Fordnatics List Archive

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Mail From: Cory Erickson <(email redacted)>

I have an '86 Mustang GT with the HSC heads (stock-->choke! choke!) and
the speed density computer. I would like to add some SIMPLE CHEAP mods to
make it break into the 14's (which I know it's not now). I of course know
of the first things to do- Tune up with plugs, wires, cap, rotor, and timing
adjustment. Which brands are best for these? U-grooves? spiral wound wires?
What do I have to do to set the timing? anything special because of the comp-
uter? What about more involved mods, like 1.7 rockers? Will the speed density
allow for the computer to adjust to such a mod? Is there real gains from short
belts, headers, plenum spacers, K & N filters, or underdrive pulleys?

I have read the Archives but am still confused because of all the cars (well
tuned) running these mods successfully into the mid 12's.

Any help or advice would be greatly appreciated,

Cory Erickson
(email redacted)

1986 blue (stock) Mustang GT 5.0

This read-only message was archived from a public mail list.
Mail From: (email redacted) (Robert King)

> I have an '86 Mustang GT with the HSC heads (stock-->choke! choke!) and
> the speed density computer. I would like to add some SIMPLE CHEAP mods to
> make it break into the 14's (which I know it's not now). I of course know
> of the first things to do-

Always a good place to start...


> Tune up with plugs, wires, cap, rotor, and timing adjustment.
> Which brands are best for these? U-grooves? spiral wound wires?

I've had the best results with the stock Motorcraft plugs with the stock heat
range and the stock gap. Platinum plugs are OK, except they are more expensive,
don't give *me* any more horsepower, and can't be re-gapped. Stay away from
gimick plugs like split-fires, my car can't tell the difference, but my wallet
can!

Ford Motorsport plug wires have a good reputation. I use Mallory spiral core
wires myself.


> What do I have to do to set the timing? anything special because of the comp-
> uter?

Not really. On earlier ignitions, you had to disconnect the vacuum advance to
keep timing at base. On EEC-IV equipped cars, you do this by disconnecting the
SPOUT connector. This is located on a (yellow) wire coming from the TFI module
on the distributor. Pull the plug from the connector - this keeps the computer
from adjusting the timing while you time the engine.

Next, time the engine as you normally would. My engine's old (175,000 miles,)
so I keep it at stock timing (10 degrees,) unless I'm running race gas at the
track, then I bump it to between 13 degrees and 16 degrees - whatever works best
that evening. BEWARE OF DETONATION! If the engine knocks or ipings under a heavy
load or heavy acceleration, back off the base timing a bit. One last thing, DON'T
FORGET TO REPLACE THE SPOUT CONNECTOR! Engines don't run well with no spark
advance.

> What about more involved mods, like 1.7 rockers? Will the speed density
> allow for the computer to adjust to such a mod? Is there real gains from short
> belts, headers, plenum spacers, K & N filters, or underdrive pulleys?

With Speed Density, your options are limited. Anything significant you do to
improve breathing will affect your idle quality and drivability, because the Speed
Density system can't compensate for it.

1.7 rockers *may* be ok, but I don't really know.

I wouldn't recomend a short belt for anything but the occasional drag strip
session. My steering box makes funny noises when I steer with power assist, so
I avoid shorty belts. Besides, my best run (14.527) was with the stock belt.

Headers are a definate area for improvement. Ford smallblocks have always
liked free-flowing exhaust. The 86's are particularly restricted here because of
their crappy heads, but headers would help out, and I don't think they would
screw up the Speed Density calculations.

I don't think a plenum spacer would help at all.

I run a K&N filter on the street, and no filter at the track.

I have yet to see that underdrive pulleys can give any more than 1-2 HP.
There's better places to spend your money.


If you are serious about performance in your Mustang, I believe your first
step should be to replace your Speed Density system with a Mass Air system, I
did this in my '88 GT for about $350 and half an afternoon's labor. This will
open your options considerably. Then you can start replacing your intake,
heads(!), camshaft, and do basicly anything you want.

HOWEVER, if you want to break into the 14's right now, I'd either opt for
a small nitrous setup (50-75 HP,) or rear end gears (3.55 or 3.73.)

- -- Robert King


+-----------------------------------------------------------------------+
| Robert A. King | |
| Systems Software Engineer | |
| Kodak Health Imaging Systems | "I drank WHAT?!?" -- Socrates |
| | |
| (email redacted) | |
+-----------------------------------------------------------------------+
| The opinions expressed here ain't even mine, much less my employer's! |
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This read-only message was archived from a public mail list.
Mail From: David Schwarze <(email redacted)>

Robert King writes:
>

<lots of good advice deleted>

> Headers are a definate area for improvement. Ford smallblocks have always
> liked free-flowing exhaust. The 86's are particularly restricted here because of
> their crappy heads, but headers would help out, and I don't think they would
> screw up the Speed Density calculations.

They didn't screw up mine (and I don't think they screwed up Scott Griffith's
either).
> I have yet to see that underdrive pulleys can give any more than 1-2 HP.
> There's better places to spend your money.

I'm not so sure. I noticed a little more oomph at the top end, and the engine
doesn't sound as "busy" at the top end. When you consider the reduced
wear to the accessories, and the lack of negative side-effects, I
consider this to be a great modification, especially for $69 (check Jan.
'95 issue of MM&FF ads).
>
> If you are serious about performance in your Mustang, I believe your first
> step should be to replace your Speed Density system with a Mass Air system, I
> did this in my '88 GT for about $350 and half an afternoon's labor. This will
> open your options considerably. Then you can start replacing your intake,
> heads(!), camshaft, and do basicly anything you want.

