Brettus

iTrader: (2)

agreed .
But people commonly refer to the difference between the two hp numbers as 'drivetrain losses' .
They don't mention anything about rotational losses normally.

So my belief (correct me if I'm wrong) is that the term 'drivetrain losses' refers to the difference between those two numbers.

paulmasoner

iTrader: (1)

well, i dont know that much detail about how dyno's operate cause they do some screwy "calculating" IMO

but Torque is an instentaneous number with no relationship to time. and any given instant in time, the TQ produced would be the same regardless what the flywheel weight. so the plotted curve of points should be the same. the difference is you achieve progression through that curve much faster with less rotational mass

paulmasoner

iTrader: (1)

depends i suppose on who you are.

if all you care about is an arbitrary number with no detail of usefullness, then sure, call it what you will. see the example of a 700millionHP motor taking 37 days to reach peak power, its "drivetain loss" in that view may only be 40HP(frictional loss)

but thats like trying to measure temperature with a ruler.

in the REAL world, the losses of that 700million HP motor is much more significant than saying "40HP" gives the appearance of.. what good is the power if it takes a month to make it? the race will be over already. and those losses can NOT EVER be defined by Horsepower. It would have to be defined by the rate of change of horsepower made

this is an excellent example of why dyno's are just tools, and basic ones at that. what a dyno can meaure is only a portion of the equation. it can tell you a HP figure to attach with your scales and get a HP/Wt ratio. but a dyno cannot tell you if you make your peak power from idle in 1.4 seconds(as say a high dollar track bike might) or if it takes all day long like an old 3 cyl beat up Geo Metro.

You could make up examples all day long(and better ones) until you had equal total power, identical curves, and equal HP/Wt... but the one that makes te power faster will always win. and it can do that with less rotational weight in the drivetrain, tell me you cant call that less "loss".

Brettus

iTrader: (2)

Well , all your bashing of me was based the definition of a term that you now admit could be viewed either way .

You can take back the sarcasm any time you want .

Revolver

Thank you - I understand that.

So the only way to really measure any benefit from a lightened flywheel is to introduce a time component? Although I suppose it's such an incremental improvement that devising such a test would be difficult - i.e. removing all variables (such as driver response in a drag or a million other things in a lap time).

I guess you could get the same car and time the difference from, say, 40-80km/h, in the same gear before and after installation - that might be a useful real world test. Or am I missing something again?

Brettus

iTrader: (2)

A lightened flywheel only has any tangible benefit in 1st and 2nd gears - possibly 3rd as well in a turboed car . Because acceleration in the higher gears is not great enough for the FW to make much difference .

Mawnee

^ Dont forget reving in nuetral.

paulmasoner

iTrader: (1)

I apologozed for being an *** about things, but take it back no. Because as you say the "industry standard" is the difference between 2 arbitrary numbers. But thats really not how it is. Thats what ppl can understand, nothing more. Its half of an answer, just like any other aspect of a dyno is. And anyone who believes they are remotely a motorsports enthusiast should be able to tell the difference and understand this

realistically, losses could be measured properly, just as power delivery could be. but i dont know of it, and have never heard such a thing. but i'm also not the expert in the world of dyno's and their manufactures etc..

a proper dyno would not be 2 dimesional. it would be 3 dimensional. HP/TQ, RPM, and time each with their own axis. in that manner you could differentiate actual losses and also not just power, but HOW and WHEN power is delivered in relation to time, which is what all motorsports is based around..

Mawnee

so um..we should all wear those new fangled glasses when looking at our dyno charts?

paulmasoner

iTrader: (1)

again, until you can do the math to back that up... dont try feeding that to anyone.

the loss(in your rate of change in power output) is directly tied to angular momentum, which does not care if it 300rpms or 3 million. it ONLY cares about CHANGE in RPM

the losses reduced are the same in any gear at any speed at any rpm. you just have to be able to think 3 dimensionally to understand that.

Brettus

iTrader: (2)

yeh - thanks for that Mawnee LOL

Actually THE most noticable benefit from a light flywheel for me was the improvement in heel/toe downshifting .

paulmasoner

iTrader: (1)

hey, i'm just saying... a dyno gives you just enough information to be stupid

if ppl REALLY wanted usefull stuff out of them, they would be 3D just like your tables in your PCM. but thats not what is easy for ppl to understand and wrap their head around, that would destroy armchair racing, and ricer kids wouldnt even know what to brag about anymore

Brettus

iTrader: (2)

Here we go again .
I don't need to back it up with math . I understand how this works and have experience with a LWFW so I know I'm correct .

fixed it for you ....

I actually thought you had a clue till you wrote this

Mazfix Racing

Anyways back to me for a bit . . . .

Engine Bay shot as requested

Mawnee

Very clean

Wait! Theres no turbo in there!

zoom44

THIS!!!

I know, right?!!! thats why I said

way back at the beginning

and we will hold you to it- unless you actually strap the engine onto an engine dyno


Congratulations! to both of you you survived and managed to get to the bottom line which was so eloquently stated by someone way back at the beginning


oh wait look

I SAID IT FIRST!!

bold for clarity

paulmasoner

iTrader: (1)

and again, when you can do the math, you'll see why i am right

zoom44

nope you got it.


brettus and paul play nice now- you guys got to a good spot. dont f-it up now

paulmasoner

iTrader: (1)

you're still negating the fact that there are losses that a dyno can not physically measure. percentage, static number, bit of both... none of them are entirely correct. because static power means nothing. for it to be useful it HAS to be related to time. unfortunately that not the world we live in, and i dont think ppl would accept it if it was availible to be done properly.

Brettus

iTrader: (2)

I'l try . But being called stupid several times does tend to get one a tad miffed

Mawnee

I think Zoom is stoopid, cause he quoted everyone but me!

Brettus

iTrader: (2)

The rate of acceleration in 1st gear is much greater than the rate of acceleration in 6th gear . Therefore the math will tell me that the effect of the flywheel is (in exact proportion to acceleration) better in 1st .

Brettus

iTrader: (2)

zoom44

no im not. 2 things

1. in the context of this thread the only thing that mattered was "on a dyno". all of your points(well, mostly) are valid if we we'rent talking about "on the dyno". you and brettus were having 2 different debates. you and I are not

2. I purposely didnt go into all of that because, as I said, I love this debate. it's much more fun to watch it unfold then get involved in it. this must be the 8th time i've seen it just on this forum

zoom44

well i was going to quote you about the dump the clutch post and correct you but then i figured i'd just let it go. besides 42 was wrong.if you had added a rolleyes at the end of your welcome to mazfix the sarcasm would have come across better.nitrogen is too expensive use helium.


oh wait... does this count towards quoting you?