[CLB1098]

New to this site and have spent hours over the last few nights reading and I'm starting to go cross-eyed. I'm addicted!
I have a 68 GTO with a stock 400 and want to get some more power out of it. This is my weekend driver and not looking to get carried away...but it will probably happen. I have read good and bad on everything here. Carb? (Currently QJet) Intake? Distributor?
First step is exhaust for me. Thinking of going with the Ram Air Restorations manifolds and 2.5" exhaust. I want to keep it looking as stock as I can.
Trying to get as much HP at minimal $$$...but who isn't! Any thoughts?

[guccieng]

first off, welcome to the site!

if it's a street car, you should looking for torque, not horsepower, imho. horsepower numbers get big in the higher rpm ranges. street cars are almost never in those high rpm ranges. if you make the torque, the horsepower will come. also, keep in mind the car is a combination of things. simply increasing horsepower won't necessarily make things better. you have to take into account what type trans, converter in an automatic, rear gear, tire height, cruise rpm, etc. as for the things you listed: carb-working correctly, no hidden hp here. intake-stock iron intakes are best for a street car. distributor-working correctly and advance tuned to motor, some hidden torque. exhaust-matched to engine combo, some hp and torque to be gained, but will required carb tuning. remember, if you change one thing, you have to change everything! tell us what your combo is first and i'm sure you'll get some great info when it comes to 'bang for your buck'.

[SRR]

Go with a Pypes 2 1/2" mandrel bent system. A car has to breath to make power.

[steve25]

If you are stepping up to the far better flowing RA manifolds you need to go to richer secondary metering rods for the carb other wise you will not get the full bang for your exhaust buck plus you may be lean enought at 3/4 to full throttle to detonate, run hot or both!

[grandville455]

[QUOTE=CLB1098;3824823]
I have a 68 GTO with a stock 400 and want to get some more power out of it. This is my weekend driver and not looking to get carried away...but it will probably happen.

Too Late! As you are a pontiac owner!... I would look at getting dist set up right and carb,Lots of hidden power right there usually and yes a good 2 1/2 X system would be very nice also.. What gears are u currently running? Welcome aboard!

[David Jones]

Automatic or manual transmission? Rear gear?

One of the new generation RAIII size cams (I like a hyd roller...EVERYBODY has an opinion what's best), a good qjet on a factory intake, RA exhaust manifolds into a 2.5" mandrel exhaust system and a well tuned distributor.

[track73]

Look, lets get something straight. As I was told by an auto engineer "all engines produce torque". In fact a dyno measures torque and multiplies it by the rpm and divides it by 5250. The question should be: where do you want the max torque to be? At low, med range or higher rpm. After you have that figured out, then plan your engine combo. Torque is a twisting force.(force=push or pull) (work=push or pull x distance)and hp is work / time. In other words how fast a car of a given weight traverse a 1/4 mile in a quickest time needs hp. Getting the car to move from a stand still requires torque.

[FLYNLOW]

Originally Posted by amcmike

Besides this being inappropriate, "build a torque monster" is terrible advice for a fast car - ESPECIALLY on the street where traction is limited. I'd much rather have 350 lb/ft@6000 than 500@3000. This article is still a great way to read about "torque vs horsepower" as they are one and the same. http://www.vettenet.org/torquehp.html

Alright... first and foremost. Whats your budget? Your mechanical ability? Performance goals?

[Thomasmoto]

I always tried to explain it like- torque gets the car going and then horsepower pulls it from there, at what intervals those things happen is how you plan your build/tune.

[carbking]

Welcome to the world of Pontiac, and to the forums.

Lots of good advice to be had on the forums; but to sift through it all, you need to do some homework (maybe just in your head) and determine goals. Some things to consider when you consider your modifications:

Generally, one modification requires at least 6 more to work properly.

Do you want to use pump fuel, or do you wish to mix race fuel and pump fuel?

Do you have any constraints required by either local regulations (eg. noise) or insurance regulations?

Anyone besides you that will be driving the car? Do they have special needs (eg auto trans)?

As virtually ALL of us have found, very easy to spend money, and then spend more because we didn't think of everything ahead of time.

Again, welcome, and feel free to ask questions.

Jon.

