Skyline Transmission Loss Question..........................
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From: *PF TERRORISTS CARTEL* Bin flocking Youngens :cry:
Skyline Transmission Loss Question..........................
Was wondering to myself the other day, after thinking skyline transmission is ideal, I remembered seeing on rolling road power graphs etc they always (the ones I saw) lost WELL over 100bhp from the flywheel to the wheels 
Why do they lose so much power if they convert to rwd when they have enough grip (which they must do on a rolling road power run, if they didnt it wouldnt be correct anyway).
Almost sort of pointless having a fancy gearbox that runs rwd until grip is lost if the benefits of rwd i.e less transmission loss are not there anyway.
anyone??
Why do they lose so much power if they convert to rwd when they have enough grip (which they must do on a rolling road power run, if they didnt it wouldnt be correct anyway).
Almost sort of pointless having a fancy gearbox that runs rwd until grip is lost if the benefits of rwd i.e less transmission loss are not there anyway.
anyone??
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From: *PF TERRORISTS CARTEL* Bin flocking Youngens :cry:
yeah, I realise that it is done in percentages and chances are these were reasonably high powered ones. but in theory they are rwd (on rolling road). just seems a hell of a lot to lose.
would be VERY interesting to see what Rod's car's transmisison losses are...
would be VERY interesting to see what Rod's car's transmisison losses are...
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I bet rod loses more than 100bhp on his car.
Its a very hard thing to really meausre though, the way rollers do it by dipping the clutch and watching it coast down isnt really ideal, only real way of doing it is to dyno the engine, then fit it to the car and stick it on the rollers and spot the difference.
Its a very hard thing to really meausre though, the way rollers do it by dipping the clutch and watching it coast down isnt really ideal, only real way of doing it is to dyno the engine, then fit it to the car and stick it on the rollers and spot the difference.
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From: North Korea
They make it up as they go along, IMO almost all RR tranny loss figures are greatly exadurated to make the owner feel like they got their moneys worth, skylines included.
Some very interesting (and old) quotes for you...
Heres a quote from a PM i kept from 2003 from Guy who used to own the mad ProjectX R32 (ie that thing that was doing 155mph terminal speeds
).
It was after i said on the GTR board that the huge tranny losses people claim are bullshit, and he was backing me up.
Heres another VERY interesting quote, Guy again, just after the first TOTB...
So bearing in mind a Skyline is FAR heavier and has potentially more transmission loss due to it being 4wd, whys the terminal speeds at 500m higher even vs cars with the same (claimed by the cossies) power?
Some very interesting (and old) quotes for you...
Heres a quote from a PM i kept from 2003 from Guy who used to own the mad ProjectX R32 (ie that thing that was doing 155mph terminal speeds
).It was after i said on the GTR board that the huge tranny losses people claim are bullshit, and he was backing me up.
GTRs on the rollers do not get the huge transmission losses that many suggest occur. G-Force do not like stating 4wd losses and have indicated a 27% on the fixed 4wd transmission of an Evo 6 and this has been taken by some (Dirk) to mean that a GTR has 27% losses.
This is rubbish for several reasons.
Firstly losses are not a straight proportion of power.
Secondly there is no way his transmission is losing 250bhp, this kinetic energy can only be lost to heat and there's no way his transmission is absorbing 250bhp of heat.
Thirdly, running high cars such as Project X on the Dynapack (hub dyno) proved that only about 25% max torque was passed to the front wheels and this percentage reduced as the revs increase, once past the torque peak.
My guess is that a truer transmission loss would be about 20% or less. Of course that doesn't produce the same claimed flywheel figures......
This is also validated by running the car in rwd only on the dyno, the power figures do not jump massively, thus proving the car was nearly rwd to start with, in which case a loss of 15%-20% is more reasonable.
This is rubbish for several reasons.
Firstly losses are not a straight proportion of power.
