Lies, Damm Lies, and Flywheel Dyno numbers

[GMan]

No, you misunderstand. I meant have the ran any stock cars on the dyno to get some figures to crunch.

 

Say for example they ran a BMW M3 DCT. According to the manufacturers they have 414fwhp. If that company had ran one on the dyno and got the RWHP you could then calculate the transmission losses.

 

I think the BMW figures come from a chassis dyno and are accurate, no?

 

NO BMW engine dynos all of their M engines to make sure the put out at least the claimed HP, most actually put out more.

One of my old buddies used to work there.

[Scott]

Surely that would be a good comparison to back up your argument then?

[GMan]

NO BMW engine dynos all of their M engines to make sure the put out at least the claimed HP, most actually put out more.

One of my old buddies used to work there.

 

sorry I'm so tired that I read fwhp as front wheel horsepower. not fly wheel hp. I need to get to bed

[GMan]

Surely that would be a good comparison to back up your argument then?

 

True, unfortunately there were no conventional automatic M's,

100% used to be manual, then came the SMG, now anything without a clutch pedal is a DCT

[scotty71]

Spot on ScottM, thought everyone knew this

 

The J Spec TT,s were putting the same 326 Fwhp as the Euro/US exports but because of Japan's gentlemans agreement between the major Japanese car manufacturers the claimed output was put at the level of agreement. (276 bhp)

 

From the web:

 

Since 1989, Japanese automakers have all endorsed—at least on paper—a kind of gentlemen's agreement that limited their advertised horsepower to 276 on domestically produced vehicles. Their primary goal was to avoid a horsepower war in a country where the maximum speed limit is 62 mph. But in October, Honda officially broke the agreement at its Legend (Acura RL in the U.S.) press conference when it unveiled the model's 300-hp, 3.5-liter V-6.

 

For years, it's been presumed that once an automaker stuck out its neck and ignored the 276-hp mark, the rest would quickly follow. And judging by what's in the Japanese production pipeline, it looks as if the conventional wisdom was correct. Coming on the heels of that new Acura RL will be the Lexus RX400h with an estimated 300 horsepower, and then the flood gates open—Mazda will introduce a 300-hp two-seat RX-7, Acura will again cross the line with a new NSX with at least 400 horses, and Toyota will mark its territory with the supercar on page 36.

 

Japanese engine designers, however, will readily concede that the country's manufacturers have been building cars with more than 276 horsepower. It's just that none of the automakers wanted to officially break the agreement. It's no secret that Mitsubishi Lancer Evos, Toyota Supra's, Subaru Impreza WRXs, and Nissan 300ZX twin-turbos have been in violation of the agreement for years, but at least in Japan, they all claimed to have 276 horsepower. The false advertising was ignored for the sake of harmony. Not anymore.

 

scotty

[j_jza80]

I thought you said flwheel HP didn't matter, so why all the info on transmission loss? Quite a few forums only deal in RWHP now and I think it's a much better measure.

[dr_jekyll]

giggles and icecream

[Ian C]

I see a lot of misuse of the word "Proof" going around here.

 

Lets take the opening thread shall we. There are links to six articles from a magazine, and these figures are taken as accurate gospel. Now, I'm not saying the mag lied or exaggerated but:

 

Ultimate Tuning's Dynojet Dynamometer

Dyno Dynamics 450 single axle Chassis Dynamometer

SP Engineering Dynojet

Mustang Dynamometer MD-AWD-500

Dynojet Dynamometer

SP Engineering Dynojet Chassis Dyno 248E

 

So all these numbers you are using come from a disparate selection of various dyno makes and models, some of which are tuning shops who may have a vested interest in bigger numbers. Proof demands accuracy which demands repeatable and consistent conditions, none of which we have here.

 

Also, none of the tests were for an auto, so you cannot extrapolate any values for an autobox from these results. However, you make a massive assumption that an autobox in the equation automatically equates to "more driveline loss" - where has this assurance come from? What if auto's are the same as manuals when it comes to efficiency? Sounds crazy? Ok that probably is, but then we come to exactly *how* much worse they are. What if they only increased the loss figure by another 3%? If that were the case, a 20, 21, 22% loss for example would easily fit within the cited examples that range from 17 to 25%. Don't forget the Supra autobox is regarded as an excellent one by those in the trade, so that's not much of a stretch.

 

Instead you pull a 30% figure out of precisely nowhere? The only justification for this is:

"most conventional automatic transmissions lose between 27% and 34% to the wheels" and a dyno plot with no context.

 

Well, the loss is bearings, gearbox, differential, brake drag, and even more bearings. Not all the loss is through the gearbox, so the final figure is influenced by the chassis/driveline that the 'box is bolted into. So a Supra driveline compared to a test driveline at a college is probably going to be different, and probably in the direction of "more efficient". So take the bottom end result and a better driveline, you can reach 25% if you try hard enough, and that's still within your realms of 'proof'. Really, it's just 'guessing'.

