Tin Indian

Don't know if this is the correct forum to post this, but there is so much talk about RWHP and ETs in here with the various head/cam/headers packages, I guess this is as good of a place as any.

Some of you folks don't have dyno numbers, but have track results. Some people have dyno numbers without track numbers.

Here is a great calculator that you can get all these numbers. It is [very] accurate. It was with with my car. You will need to know what your car's weight as raced is (car with you in it).

Some folks have already used these calculators before. This is for the guys that haven't.

Remember, this is based on a car with good traction. BTW, if you don't think it is at all accurate; It takes so much HP to accelerate a certain weight a givin distance to a givin terminal speed. That's just a fact of life. Again, this calculator is very accurate [if] you have good traction.

Enjoy ....

http://www.speedprogroup.com/calc.html

Ron,

Tally TransAm

iTrader: (17)

that thing is about 20 hp high for me

raceweight: 3510
trap: 113
their rwhp: 395

i only made 367 on the dyno

CAT3

iTrader: (9)

yep, pretty damn close...checked it with 4 various timeslips i have had since modding and begining last year...not more than a tenth off at any of them.

Tin Indian

Thats is suprising. What is also suprising is that your TA weighs 3510 with you in it.

My TA weighs that much empty.. A 113 trap speed is very good.

With that trap speed, I can guarantee the car makes more that 367 to the rear wheels.

Tally TransAm

iTrader: (17)

i only weight 120 pounds, hehe

people call my skinny, i call it weight advantage

ive been trapping mid to high 112's with a DA of 1500-1800 (running in the summer in florida sucks)

any guess on the mph in the winter when the temp drops, how much to you think i could gain? ive never run my car in the winter

you really think thats a decent trap (mods are basic bolt ons, macs, 224/581/112) i always thought my car performed kinda lower than other cars of similar mods (this is primarily from seeing dyno numbers on here), but i guess you only hear about the fast ones.

Tin Indian

You also need to remember that these figures are based on a SAE "standard day". The dyno numbers are corrected to that. Your ET/Trap speed should be too.

Tally TransAm

iTrader: (17)

i have absolutely no idea what that means

(i get the dyno correction factors, not to sure how to correct on a track day)

i made 367 SAE, and according to that i should be trapping 110 on an "SAE" day, but i average mid 112's with not the greatest DA's

im confused now

Tin Indian

Sure, I can e-mail anyone the Correction Calculator as long as they input Temp, Humidity, and Baro Press for the day/time thay ran the car. This info can be obtained from "Weather Underground" for any date and time in history. This will correct the ET/Speed for standard Sea Level SAE conditions (zero density altitude)

Remember, your SAE RWHP numbers were corrected before they ever printed on your dyno sheet.

Ron,

turbota@knology.net

99 Black Bird T/A

iTrader: (4)

My traction impaired results were as follows...

~3450 pound T/A + my fat *** another 350 is 3800 pounds. My trap speed was 107.2, the calculator said 365 rwhp. This as when the car was a bolt on car, best dyno was 323rwhp...traction skewed results.

Tin Indian

There is a posibility that some dyno operators don't adjust the figures for SAE standard conditions, but from what I have seen, they all do. All Dynojet's have the capability as they can measure OAT temp and baro press and then apply it to the RWHP numbers (not sure about humidity). Again, only the SAE corrected (to "0" feet Density Alt.) RWHP numbers are shown on your dyno sheet.

Ron,

Tin Indian

And I can tell you, the [only] way to actually see if a givin mod has made you more power is to correct your ET/Speed slips at the track to zero feet density altitude.

You may run 13.00 @ 102 on a cold winter day. Then put some parts on the car in the summer. Go run again on a day thats 100 degrees outside. The car may actually be slower than it was in the winter. You say; I lost power with my new cam. Well, maybe you didn't. Had you corrected both the before and after runs to SAE standard conditions, you would have found that the new mods actually made the car run stronger....

All runs need to be "corrected" to standard conditions [if] you want to see if a particular "bolt-on" actually worked to your benifit.

Make sense?

99 Black Bird T/A

iTrader: (4)

My dyno numbers were correct SAE and the time slip was corrected too.

offaxis

iTrader: (19)

ITs not accurate atleast for me. It is reading too high

The best one i have found was at

http://smokemup.com/auto_math/hp_mph.php

I find this to be pretty darn accurate

Colonel

"BTW, if you don't think it is at all accurate; It takes so much HP to accelerate a certain weight a givin distance to a givin terminal speed. That's just a fact of life."

Ron, your calculator was WAAAAAAAAAAAAY off for my 9 second car. It claimed I had about 580 RWHP. That's off by about 60 RWHP. It claimed my ET would be 10.33 at 132. That's off by over HALF a second and about 4 MPH.

Maybe it works better for slower cars. Let's check my '02 out...

It claims my RWHP is 403. It was 359 for a difference of 44 RWHP.

It says the car should run 12.5 at 109 MPH. It ran 11.82 at 113 MPH. That's 7 tenths of a second and 4 MPH.

Verdict? Well, so much for the facts of life!

FDLS6

iTrader: (4)

I'd have to agree it's a rough calculation.. there are just too many variables to calculate an et.. it say's I'll only do 10.8 in my 3000 race weight car, with approx 470 rear wheel hp... ouch

98sspullin'em

iTrader: (-1)

i dont know how much my camaro weighs, i have all the seats and spare tire out and i weigh 165, any estimates on weight?

CAT3

iTrader: (9)

You sittin on the floor?

Ok, about 3340lbs with short tank o gas. We both have A4's, T's, and seats out, although my scaled weight was front seats and rollbar, with 10# bottle of instant whoop-***.

Warbird

Trap speed = 127.88
Weight = 3820 w/driver

Calc = 623.48 HP
ET calc = 10.65

I wonder if it takes FI into account. The number I get HP wise is 65 HP high from what my dyno says

Paul

Tin Indian

Well, maybe the math is off on the calculator.

I'm Sorry!

Well, it still takes a certain HP to accelerate a givin weight, a givin distance, to a givin velocity.

Just too bad this calculator don't have a clue what the math actually is!

SouthFL.02.SS

It was only off 5hp with my setup.