Secondly there is no way his transmission is losing 250bhp, this kinetic energy can only be lost to heat and there's no way his transmission is absorbing 250bhp of heat.
Thirdly, running high cars such as Project X on the Dynapack (hub dyno) proved that only about 25% max torque was passed to the front wheels and this percentage reduced as the revs increase, once past the torque peak.
My guess is that a truer transmission loss would be about 20% or less. Of course that doesn't produce the same claimed flywheel figures......
This is also validated by running the car in rwd only on the dyno, the power figures do not jump massively, thus proving the car was nearly rwd to start with, in which case a loss of 15%-20% is more reasonable.
Two 3 door rear wheel drive RS's:
Andy Wornell 126mph at 500m
Rob Wiles 123mph at 500m
Both with claimed 500+bhp on the website.
Pick a few of our GTRs at 500m:
Andy Barnes 130mph (550bhp est)
Glen H 127mph (540+bhp)
Mike Smith 126mph (515bhp)
The GTRs also pulled higher 1.25mile times, so in conclusion:
The GTRs were better off the line.
The GTRs were travelling faster at 500m (ie were not being caught)
The GTRs were travelling much faster at 1.25miles.
So if the 500+bhp Cossies are slower than the GTRs, how is a 420bhp Cossie ever going to keep up?
I use the speed at 500m, since that is a determinant of rate of acceleration from meaningful speeds ie 30mph+. The traction really only has an effect on the ET (elapsed time), hence why I ignored the times
Andy Wornell 126mph at 500m
Rob Wiles 123mph at 500m
Both with claimed 500+bhp on the website.
Pick a few of our GTRs at 500m:
Andy Barnes 130mph (550bhp est)
Glen H 127mph (540+bhp)
Mike Smith 126mph (515bhp)
The GTRs also pulled higher 1.25mile times, so in conclusion:
The GTRs were better off the line.
The GTRs were travelling faster at 500m (ie were not being caught)
The GTRs were travelling much faster at 1.25miles.
So if the 500+bhp Cossies are slower than the GTRs, how is a 420bhp Cossie ever going to keep up?
I use the speed at 500m, since that is a determinant of rate of acceleration from meaningful speeds ie 30mph+. The traction really only has an effect on the ET (elapsed time), hence why I ignored the times
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Originally Posted by Itsmeagain
Chip- Looking at comparision times for Saffs vs Sierras (or Escorts) id say the effect is far less than youd think.
Basically there are a LOT of factors involved, so drawing conclusions about the gearbox whilst ignoring them all seems a stupid idea to me.
BUT i do agree with his fundamental point that it cant be *MUCH WORSE*, it may be a little worse, or a little better, but its not going to suddenly sap all your power if you convert to one.
Steve,
You probably have the Revs magazine where I did the second top speed challenge?
I was running 400bhp on light blues on a T4. Because I had a standard diff, I pussy-footed off the line (0-60 6.6s and standing quarter in 15s according to the Stack), but still did 172mph. There were several Skylines there claiming 500-550bhp that did those amazing brutal launches that only Skylines can do (like a golf-ball being hit) and the best they could do was 169mph in 1.25miles.
Please explain that one
.
You probably have the Revs magazine where I did the second top speed challenge?
I was running 400bhp on light blues on a T4. Because I had a standard diff, I pussy-footed off the line (0-60 6.6s and standing quarter in 15s according to the Stack), but still did 172mph. There were several Skylines there claiming 500-550bhp that did those amazing brutal launches that only Skylines can do (like a golf-ball being hit) and the best they could do was 169mph in 1.25miles.
Please explain that one
.
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From: *PF TERRORISTS CARTEL* Bin flocking Youngens :cry:
you painted the injectors 
I reckon a lot of these so called 600bhp skylines are like the so called 200+bhp rs turbos that everyone has
I reckon a lot of these so called 600bhp skylines are like the so called 200+bhp rs turbos that everyone has
Paul,
They didn't at the Revs shoot-out, I believe Martin won it in his Mondeo .