Another option to consider (and one I am probably going to take) is to
keep the speed density system and get a Crane Interceptor. I know a
guy who is at the track every weekend who has an 86 with speed density and
the Interceptor and he runs low 13's all day. He has lots of bolt-on
parts (heads, intake, etc) and uses the Interceptor to adjust the speed
density system to where it works great. The Interceptor costs close to
what the mass-air conversion does (~$500) and doesn't add another
restriction to the intake like the mass-air conversion would.

Just my two cents... no connection with Crane... blah blah blah

-David

=============================================================================
David Schwarze '73 VW Safare Custom Camper (Da Boat)
SAIC Comsystems, San Diego '73 Capri GT 2800 (Da Beast)
(email redacted) '87 Mustang Lx 5.0 (Da Bruiser? Soon...)
=============================================================================

This read-only message was archived from a public mail list.
Mail From: (email redacted) (Scott Griffith, Sun Microsystems Lumpyware)

On Dec 28, Robert King wrote:

> Platinum plugs are OK, except they are more expensive, don't give *me*
> any more horsepower, and can't be re-gapped. Stay away from gimick
> plugs like split-fires, my car can't tell the difference, but my
> wallet can!

Near as most of my race buddies and I can figure, the Ford heads are
designed to run reliably regardles of _any_ plug you shove in them.
They just don't seem to care, until you start running stratospheric
boost levels or other off-the-scale setups. I've gotten to the point
where I've stopped caring what flavor of plug I put in. Autolite,
Motorcraft, or Champion in the right heat range all do the right
thing. Some folks on this list, and on the Mustangs list, have reported
part-throttle driveability problems with the platinum plugs. One can
only assume that it is the car's way of laughing at its owner...

> 1.7 rockers *may* be ok, but I don't really know.

I'd watch out, here, and check the clearances _very_ carefully. The
valve-to-piston clearances in the '86 motor are the tightest of all
the late 5.0 family, due to the flat-top pistons. Mathis has something
to say about 1.7 rockers on a stock '86 motor, but I can't put my
hands on his book right now- I'll look that up later. Anyway, proceed
with some caution.

> Headers are a definate area for improvement. Ford smallblocks have
> always liked free-flowing exhaust. The 86's are particularly
> restricted here because of their crappy heads, but headers would help
> out, and I don't think they would screw up the Speed Density
> calculations.

I run the MAC 1-5/8" unequal lenth shorties on my '86, and noticed a
nice (but not earthshaking) improvement in the upper RPM ranges, with
no loss of low RPM torque at all. Of course, when I took a look at my
stock headers, I could see why. I had one header flange that was about
30% full of weld metal (with a big chunk of MIG wire about 1" long
just sort of bent over up inside the primary tube), and none of them
had openings as large as the port in the head that they were supposed
to match. It seems that in '86, Ford didn't really have the recipe for
making these headers quite dialed in just yet.

> I have yet to see that underdrive pulleys can give any more than 1-2 HP.
> There's better places to spend your money.

Right. Underdrive pulleys should only be used to correct accessory
drive problems, such as overspeeding the power steering pump. This is
a major problem with '86s used in roadracing, where engine revs stay
up near 5000 for 20 minutes at a stretch. Cooling can also be helped
by judiciously underdriving the water pump, to keep it out of
cavitation at high revs. The total power "freed up" in this manner is
pretty trivial. You'd save more power by going to an electric fan, and
doing so provides a _nice_ improvement in low-end throttle response.

-skod

- --
Scott Griffith, Sun Microsystems Lumpyware
expatriate SCCA New England Region Flagging/Communications worker
(and driver, of anything that turns both right and left,
and can pass tech...) Return Path : (email redacted)

This read-only message was archived from a public mail list.
Mail From: (email redacted) (Robert King)

> > If you are serious about performance in your Mustang, I believe your first
> > step should be to replace your Speed Density system with a Mass Air system, I
> > did this in my '88 GT for about $350 and half an afternoon's labor. This will
> > open your options considerably. Then you can start replacing your intake,
> > heads(!), camshaft, and do basicly anything you want.
>
> Another option to consider (and one I am probably going to take) is to
> keep the speed density system and get a Crane Interceptor. I know a
> guy who is at the track every weekend who has an 86 with speed density and
> the Interceptor and he runs low 13's all day. He has lots of bolt-on
> parts (heads, intake, etc) and uses the Interceptor to adjust the speed
> density system to where it works great. The Interceptor costs close to
> what the mass-air conversion does (~$500) and doesn't add another
> restriction to the intake like the mass-air conversion would.

The Interceptor is very nice, heck, I'm even going to get one, but I
think its a bit advanced for an entry-level hot-rodder. Also, Mass Air
need not cost $500. I got my system (Cobra air meter, '91 ECU, and wiring
harness,) from Maximum Motorsports for $350. And yes, it *does* work with
19# injectors!

- -- Robert King


+-----------------------------------------------------------------------+
| Robert A. King | |
| Systems Software Engineer | |
| Kodak Health Imaging Systems | "I drank WHAT?!?" -- Socrates |
| | |
| (email redacted) | |
+-----------------------------------------------------------------------+
| The opinions expressed here ain't even mine, much less my employer's! |
+-----------------------------------------------------------------------+