Horsepower Talk

[simonster]

street, if you're going to do exhaust, you might as well spend the $30 and at least get a k&n air filter. that way, instead of the jet 1 chip (for unmodified intake/exhaust), you can really benefit from a jet 2 (for modified intake/exhaust) and free up some real ponies.

i've been really happy w/ my k&n. w/ the stock exhaust, i'd hear a little intake hiss when i jumped on the throttle. w/ the catback, it sounds like i have a supercharger. even when i had a full intake system on my bmw, i can't recall the intake noise being that loud, so i suspect that the stock hemi intake w/ a k&n might be sufficiently free-flowing to not warrant getting an airaid.

[Street LX]

will a filter be enough or do i hae to get the full system? also it says a 180 thermostat is required and 91 fuel

[simonster]

i think filter should be enough. i'm getting a lot of air, although i think if i decide to get a jet 2, i'll probably get the airaid as well.

i don't think anybody has put in a different thermo, and i always run 91.

[FlyinLo]

Are there any dyno results for these Jet Chips? And are these the ones that the Jeep's computer will adjust for after a while?

[simonster]

that one guy on JU raced his w/ an airaid, magnaflow catback, and jet 2, and significantly reduced his 1/4 mile time. he's thinking 30hp or so to the wheels, which is impressive and about right.

i've found that doing an intake, chip, and exhaust on a car typically gives me about 10% HP boost at the crank. allow for 20% reduction to the wheels, and there ya go. he said jet 2 claims 20hp for just the chip alone without intake/exhaust.

[Street LX]

^ that guy you speak of is now on these forums ;)

[FlyinLo]

Assuming the 0-60 time is 8 seconds (according to Consumer Reports, I think) for the 4.7L, if it had an additional 20-30 horses, is there any way to estimate a new 0-60 time?

[simonster]

Originally posted by FlyinLo
Assuming the 0-60 time is 8 seconds (according to Consumer Reports, I think) for the 4.7L, if it had an additional 20-30 horses, is there any way to estimate a new 0-60 time?

dunno if this works:

http://www.cars-cars-cars.org/0-60-Times-Calculator.htm

seems a bit random, since you have to take gearing into account...

[simonster]

maybe you could estimate w/ algebra.

265/235 = 8.00/x

x=7.09

that seems to work pretty well. i just tried it with a couple other cars. makes sense, because it assumes that car, weight, gearing, driver, etc. stay the same. only horsepower changes.

[Edited on 3/16/2006 by simonster]

[FlyinLo]

Hmm, okay... my registration says my Jeeps gross weight is 5400 lbs that can't be right

[Edited on 16-3-2006 by FlyinLo]

[Street LX]

4441 for me w/ no 4x4

[blackattack182]

Algebra wouldn't work. You have to take into account acceleration. Velocity never flatlines, it continuously increases.

What you could do is use this formula, I think. Lets see what happens (thank you physics):

Vf=Vi + at

Well final velocity (Vf) equals 60 mph, which equates to 26.8 meters per second. Second, Vi equals 0, and t is what we are looking for. Now if 3.82 m/s^2 is the acceleration of a stock HEMI, using that as a proportionality constant, we would get 4.16 m/s^2 for the upgraded HEMI with 360 HP (as per simonster's claim of QBNKID's claim). So, 4.16 is going to be a.

Now that we established variables,

26.8 = 0 + 4.16*t
26.8=4.16*t

26.8/4.16=t

6.43=t

So, if everything was correct, this means that a HEMI with all of QBNKID's upgrades would do 0-60 in 6.43 seconds, as opposed to the stocker's 7.0 second 0-60. This kind of sounds possible. Maybe not. Anyone else?

Also, if this is correct, then a 4.7L could do 0-60 in 7.4 seconds.

[Street LX]

Alex! Comment on my thread in members gallery