Steve,
I think if you pulled up Rod's times through the 500m that would be more representative for the Cossies. Neither of the RS500s quoted could get anything remotely ressembling a good launch and struggled to put in the times you would hope for or expect. I blame it on the fact that Rob and Andy are well past their sell-by dates .
They didn't at the Revs shoot-out, I believe Martin won it in his Mondeo
.Steve,
I think if you pulled up Rod's times through the 500m that would be more representative for the Cossies
. Neither of the RS500s quoted could get anything remotely ressembling a good launch and struggled to put in the times you would hope for or expect. I blame it on the fact that Rob and Andy are well past their sell-by dates .
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From: Essex... and Birmingham!
Originally Posted by pgtips
the cossies always seem to loose to the skyline crew 
Won by this
No-one could believe it on the day, was supposed to be very funny
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From: supercar heaven
Originally Posted by pgtips
the cossies always seem to loose to the skyline crew
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From: North Korea
Mike- Good launch has very little effect on terminal speed over the 1/4mile, even less so on 500m. Remember we talking terminals not times.
What was Rods 500m terminal speed at TOTB1?
Methinks it was more of an issue of the 2 cossies mentioned "claimed" 500bhp, rather than real bhp like Rods obv was.
Are the TOTB1 results around anywhere? I ued to have them on a spreadsheet i think.
I use the speed at 500m, since that is a determinant of rate of acceleration from meaningful speeds ie 30mph+. The traction really only has an effect on the ET (elapsed time), hence why I ignored the times
What was Rods 500m terminal speed at TOTB1?
Methinks it was more of an issue of the 2 cossies mentioned "claimed" 500bhp, rather than real bhp like Rods obv was.
Are the TOTB1 results around anywhere? I ued to have them on a spreadsheet i think.
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Just found the results on a spreadsheet i got, Rod got a best terminal of 129mph, so i guess the point Guy made still makes sence 
Tho Steve Scott got 131mph in the Focus
Derek B got 121mph
Gareth Lloyd got 129mph
Kev Sharp 122mph
Dan H 117
SeanB 118
All "500bhp" cars
Tho Steve Scott got 131mph in the Focus
Derek B got 121mph
Gareth Lloyd got 129mph
Kev Sharp 122mph
Dan H 117
SeanB 118
All "500bhp" cars
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anything on the road is potential competition, so if people want to compare to skylines thats fine.
people want to be the quickest, not the quickest 2 litre
or the quickest 2 litre from the 80s etc
Its like saying "ive got the fastest 3 legged dog"
people want to be the quickest, not the quickest 2 litre
or the quickest 2 litre from the 80s etc
Its like saying "ive got the fastest 3 legged dog"
, that that i would like to see, care to take a wager
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From: barry-south wales
Originally Posted by Porkie
Originally Posted by chip-3door
Its like saying "ive got the fastest 3 legged dog"
mine makes 39 at the hips using the new hip dyno
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From: North Korea
There was a 3legged Greyhound in the local paper yesterday, its at the animal shelter, needs a good home, shall i buy it and enter it into Ten of the Best 3legged dogs? I reckon itl do well
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From: *PF TERRORISTS CARTEL* Bin flocking Youngens :cry:
I'm going out on the look out for a 3 legged dog later if I cant find one I'll just try and precisely run over a goodun to make him a 3 legged one
Whens the first passionpaw meet then??
if I cant find one I'll just try and precisely run over a goodun to make him a 3 legged one Whens the first passionpaw meet then??
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Originally Posted by wee-homer
Why do ppl always compair cossy's to skyline's? look at the real compotition to our cars the evo's scoobie's gtir's and other 2 liter 4 cylinder cars 
the skylines beat cars (normally) with much bigger engines, didn't they beat all the dodge vipers at TOTB? vettes etc. (well the big bhp skylines anyway)Porkie/Mike: so whats the story? i didnt hear about the rev's shootout?
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