[ta man]

Originally Posted by FLYNLOW

Besides this being inappropriate, "build a torque monster" is terrible advice for a fast car - ESPECIALLY on the street where traction is limited. I'd much rather have 350 lb/ft@6000 than 500@3000. This article is still a great way to read about "torque vs horsepower" as they are one and the same. http://www.vettenet.org/torquehp.html

Alright... first and foremost. Whats your budget? Your mechanical ability? Performance goals?

I think I'll take the 500plus at 3000rpm.

[i82much]

This debate could be solved pretty easily if everyone was required to take a good calculus-based physics course or two.

Absent any other considerations (streetability, etc.), take the car with more horsepower over the range of RPM you need to operate in - NOT the car with more torque. It's math, it's physics, you can't get away from it.

As a matter of practicality, muscle cars in general and Pontiacs more specifically tend to produce enough low-RPM horsepower to get the job done without spinning at such high rpm. As a consequence, such engines have higher torque figures than engines of similar horsepower operating at higher RPM.

Make no mistake, however. It is horsepower that is getting the job done, NOT torque. How fast would you go with 500 ft. lbs. of torque at 1 RPM? How fast would you go with 250 ft. lbs. of torque spinning at 10k RPM? Put some steep gears in the car w/250 ft. lbs. and it will FLY. You're not getting anywhere in that dog running 1 RPM.

Power gets the job done. It's physics - you can't change it.

Off the soapbox.

[JohnTN]

Torque is physics. HP is just math.

[i82much]

Originally Posted by JohnTN

Torque is physics. HP is just math.

No idea what you mean by that.

[carbking]

Gentlemen (and ladies, if present):

The torque vs horsepower issue has been argued to death. For those who have not had any high school physics: torque is a measurable amount of work and has a defination. Once one has MEASURED torque, horsepower may be DERIVED from torque by a mathematical formula. Thus JohnTN is quite correct that torque is physics, and HP is just math.

However, the renewal of this discussion probably does not help the original poster of this thread.

Jon.

[i82much]

Originally Posted by carbking

Gentlemen (and ladies, if present):

The torque vs horsepower issue has been argued to death. For those who have not had any high school physics: torque is a measurable amount of work and has a defination. Once one has MEASURED torque, horsepower may be DERIVED from torque by a mathematical formula. Thus JohnTN is quite correct that torque is physics, and HP is just math.

However, the renewal of this discussion probably does not help the original poster of this thread.

Jon.

Stick with carburetors or take a class. The notion of drawing a line between physics and math is laughably preposterous. And, to the extent the OP wants to go down the road of building a faster, higher powered engine that is faster by virtue of revving higher, it is entirely germane to the subject at hand.

I agree the discussion gets old, but the real problem is that some folks perpetuate these notions that ignore basic science. There is a mathematically precise way of discussing these things and some here are way off base.

Question for you Jon - can you not "derive" torque by multiplying the applied force times the length of the torque arm? Why, then, could we not say:

"Once one has MEASURED force, torque may be DERIVED from force by a mathematical formula."

Point being, you can't just measure torque to derive HP. You must also MEASURE rpm.

Another question - which is faster, a car making 500 ft. lbs of torque at 3000 rpm, or the same car making the same torque at 6k rpm? Hint: think PHYSICS.

[jime1]

"Stick with carburetors or take a class."


What a jackass. U82much all right...you're obviously full of yourself.

[rad400]

[i82much]

Originally Posted by jime1

What a jackass. U82much all right...you're obviously full of yourself.

My apologies, that was too harsh. I maintain that there are some really fundamental misconceptions about these things and I do get tired of seeing them perpetuated. And I do think anyone who is going to offer their opinion has a responsibility to understand the topic before stating things that are simply incorrect.

None of that is a good excuse for being a jerk, and I apologize.

[SRR]

Originally Posted by CLB1098

New to this site and have spent hours over the last few nights reading and I'm starting to go cross-eyed. I'm addicted!
I have a 68 GTO with a stock 400 and want to get some more power out of it. This is my weekend driver and not looking to get carried away...but it will probably happen. I have read good and bad on everything here. Carb? (Currently QJet) Intake? Distributor?
First step is exhaust for me. Thinking of going with the Ram Air Restorations manifolds and 2.5" exhaust. I want to keep it looking as stock as I can.
Trying to get as much HP at minimal $$$...but who isn't! Any thoughts?

Stick or auto?