Engine cam upgrade to stock 87 foxbody gt 5.0 speed questions

87foxbodystock

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Good morning,
New here nice to meet you all! I am looking to meet some folks to discuss options and concerns to upgrading my stock 87 gt 5 speed foxbody. Well I mean it is stock except full exhaust prior owner put on and shorty headers. Looks like a brand for the headers say compton? not sure.

What I am hoping for is some input and direction on what I would like to do and some tips to keep me from destroying my foxbody. I drive this vehicle probably 700-800 miles a year and want to continue to have this as a driver. What i want to do is gain a little more low end torques and some hp but absolutely am looking for that real lumpy tune coming from it at idle. From what I understand and see on you tube from an individual that said they had a f303 cam in theirs sounds just like what I wan mine to sound like. I dont want to race this but would like to get on it once and awhile. But I am mainly looking for that thump. Can I do this with just a cam and does it need to be tuned after? Does it need a chip? Will the stock MAF, Fuel injectors, Fuel pump, be sufficient? More questions will come once I get some feedback hopefully!
Nice to Meet you!
 
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Mustang5L5

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If your car is stock, and you value your drivability, i would not run an F303 cam.

Your 1987 was not originally equipped with a mass air meter. It should be speed density originally, which runs strong, but is sensitive to vacuum changes, such as when you change out the cam. Step #1 if you are considering a cam swap is to swap to Mass Air.

There are camshafts that do with speed density. I beleive duration is key in terms of picking out a SD friendly cam. You can also run 1.7 Roller Rockers to gain a bit more lift.

Keep in mind, a cam swap on a stock 5.0 HO isn't really going to get you much in terms of HP and TQ gains. Believe it or not, the stock HO cam (especially the 85-88 version) is really good at bottom end torque production and drivability. I can understand wanting a little bit of chop, but by the time you convert to MA, and install the cam and supporting parts for the install, you are probably close to $1K in total cost, for little gain other than some sound.

I don't mean to discourage you, but a better bang for the buck mod might be to install a set of 3.55 or 3.73 gears. You'll retain your drivability and gain some low end grunt.
 
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Willybill32

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MAF wasn’t stock on an ‘87, so someone has added that, and there may be additional mods as well.

I have the E303 cam in mine along with aluminum heads, headers and Edelbrock intake, and it sounds really good at idle and runs well, although I get some bucking when driving at idle speeds. The F cam is more aggressive, and probably not a good choice without other engine mods.
 

87foxbodystock

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Aug 13, 2021
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If your car is stock, and you value your drivability, i would not run an F303 cam.

Your 1987 was not originally equipped with a mass air meter. It should be speed density originally, which runs strong, but is sensitive to vacuum changes, such as when you change out the cam. Step #1 if you are considering a cam swap is to swap to Mass Air.

There are camshafts that do with speed density. I beleive duration is key in terms of picking out a SD friendly cam. You can also run 1.7 Roller Rockers to gain a bit more lift.

Keep in mind, a cam swap on a stock 5.0 HO isn't really going to get you much in terms of HP and TQ gains. Believe it or not, the stock HO cam (especially the 85-88 version) is really good at bottom end torque production and drivability. I can understand wanting a little bit of chop, but by the time you convert to MA, and install the cam and supporting parts for the install, you are probably close to $1K in total cost, for little gain other than some sound.

I don't mean to discourage you, but a better bang for the buck mod might be to install a set of 3.55 or 3.73 gears. You'll retain your drivability and gain some low end grunt.
 

87foxbodystock

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Aug 13, 2021
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Thanks for all the info….. lot to digest and consider but that is what my goal was so hope to hear more from others as well.

How do I know what type of mass air flow or if i have a sd setup? I never really paid attention and assumed with the fuel injection it had a mass air flow
 

87foxbodystock

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Aug 13, 2021
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Thanks for all the info….. lot to digest and consider but that is what my goal was so hope to hear more from others as well.

How do I know what type of mass air flow or if i have a sd setup? I never really paid attention and assumed with the fuel injection it had a mass air flow
 

Willybill32

But at least it's tight!
Jul 16, 2019
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Lexington, KY
Thanks for all the info….. lot to digest and consider but that is what my goal was so hope to hear more from others as well.

How do I know what type of mass air flow or if i have a sd setup? I never really paid attention and assumed with the fuel injection it had a mass air flow
Mass Air Flow became a standard item in 1989, I believe. Prior to that, it was speed density. To determine if it has MAF, look at the air inlet tube running from the air filter to the throttle body. If it’s mass air, you’ll see the meter in that section of tubing.
 

