Speed Density......what do you do with it???

[nunly94gt]

Im looking at an 88gt with 100k on the car. Its good ole speed density and the last fox body I owned went carbuerated. Is everyone doing the same thing? Is there anything, you can even do with it?

Thanks in advance!!!

 

[stangboy]

My 88 still has SD and I plan to convert it to Mass Air at some point. While the car is still stock I'm gonna keep the SD but when I start modding I'll go ahead and convert it. I don't really want to go carb'd.

 

[nunly94gt]

What is needed to go MAF on one? Ive never even contemplated doing that.

 

[parrish5o]

Not a whole lot you can do with SD. It's really easy to swap over to mass air. They make a kit with everything you need.

 

[jrichker]

The Speed Density will work fine for most simple mods. Anything that makes a major change in vacuum upsets Speed Density. High flow heads and long duration cams are two of the items that can make a major change in vacuum.

All of the other bolt ons such as bigger throttle body, intake manifold, headers will work fine with Speed Density.

Here's the tech note for Speed Density to Mass Air conversion...
MASS air conversion instructions from MAF - Mustang Mass Air Conversion - StangNet - The Mustang Network FREE
A9L (5 Speed) computer from junkyard $100-$150
A9P (Auto or in a pinch, 5 Speed) computer from junkyard $100-$150
70MM MAF from 94-95 Mustang GT - $40-$70
MASS Air wiring harness kit $30-$85

The whole thing is probably less than $300 using junkyard parts.

The conversion harness seems to work well for most folks. It avoids the compatibility problems in using a harness from the junkyard. Simple and cheap, it is actually less work that swapping the wiring harness. I have pulled the stock harness out of a wrecked car and it was like wrestling a big python.

Conversion Harness kits & parts
Interactive Systems & Technologies Mass Air Home Page
Ford Fuel Injection EFI Harness Pigtails

If the idea of moving & soldering wires scares you, here's a list of compatible Mass Air wiring harnesses.

Copied from bbunt302
Just for reference, here's a list of all the compatible years:

89 harness should work for 86-89 as long as you're using mass air.
90 harness will only work in a 90. (B/c of air bags and dual dash connectors)
91 through early 92 harnesses should be compatible (single dash connector, fuel pump relay under driver's seat)
Late 92 through 93 harnesses should be compatible (single dash connector, fuel pump relay under the hood)

Larger MAF to go with Mass Air conversion:
94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

*1.) Metal flange adapter Kurtz Kustomz Motorsports, Inc. KKM Buy the TR70 for $44.95. Or spend some time on eBay looking for one that may fit.
Try AutoZone and ask for 81413 - Spectre / 3 in. Aluminum Intake Mass Air Flow Sensor Adapter at $12.00. You may have to order it online.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.

A Also see Ford Fuel Injection for help with the harness parts RJM Injection Tech EFI Harness Pigtails:, and connector pins, RJM Injection Tech Ford Terminals:

 

[strtrcr50]

I have pulled the stock harness out of a wrecked car and it was like wrestling a big python.

I did my mass air swap using an 89 harness and never thought about it that way. That is an amazingly accurate description.

 

[lang williams]

you can read up on speed density mods on Portal

 

[1987stangman]

Not a whole lot you can do with SD. It's really easy to swap over to mass air. They make a kit with everything you need.

Not true. Folks can argue this forever. I still run SD with my mod's in my sig with NO driveablity issues. Taking this setup to a new level IE: power adders, etc could/would be a differant story, I have not been down that road yet. But If your looking to make big power with endless oppertunities, then, upgrade to mass air. If your looking for cheap horsepower with room to grow start with the SD car.

 

[nunly94gt]

The Speed Density will work fine for most simple mods. Anything that makes a major change in vacuum upsets Speed Density. High flow heads and long duration cams are two of the items that can make a major change in vacuum.

All of the other bolt ons such as bigger throttle body, intake manifold, headers will work fine with Speed Density.

Here's the tech note for Speed Density to Mass Air conversion...
MASS air conversion instructions from MAF - Mustang Mass Air Conversion - StangNet - The Mustang Network FREE
A9L (5 Speed) computer from junkyard $100-$150
A9P (Auto or in a pinch, 5 Speed) computer from junkyard $100-$150
70MM MAF from 94-95 Mustang GT - $40-$70
MASS Air wiring harness kit $30-$85

The whole thing is probably less than $300 using junkyard parts.

The conversion harness seems to work well for most folks. It avoids the compatibility problems in using a harness from the junkyard. Simple and cheap, it is actually less work that swapping the wiring harness. I have pulled the stock harness out of a wrecked car and it was like wrestling a big python.

Conversion Harness kits & parts
Interactive Systems & Technologies Mass Air Home Page
Ford Fuel Injection EFI Harness Pigtails

If the idea of moving & soldering wires scares you, here's a list of compatible Mass Air wiring harnesses.

Copied from bbunt302
Just for reference, here's a list of all the compatible years:

89 harness should work for 86-89 as long as you're using mass air.
90 harness will only work in a 90. (B/c of air bags and dual dash connectors)
91 through early 92 harnesses should be compatible (single dash connector, fuel pump relay under driver's seat)
Late 92 through 93 harnesses should be compatible (single dash connector, fuel pump relay under the hood)

Larger MAF to go with Mass Air conversion:
94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

*1.) Metal flange adapter Kurtz Kustomz Motorsports, Inc. KKM Buy the TR70 for $44.95. Or spend some time on eBay looking for one that may fit.
Try AutoZone and ask for 81413 - Spectre / 3 in. Aluminum Intake Mass Air Flow Sensor Adapter at $12.00. You may have to order it online.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.

A Also see Ford Fuel Injection for help with the harness parts RJM Injection Tech EFI Harness Pigtails:, and connector pins, RJM Injection Tech Ford Terminals:

Very, Very good info!!!!! I will probably do this instead.
Thanks for all the info guys!!!! I will keep posted on the car if I get it this weekend.

 

[Manewaymja2]

I have to wonder what you guys mean buy major mods. Is adding a 100 shot of nitrous major as it seems to work fine in my SD 87 mustang. even though im going to convert to MAF shortly and just for the hell of it, but glad to know that major mods will require this.

 

[jpchefz]

You could always get a kenne bell Supercharger for speed density as well. Don't know how it works with bigger head, but it sure gives a nice boost for stock.