Bhp From The Engine?

[KEN-R34]

I never said it was linear.

You know what the car losses through the drivetrain from factory.

Example, the old GTS HSV Monaro's. Rated at 300kw, make about 220-240kw@wheels.

Standard GTST, rated at 180 odd kw, make anywhere from 120-140kw@wheels.

So if the same GTST makes another 110kw@wheels to 250kw@wheels, we re-add that 60-40kw loss, so it pumps it up to 290-310kw@engine. However the engine is now producing more power, therefore everything is slightly increased in loss. This is the figure that can not be given by a percentage, or a fixed linear figure. It varies. I'm sure there would be a close equation you could do to work it out more accuretly. The more power you make, the higher the additional loss through friction, fluids, heat etc.

So in a bit of a maths equation.

kw@motor = kw@wheels + original factory loss (say 50kw to be a nice number) + 'unknown variable' (additional loss as power increases)

= 250kw@wheels + 50kw original loss + 'x'

= 300kw@motor + 'x'

This 'x' value is one that you have to guess logically. It aint going to be 100kw, it aint going to be .5kw. A good educated guess in this case could be 5kw. It will obviously slightly increase with the more power you are making. at 1000kw@motor it might be 50kw.

That is about as accurate as you can get with guessing, and for most people i think it is good enough to have that minium value and a little bit extra. I'd rather under qoute something than over qoute.

This logic makes sense when making a calculated estimate.

[HEKT1K]

I like to know it due to conversation with people that aren't that into cars. Since most manufacturer's qoute engine HP figures and all modified car owners qoute @ wheel figures it makes discussions with people that aren't into cars difficult.

Classic case, talk to some one that bought a brand new HSV "My HSV makes 307kw, what does yours make" "My car makes 280kw@wheels" "....Haha my stock HSV has more power". Therefore if you are talking to some one, say your friends parents or something, i always use engine HP figures cause by the time i start explaining drive train losses they will tune out and the discussion will be over.

+1. but your problem is having that conversation with the HSV boofhead in the first place

[KEN-R34]

at the end of the day, who f**king cares?

Well if you don't care why did you click on the thread and make a sexually frustrated comment?

[SECURITY]

I like to know it due to conversation with people that aren't that into cars. Since most manufacturer's qoute engine HP figures and all modified car owners qoute @ wheel figures it makes discussions with people that aren't into cars difficult.

Classic case, talk to some one that bought a brand new HSV "My HSV makes 307kw, what does yours make" "My car makes 280kw@wheels" "....Haha my stock HSV has more power". Therefore if you are talking to some one, say your friends parents or something, i always use engine HP figures cause by the time i start explaining drive train losses they will tune out and the discussion will be over.

then you line them up and their bullshit about how they missed 2nd gear starts.

you fight fire with fire when it comes to n00bs. 'wow, your type r has an exhaust and makes 180kw at the engine... awesome!! now see that charade over there? 100 bux says you cant beat it."

[SECURITY]

Well if you don't care why did you click on the thread and make a sexually frustrated comment?

lol thats cute, you obviously missed the point. but thats all good.. n00bs are allowed to do that around here.

[KEN-R34]

Nah I got your point.

I'm just at work on a break killing some time, and thought I would throw a sexually frustrated comment at the guy with the yellow skyline

[The Dan]

Nah I got your point.

I'm just at work on a break killing some time, and thought I would throw a sexually frustrated comment at the guy with the yellow skyline

Nah, purple is the colour or sexual frustration.

[SECURITY]

and from experience, yellow is the colour of awesomeness. true story.

[The Dan]

http://www.roymech.co.uk/Useful_Tables/Dri...Efficiency.html

Have a read.

[DuFFR32]

Easy, pull the engine out of the car and put in on an engine dyno, then put the engine back in and put the car on a dyno, then you will know what the difference is. IF you have a money tree that is. guestimation is the only way

saying that tho no 2 cars are the same UNLESS they are both factory spec, even then there will be differences as nothing is perfect.

[Super Drager]

The main reason people use % figures are so they can over-inflate their flywheel HP for bragging rights. Hell i've had one monkey try and tell me that all cars lose the same amount of power through the gearbox, manual/auto/skyline/commodore/300zx. When, for fun, i asked him how much he thinks my car is making at the flywheel he says "oh around 150" because he thinks all cars lose 20kw or some such bullshit.

Hmm lets see, 300ZX NA's make 120rwkw when freshly rebuilt with good compression, thats at 165kw atf. One that hasn't been rebuilt will normally see about 110rwkw which is about right for wear and tear which would bring it down to 155kw atf roughly. Mine makes 131.4rwkw so taking into account that 45kw loss i'd be making 176.4kw atf, which isn't correct as i also have an Underdrive crank pulley which reduces powerloss through all the accessories from memory it added 7rwkw on the dyno, so: 131.4+45-7=169.4kw atf which i think sounds correct.

[rtune]

there is a youtube video of a "1000 hp" r32 (looks like dyno @ croydon).

it was logging 500 and something awkw

the explanation given by someone connected with the car in the comments was

that they took 180hp off the 1000hp "for the back wheels" and another 100

"for the front wheels" and the result was ~730hp at the wheels, making the

car 1000hp at the crank, (and a 25% drive train loss).

So goes to show you can say anything about crank hp you want. Pick a nice

round number then work out the explanation!

[The Dan]

there is a youtube video of a "1000 hp" r32 (looks like dyno @ croydon).

it was logging 500 and something awkw

the explanation given by someone connected with the car in the comments was

that they took 180hp off the 1000hp "for the back wheels" and another 100

"for the front wheels" and the result was ~730hp at the wheels, making the

car 1000hp at the crank, (and a 25% drive train loss).

So goes to show you can say anything about crank hp you want. Pick a nice

round number then work out the explanation!

Was the engine from that car ever dynoed by itself?

If not, then the 1000hp is just speculation.

180hp loss to the back wheels and 100 loss to the front is ridiculous.

[rtune]

Was the engine from that car ever dynoed by itself?

If not, then the 1000hp is just speculation.

180hp loss to the back wheels and 100 loss to the front is ridiculous.

dunno, all I saw was the youtube clip and laughed.

[Fastrotor]

I like to know it due to conversation with people that aren't that into cars. Since most manufacturer's qoute engine HP figures and all modified car owners qoute @ wheel figures it makes discussions with people that aren't into cars difficult.

Classic case, talk to some one that bought a brand new HSV "My HSV makes 307kw, what does yours make" "My car makes 280kw@wheels" "....Haha my stock HSV has more power". Therefore if you are talking to some one, say your friends parents or something, i always use engine HP figures cause by the time i start explaining drive train losses they will tune out and the discussion will be over.

Hahah Phil, but when i say im making 650-700 hp ......at the wheels.... thru an auto ...... they all just tend to say FAARRRKKKKKK....so all technical conversation bullshit stops and they all become riceboy fans

hahah

Gary

[PM-R33]

Hahaha yeah well thats different