How Much Hp/Tq Does My Combo Have?
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STANGateURlilSS
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88Stang331
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how many times is somebody gonna say "between 210-220" at the wheels?
Anyway i'm gonna break the mold....I'm gonna say 225rwhp
Anyway i'm gonna break the mold....I'm gonna say 225rwhp
DMAN302
My mom says thanks for the pearl necklace.
I will give anyone who can show me 5HP gain with a CAI (anderson power pipe aside) over K&N panel filter....ain't gonna happen.
88Stang331
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DMAN302
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ninety15.0
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65mm throttle body...dont go any bigger. That is one of the biggest mistakes people make. Air velocity is just as important if not more important that air volume. With stock heads and minor mods...a 70 or 75 might actually hurt you. In terms of the MAF a 75 or77mm Pro-M is the way to go. good luck man
TB size depends on the intake you choose. You don't want to run a TB that is bigger than the intake port or it will disturb airflow - you want a smooth transition from the TB into the intake. IMO, don't worry so much at air velocity at the TB.
You can increase air velocity there by running a smaller and smaller TB, but all you accomplish is choking the intake off. When that high velocity at the TB air moves into the upper plenum, it's going to slow way down because now the plenum is moving less air through the same cross-sectional area, i.e. a slower air velocity in the intake.
Where air velocity really counts is in the runners and most importantly in the heads' ports. That way, it helps to move air into the cylinder when the valve opens, and particularly, right before the valve closes.
You can increase air velocity there by running a smaller and smaller TB, but all you accomplish is choking the intake off. When that high velocity at the TB air moves into the upper plenum, it's going to slow way down because now the plenum is moving less air through the same cross-sectional area, i.e. a slower air velocity in the intake.
Where air velocity really counts is in the runners and most importantly in the heads' ports. That way, it helps to move air into the cylinder when the valve opens, and particularly, right before the valve closes.
ninety15.0
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FastDriver said:
Thats really not true man. I do agree with you that intake runners and most importantly the heads are greatly affected by the velocity vs. volume....but the air comming into the intake makes a huge difference too. You mentioned that the air slows down as soon as it enters the intake manifold...but if its going slower when it gets there b/c your TB and MAF are too big...then its going to slow down even more as it travels thru the intake and heads. Its not like the air can be drastically sped up as it travels through the heads without reducing the volume...thats a basic airflow principle. Flow rate/Area = Velocity...so reducing the area increases velocity. Engine builders today have found that they can achieve the same velocity with smaller ports and valves by controling the ports' shape and the air flows' path. the smaller the ports...the higher the velocity and thus more power. Your exhaust follows the same principles bigger is not always better. Its all about matching everything to work together. Oversizing everything will make good top end power if its not too oversized, but throttle response, driveability, and low end torque are going to seriously suffer. So on a street car, i think velocity is more important than volume in most cases.
ninety15.0 said:Thats really not true man. I do agree with you that intake runners and most importantly the heads are greatly affected by the velocity vs. volume....but the air comming into the intake makes a huge difference too. You mentioned that the air slows down as soon as it enters the intake manifold...but if its going slower when it gets there b/c your TB and MAF are too big...then its going to slow down even more as it travels thru the intake and heads. Its not like the air can be drastically sped up as it travels through the heads without reducing the volume...thats a basic airflow principle. Flow rate/Area = Velocity...so reducing the area increases velocity. Engine builders today have found that they can achieve the same velocity with smaller ports and valves by controling the ports' shape and the air flows' path. the smaller the ports...the higher the velocity and thus more power. Your exhaust follows the same principles bigger is not always better. Its all about matching everything to work together. Oversizing everything will make good top end power if its not too oversized, but throttle response, driveability, and low end torque are going to seriously suffer. So on a street car, i think velocity is more important than volume in most cases.
I agee.I see so many crappy running modified street Stangs because of committing the cardinal sin...."Bigger is Better".It is all about balancing/matching components if you want to retain streetability (good throttle response,low end torque) while getting good power and torque increases at higher rpm.I'll give up a little power at 6000+ rpm.
ninety15.0 said:
You're on the right track, but it's not the velocity of the air at the throttle boddy that counts. You'll actually slow the air down more in the runners where it does count because by restricting the TB you will move less volume of air into the manifold. Then, in reference to your formula, you will have a lower flow rate moving through the same cross-sectional area in the intake which results in a lower velocity where that velocity actually counts.
If you stick a straw on the intake instead of a TB, you'll get huge air velocity at the straw, but since so little air will be getting into the intake, the air inside is going to be stagnant.
and by volume you mean, cross-sectional area... gotcha
You're not reducing the area in the intake or heads... you're talking about the TB. You've got the right ideas, but you're applying them incorrectly.
Thanks for the lesson. Smaller ports and valves already have a higher velocity, but a lower flow rate, generally, than a larger port/valve. In the quote above replace "velocity" with "flow rate" and it makes more sense.
No. Velocity is only one part of the equation. The other part is actual flow, i.e. CFM.
Your exhaust follows the same principles bigger is not always better. Its all about matching everything to work together. Oversizing everything will make good top end power if its not too oversized, but throttle response, driveability, and low end torque are going to seriously suffer. So on a street car, i think velocity is more important than volume in most cases.
Chris
DMAN302
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onefstsnake
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well my 93 put down 220rwhp and 284rwtq
With only the following:
-Crank/WP underdrive pulleys
-O/R H pipe (kinda smashed from speed bumps)
-Flowmaster 2 Chamber catback
-FRP 9mm wires
-MSD cap/rotor
Stock Timing, super dirty air filter, 87 octane gas, and leaky headers.
With only the following:
-Crank/WP underdrive pulleys
-O/R H pipe (kinda smashed from speed bumps)
-Flowmaster 2 Chamber catback
-FRP 9mm wires
-MSD cap/rotor
Stock Timing, super dirty air filter, 87 octane gas, and leaky headers.
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DMAN302
My mom says thanks for the pearl necklace.
Decent numbers for a near stock mustang, but every car will be different, as will every dyno session.
onefstsnake said:well my 93 put down 220rwhp and 284rwtq
With only the following:
-Crank/WP underdrive pulleys
-O/R H pipe (kinda smashed from speed bumps)
-Flowmaster 2 Chamber catback
-FRP 9mm wires
-MSD cap/rotor
Stock Timing, super dirty air filter, 87 octane gas, and leaky headers.
Very Nice what headers?
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onefstsnake
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