Intake/Head/Cam package that does work well with 5.0 Speed Density?

1987LX5.0

New Member
Dec 30, 2020
6
0
1
56
London, Ontario
I'm new here. Have a 1987 Fox 5.0LX, 5 speed with 170K on odometer. Roller Rockers, K&N filter, upgraded throttle body, underdrive pullies, headers, flow masters and 3.55 gears have been added. I live where the car is stored for our winter months and typically only drive this Mustang on decent weather days and only about 2 - 3 thousand kilometers a year. While preparing the car for winter storage this year, I ran into what may be a head gasket issue, which brings me to my question. If the heads are coming off, I would like to upgrade the heads which to me would be a logical time to also upgrade the intake and cam. I have taken some time to read up on the speed density to mass air conversions and am considering the best approach for me. I'd like to know if there are known packages of intake, head and cam that could add in the range of 100hp and 50 lb/ft of torque that work well with SD? If someone has a suggestion as to a package, or the individual components that would make a package I'd appreciate hearing what you'd suggest. Thanks.
 
  • Sponsors(?)


MustangIIMatt

I need something stupid to play with
Mod Dude
Mar 7, 2002
9,019
4,711
224
Twister over on AFM ran the stock speed density ECM on his '86 LX with the following build:

Ford 302 crate engine short block
Ford Y303 heads
Isky 371-252/257 cam
Cobra Intake
24lb injectors
65mm Accufab throttle body

It'd hunt at idle until it warmed up, then it had excellent drivability, returned mid 20s for highway fuel economy, ran low 13s in the 1/4 (car was set up for autocross), and dyno'ed at just under 300rwhp... all while passing California's smog check (that's right, it still had a smog pump, egr, and cats).

I thought the build was BS until I drove it myself in St Louis, Missouri in 2003 when he and I were both in town for WFC 6.

The hard part of doing a speed density build with the stock computer is that you have to keep manifold vacuum high (meaning your choice of off-the-shelf cams is limited to stock and the Isky I mentioned), and keep the increases in air and fuel intake balanced.

Building it and then having a custom chip burned for it will make life easier, and converting to either mass air or a modern standalone aftermarket ECM easier still.
 

7991LXnSHO

Now I want a 10 year badge
10 Year Member
Sep 1, 2010
3,764
906
174
Kearney, NE
Now that Matt answered the “how” question, there will be a lot of “should you” answers.
I am betting a MAF conversion will be easier to support than finding a tuner and a chip in a lot of less populated regions. Are you up to doing the switch? If so, your power goals should be fine with this method, and diagnosis of problems will be like a stock Ford.
The stand alone efi will also require DIY, even with some expert help here. It will have a lot of adjustability and should run a much faster computer. How good are you with electronics and programming?
 

1987LX5.0

New Member
Dec 30, 2020
6
0
1
56
London, Ontario
Twister over on AFM ran the stock speed density ECM on his '86 LX with the following build:

Ford 302 crate engine short block
Ford Y303 heads
Isky 371-252/257 cam
Cobra Intake
24lb injectors
65mm Accufab throttle body

It'd hunt at idle until it warmed up, then it had excellent drivability, returned mid 20s for highway fuel economy, ran low 13s in the 1/4 (car was set up for autocross), and dyno'ed at just under 300rwhp... all while passing California's smog check (that's right, it still had a smog pump, egr, and cats).

I thought the build was BS until I drove it myself in St Louis, Missouri in 2003 when he and I were both in town for WFC 6.

The hard part of doing a speed density build with the stock computer is that you have to keep manifold vacuum high (meaning your choice of off-the-shelf cams is limited to stock and the Isky I mentioned), and keep the increases in air and fuel intake balanced.

Building it and then having a custom chip burned for it will make life easier, and converting to either mass air or a modern standalone aftermarket ECM easier still.
Thanks Matt. So best practice would be if purchasing the above components to still do a custom chip or convert to mass air correct? Thanks.
 

1987LX5.0

New Member
Dec 30, 2020
6
0
1
56
London, Ontario
Now that Matt answered the “how” question, there will be a lot of “should you” answers.
I am betting a MAF conversion will be easier to support than finding a tuner and a chip in a lot of less populated regions. Are you up to doing the switch? If so, your power goals should be fine with this method, and diagnosis of problems will be like a stock Ford.
The stand alone efi will also require DIY, even with some expert help here. It will have a lot of adjustability and should run a much faster computer. How good are you with electronics and programming?
Thanks for your reply. I've read different approaches to convert to mass air, I understand one could take components from a mass air Mustang, something about a Mega Squirt set up and even a Ford OEM conversion. Would you have a preferred approach if going to mass air? Thanks.
 

