Mass air conversion from speed density

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Jun 8, 2011 | 03:52 PM

wreckless93

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Mass air conversion from speed density

last winter i purchased a 94 F-250. since that time i have replaced trans and done alot of mechanical work to the truck. about a month ago i pulled the motor because it was burning oil, and making an odd screeching noise through the exhaust. I figured while it was out i would make some altercations to the motor ( cam, intake, flat top pistons ect.) well after calling summit and doing some research i found out i am stuck with a "speed density motor" and to make the altercations i need to wire in a MAF sensor. Correct me if im wrong. But this means i need a new ECM? And my trans is the E4OD. so what is my solution? I want to go big with this motor but i cant without a new computer? If someone has any idea what im talking about please give me so clues as to what i should do. The machinest said the motor has to be bored over. Can i even do that? Seems like these speed density motors arent the best to build. If u can help i would appreciate it, thanks

Jun 8, 2011 | 04:21 PM

redneckin2010

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From: michigan

you didnt state which engine you currently have, but being a 94 f250 i would say 351? if you do have the 351, in order to do engine upgrades it will need to be maf due to the sd system not fluctuating with engine needs. the best thing to do is find a 94 or 95 302 and take its comp, harness and maf sensor. when looking for a computer make sure you find one that is for the e40d, some trucks had the 4r70 trans and its not the same.
this link will tell you what comp you need- Ford Fuel Injection » EEC Program Codes
the speed density is not "stuck" to that engine, its just the computer style. so once converted to maf you can add your mods and maf usually adds power also.

Jun 8, 2011 | 06:39 PM

strokin'_tatsch

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From: Austin, TX

Yes, you can bore the engine over. You can build the engine however you want, but if you get too wild on the cam, compression, or higher than stock displacement, you won't be able to run the speed density computer system. You will have to switch to mass air.

There are a bunch of threads on this forum relating to MAF(mass air flow) conversions, so you might try finding a few of them and reading through just to gain knowledge on the subject.

Here is a little more reading on the subject to pick through.

Ford F-150 Mass Air Conversion - FordMuscle

If you have a a 351, this harness might work for you. Ford Fuel Injection » OBD-II E4OD Mass Air conversion

Jun 8, 2011 | 08:09 PM

wreckless93

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i read through about 5 posts. and the confusing part to me is, say all i want to do is put as big of a cam as i can go ( without converting). I called summit and they said they dont carry one. it is a 351 W. also cant i bypass all of this by switching to a carb and buying a trans controler? i had a buddy who did some major mods to a 69 351 W and put it in his 95 f-150. The cost was far from cheap so i just want the most cost efficient option. thanks for your replys

Jun 8, 2011 | 09:07 PM

Conanski

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From: Ottawa, Ontario

Summit sells lots of SD friendly cams, the Comp cams 35-512-8 and 35-349-8 are a couple good ones that will really wake the motor up without upsetting the stock computer.

Jun 8, 2011 | 09:12 PM

lasg4

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Quote:

Originally Posted by Conanski

Summit sells lots of SD friendly cams, the Comp cams 35-512-8 and 35-349-8 are a couple good ones that will really wake the motor up without upsetting the stock computer.

How much vacuum does your engine pull at idle with the cam you have in it?