awkw vs rwkw

[mcnamg]

just a question for the ill informed

what is the difference between awkw and rwkw?

obviously the rwkw calculation is at the two rear wheels but awkw if at all 4 wheels so is the calcualtion different.

I must admit i am very interested to find out about this.

is anyone can fill me in i would muchly appreciate it

[Sydneykid]

just a question for the ill informed

what is the difference between awkw and rwkw?

obviously the rwkw calculation is at the two rear wheels but awkw if at all 4 wheels so is the calcualtion different.

I must admit i am very interested to find out about this.

is anyone can fill me in i would muchly appreciate it

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

[geno8r]

Sydneykid.. your the Dr. Karl of the skyline forums.... lol! *and im not talking about neighbours....

[mcnamg]

yeah that makes sense

so basically like when your talking about a rwd drive car and you can make an estimate of rwkw by working out an aprroximate powerloss percentage thru the drive train the same applies in the awd but there is more areas for power loss

btw whats the stock kw at the engine for a 34 model stagea series one and whats the awkw stock as well if you know

[BU5TER]

I'm pretty sure the percentage theory never works better to work off a set figure like SK said and maybe allow a touch more for bigger hp cars?

[mcnamg]

so basically worst case your going to allow for about 80-90 kw loss on a stagea?

just trying to figure out what i will need to spend to get to my power figure i would like

finally convinced the missus to get an import and the stagea looks like the most logical car for us plus having the awd and turbo is a huge bonus

thanks for the quick replys guys

[Sydneykid]

whats the stock kw at the engine for a 34 model stagea series one and whats the awkw stock as well if you know

That's a good question mcnamg. I have seen 185 kw and 173 kw quoted for Stageas. I am going to run ours up on the 4wd dyno next week, while it is standard. I expect to see around 100 awkw. I will then drop the exhaust from the front of the cat and do a quick (and noisy) run to see what's in the exhaust upgrade. If I have time I will stick the Pipercros panel filter in and see what difference it makes at standard power, not much I expect.

I'll post it up when done.

[mad wagon]

with the mods i got mine clocked 195awhp (145.411awkw) at 10psi.

[rs73]

In a 2wd Skyline (like na R33 GTST) this works out around 50-60 kw, based on the cars we have tested.  

Just interested with your test data, was it tested using stock clutch or aftermarket clutch? and was it auto or manual? Cos my auto when it was 100% stock was suppose to have 184kw and it made 138rwkw on dyno, so I'd imagine manual example should made well above 140rwkw with a good stock clutch.

[TurboX]

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

SK, I dont know how you find the time to contribute so much to this forum!

Thank the great spartan air god you do!

My question is,

if my AUTOMATIC GTS4 made 170 RWKW (AWD fuses Pulled) on the dyno and ran 14.1@98Mph(0-60/2.6) at the drags, what sort of AWD KW do I need to make to get into the high 12's??

And, what would the difference in times be between AWD and RWD(fuses pulled) if I did manage to make 250 AWKW? (My long term goal for my Stock bottom end RB20)

[mcnamg]

Thanks heaps for all the information would be very interested to see what your cars power figures are like when you dyno it

when you post it up post the dyno sheet if u got it

can you also tell us what zorst u are using as well just to give us an idea of whats power it is capable of adding to the car

you seem to be an absolute hive for information. I suppose its good that someone knows this information because if not we would still be trying to translate one of a million japanese car sites to english to figure it out

[mad wagon]

:aroused:

[Sydneykid]

Just interested with your test data, was it tested using stock clutch or aftermarket clutch? and was it auto or manual? Cos my auto when it was 100% stock was suppose to have 184kw and it made 138rwkw on dyno, so I'd imagine manual example should made well above 140rwkw with a good stock clutch.

