increasing horsepower/low and mid-range torque

[chiaronate]

hi again. i have a 1994 mustang gt with automatic transmission and 2.73's. i was wondering how to greatly increase horsepower, without losing low and mid-range torque. i'd like to do this without a supercharger, turbocharger or nitrous. i read in a book that i have ("how to build and modify ford fuel-injected 5.0-liter v-8 engines") that "The stock 5.0 HO is optimized for torque. no other combination of parts produces as much low-rpm torque than the stock motor." i was thinking of buying a kit, such as the systemax kit from holley, but i'm guessing that it will ruin low-end power. you guys have been a great source of information in the past, and any info you have i'm sure would be very helpful.

[88workcar]

Lower gears will do the same thing. I think the recipe for torque is big heads, big intake, small cam. Personally, I like what compression does. Makes every thing better.

[chiaronate]

what i was thinking of doing is porting the stock heads on the exhaust side, getting a trick flow street intake, 65mm throttle body, 3.73 gears and keeping the stock cam. i thought this would get me decent power while keeping good low-end torque. could i be doing better?

[tmoss]

You absolutely need some gears - 4:10s I think, 3:73 minimum. I agree - compression is your friend.

The stock 5.0 makes excellent torque, but my opinion is it is not "optimized" as the lower half of the intake is quite restrictive. I port these lowers all the time and I have not had one SOTP or dyno or track test show anything but improvement over stock. Going with big heads and big runners shifts the torque curve out of the "lower" portion of the curve and shifts it higher. That's not a bad thing but it can hurt an auto if it's not set up right.

Just to illustrate my point, I am attacheing a dyno of my car which is totally stock except for removed air silencer, 13° timing, 2.5" Flowmaster catbacks, and a K&N filter with my ported lower as the only "major" mod. If you look at the torque curve, you'll see that torque is over 250# from 2,000 - 4,600 rpm. That makes for great street driving - especially in automatic cars with good gears.

Don't get hung up on peak power numbers. Look at average numbers over the usable power band of any combination. You'll be surprised at what you see sometimes.

[Dark_5.0]

Originally posted by tmoss
You absolutely need some gears - 4:10s I think, 3:73 minimum. I agree - compression is your friend.

The stock 5.0 makes excellent torque, but my opinion is it is not "optimized" as the lower half of the intake is quite restrictive. I port these lowers all the time and I have not had one SOTP or dyno or track test show anything but improvement over stock. Going with big heads and big runners shifts the torque curve out of the "lower" portion of the curve and shifts it higher. That's not a bad thing but it can hurt an auto if it's not set up right.

Just to illustrate my point, I am attacheing a dyno of my car which is totally stock except for removed air silencer, 13° timing, 2.5" Flowmaster catbacks, and a K&N filter with my ported lower as the only "major" mod. If you look at the torque curve, you'll see that torque is over 250# from 2,000 - 4,600 rpm. That makes for great street driving - especially in automatic cars with good gears.

Don't get hung up on peak power numbers. Look at average numbers over the usable power band of any combination. You'll be surprised at what you see sometimes.

Thats a nice torque curve!................I just bought a GT-40 lower that is ported out big time. I already have a GT-40 lower on my car with the explorer upper.

Should I just use the stock explorer upper intake with this ported lower intake or get my upper ported too.

Later,

[tmoss]

Originally posted by Dark_5.0
Thats a nice torque curve!................I just bought a GT-40 lower that is ported out big time. I already have a GT-40 lower on my car with the explorer upper.

Should I just use the stock explorer upper intake with this ported lower intake or get my upper ported too.

Later,

Do you know the runner cross section (width & height) of the "big time" porting on the intake - what gasket is is matched to or is it matched to a head? Is cross section of the intake runner consistant towards the bottom of the intake runner or does it taper? Does that dimension come close to matching the head intake runner? Several things have to be considered - you need to know or closely estimate the flow potential of both parts and how well their mating surfaces match to be sure your not mis-matching anything.

If the ported GT lower matches (or is slightly smaller than) the head then I'd put it on and try it out. The stock GT40/Cobra/Explorer lower intake runner is on the smallish side at the opening to the head. The stock Explorer upper should be good to go without mods for your combo IMHO.

[Dark_5.0]

Thats what I wanted to hear.

[Dark_5.0]

Here are some pics of the intake I bought.

[tmoss]

That looks like a 1250 size port (1.15" x 2.0") measure it and if it's much bigger than the E7 head (1.05" x 1.90") you;ll have some "lip" of the head showing at the end of the intake runner. If it's well centered and only hangs out like 5 thousandths or so, It shouldn't hurt too bad.

[Dark_5.0]

The intake ports shouldnt be bigger than the head intake ports on my heads. My heads are hogged out as much as possible with a nice polish job I even got the combustion chambers polished.

I cant wait to go to the dyno

[Coupe50h]

Thats about what my lower looks like i run the 1250 gasket, my head ports match up to the 1250 pretty good, but my lower intake ports are slightly smaller than the 1250, i will be runnin it tommorrow at the track, in severe humidity.