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Ask what the power was at the wheels in both cases, I bet that wasn't 25bhp difference....

The key thing in measuring power output is to be able to tell what difference a change in setup has made - hence why there's before and after figures - no point in changing something if it doesn't give an improvement.

Hence, no point in comparing outputs from different RRs and IMHO no point in paying money to put a car on the rollers unless you've made or are making a change that you want to measure....
 

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Quote: posted by Richard W on 15/11/2004 15:03:15

Back to Topic....

Accuracy of RR figures is a myth, they can be set up to a degree of accuracy, but each will differ over time/wear etc. The important thing is to measure under the same conditions - the same RR will probably give slightly different readings on the same car on different days. As someone has already mentioned the figures are almost immaterial, it's the quality of improvement that counts!

Just some of the worms......[:eek:)]

Well if you talk to Mustang Dyno and the only one in the UK in Tewksbury they insit theirs is the ONLY accurate dyno no matter how low it reads.. Well its American is'nt it so it has to be the biggest, bestest, baddest mofo on the planet..

For ref.. the vehicle simulation mode on the mustang was replicating my bruntingthorpe times for standing starts 0-60, 0-100 etc which is a cool different way to play on a dyno.. As for its power figures tho.. 255atw for mine.. and 320atw on JBS rollers as a recent comparison, where std LCR's did std power.

As a tuning tool.. its great.

Is it accurate tho? who knows.
 

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Quote: posted by Richard W on 16/11/2004 15:37:51

Quote: posted by Badger5 on 16/11/2004 14:47:25

...snip...

As a tuning tool.. its great.

Is it accurate tho? who knows.

My point exactly!

Another question then..

(IF) you go to a RR where stock cars put out over stock figures.. and its said they always do, conservative manufacturers etc... and then go to another which reads stock power cars at stock power.. which do you believe to be more realistic? Comparisons on the same day same dyno between stock and modded/chipped cars is the closest you would be able gauge differences..

Not even same RR different day compares.. as you can see from JBS dyno on the previous MKIV's day and after its lightening strike and repairs for a more recent seatcupra.net day there. (write up below)

http://www.seatcupra.net/JBSrollingroadday_071104.htm

things change..

Compare relative to the day and make your own mind up.. One good thing about these 'fun' dyno days..
 

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I would suggest that you ignore the flywheel figure and look at the wheel power figure.

At the end of the day it's the power going to the wheels that is more important because power is lost through the transmission, etc.

Also variables such as the temperature, tyre pressure, is there a fan blowing cold air at the front of the car, etc can make a difference to power output.

My old car was run once on one rolling road and three times on another and each time the result was slightly different.

A rolling road shoot out is a good way of comparing cars because they are all going on the same rollers on the same day with similar conditions. Then you can compare one car with another.
 

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Quote: posted by Badger5 on 16/11/2004 14:47:25

Quote: posted by Richard W on 15/11/2004 15:03:15

Back to Topic....

Accuracy of RR figures is a myth, they can be set up to a degree of accuracy, but each will differ over time/wear etc. The important thing is to measure under the same conditions - the same RR will probably give slightly different readings on the same car on different days. As someone has already mentioned the figures are almost immaterial, it's the quality of improvement that counts!

Just some of the worms......[:eek:)]

Well if you talk to Mustang Dyno and the only one in the UK in Tewksbury they insit theirs is the ONLY accurate dyno no matter how low it reads.. Well its American is'nt it so it has to be the biggest, bestest, baddest mofo on the planet..

For ref.. the vehicle simulation mode on the mustang was replicating my bruntingthorpe times for standing starts 0-60, 0-100 etc which is a cool different way to play on a dyno.. As for its power figures tho.. 255atw for mine.. and 320atw on JBS rollers as a recent comparison, where std LCR's did std power.

As a tuning tool.. its great.

Is it accurate tho? who knows.

Name the cars that are quicker from 60 - 100 that from 0-60

all you get is exotica.... there is no way that Dyno is Accurate

I bet those guys with big power K04'S on vwvortex are not using that Dyno
 

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Quote: posted by LIAMH on 20/11/2004 02:39:48

Quote: posted by Badger5 on 16/11/2004 14:47:25

Quote: posted by Richard W on 15/11/2004 15:03:15

Back to Topic....

Accuracy of RR figures is a myth, they can be set up to a degree of accuracy, but each will differ over time/wear etc. The important thing is to measure under the same conditions - the same RR will probably give slightly different readings on the same car on different days. As someone has already mentioned the figures are almost immaterial, it's the quality of improvement that counts!

Just some of the worms......[:eek:)]

Well if you talk to Mustang Dyno and the only one in the UK in Tewksbury they insit theirs is the ONLY accurate dyno no matter how low it reads.. Well its American is'nt it so it has to be the biggest, bestest, baddest mofo on the planet..

For ref.. the vehicle simulation mode on the mustang was replicating my bruntingthorpe times for standing starts 0-60, 0-100 etc which is a cool different way to play on a dyno.. As for its power figures tho.. 255atw for mine.. and 320atw on JBS rollers as a recent comparison, where std LCR's did std power.

As a tuning tool.. its great.

Is it accurate tho? who knows.

Name the cars that are quicker from 60 - 100 that from 0-60

all you get is exotica.... there is no way that Dyno is Accurate

I bet those guys with big power K04'S on vwvortex are not using that Dyno

I know..

try convincing them that tho.. [8)]
 
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