HemiRick

Active Member
Jun 28, 2020
464
148
53
57
Memphis TN
OEM puter is sequential injection and a Megasquirt is batch. I'm thinking if I were in your spot convert to OEM and use a Motes chip if you want to see whats going on/tune things.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
18,841
6,218
193
polk county florida
Swap to maf can take the WTF factor out of the build, I've read some 'runs good' and 'can't get it to run right' stories, a chip is always a choice but again, can be trouble down the road requiring another chip, the aftermarket ecu like ms and others offers endless tuning with the added new components compared to 30 year old wiring and components.
Me? I would do a maf swap first, make sure everything is good then do the h/c/i swap.
Just my thoughts.
 

MustangIIMatt

I need something stupid to play with
Mod Dude
Mar 7, 2002
9,019
4,711
224
Thanks Matt. So best practice would be if purchasing the above components to still do a custom chip or convert to mass air correct? Thanks.
With Megasquirt and others being so affordable these days, I'd probably go that route. Like I said, that combo is one that I know works with the stock ECM and tuning, but there's room for improvement.
 

a91what

SendMeUrDataLog
Mod Dude
Apr 6, 2011
10,105
6,257
204
32
Hillsborough county
Not all Megasquirt are batch fire....

MS2PNP is batchfire and I have customers making over 1000hp with these
Microsquirt is batchfire and same as above
Stinger PIMPXS is Ms3 based and is full sequential
EFI source gold box for the fox [best value IMO] is ms3 based and full Sequential
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
35,080
11,206
224
Massachusetts
I’m doing the same thing. My car was SD and I did a healthy amount of bolt ons. I finally did a HCI upgrade and before pulling the engine out, I converted to mass air.

most expensive part is the ECU. The wiring kit is $50 and LMR reproduces the hoses now. Given the cost of my engine upgrades, it was cheap relatively speaking.

only took me an hour or so to do the wiring, and car ran beautifully after. I used a SN95 70mm MAF.

Then I ripped the engine out and put together my combo. It will go back in with the A9L .

I built an MS3X. Once the car is back running and I’m “done” and all the kinks are ironed out, I’ll swap to the MS3x setup.
 
  • Like
Reactions: General karthief

Monkeybutt2000

Advanced Member
Aug 11, 2019
517
355
73
49
Lafayette,IN
I built an 87 LX for Factory stock class way back in 98'. Engine was basically a stock 95 Cobra engine, so GT40 irons Cobra intake and stock cam. Went [email protected] And it was a "slow" car in the class. I honestly wouldn't bother with a cam in a SD car these days.
 

Willybill32

Active Member
Jul 16, 2019
231
93
38
Lexington, KY
I converted my ‘86 to mass air years ago using a Ford kit. It wasn’t difficult, although I had to move a couple of pins in the ECU connector block. I now have aluminum heads, cam, headers, etc. and it runs great!
 

1987LX5.0

New Member
Dec 30, 2020
6
0
1
56
London, Ontario
Well gentlemen, thank you all for your replies. Lots of good information to digest. To be honest what I'm kinda struggling with is engine performance gain vs cost for that gain. For example, I look at something like the Trick Flow 350 HP Street Heat Twisted Wedge Top-End Engine Kit for 86-95 Fuel Injected 5.0L engines which cost around $3100.00 US and then add in the MAF conversion for about ~ $1200.00 US and say help with this install another $1500 and I'm around $5800.00 US. Now what I'm comparing this with is trying to figure out if it would make sense value wise to consider just adding a decent upgrade in heads and intake to see if I could at least get another 60 hp and ~ 30 lb/ft torque from my current engine and bolt ons while finding a way to have the current SD manage this upgrade with no issues of driveability? I could be receptive to purchasing rebuilt heads and a good quality intake since the lower end of my current 5.0 is original. If this approach is realistic, I'm guessing it would be about 1/4 cost but would be about a 50% gain as compared to the complete Trick Flow Top End Kit upgrade? I would get my current engine leak down tested to insure the bottom end is fine before any top end work is done for whichever direction I do end going. Again I do appreciate all replies, I have written down all the key points in replies above so if I do go the complete top end kit I have expert advice of MAF conversion options. Thanks.
 

vrm71

Member
Dec 13, 2017
39
8
18
50
Sacramento
Probably 50+ over stock, it was a good combo for street, way more power than stock. I also liked the gt40 heads, explorer intake with 1.7 roller rockers on the stock cam, almost as well.
 
  • Like
Reactions: Potomus Pete