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AUPS Member
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Discussion Starter #1
Just wondering why some cars with more KW do slower times than cars with lower KW's. Like the 195kw WRX does better times than an BAXR8? accourding to subaru it does 0-100 in 5.1secs. So technically shouldnt the WRX have more KW?
 

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The Subaru has about 300kgs less to move than a XR8 and has the traction of four driving wheels compared to the Falcons two. Power to weight determines how fast cars usually are. For example if two people can run as fast as each other but one has to carry a 50kg back pack than the other guy will be faster. Gearing and traction also play a part.
 

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spaced out
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power to weight and gear ratio's
Good example of gear ratios, i saw a push bike do over 200kms a hour, due to its gear ratio the rider needed a tow to 150kms a hour before he could pedal the bike ok this is top end speed but the same applies in reverse given the correct ratio's
 

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0-100kmh technique for WRX: Hold 7000rpm, dump clutch and floor it, change gear, 100kmh

For the XR8. Hold 2000rpm, slip clutch and feed throttle, either bogg down or wheelspin, floor it (wheelspin), change gear, change gear again, 100kmh.


0-100 times is reliant on traction more than anything. The 1/4 mile and the trap speed is a better indication of the power of a car.
 

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AUPS Member
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Discussion Starter #5
Thanks for explaing that!

So i guess the KW can be very misleading then? and that it doesnt mean just cause you have more KW doesnt mean your gonna be someone with less?
 

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Blue Blood
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Martin said:
0-100kmh technique for WRX: Hold 7000rpm, dump clutch and floor it, change gear, 100kmh

For the XR8. Hold 2000rpm, slip clutch and feed throttle, either bogg down or wheelspin, floor it (wheelspin), change gear, change gear again, 100kmh.


0-100 times is reliant on traction more than anything. The 1/4 mile and the trap speed is a better indication of the power of a car.
Which is why, on the road an XR8 will almost always eat a WRX in a traffic light drag... no sane WRX driver would dump a clutch at 7000rpm. Magazine test drivers do that to extract every last performance drop out of a car they aren't keeping more than 24 hours.

Also if a WRX driver while dropping the clutch falls below 3000rpm, the engine basically falls 'off-boost' and then the WRX is no more than a low powered 2L 4cylinder 4WD car. If an XR8 falls below 3000rpm, its still going to be producing some 400Nm of torque to keep it moving.
 

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BOFH
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there are just so many factors to consider.
Power (KW)
Weight (KG)
Traction
Gearing
Torque (NM) - something that really is important
Engine power range - especially for turbos
road surface
actual track - is it a straight line or a blast up a windy road?
suspension set up
weather/Temp
and of course how brutal and or skillfull a driver is.

All these things combine to determine just how quick a car will reach the other end of a designated point to point run.
Just raw KW is very overrated. It may sell cars (see Holden) but it really is just 1 of many, many factors to consider.
 

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I am a Turbo Wanker
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ianmcginley said:
Which is why, on the road an XR8 will almost always eat a WRX in a traffic light drag... no sane WRX driver would dump a clutch at 7000rpm. Magazine test drivers do that to extract every last performance drop out of a car they aren't keeping more than 24 hours.

Also if a WRX driver while dropping the clutch falls below 3000rpm, the engine basically falls 'off-boost' and then the WRX is no more than a low powered 2L 4cylinder 4WD car. If an XR8 falls below 3000rpm, its still going to be producing some 400Nm of torque to keep it moving.
What your syaing is soo true, but I do have a mate at work with MY96 WRX wagon and he dumps the clutch at 8,000rpm all the time for fun?! Car is still going, he also has 19psi, front mount and unichip to push things along... crazy bastard just doesn't care!
 

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To ianmcginley you sure do know about the engines and how they perform,great stuff.
 

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Yeah I to know of a WRX driver who dumps the clutch all the time to keep boost up and he's gone through two boxes in just over 45,000 km. I cant wait till the warranty runs out. I mean i can usually flog them up until around 40 - 60km until they go on boost. Also some guys that drive them really have no idea how to push a lawn mower let along set foot in a car.
 

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94ED_Fairmont said:
What your syaing is soo true, but I do have a mate at work with MY96 WRX wagon and he dumps the clutch at 8,000rpm all the time for fun?! Car is still going, he also has 19psi, front mount and unichip to push things along... crazy bastard just doesn't care!
Heh, like aus1sixa, I'm also wondering how many boxes he's been through :)
 
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