340Whp & @260TQ NISMO

kcquinn49

The OP was assuming 20% loss to the wheels. If you are looking at WHP, and want to reverse the 20% loss, you multiply by 1.25.

(if you take away 1/5 of any number, then you add back 1/4 to the new number, to get back to the original number.)

From other postings here I was thinking the loss is about 15%. But who knows. How can you actually tell?

Cmike2780

That's 25%

__________________

[09][MB][6-Spd MT][Touring][Stillen Gen III][K&N][Borla CBE][Evo-R]

Spikuh

May be misunderstanding with what you are meaning, but it's the correct amount for what he is saying.

100 x 20% = 20 which when subtracted would leave you at 80.
80 x 25% = 20 which when added back brings you to 100.

Edit: Now that I think about it, my math from earlier may be wrong. To sleepy to look. Maybe tomrrow.

Red__Zed

Do they not teach math in schools anymore?


100*.8 = 80

When the bhp is unknown:

X*.8=80

80* (1/.8) = x



80 *1.25= 100

Cmike2780

Why are you multiplying percentages?

1.25 (25%) number is the percentage factor. 1.20 would be 20%

for example:

300hp @ the wheels x 1.25 (25%) drivetrain loss=375 hp @ the fly

or reverse

375 hp @ the fly/1.25 (25%) drivetrain loss=300hp @ the wheels

__________________

[09][MB][6-Spd MT][Touring][Stillen Gen III][K&N][Borla CBE][Evo-R]

Red__Zed

Cmike, I honestly can't tell if you are just messing with me. If you are, please disregard the following (and insert joke about NYC schools)


OK. Let's talk through this slowly.
Let's say you have a car with 100HP at the crank.

If there is a 20% drivetrain throughout, you will have 80HP at the wheels, because:

drivetrain throughput = 1- drivetrain loss = .8

100*.8=80

Are we tracking this far?


Now, we want to calculate BHP from WHP. To use the same numbers, we have 80HP at the wheels. We know we have an equation that looks like this:

80*Y=X

Where:
X= BHP
and Y = 1/(drivetrain throughput)

How do we get this Y?
Well, from our first equation, we have:
100*(drivetrain througput) = 80

Or

X*(drivetrain throughput)= 80

Or:

80/(drivetrain throughput) = X

Which is of course:

80*Y = X

To get Y, we take

1/.8 == 1.25

Cmike2780

Lol. You're over complicating it. The 1.25 referring to the original post is just used to see what a 25% would be added to the Dyno number. For 20% you would use 1.20.

__________________

[09][MB][6-Spd MT][Touring][Stillen Gen III][K&N][Borla CBE][Evo-R]

Red__Zed

Adding 25% is simulating a 20% loss

Red__Zed

The math you are doing here is 300 + (300*.25) = 375

Which is 25% more than 300


And 375/1.25=300

Which is the same as saying 375*(0.8)=300


300 is 20% less than 375. 375 is 25% more than 300.

You are interpreting the results wrong.