1985 GT - NEW COMER NEEDS HELP.

[8550]

whats good wuth you guys? ive recently graduated from those sport compacts, to these v-8s.
anyways, i bought a 85 gt in fair condition.
heres the get down..
basically, i need help on fixing this car up. i dont have the manual and i have no clue what the engine is, the name, size and all that. my overall goal is to turn this mustang into a camaro killer. folks are telling me about 373 gears(whats that), a thorough tune up (whats the best stuff to get), and exaust. like i said,i have no clue and i NEED all the help i can get. many thanks..

 

[Daggar]

Wow... a virgin!

Your motor is a 302HO.
If stock, you're running a carb.
The gears they are referring to are the differential gears. You've probably got 2:73s in there now. 3:73s will let you rev quicker and put more torque to the pavement. There are all sorts of things that we could all go on and on and on about. Your best bet at this point, I think would be to go out and get a fistfull of magazines and just start going through the articles. That will at least get you started and help you figure out what questions to ask. Good Luck and Welcome to Stangnet!

 

[85 Coupe 5.0]

Not necessiarly true Daggar. Two different 302's were offered in that car that perticular year......

the 302 four venturi (4V) H.O. with a MANUAL transmission....
the 302 CFI (central fuel injection) H.O. with an AUTO transmission.....

Sooo, basically if the car has an automatic transmission it's a turd. The CFI motor wasn't a roller cam motor and was generally just an ordinary 302 pushing around 180 HP, not much of a camaro killer.

But, if the car has a 5-speed manual, then we're talking. The 5 speed car has a 4 bbl Holley 600 CFM carb, Roller cam 302 and 7.5" trac-loc rearend, probably with 2.73 gears, the only major pitfall. This motor produced around 215 HP, and will turn low 15 sec 1/4's with the right conditions and driver.

Like Daggar said though, there are a buttload of things you can do IF, IF, the motor is a roller motor. If not, you can still make it quick, but more has to be done to get there.

 

[Daggar]

I constantly neglect the CFI engines. I've think I've only ever seen two of them. Good catch Coupe.

 

[85 Coupe 5.0]

One other note.....

Either way a set of gears will help the most for the least money. As Daggar said, the 'gears' we are referring to are the differential gears in the rearend of the car. The function sort of like a bicycle does. If you ever had a mountain bike and started out in high gear, that's what your car basically is doing with the factory gearset. The factory gears are made for fuel economy, which is acheived by keeping the engine revved low at cruising speeds, which is partially controlled by the ratio of the rearend gears.

Many other factors make up the final drive ratio, but the easiest modification is to change the rearend gear to a higher ratio, much like swiching to a lower gear on a bike. The lower gear makes it much easier to take off and pull the weight of the bike and you up to speed. If you notice you also have to pedal faster to get up to the same speed as when you were in high gear, this is what people mean when they say you will revv higher with gears. With gears in your car, each shift drops your RPM's less, keeping the engine revved up and in it's torque curve. Basically, it keeps your engine right in it's 'sweet spot' for making power.

The downfall, you are going to loose some top end speed. But hey, what's the sense in going out and topping your car out? wouldn't you rather have your car setup to be the quickest from 0 to 100 than being capable of going 130+?

Again, it all depeds on what you are planning to do with the car. Selecting the wrong gearset, say 4.56's or so on a STOCK motor and car would be stupid, unless you don't take the car above 60 MPH and only race in the 1/8th mile, because the car would be maxed out by 90 or so mph.

A wise choice of gears is usually 3.73's or 4.10's. the 4.10's work best with an automatic equipped car because the auto's have slightly steeper gearing than the 5-speed cars do.

Do some searching here on stangnet, and the internet, there is a TON of info about how to hop up these car's. All it takes is a little patience and reading.

 

[8550]

what are the changes/ things you would do first?

 

[85 Coupe 5.0]

I constantly neglect the CFI engines. I've think I've only ever seen two of them. Good catch Coupe.

There are 3 of them here in my hometown, one is a Capri and the other's are GT's. Weird huh?

