favor of a ProM 80mm MAF. Second choice would be one of the ProM bullets. Some folks have decent luck w/ the C&L meters, some don't. If you're having cold start problems, idling problems, burning eyes in the garage, lean misfires, lean HEGO codes, etc, then you're in the same exact boat I was with the two C&L's I've owned (76 and 73mm).

Good luck!

[MJN]

Rick

You don't say in the post but I am assuming that you still have the 19 # injectors in the car. With the mods that you mention you are way beyond the capability of the stock injectors and are probably much too lean at the top end.

I have also used C&L meters and have had much better luck with Pro M. I currently have the 80mm unit that Wade mentions and it is by far the best meter I've used so far. If there is a supercharger in the future plans I would jump straight to 42 # injectors (Bosch). They have excellent low duty cycle response and work well even in a stock motor but are good up to about 600HP. I have them in my blown small block with the TFS stage 1 cam that has similar specs to the E303 and the idle, part throttle response and driveability with the 80mm Pro M is as good as any other set up I've had on the car.

By far the best step to take is to get to a chassis dyno that can monitor air / fuel ratio and have the car tuned with a custom chip. You can try doing it with fuel pressure by using an adjestable regulator but it will save both time and money in the long run to just have a chip burned. The chip can also be recalibrated at a later date if I change my combo so it's a one time purchase. Of course you'd have to pay for some more dyno time.

Just to give you an idea as to how far off a calibrated meter and injectors can be, I spent $600 for a chip and 14 dyno pulls to have mine tuned, the A/F ratio was so far off that I came off the dyno with over 60 more HP, and that was with the Pro M 80mm meter that was "calibrated" to the injectors. The out of the box calibration was dangerously lean for a supercharged motor. The more you affect the efficiency of the motor with modifications the more the chance that the meter will not be very close to the ideal calibration. The mods you mention will have significantly changed the BSFC (brake specific fuel consumption) of the motor.

[Rick Parker]

Thanks guys. Appreciate your input.......

Rick