1/4 Mile Vs Hp

[dbsupra90]

what's the big fuss over 10's? ive already ran 9's in mine. oh wait. that's 1/8mi.

yeah anyway, besides what has been said, suspension, tires and driver will have a lot to do w/ it. be prepared to have a good 60' time in the 1.5-1.6 range to get you there.

 

[IJ.]

Thanks guys this came back on track nicely!

 

[Jspec7m88]

oh man i am so excited about this post. i have my physics 101 final in 2 weeks so i am totally gonna be a smartass right now: Xo= x subscript o, your starting position. Vo= your starting speed(zero in this case).

distance is given by x(t)=Xo+VoT+.5aT^2
1/4mile=1320ft=402.336m

using this equation we solve for a(acceleration)

402.336= 0+0(10sec)+.5a(10sec^2)
we get a= 8.04672m/sec^2

this is the AVERAGE rate of acceleration you must maintain to run a 10 sec 1/4 mile.

so we then use that acceleration to find the force applied over the 1/4 mile.
i am using 3500lbs as the weight of an average mkiii. 3500lbs=1587.56kg

F=MA

F=(1587.56kg)(8.04672m/sec^2)= 12,774.6508 newtons

use that force to find work

w=FD

w=(12774.6508N)(402.336m)= 5139701.906 Jouels

convreted to horsepower/hour divided by 264000. that is 1.914xxxx horsepower per hour. multiply by 3600 seconds in one hour and then divide by 10 and i get a grand total of

689.245hp

that is of course with perfect traction, perfect linear acceleration, no wind resistance, no drivetrain loss. that is, it is impossible to run a 10 second with anything less than 689.245hp. i think in real life 800 is alot more resonable.

sorry, i just had to practice my physics. wish me luck on the final, just 2 weeks away!

I'll smack you.:slap: lol...Probably made a few of us feel like dummies but hey, you should be good for the final!:x:

 

[miggles]

^^^ my cats name is mittens,
it tastes like burning
my head is hurting looking at all those numbers. It would make sense that you need a lot of hp to pull a faster time. When i was watching the 0-300kph cars in japan they had around the same hp (700-1100ps power stroke) and were cutting 12sec quaters but due to the gearing they were hitting 300kph+. Do you know what speed you will cross the finnish line at?

 

[turbodriz]

Yo jspec that math sh**was diffinitly crazy ...... :icon_bigg good luck on the test.

 

[suprasport91]

Long time since ive seen anything mechanics related, pretty good application, good job, good luck on the test

 

[souprat]

you asked for it miggles so here it is:

velocity is = V(t)=Vo+at

Vo is again zero(standing quarter) so:
v(t)= 0+(8.04672m/sec^2)(10sec)= 80.4672m/s

this gives velocity in m/s and then we convert to mph.

(80.4672m/sec)(3600sec/1hour)(1mile/1609m)=180mph:nono:

this is after all a theroretical situation. as you can see cars rarly have linear acceleration. that would be some GREAT top end power. i guess this means that at the start of the quarter the car accelerates faster than the average and then slows down to below the average. we could demonstrate that with a graph of the cars acceleration and then apply the mean value theroem, but thats calcules and i'm not as good at calc. so i'll just say that i once saw a vid of an orange mkiii run a 10.2 at 138mph.

hey thanks guys. i'll see what i can do on the final. school is not usually my friend but this was related to something that interests me so it was easy to get inspired and apply what i picked up.

 

[BTZ]

acceleration is not linear, the lower the gear ratio the slower you will accelerate. 0-60 say 5sec, 60-120 more then 5.

 

[jdub]

hey thanks guys. i'll see what i can do on the final. school is not usually my friend but this was related to something that interests me so it was easy to get inspired and apply what i picked up.

Both posts was one of the nicest use of applying what you've learned I've seen in a while. Well done! And good luck on your test, but I don't think you doing well will have anything to do with luck :biglaugh:

 

[MassSupra89]

i find it funny that an f-body can run 10's with less than 500rwhp. it's all in the setup. shit i ran mid 12's with 290rwhp on my camaro.

people need to invest in a drag setup.

