BBK shorty headers

It strikes me as odd how upset people can get when you try to save them hundreds of dollars. By not purchasing those headers he will be that much closer to buying the cams/tune he wants in the future. :shrug:

well well i guess you got a point, however i get a bonus every quarter, this quarter i only got $400 bucks, next quarter when sales pick up along with the 3rd quarter combined with were i work will get everything i need for the cam swap (cams, springs, tune, etc.) until then money is real tite till those times come. i asked for simple opinions not advice, im my own person and i had done made up my mind, i simply asked if they were worth it to yall, and how they performed. oh and i will post results and MY opinion along with the whole swap. so thanks to all i value your opinions, and those with advice i guess thank you too
 
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If you are taking the engine out and can get long tubes for 280.00 it is a "No Brainer". The coated or Stainless will last longer but seriously you will most like never keep the car long enough to have to replace them. Go with the Longs Especially if the engine will be out of it. Why not gain 20hp for the same money. Pretty and shiny does nothing. Really you cannot see much of them on the 4.6 anyway.
 
Oh and question to nightfire, how can you have an opinion and call others idiots when you dont have headers as part of your mods? if you dont run them you cant have an opinion, if you do run headers i stand corrected.
 
ive been ask to post results and here they are, ive swapped the old 220k mile npi to a 2005 crown vic pi motor which weres the bbk shortys along with there cai and the car runs perfect and absolutly love the new sound. took 12hrs to swap it all. theres no leaks (coolant, oil, etc.) im so excited and the car runs and pulls so much harder then my npi motor. although i can tell a difference in were the power band is.
 
Shortys are worthless.


I have the pypes shorties and I doubt i even gained 1 hp. Only reason they are on my car is that i bought the car with the heads off and it came with the brand new headers mounted to the pi heads and I did not have the stock manifolds. If I had the stock manifolds those would have went on the car and the shorties on ebay or CL

The person who owned my car before me spent a lot on retarded mods that I am going to have to change out and those shorties are at the top of the getting out of my car soon list.
 
Even if there was an increase in torque (it would be slight if anything) it would not serve you any good, horsepower is what makes a car faster or slower... torque just moves the power curve around.

Torque is what we actually measure. It's the turning force at the wheels. Divide torque at the wheels by the tire's radius and you have pounds of thrust.

If you don't gain any torque but move the peak to a higher rpm, you just gained horsepower. Torque * rpm = horsepower. By the same token, if you don't move the peak but increase torque across the powerband, you also increase horsepower.

If you measure acceleration across a powerband, you'll find that acceleration is greatest at the torque peak. Increase torque, increase acceleration.
 
Torque is what we actually measure. It's the turning force at the wheels. Divide torque at the wheels by the tire's radius and you have pounds of thrust.

If you don't gain any torque but move the peak to a higher rpm, you just gained horsepower. Torque * rpm = horsepower. By the same token, if you don't move the peak but increase torque across the powerband, you also increase horsepower.

If you measure acceleration across a powerband, you'll find that acceleration is greatest at the torque peak. Increase torque, increase acceleration.

No, increasing torque does not always mean increasing acceleration. Increasing horsepower does because it is a relationship between torque and RPM... that means that torque has increased in a meaningful place. Power is a specific calculation of work done, torque is just a moment force.
 
No, increasing torque does not always mean increasing acceleration. Increasing horsepower does because it is a relationship between torque and RPM... that means that torque has increased in a meaningful place. Power is a specific calculation of work done, torque is just a moment force.

Power is not a calculation of work done. Power is the rate at which work is being done.

P = dW/dt

Work done = Integrate [P(dt)]

P does not equal W.

Oh, and don't forget F = ma.

Don't mean to get all nerdy here, but this is science, not opinion. :rolleyes:
 
Torque is what we actually measure. It's the turning force at the wheels. Divide torque at the wheels by the tire's radius and you have pounds of thrust.

If you don't gain any torque but move the peak to a higher rpm, you just gained horsepower. Torque * rpm = horsepower. By the same token, if you don't move the peak but increase torque across the powerband, you also increase horsepower.

If you measure acceleration across a powerband, you'll find that acceleration is greatest at the torque peak. Increase torque, increase acceleration.

All true and I agree with you on all of it, except the last sentence. Well, it is actually true as well, but kinda misleading. An increase in torque does not necessarily mean better track times, which is what we usually use to measure the performance aspect of a modification. Let's say that a mod increases torque from 1500 rpm to 3000 rpm, but none above that; if a racer is launching at 5000 rpm, he will never see the benefit of that increased low-range torque, as when he shifts he will never get below about 4500 rpm. Because the high rpm torque values (horsepower) are what are used in a drag race is why the higher horsepower car usually wins, assuming all other things equal (weight, gearing, driving, etc.).

Now all that goes out the window when you don't care about track times and just want a fun car to drive. My granddad has a mild HCI full bolt on 5.0, and a 04 Mach 1. The Mach will win in a race every time, but the 5.0 has more than enough torque to make it a lot more fun to drive than the Mach.
 
Power is not a calculation of work done. Power is the rate at which work is being done.

P = dW/dt

Work done = Integrate [P(dt)]

P does not equal W.

Oh, and don't forget F = ma.

Don't mean to get all nerdy here, but this is science, not opinion. :rolleyes:

This is really funny to me. I've got a test in Dynamics in about two hours on this exact stuff right here. I'm supposed to be studying for it right now, but I'm on Stangnet instead. But hey, now I'm studying anyway. :D
 
The reason HP is important to acceleration is because engines cannot continue to create torque through infinite engine speeds. That’s why transmissions with differing gears are needed. These gears allow torque amplification and a wide range of vehicle speeds given the engines relatively narrow operating range.

As stated above, the HP gives a little more meaning to a torque value, but only because of the engines limited operating range.
 
In other words, acceleration is maximized by maximizing torque but... Torque can only be increased in two ways, increasing engine torque, or increasing gears ratios. Increasing engine torque will increase acceleration, but increasing gear ratios reduces the vehicle speed at which you achieve that increased acceleration.
To increase acceleration at a given vehicle speed, you must increase hp.
a = F/m …(F ~Tq keeping r constant)
so, a = Tq/m
Hp = F(v), again Hp ~Tq(v), and Tq = Hp/v
So,
a = Hp/(vm)
so if you want to increase acceleration at any given speed, you must increase Hp, not Tq.
 
Power is not a calculation of work done. Power is the rate at which work is being done.

P = dW/dt

Work done = Integrate [P(dt)]

P does not equal W.

Oh, and don't forget F = ma.

Don't mean to get all nerdy here, but this is science, not opinion. :rolleyes:

Sorry you're right, I mispoke. I am actually an Aerospace Engineering major... be that a scary fact or not. :p
 
In other words, acceleration is maximized by maximizing torque but... Torque can only be increased in two ways, increasing engine torque, or increasing gears ratios. Increasing engine torque will increase acceleration, but increasing gear ratios reduces the vehicle speed at which you achieve that increased acceleration.
To increase acceleration at a given vehicle speed, you must increase hp.
a = F/m …(F ~Tq keeping r constant)
so, a = Tq/m
Hp = F(v), again Hp ~Tq(v), and Tq = Hp/v
So,
a = Hp/(vm)
so if you want to increase acceleration at any given speed, you must increase Hp, not Tq.

If you increase the hp at any given rpm, you also increased the torque at that rpm. In other words, in order to increase horsepower, you need to increase torque at that rpm.

You cannot separate torque and hp as if they are independent variables.

Horsepower is simply a way to compare two similar engines.