 

So, in a nutshell, you have a load of different figures off different dynos, spanning near 20 years, and they are all from manual boxes. How can you then say this is anything like proof of a 30% driveline loss in a different car with an autobox?

 

-Ian

Edited March 23, 2010 by Ian C (see edit history)

[Ian C]

Any other Myths you guys want me to dispel, just ask

 

All manual gearboxes are automatically more efficient than all automatic gearboxes I believe I last heard this myth here.

 

By the way, I do notice that a 22% driveline loss gives you 232fwhp, an increase of 12 horsepower, pretty much what a nice cold day can give you. I can understand your need for a higher drivetrain loss figure

Edited March 23, 2010 by Ian C (see edit history)

[Matt H]

That is the truest indicator of relative power...

 

Cheers,

 

Brian.

 

You're actually trying to say that you can judge HP based on drag racing, when the very reason your car is fast through the quarter is the way it's set up. You've beaten single turbos with loads more power than your car.

 

tDR is a law to himself.........

[tDR]

You're actually trying to say that you can judge HP based on drag racing, when the very reason your car is fast through the quarter is the way it's set up. You've beaten single turbos with loads more power than your car.

 

Ran your 10 yet?

 

Surely the aftermarket chassis bracing would help with that?!?

 

tDR is a law to himself.........

 

Don't you mean upon himself?!?

[j_jza80]

ran your 10 yet?

 

Surely the aftermarket chassis bracing would help with that?!?

 

 

[GMan]

I see a lot of misuse of the word "Proof" going around here.

 

Lets take the opening thread shall we. There are links to six articles from a magazine, and these figures are taken as accurate gospel. Now, I'm not saying the mag lied or exaggerated but:

 

Ultimate Tuning's Dynojet Dynamometer

Dyno Dynamics 450 single axle Chassis Dynamometer

SP Engineering Dynojet

Mustang Dynamometer MD-AWD-500

Dynojet Dynamometer

SP Engineering Dynojet Chassis Dyno 248E

 

So all these numbers you are using come from a disparate selection of various dyno makes and models, some of which are tuning shops who may have a vested interest in bigger numbers. Proof demands accuracy which demands repeatable and consistent conditions, none of which we have here.

 

Also, none of the tests were for an auto, so you cannot extrapolate any values for an autobox from these results. However, you make a massive assumption that an autobox in the equation automatically equates to "more driveline loss" - where has this assurance come from? What if auto's are the same as manuals when it comes to efficiency? Sounds crazy? Ok that probably is, but then we come to exactly *how* much worse they are. What if they only increased the loss figure by another 3%? If that were the case, a 20, 21, 22% loss for example would easily fit within the cited examples that range from 17 to 25%. Don't forget the Supra autobox is regarded as an excellent one by those in the trade, so that's not much of a stretch.

 

Instead you pull a 30% figure out of precisely nowhere? The only justification for this is:

"most conventional automatic transmissions lose between 27% and 34% to the wheels" and a dyno plot with no context.

 

Well, the loss is bearings, gearbox, differential, brake drag, and even more bearings. Not all the loss is through the gearbox, so the final figure is influenced by the chassis/driveline that the 'box is bolted into. So a Supra driveline compared to a test driveline at a college is probably going to be different, and probably in the direction of "more efficient". So take the bottom end result and a better driveline, you can reach 25% if you try hard enough, and that's still within your realms of 'proof'. Really, it's just 'guessing'.

 

So, in a nutshell, you have a load of different figures off different dynos, spanning near 20 years, and they are all from manual boxes. How can you then say this is anything like proof of a 30% driveline loss in a different car with an autobox?

 

-Ian

 

Lets see, where do I start,

 

1) I thought I did say all drive line losses were guesses? Oh yep post 1.

 

2)You say I pulled 30% out of nowhere, then you go and discredit what I learned at university, where I got the 30% from. Really? Ok

 

3)Where precisely do you get your figures from?, the internet?, guessing? or from "tuning shops who may have a vested interest in bigger numbers." ? And all of that is more valid than What I learned from someone with a PhD in engineering in college!!

 

4) I pulled as much different data from as many different dynos on stock cars as i could find to show how much less most cars make when on the chasis dyno

 

5) the supra auto box is good, as an engineer I agree (what are you by the way? Since you obviously know more than me or my professor, or all of the equipment we use), but there is nothing amazing about the box to indicate it has higher efficiencies than Manual transmissions. so you get to pluck a higher efficiency number out of the air ?

[GMan]

and here it is

http://www.importtuner.com/powerpages/impp_0105_1997_toyota_supra/index.html

dyno testing of a stock auto N/A facelift then upgrades.

