I am interested in putting a new 302 engine in my speed density 93 f-150. I am considering an engine much like the ford motorsports engines with the gt40 heads and e303 cam. I have read a good deal about upgrading to mass air in order to get the benefits of increased flow through performance heads, cam and induction etc..., however my vehicle is equipped with the e4od transmission. The mass air kit available through ford motorsports appears to only work with either an aod, or manual transmission. I am aware of the transmission control system built by Baumann and that it is possible to install the mass air conversion and the Baumann transmission control unit to achive a mass air system that will work with an upgraded 302 and the e4od. I am also aware of some of the other systems that piggyback 2 computers, one to control the mass air, the original to control the transmission. What I am also aware of is the roughly $1,300.00 cost associated with this type of mass air conversion.

Is it possible to upgrade the existing speed density system with larger injectors, higher volume fuel pump and adjustable fuel pressure regulator to increase fuel delivery so that the proper air/fuel mixture can be maintained? To purchase these items my cost would be nearly $1,000.00 less.

My logic in this thought is that the pumping characteristics of the ford motorsports 302 with gt40 heads etc... will increase a proportional percentage to the stock 302, and the algorithm that the speed density system uses to calculate fuel/air will be off only by that percentage. By using the larger injectors, higher volume fuel pump the increase in air flow can be off set with more fuel. To achive proper air fuel mix the o2 sensor can be metered to determine rich or lean conditions. The fuel flow can then be fine tuned by manipulating the adjustable fuel pressure regulator.

Potential problems:

Will the dynamics of air flow vary significantly at different rpm with the gt40 heads? (will the engine run lean or rich at different rpm). Or will they follow the same curve used in determining the formula used in the speed density system using stock heads?

Will the speed density system work with, say the 24lb injectors? Impeadence, pulse width etc...

Will the fuel rails and lines need to be upgraded?

Is this another one of my hairbrained ideas?

My practical knowledge of ford fuel injection systems is zero and I hope to gain some insight from others who may have tried setups similar to what I have described above. Or to hear from those experienced with fuel injection as to whether or not I have sound reasoning.

 

[updated:LAST EDITED ON 27-Nov-01 AT 04:07 PM (EST)]You could just have a new chip burned for your combo.
Shouldn't cost more then a couple of hundred to get it done.
Correct me if I'm wrong, but I think one of the sponsers of this site can burn custom chips. I think their name is DiabloSport?

Roger

Found it!
http://motorhaven.autoanything.com/cgi-bin/Web_store/webshop.cgi?yearmodel=&product=diablochips&cart_id =3838915_28226

 

Thank you for your reply Roger.

Several years ago, when I was shopping for a chip for my truck, I had spoken with the folks at SuperChips and had asked them if the could custom burn a chip for me for an engine like I had described in my first post. The fellow I spoke with indicated that there was some limitation to what they could do with the speed density system. The specifics of the discussion elude me now, but I had not considered it an option since then, until you pointed it out to me. At the time I wasn't seriously considering an engine change as my truck only had about 100k miles on it. It occurs to me that I may not have been speaking to an authority on the subject at SuperChips. I'll contact the people at Diablo and see if they can provide another point of view and post my findings. I'll be sure to mention that that I heard about them through this site, as I noticed they have banner ads here.

I think I will still have to upgrade the fuel pump, injectors and pressure regulator as I understand that the stock 88lph pump in conjunction with the 19lb injectors will only provide enough fuel for about 300hp. A strong short block with the GT40 heads, 1.7 rockers, e303 cam, and a good intake manifold, like those available from Edelbrock, should flow for around 350hp. So, I don't think the chip alone would get me where I want to be, but it might be a means to correct any variables in the formulas in the eeciv. I wonder how accurate the chip makers can be without actually having the engine they are trying to map on a dyno?

Thank you again for taking the time to give me your input. I really do appreciate it.

Clear Skies,
Denis

 

why not just do what ford did to their trucks in 95-96 f150 and bronco .... those trucks came mass air w/ e4od , use that computer , harness and mass air meter . problem solved
i don't think that any chip manufactors can really do much with the factory speed denisty system ... could be wrong though