Middleagecrisis

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You'll have to convert to mass air to do anything other than the 1.7 ratio roller rocker swap. Any swap you do with stock heads, intake, gears, etc. is going to be for sound only, as the stock cam is about as max performance as you can get with the stock stuff. Something worth considering, the factory valve springs will need to be changed, even for performance use with the stock cam. Your factory springs were prone to valve float even when new, start twisting up the motor to 5500 rpm and they'll start floating real quick. You also need to upgrade (If still stock) your factory fuel pump and regulator. Not trying to discourage you, just keeping you aware of the bigger picture. I've run the stock cam with 1.7 roller rockers, the B, F, X and a few aftermarket cams. They all have pluses and minuses. If the short block is in good shape, you can always do a head/cam/intake (H/C/I) swap on your stock short block, but you'll spend a couple thousand by the time it's all said and done. The stock 5.0 with valve spring upgrade, 1.7 roller rockers and 3.55 - 3.73 gears is a proven strong runner. This combo (valve springs/1.7 RR) can and has outrun many other fox bodies with the HCI upgrade.
 
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87foxbodystock

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so If i change out the hci on it and leave everything else alone what would I have at that
point? all good feedback just trying to figure out what my next steps are I really want that thump as well but may have to compromise or do it in stages …. interested in hearing what i would have to swap and what is recommended that people have used for HCI would it still need new injectors fuel pump etc
 

TIGGER

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Thanks for all the info….. lot to digest and consider but that is what my goal was so hope to hear more from others as well.

How do I know what type of mass air flow or if i have a sd setup? I never really paid attention and assumed with the fuel injection it had a mass air flow
If your car is SD then from the air box to the TB would be a plastic hose connecting the two. Mass air would have an air meter in between the air box and the TB. Hope this helps.
 

Willybill32

But at least it's tight!
Jul 16, 2019
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Lexington, KY
so If i change out the hci on it and leave everything else alone what would I have at that
point? all good feedback just trying to figure out what my next steps are I really want that thump as well but may have to compromise or do it in stages …. interested in hearing what i would have to swap and what is recommended that people have used for HCI would it still need new injectors fuel pump etc
I used Trick Flow Twisted Wedge aluminum heads on mine with the E303 cam and an Edelbrock intake. On a budget, look for stock heads off another Ford, such as GT40 heads, and an Explorer intake. Not as much power, but less money. Your stock 19 lb/hr injectors will handle the fuel demands, and your stock fuel pump is probably OK, or a second stage replacement. If you add the cam, consider doing a MAF conversion.
 

87foxbodystock

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So i verified that it has a stock sd setup and not mass air flow

does anyone have information on the procedure to swap out the heads and intake? can i start there and leave the stock cam for now? i am pretty mechanical but just want to here how you all say the procedure is
 

General karthief

wonder how much it would cost to ship you a pair
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If you go to the main 5.0 tech page (you are there now) and look for the 5.0 tech/how to threads, there you will find a lot of info on swapping heads, cams and other information.
I would also caution against the F cam (or any of the 'letter' cams) mostly because of the low RPM bucking,
I would also go with the 1.7 rockers and a 3.55 gear and ride
 

jrichker

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@87foxbodystock

I'm a little late to this party, but for sake of sharing information, I will share this...

Computer system differences in 86-95 Mustangs.

Revised 15-Jan-2018 to add requirements for larger fuel system components to support large changes in airflow through the engine.

All 5.0 foxbody engines from 86-95 are OBDI
OBD1 comes in Speed Density and Mass Air Flow versions. It differs from OBDII in that diagnostic data cannot be streamed through the diagnostic port in a real time mode. The diagnostic data is stored in volatile memory and dumped on command by an external jumper or code reader connected to the computer’s diagnostic port. Watching the Check Engine Light, an external test light or voltmeter are all that is need to dump the codes on an OBDI system. An OBDI code reader can be used, but it isn’t an absolute necessity.

ODBII is capable of streaming data through the diagnostic port in real time mode. It requires a code reader that handles the OBDII data format. No code reader, no way of knowing what the codes are. The plus is you can watch changes in sensor data as they happen, and use the information to plan changes in the computer's program. OBDI requires a laptop & some specialized hardware to do the same thing.

Both OBDI & OBDII have adaptive learning to accommodate changes in sensor output, so as the sensors and airflow values change, the computer adjusts for them. Mass Air systems have a greater range of adaptive learning than Speed Density.

Speed Density uses Manifold vacuum (MAP), Throttle position (TPS) and RPM, & Air Temperature (ACT) to guess how much air the engine is pulling in. Then it uses all of them plus the O2 and ECT sensors to calculate the air/fuel mixture. It is dependent on steady manifold vacuum and minimal changes in airflow from the stock engine configuration to maintain the proper air/fuel ratio. Change the airflow or vacuum too much and the computer can't compensate for the changes, and does not run well. Forget about putting a supercharger, turbocharger or monster stroker crank in a Speed Density engine, because the stock computer tune won’t handle it. Every time you seriously change the airflow through the engine, you need a new custom burned chip to make the engine run at peak performance. Most aftermarket cams will not work well with Speed Density, and that includes the Ford letter cams.