Hi rs73, clutch is irrelevant, as long as it isn't slippimg of course. Auto's seem to loose around 10 kw more than manuals, if the torque converter locks up solidly maybe a few less. And lastly, all dyno's are different and climatic conditions make a difference (not withstanding DynoDynamics good attempt with Shoot Out Mode). So your 184 - 138 = 46 kw is well within tolerances.

Data source, we have run 2 X RB26DETT's on the engine dyno and then put them in the GTR and one RB30DET and put it in the GTST. Along with untold Holden and Chevy V8's (both big and small block). Plus over 30 Skylines (standard and modified) on the chassis dyno only. So I am pretty confident the data base is large and the results consistent enough to make a judgement.

Hope that helps

[Sydneykid]

SK, I dont know how you find the time to contribute so much to this forum!

I only sleep 4 to 5 hours a night, take a look at some of the times I post at.

if my AUTOMATIC GTS4 made 170 RWKW (AWD fuses Pulled) on the dyno and ran 14.1@98Mph(0-60/2.6) at the drags, what sort of AWD KW do I need to make to get into the high 12's??

That's a tough call, average power makes more difference than the sinlge max power number and RB20's get narrow in their power band as you move up the max power ladder. I would think 200 rwkw would do it, but it might need 210 rwkw if the auto isn't transferring the power well.

And, what would the difference in times be between AWD and RWD(fuses pulled)  if I did manage to make 250 AWKW? (My long term goal for my Stock bottom end RB20)

My experience (and I am not a drag racer) is the traction from 4wd makes more difference than the power losses by a good factor. Your target of 250 awkw is getting up there for an RB20. That's ~410 bhp, I have only ever seen 1 X RB20 make more than that and it didn't have standard internals. Ours makes 225 rwkw with good average power, it is tricky to get off the line and you really need to be paying attention to keep it firmly in the power band. The auto and 4wd will assist you there.

Hope that is of some help

[TurboX]

I only sleep 4 to 5 hours a night, take a look at some of the times I post at. I would think 200 rwkw would do it, but it might need 210 rwkw if the auto isn't transferring the power well.

My experience (and I am not a drag racer) is the traction from 4wd makes more difference than the power losses by a good factor.  Your target of 250 awkw is getting up there for an RB20.  That's ~410 bhp, I have only ever seen 1 X RB20 make more than that and it didn't have standard internals.  Ours makes 225 rwkw with good average power, it is tricky to get off the line and you really need to be paying attention to keep it firmly in the power band.  The auto and 4wd will assist you there. Hope that is of some help

Thanks, SK

If I can make 12's with only 210AWkW I will gladly reduce my expectations and COST

Its easy to throw numbers around and 250 didnt sound too much to expect from reading ZOOM etc. on their experience with RB20's.

The Auto has been completely rebuilt with kevlar clutches , 2800RPM Stall etc so should do the job and handle any power the RB20 can throw at it.

AS my GTS4 is reg as a GTR I probably should put an RB26 in it and have an Auto GTR! :throwup:

[CoolPC]

:aroused:

You're still running stock boost though? And no S-AFC or similar?

[Sydneykid]

Yuko, look at the A/F ratios at 60 kph, no wonder ours guzzles the gas. :headspin:

with the mods i got mine clocked 195awhp (145.411awkw) at 10psi.

What mods are there, sorry I know you mentioned it in another thread but I forgot....

[CoolPC]

 

Yuko, look at the A/F ratios at 60 kph, no wonder ours guzzles the gas. :headspin:  

 

What mods are there, sorry I know you mentioned it in another thread but I forgot....

Well according to his profile he's got a FMIC and a 3" exhaust... looking at the AFR doesn't look like he's got anything to correct the fuel, and it looks like it would really benefit from it Add a bit of boost and it should make a fair bit more power again...

[mad wagon]

with a turbosmart boost tee i've got it on 10psi and i dont have a safc coz im planning on getting an aftermarket computer soon. when i do wooooohooooo

:wassup:

[mcnamg]

mad wagon what computer are you planning on using?

do you have an auto?