One other note 8550,

Either way your car has the smaller 7.5" rearend. the bigger 8.8" wasn't introduced untill 1986 in the 5.0's. I've seen a lot of people pound the hell out of those rearends and not break them. Then there are people like me that broke 2 of them before i put in an 8.8", so if you get serious you might look at upgrading to the bigger rearend.

Also, your car has single exhaust from the motor to the mufflers. 1986 and later 5.0's had true dual exhaust. It would be a wise upgrade also for starters, helping the motor breathe a little better.

 

[85 Coupe 5.0]

what are the changes/ things you would do first?

depends, do you have the stick or automatic car?

 

[8550]

depends, do you have the stick or automatic car?

its a stick

 

[8550]

There are 3 of them here in my hometown, one is a Capri and the other's are GT's. Weird huh?

One other note 8550,

Either way your car has the smaller 7.5" rearend. the bigger 8.8" wasn't introduced untill 1986 in the 5.0's. I've seen a lot of people pound the hell out of those rearends and not break them. Then there are people like me that broke 2 of them before i put in an 8.8", so if you get serious you might look at upgrading to the bigger rearend.

Also, your car has single exhaust from the motor to the mufflers. 1986 and later 5.0's had true dual exhaust. It would be a wise upgrade also for starters, helping the motor breathe a little better.

8.8 rear end and 3;73's. best bet. but what do you guys know about POSI?
and on the exhaust, what do you suggest with that?-could you get new piping?

-thanks for all your help!

 

[BaXTeR3221]

If you want to learn about mods, just search through this site. In the past month there have probably been about 10 threads about what order to mod a car is and what are the best mods etc. It usually ends up being gears, subframes connecters(strength the body), a short shifter, h-pipe with less or no cats, a catback(though its basically there for sound) and the list goes from there. Run a search and you can read about all the pros/cons of each mod and peoples opinions on the order things should be installed. good luck

 

[Stang8URMPRT]

Not necessiarly true Daggar. Two different 302's were offered in that car that perticular year......

the 302 four venturi (4V) H.O. with a MANUAL transmission....
the 302 CFI (central fuel injection) H.O. with an AUTO transmission.....

Sooo, basically if the car has an automatic transmission it's a turd. The CFI motor wasn't a roller cam motor and was generally just an ordinary 302 pushing around 180 HP, not much of a camaro killer.

But, if the car has a 5-speed manual, then we're talking. The 5 speed car has a 4 bbl Holley 600 CFM carb, Roller cam 302 and 7.5" trac-loc rearend, probably with 2.73 gears, the only major pitfall. This motor produced around 215 HP, and will turn low 15 sec 1/4's with the right conditions and driver.

Like Daggar said though, there are a buttload of things you can do IF, IF, the motor is a roller motor. If not, you can still make it quick, but more has to be done to get there.

ACTUALLY, it was not a 600 cfm Holley, it was a 575 Holley and it produced 210 HP in stock trim. Also, if it was orginally a 5 speed originally, it would have come stock with 3.08's.

Nick

 

[Stang8URMPRT]

Also, the Fuel Injected CFI only produced 165 HP and they are a total bitch to work on.

 

[HISSIN50]

please get a repair manual. you will need it for torque specs alone. as said, searching in here is good, but most of the info is toward the aero foxes (and 86's) - know what differences you have from those cars to know what info is relevent.
i dont know snot about the CFI cars myself.

not sure about your POSI question. on a ford, it is called a Trac Lok.

good luck.

 

[8550]

i just have to keep thanking you guys for all th info.

 

[8550]

One other note.....

Either way a set of gears will help the most for the least money. As Daggar said, the 'gears' we are referring to are the differential gears in the rearend of the car. The function sort of like a bicycle does. If you ever had a mountain bike and started out in high gear, that's what your car basically is doing with the factory gearset. The factory gears are made for fuel economy, which is acheived by keeping the engine revved low at cruising speeds, which is partially controlled by the ratio of the rearend gears.

Many other factors make up the final drive ratio, but the easiest modification is to change the rearend gear to a higher ratio, much like swiching to a lower gear on a bike. The lower gear makes it much easier to take off and pull the weight of the bike and you up to speed. If you notice you also have to pedal faster to get up to the same speed as when you were in high gear, this is what people mean when they say you will revv higher with gears. With gears in your car, each shift drops your RPM's less, keeping the engine revved up and in it's torque curve. Basically, it keeps your engine right in it's 'sweet spot' for making power.