So true. A buddy's F-body with cams and exhaust runs 12's, Also foxbody mustangs run down the track like nothing else, so light, and so much torque.
A mustang with 600 horse could run 9's, but it will take us near 1000hp. :icon_conf

damn.

 

[Turbo. Targa. Life.]

Mass, you explained the FoxBody thing all on your own--"so light..."
Our cars weigh like 1000# more than they do. Also, our cars should be able to pull just as much torque being forcefed.

 

[Dirgle]

oh man i am so excited about this post. i have my physics 101 final in 2 weeks so i am totally gonna be a s.........

This is all fine and dandy when you’re a 3500lb, top fuel drag car with just the final drive and a crap load of clutches between your engine and the tires. When you add numerous gear ratios, torque multiplication, and non-liner variable power bands into the mix, the math goes out the window. None the less, good work on the calculations. I like numbers too

 

[Cya]

There was someone on here who ran 12's on a ct, which is very dooable. Considering a friend of mine with a slightly modded (intake, full exhaust, chip) M3 ran a 13.3 on the strip. This is applies because from a stop,in 1st he kicks my ass manily beacause of the ct drop off at 5-5500 rpms. From a roll in 2nd and thrid were dead even (well he pulls slightly and I do mean slightly in second). Being that my mods are a KN intake, 3" exhast (minus elbow), sucky manual boost controller (it jumps the boost from 8lds to 12) and when we race its at 8 due to fuel cut. It very duable to run a 12 on the ct on stock suspension, so... with reasoning 680 for a 10 is not farfetched with a proper setup i.e. weight, suspension, tires, drivetrain. Keep in mind the M3 is far lighter than our fat beasts.

 

[Nick M]

Fox body Mustang production ran from 79-04. They werent 1000 lbs lighter. Although a low option 5 litre LX was just about 2900 out the door. My 91 GT with me in it weighed 3395 at 5800 ft. I weigh 230. That is a huge advantage. So is the factory solid axle and 4 link suspension. While the production 4 link was shit, like most production pieces, it is easy and cheap to upgrade to pieces that will rip the subframe at a point called the torque boxes from so much traction.

And the LS1 F Body is probably the best bang for the buck today. A clean 98 and up Camaro can be had for 10,000. SS goes for 3 times that much, but it isnt necessary. I know, stay on topic. But the same rules apply. Weight, traction, area under the curve.

 

[suprarich]

Slow66 ran his low 10 sec pass with a full weight auto supra with around 550 hp at the time.

 

[Red7m]

If you get the car down to 3200lbs it should only take 400rwhp (with and properlly set up auto and rear suspension) to run mid 10's at around 125. If you are trapping more than 125mph in your drag car and are running 11's you plan and simple didnt set the car up right, Or cant drive.

I followed a project in MM&FF where they took a stock rebuild 5L, TCI AOD trans w/lockup stall and line lock, and HP perfomance base turbo kit. It ran 10.6's at 136mph with around 400whp@3200lbs (last dyno was 370whp before rebuilt motor and 12psi v.15psi)

Suprarich I belive Slow66 made that 10sec pass with high 400rwhp, i link it was 496rwhp.

 

[suprarich]

I was just quoting Slow from a post he made on SM about the run. I have that pass on video on my computer. I think he also said that less than 13K including the purchase of the car, was invested in it.

 

[IJ.]

Rich: Can you post the vid up please?

(I had hoped Bryan would jump into this thread and share his wisdom)

 

[Slow66]

Rich: Can you post the vid up please?

(I had hoped Bryan would jump into this thread and share his wisdom)

:wavey:

Simple formula for mid 10s. 540whp/490wtq, 3600 converter, built auto, ET streets, and no real weight reduction minus CF hood and A/C delete.

With a 5speed its a bit harder as youll need a bit more power, and a strong clutch and some better tranny parts (shift forks, thrust washer etc) to make it to it RELIABLY.

Choose whatever turbo/mani/fuel combo you want to make the power, but mid 500s will get you there....

 

[IJ.]

Bryan: Thanks!

Nice to have some first hand knowledge!
(Not that I'm totally discounting the theory and calculations but we don't race calculators )