Please read all of it

 

150 rwhp to start

172.1 rwhp after bolt ons On the same dyno

 

Yes it is a different dyno but xs enginnering is no fly by night tuner shop.

[Purity14]

Go Apexi

[GMan]

So does anyone have a problem accepting 150rwhp as the baseline for an NA auto?

 

Check my math please, I'm only an engineer 220/150= .6818 still with me?

1 - .6818 = .3182 Multiply that by 100 = 31.82%

 

31.82% loss to the wheels OMFG wasn't what that F-ing SAE certified engineer has been saying from the beginning!

 

Must have been a lucky guess, Those Engineers don't know shit anyways they just pull numbers like 30% out of their ass. What you read on the Internet is much more reliable

Edited March 23, 2010 by GMan (see edit history)

[RobSheffield]

and here it is

http://www.importtuner.com/powerpages/impp_0105_1997_toyota_supra/index.html

dyno testing of a stock auto N/A facelift then upgrades.

Please read all of it

 

150 rwhp to start

172.1 rwhp after bolt ons On the same dyno

 

Yes it is a different dyno but xs enginnering is no fly by night tuner shop.

 

Funny isnt it how Apexi were testing various items and the dyno showed they improved power. Not impartial in the slightest.

 

Who actually are XS Engineering?

 

 

Ohhhh, you are an American. Sorry, should have spotted that earlier. Carry on trying to prove that you are right and the rest of the world is wrong

[Terminator]

This Dyno figure, that dyno figure losses, gains, who gives a ****. It is only the clock that never lies.

[GMan]

Funny isnt it how Apexi were testing various items and the dyno showed they improved power. Not impartial in the slightest.

 

Who actually are XS Engineering?

 

 

Ohhhh, you are an American. Sorry, should have spotted that earlier. Carry on trying to prove that you are right and the rest of the world is wrong

 

oh yes that constructive!

 

I guess just because I'm American I can only ever believe I'm right, never can be though, The Brits are always right however.

What kind of narrow minded Idiot brings politics and nationality into a discussion like this?

You want to debate on the basis of my facts, Sure, My education, ok, My Experience, I can accept. but my FUCKING NATIONALITY! You know what I have never said anything to anyone on this forum demeaning their nationality and in return I get all of this Racism/Nationalism.

Maybe I do need to move to a less biased forum.

[RobSheffield]

Maybe I do need to move to a less biased forum.

 

LOL!!!!

 

Maybe you need to chill out and remember there is a wide world out there?

 

Lighten up man FFS

[GMan]

LOL!!!!

 

Maybe you need to chill out and remember there is a wide world out there?

 

Lighten up man FFS

 

Yes I have only lived in Europe for 10 years been to every continent except Antarctica and speak 3 languages fluently to get told by some one that I need to remember that there is a whole wide world out there.

[RobSheffield]

Yes I have only lived in Europe for 10 years been to every continent except Antarctica and speak 3 languages fluently to get told by some one that I need to remember that there is a whole wide world out there.

 

Yeah, so therefore maybe you should also remember there is more to get excited about than flywheel horsepower losses, and more to get wound up over than when someone jokingly says 'oh you are an American' (line from a comedy show in the UK btw) did you utterly miss the smiley?

[GMan]

Yeah, so therefore maybe you should also remember there is more to get excited about than flywheel horsepower losses, and more to get wound up over than when someone jokingly says 'oh you are an American' (line from a comedy show in the UK btw) did you utterly miss the smiley?

 

Sarcasm doesn't translate well into a forum, I did see the smiley but have had much worse things said to me by someone with a smile on their face.

 

My frustration is this,

I learned engineering in a University

I'm told here what I learned there is wrong

 

I find dyno plots on a bunch of different cars to show that regardless of the dyno type, or the car type Driveline losses are more than most so called experts say.

All of them are show consistently low by the amounts I learned at University

So I get told It's all the dynos are wrong and trying to make money.

 

I'm told my own dyno is bull shit

 

Finally I find one that meets all of the criteria, same car/engine/gearbox and the number is spot on to what I said before and still get told I'm full of shit without one shred of contrary evidence

 

 

So being told that now I'm wrong because I'm American is downright infuriating, joke or not.

[RobSheffield]

I wouldnt say being an American is making you wrong at all, my jokey comment was based on how you seemed to fly off the handle when asked to clarify what you were saying.

 

Ill try not to ever joke with you again, much less respond in any of your threads!

 

Its far too late for me to go back and read anything you are saying, ill let Ian read it all tomorrow

[GMan]

By the way XS Engineering is one of the largest tuning companies and aftermarket parts manufacturers in the US

They produce components that directly compete with APEXI

ALL of the dyno tests were conducted by Import tuner, Who are Generally impartial.

Why not use all APEXI parts? If I could afford it everything on my car would be apexi too

Are they not one of the largest highest quality part makers out there?