WHAT EXACTLY DOES SPEED DENSITY MEAN?
AND IF YOU MODIFY AN ENGINE THAT IS SPEED DENSITY WHAT DO YOU NEED TO COMPENSATE FOR THE MODIFICATION? AND WHERE DO I GET IT?
THANKS JERRY D.

 

Speed density means the vehicle has no Mass Air Flow (MAF) sensor. This means the computer is programmed to run within set parameters and doesn't read air flow through a MAF sensor and then adjust accordingly. Consequently, speed density vehicle can't respond to certain modifications because the computer lacks the brain power to recognize and respond to these modifications. If you have a speed density vehicle, you can retrofit it with a MAF sensor and computer for a MAF-equipped vehicle. Otherwise, you're spending money for mods the computer can't recognize. Replacement computers are that expensive and you can find a MAF setup for your vehicle off of similar vehicle in the bone yards...if you're lucky. Takes some research, but can be done if you're willing to spend the time and money and effort.

 

Hi Jerry,

Speed-density systems get their basic load signal for the engine not from a mass airflow meter, like in mass-air systems as we refer to them, but instead, they use a MAP sensor (manifold absolute pressure), to measure the vacuum drop in the manifold to determine load, and these are very unforgiving systems with regards to many types of modifications, though they work just fine stock.

You can generally do things like a Superchip, a K&N air filter or airbox elimination kit, and exhaust system changes with speed-density systems. Anything that is much more involved, like porting cylinder heads, camshaft changes, etc., that's when you need a mass-air system.

You can convert many of the speed-density systems over to mass-air. Your best bet, if you want to do serious modifications to this vehicle, is to use the Ford Motorsports mass air conversion kit, as that will get you into the 21st century, so to speak, and you won't have to try to guess & piece things together.

But if all you want to do are relatively minor bolt-ons like I mentioend above, then you can stay with that speed-density system, so it really all gets down to just how far you want to go with your modifications, and of course, exactly which speed-density vehicle we're talking about here.

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

 

THANKS GUYS!
I HAVE A 1991 F-250 4X4 WITH A 5.0L AND E4OD AUTO TRANS.I REALLY WANT TO BEEF IT UP.I ORDERED A CRANE COMPU CAM (PART # 364112 DURATION 190/198 AND LIFT .416/.432)AND A SET OF EDELBROCK ALUMINUM CYLINDER HEADS (PART # 6037) WITH 1.90 INTAKE VALVES.I ALSO PURCHASED A SET OF FORD MOTORSPORT 24lbs FUEL INJECTORS.I GUESS I SHOULD LOOK INTO CONVERTING OVER TO MASS AIR.WHERE CAN I GET THIS SETUP?AND ABOUT HOW MUCH WILL THIS COST?
THANKS AGAIN GUYS!
JERRY D.

[This message has been edited by dvldog458 (edited 04-02-2001).]

 

dvldog
that's some nice stuff you have ordered. I would convert to MAF before anything. Kits are available from Ford SVO on your search engine. Your Ford dealer can get it if they will.

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97 Lariet-sc-4.6-4x off road-auto-3.55 LS-
superchip-Airraid-Perma-cool electric fan & controller

 

HEY GUYS,
I JUST RECEIVED TWO PRICE QUOTES FOR A MAF SETUP.ONE FROM DOWNS FORD IN TOMS RIVER NJ FOR $1,250(THEY CLAIM IT'S AN ALL PLUG IN SETUP).AND THE OTHER ONE IS FROM McCARVILLE FORD IN NY FOR $675(THEY CLAIM SOME HARD WIRING INVOLVED).AM I MISSING SOMETHING HERE?
JERRY D.

[This message has been edited by dvldog458 (edited 04-03-2001).]

[This message has been edited by dvldog458 (edited 04-04-2001).]