street setup

[TOOLOW91]

so i want to wake my 5.0 up a bit but nothing crazy at all. the car already has longtubes into either 2/12 or 3 inch pipes into flow 40's, no cats or no x or h pipe..


my first question is it worth it to do an h or an x and add high flow cats for some back pressure?

i was looking into doing Gt40 heads, Cobra Intake, an E303 cam .. what do you guys think? what are the diffrent castings on the heads and which are better as im not totally familiar with this.

another question is should i run a little bit bigger injectors and change the throttle body and mass air meter?

im just trying to pick a direction and i want a goal to hit seeing as its my everyday car im not looking to change gears in the rear simply for gas miliage purpose because its my dd but i do see a 5speed swap in the future..

so talk to me my fellow techs lmk what you think

 

[83T-top]

You can tell the difference between the GT40 and GT40P by the markings on the end of the head.

The GT40 has 3 bars and also has the casting GT on the corner and the GT40P has 4 bars on the end of the head and has GTP casted on it.

From what I've read the GT40P perform a little better even though the exhaust valve I believe is a little smaller.

The GT40P heads will raise the compression slightly and require a certain header, some people use shorter spark plugs and wires with an angle on the boot and just go throught the trouble of taking off the header when needing to get to the plugs.

The GT40 will just bolt on. IMO they are a little pricey for stock iron heads, unless you can find for a good deal. If you look on like ebay they are generally around $400 bucks and sometimes higher with shipping and that's used. Throw in another $2-3 hundred you can get a set of used ford racing x303, trick flow, or Edelbrock heads. Just make sure you don't get the bigger 2.02/1.06 valves otherwise you'll have to worry about the pistons. Trick flow is the exception you can get away with running the bigger valves, just don't get too big of cam.

It all depends on how much you really want to save. Here's a couple of links on the flow numbers and horsepower tests.

Unltimate Guide to 5.0 Cylnder Heads, Part 1
Unltimate Guide to 5.0 Cylnder Heads, Pt 2

 

[TOOLOW91]

so something like an afr 165 would work for my application then ?

 

[Saleen8786]

just install an upper and lower intake.throttle body,mass air flow sensor and some gears. My car had all mentioned plus full exhaust and a suspension and it was really fun for a daily driver and whopped up on alot of cars on the street,couple lt1 vettes,ws6,other mustangs etc.

 

[TOOLOW91]

the thing thatscares me about doing the rear is losing miliage .. im gettin 140 to a tank and thats being a real rreal good boy

 

[Saleen8786]

just put 3.55 in it,gas it cheaper than ever lol,no seriously 3.55's and if you drive it nice will not hurt much at all,just dont install a bigger fuel pump,thats where it killed me wit mpg

 

[Foxfan88]

just put 3.55 in it,gas it cheaper than ever lol,no seriously 3.55's and if you drive it nice will not hurt much at all,just dont install a bigger fuel pump,thats where it killed me wit mpg

a fuel pump upgrade wont affect your fuel mileage. mustangs have a return style fuel system. so all the un-necceary fuel to pressurize the rail is returned back to the tank. your fuel mileage problem lies elsewhere, not the fuel pump.

 

[warriorpluto]

a fuel pump upgrade wont affect your fuel mileage. mustangs have a return style fuel system. so all the un-necceary fuel to pressurize the rail is returned back to the tank. your fuel mileage problem lies elsewhere, not the fuel pump.

im glad to know this. i go on ahead with my bigger fuel pump as planned now.

 

[lang williams]

a change to 327 or 355 gears might actually help your city mileage. you don't have to work the engine as hard to get it moving an you can get into 4th or 5th at slower speeds to compensate for it. but when you want to rip thru the gears you get into the power band quick.

 

[jrichker]

If you only get 140 miles per tank with stock gears, you have either a lead foot or some serious tune issues. I get 270 MIles per tank mixed city/highway driving in a stock Mustang with a 5 speed. My previous 5 speed Mustang with3.55 gears, Explorer intake and 70 MM MAF would do 230 miles per tank mixed city/highway driving.

Here's where to strt to isolate any tune problems you have.

Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.

See Troublcodes.net Trouble Codes OBD & OBD2 Trouble Codes and Technical info & Tool Store. By BAT Auto Technical

If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.

89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.

The STI has a gray connector shell and a white/red wire. It comes from the same bundle of wires as the self test connector.


There is a single dark brown connector with a black/orange wire. It is the 12 volt power to the under the hood light. Do not jumper it to the computer test connector. If you do, you will damage the computer.

What to expect:
You should get a code 11 (two single flashes in succession). This says that the computer's internal workings are OK, and that the wiring to put the computer into diagnostic mode is good. No code 11 and you have some wiring problems.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

Alternate methods:
For those who are intimidated by all the wires & connections, see Actron® for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see EQUUS DIGITAL FORD CODE READER (3145) – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.

 

[57fairlane]

If you only get 140 miles per tank with stock gears, you have either a lead foot or some serious tune issues.

no kidding . . . I would probably do a little tune up first.

A friend of mine had a 92gt with ported gt40p heads, a ported cobra intake, an e-cam, 3.73s with a t5 and that thing would get 23-24mpg on the highway.

To answer your questions, doing the exhaust has its pros/cons. I would rather have a 2.5" exhaust with a x-pipe than your 3" straight out with some flowmasters.

It won't lose/gain any power but it will cost some to have a nicer and quieter exhaust.

The only way that kind of budget setup works anymore is if you can do the work yourself. I can find gt40 or gt40p heads all day for $300 but I don't spend much because I would port the heads myself and only let the machine shop surface or mill them. Same with the labor for the intake and the cam.

If you do it all yourself you might have $700-800 in swapping everything out BUT if you have to pay a shop to do it, it would be at least twice that.

 

[Boostedpimp]

Upgrading the exhaust on a stock car has always proven to be a loss in low end torque for me but that can be off set by swapping your gears. I'd also suggest 3.55's if you were to do it because there not a drastic jump from 3.08's or 3.27's

@70mph
2.73:1 - 1696 RPM
3.08:1 - 1914 RPM
3.27:1 - 2032 RPM
3.55:1 - 2206 RPM
3.73:1 - 2318 RPM
3.90:1 - 2423 RPM
4.10:1 - 2548 RPM
4.30:1 - 2672 RPM
4.56:1 - 2834 RPM

Or upgrade your intake, tb and maf to offset the freer flowing exhaust your adding

 

[TOOLOW91]

sounds good guys and yea i thought about running the codes to see if maybe there was a bad 02 sensor or something to that effect ....

the maf was changed and iac was changed as well as a full tune up but i think like jrichker said theres a tune issue because then again were talkin about a kid who i got the car from who didnt no the fuel pump relay was bad.. a day into me driving it it acted up and never shut off.. i fixed it asked him about it and he told me with a blank dumb stare oh yea i thought maybe it was on sometimes after the car wasnt runnning but i wasnt sure..


just to give u a little back round ive been workin on cars since before i can drive but thank you for the diagram for the plug as this whole mustang thing is new to me

 

[93lxcobra]

Just an FYI, I have a 93 LX 5.0 with 160k miles full exhaust with high-flow cats, 3.73 gear, March ram air (dirty filter), 3/8" intake spacer, March pulleys, and I see 20-21mpg around town being nice half the time and 28-29 on the highway keeping it around 70mph. Not too bad.

 

[TOOLOW91]

yea oviously im dumpin fuel, im gonna check codes tomorrow but im thinkin its 02's still