Mass Air uses a Mass Air Flow meter (MAF) to actually measure how much air is being pulled into the engine. The computer uses this information and inputs from the O2, TPS, ACT, ECT, RPM and Barometric Pressure (Baro) sensors to calculate the proper air/fuel ratio. It is very tolerant of changes in airflow and vacuum and tolerates wild cams, high flowing heads, and changes in displacement with minimal difficulties. Just remember that large changes in airflow require more fuel than the stock fuel system can deliver. At that point, you will need larger injectors and a larger fuel pump to make the engine run like it is supposed to. Larger injectors can be used with either an aftermarket calibrated MAF or a custom dyno tune. This makes it possible to use the stock computer with engine displacements from 302-408 cu in, and make many modifications without a custom dyno tune chip. Put a new intake manifold on your 331 stroker and the computer figures out how much more fuel to deliver without having to have a new chip burned to accommodate the extra airflow.

Computer & interchange information
The Mass Air computers from 89-93 are interchangeable with a few exceptions. Just be sure you use the MAF & MAF sensor from the same series computer. The auto transmission computers use a different start circuit than the manual computers. You can use an auto trans computer in a 5 speed car with no problems or changes. I have done it in my original 89 Mustang GT, and I know it works OK. I have no positive input or comments on using a 5 speed computer in an auto trans car. I personally would not do it.


The odd duck is the 93 Cobra computer, labeled X3Z which is internally calibrated for 24 lb injectors. Use the MAF & MAF sensor from the X3Z computer to avoid problems with the computer's internal calibration. Try and avoid the 93 Cobra computer if you can.

Some cautions about O2 Sensor harnesses need to be observed to avoid damage to the computer.
Only run a auto trans O2 harness with an A9P
Only run a 5 speed trans O2 harness with an A9L
See http://forums.corral.net/forums/gen...manual-auto-differences-year-differences.html for more O2 sensor wiring harness info

All the following are mass air unless they say Speed Density

8LD - MANUAL 88 5.0L Mustang Speed Density
8LF - Auto 88 5.0L Mustang Speed Density
A9L - 89-93 5.0L Mustang 5-spd Mass Air
A3M - 93 5.0L Mustang 5-spd Mass Air
A3M1 - 93 5.0L Mustang 5-spd Mass Air
X3Z - 93 5.0L Cobra 5-spd Mass Air internally calibrated for 24 lb injector
A9P - 89-93 5.0L Mustang Auto Mass Air
A9S - 88-93 5.0L Mustang California Mass Air
C3W - 89-93 5.0L Mustang Auto
DA1 - 87 5.0L Mustang 5-spd Speed Density
J4J1 - 94-95 5.0L SVT Cobra 5-spd
T4M0 - 94-95 5.0L GT Vert 5-spd
U4P0 - 94-95 5.0L GT Auto
W4H0 - 94-95 5.0L GT
ZA0 - 95 Cobra R
D9S - Lincoln LSC
ZXA3
LLX3
CCA1
CCA0
AOL2
AOL3

MASS air conversion instructions from http://www.stangnet.com/tech/maf/massairconversion.html FREE

Revised 2 Aug 2014 to add new links to conversion harness suppliers, diagram for repining computer wiring connector and YouTube video

A9L (5 Speed) computer from junkyard $100-$150 -maybe more – A9L computers are becoming hard to find.
A3M (5 Speed) computer from junkyard $100-$150
A9P (Auto or in a pinch, it will work in a 5 Speed car) 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.

A9L computers are 5 speed only
A9P computers are automatic, but will work with a 5 speed.

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, actually less work that swapping the wiring harness.
Conversion Harness kits & parts

Youtube video how to do a Mass Air conversion using a conversion harness kit (somewhat long but useful)

View: http://www.youtube.com/watch?v=mnnTgXkHU9Q


hrdp_0705_26_z-ford_thunderbird_harness-.jpg


Wire side 60 pin computer wiring harness connector
a9x-series-computer-connector-wire-side-view-gif.gif


Computer side 60 pin computer wiring harness connector
eec-iv-computer-connector-for-5-0-mustang-gif.gif



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. (because 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 may be compatible (single dash connector, fuel pump relay under the hood). You may end up running some extra wire for the fuel pump relay. Comments and input from someone who has actually used the 92-93 EFI harness would be nice.

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 http://www.kustomz.com/cat3.html Buy the TR70 for $40-$45 depending on if it’s on sale or not. 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
 
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mikestang63

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if you want a plug and play SD to MAF, you can use the now NOS discontinued Ford Motorsport adapter and harness, a Mass Air Meter, and either an A9l or A9P.... They are not cheap... i happen to know someone who might have one :)