The downfall, you are going to loose some top end speed. But hey, what's the sense in going out and topping your car out? wouldn't you rather have your car setup to be the quickest from 0 to 100 than being capable of going 130+?

Again, it all depeds on what you are planning to do with the car. Selecting the wrong gearset, say 4.56's or so on a STOCK motor and car would be stupid, unless you don't take the car above 60 MPH and only race in the 1/8th mile, because the car would be maxed out by 90 or so mph.

A wise choice of gears is usually 3.73's or 4.10's. the 4.10's work best with an automatic equipped car because the auto's have slightly steeper gearing than the 5-speed cars do.

Do some searching here on stangnet, and the internet, there is a TON of info about how to hop up these car's. All it takes is a little patience and reading.

ive been readin around the site and i came across wheel spin. with 3.73's, do you get that much wheel spin? and does the speed change? (ie. 35 mph on 4th gear?)

 

[HISSIN50]

ive been readin around the site and i came across wheel spin. with 3.73's, do you get that much wheel spin? and does the speed change? (ie. 35 mph on 4th gear?)

ill let Coupe speak for himself, but ill toss out my two cents.

yep, the speed on the speedo for any given gear will change with a rear gear swap. there are calculators out there that will tell you what gear will show what speed at what RPM (knowing your rear tire height helps, and is important). an example (random numbers). 2.73 gears: 70 MPH in 5th = 1800 rpm.
3.73 gears at same speed/trans gear = 2500 rpm. ive read that 3.73's in 5th gear are close to the revs of 2.73's in 4th gear. it sounds like you have 3.08's, so that example is not great for you.

one can count the DS:tire rotation ratio to get a close idea of what gear they have (in case a previous owner changed gears already). one can buy a new speedo drive gear to get the speedo back to being accurate with the new gears.

some popular gears are 3.55, 3.73 and 4.10's. others, though less popular are: 3.27, 3.90, 4.56 and some others i cant think of.


wheel spin depends on several things. quality, compound and size of rear tires, suspension and so on. wheel hop is an issue with foxes. quad shocks help, as do aftermarket control arms.

my random thoughts. good luck.

 

[jrichker]

On a budget? do the junkyard upgrade...

Gears - 87-88 T-Bird Turbo Coupe rear axle - disc brakes and 3.55 or 3.73 gears in one package for $125-$300. Add another $100-$200 or so to complete the brake upgrade.

3G alternator from 94-95 Mustangs or other Ford. $20-$120. A must have to make the electrical system work like it should. You’ll need a 4 gauge power wire and a 125-135 amp fuse to go with it about $15- $30.

Lincoln MK VIII electric fan -$40-$160. Free up some HP by not having to drive the stock fan. The 3G alternator upgrade is a must have prerequisite before you do the MK VIII fan. You won’t have enough electrical power if you don’t do the 3G upgrade.

 

[85 Coupe 5.0]

On a budget? do the junkyard upgrade...

Gears - 87-88 T-Bird Turbo Coupe rear axle - disc brakes and 3.55 or 3.73 gears in one package for $125-$300. Add another $100-$200 or so to complete the brake upgrade.

3G alternator from 94-95 Mustangs or other Ford. $20-$120. A must have to make the electrical system work like it should. You’ll need a 4 gauge power wire and a 125-135 amp fuse to go with it about $15- $30.

Lincoln MK VIII electric fan -$40-$160. Free up some HP by not having to drive the stock fan. The 3G alternator upgrade is a must have prerequisite before you do the MK VIII fan. You won’t have enough electrical power if you don’t do the 3G upgrade.

Good Call. The J/Y upgrade is a cheap alternative. I'd love to help out more, but as said above, searching stangnet is the best way to find out almost anything about the 'ol stangs. Trust me, any question you are thinking of has probably been asked already.

Thanks for correcting me on the torque specs and power output of the various engines in '85. I was just quoting off the top of my head.

Thanks for helpin the noob out everyone, we all remember our first stang, and all the questions with it.

 

[willys1]

85coupe 5.0,,,85's 5.0's "were" a roller cam!!