Flywheel KW compared to RWKW? R33 Gtst?

[benl1981]

I'm just wondering whether skylines lose a lot gettig from the flywheel to RWKW?

A stock R33 gtst Flywheel = 187kw

At the wheels = 140kw????

I saw an article in the latest motor/wheels magazine on VY SS and BA V8 falcon upgrades.

I think the SS stock was 245kw Flywheel and 221kw at the treads. After $1000 rechip it was 240RWKW and 1/4mile in about 12.8!!!!! and 0-100 in mid 5s

If these are the right figures then there is minilmal drivetrain losses with the holden compared to the skylines....

[oor33sky_]

average stock rwkw 4 a R33 GTS-T would be roughly about 130kw depending on gearbox/age of vehicle etc.

yep of course the ss & ba have minimal drivetrain losses compared with the r33 skyline! they are brand new cars..r33's are between 8 & 12 years old this year

the age/condition of a vehicle plays a big part when it comes 2 drivetrain losses

[bigcarl]

r33 rb25 losses through the drive train are about 60 to 65 kw, dont believe everything that you read in motor magazines. theres no way that a v8 losses only 20kws through their drive train! if anything they would loose more than a rb25. id say holden has paid of the magazine to talk it up!!

[Ronin 09]

as an aside - as if motor isn't on holden's payroll

explain how a commodore / variant that pisses power steering fluid at the track makes a minor placing at PCOTY??

especially since HSV are 'track oriented' eg SV6000

/end rant/

[benl1981]

I dont see why because they are brand new they would lose less. There is no major technology breakthrough in terms of gearbox/drivetrain. Maybe they are talking it up!!!

[oor33sky_]

I dont see why because they are brand new they would lose less. There is no major technology breakthrough in terms of gearbox/drivetrain.  Maybe they are talking it up!!!

So what u r saying is that a 1993 model stock R33 which was dynoed directly off the showroom floor back in 1993 would give the same figure as a 1993 model stock R33 which was dynoed in 2005? Interesting...

[benl1981]

Maybe lose 5kw. A new engine will take about 10k -20k kms before it loosens up. In fact when I was working at ford even some of the other engineers thought the cars that had done 90k kms etc were quicker than the ones that were near new.

Most R33s would have more than this amount of kays and obviously older than AU falcons but I still reckon most of the good ones would be within 5-10kw of showroom spec

[DaGr81]

how can it do 1/4 mile in 12.8 and have a speed of 0 - 100 of mid 5's wtf , a r32 gtr is quoted at doing 0 - 100 in ~ 4.94 and have a 1/4 mile of 12.94

[vsv6perth]

how can it do 1/4 mile in 12.8 and have a speed of 0 - 100 of mid 5's wtf , a r32 gtr is quoted at doing 0 - 100 in ~ 4.94 and have a 1/4 mile of 12.94

umm... tell me if im wrong but... different gearing, different touqe and a different power curve, different cars make the power at different rpm, cant compare cars guys, ones a v8 family car (lets face it) and the other is designed to get to the 400m as fast as possible. two cars designed for different reason. PS, I love my holdens, but motor is full of BS.

BUt yeah, stick the wot the guy asked For. Wots the stock RWHP of a R33 GTS

[Bobjones]

All manufacturers quote power at the flywheel, so the 225 Gen III's are in fact 225 at the flywheel not the wheels, just a point of reference.

And it is correct about drivetrain losses, it is also related to gearing and other factors such as fluids.

[Mean_R34]

A Holden engineer once told me that, as a general rule of thumb, there's approximately 30% loss of power between the flywheel & the rear wheels.

Basically 300KW @ the fly equates to around 200RWKW.

[Sydneykid]

Here is a a post I prepared earlier, that a search found for me;

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When you put a car on a chassis dyno (roller or hub style) there are power losses, in the gearbox, the tailshaft universals, the diff, the driveshaft universals, the wheel bearings, the tyres and the rollers themselves. In a 2wd Skyline (like na R33 GTST) this works out around 50-60 kw, based on the cars we have tested. A couple of which we have also run up on the engine dyno confirm this.

Obviously when you add a transfer case, front diff, front drive shaft universals, front tyres and the extra rollers you loose more power. Around 20-25 kw based on what we see with GTR's.

So if you have a 280 kw engine, it will show around 220 rwkw and 200 awkw.

I should point out that there are no "losses", Newtons law applies, "energy can neither be gained nor lost". So the 60 kw is not "lost" it is transformed into other types of energy, in the car's case that's generally heat.

Hope that is of some help

[Munna]

I have heard that the rule of thumb for this is

manual rwd drops 26%

auto rwd drops 30%

Just an estimation though and it will obviously vary from car to car

r33 gts-t manual

187 - 26% = 138

r33 gts-t auto

187 - 30% = 130

300 kw manual = 222

[Reedy]

As you add more power to a engine do you lose more power or is it the same?

e.g. does 270rwkw car have 270kw + 60kw =330kw at flywheel or 26% lose 100/74*270=364kw at the flywheel?

[Cubes]

I remember Holdesn 300kw GTS. It made 224rwkw at the wheels.

Holdens VT 220kw made 164rwkw at the wheels.

[Munna]

As you add more power to a engine do you lose more power or is it the same?

e.g. does 270rwkw car have 270kw + 60kw =330kw at flywheel or 26% lose 100/74*270=364kw at the flywheel?

Yes I guess you would loose more power as you add more engine power. You are putting more stress and adding more heat to the drivetrain.

[FATGTS-R]

As engine power increases, the drivetrain losses would increase to a point but not at anywhere near the same rate.

I think what SK was alluding to is that there is a certain amount of power the drivetrain will transform into heat and thats about it.

Using the "rule of thumb", an R33 GTST manual that cranked out say 800rwkw, using the 26% rule would have 1008kw at engine. Thats 208kw that would have to be transfered into heat. Now I'm out of my league in making any educated guess as to what the gearbox and diff temps would equate to but Im sure its damn hot.

The percentage rule seems to sell a lot of magazines though..........

[KamikazeR33]

also added into this theory is when oil and bearings etc get older they create more friction and heat meaning less power over time