Drivetrain losses

Discuss general engine, turbo and supercharger conversions in this section

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Morat
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Post Thu Nov 09, 2006 10:10 am

Just thinking about the difference between bhp "at the crank" and RWHP, is there anything that can be done to minimise transmission losses? It seems that if you're going to spend a fortune on the engine and lose over 20% of its power in the drivetrain it might be worth spending a bit to minimise these losses too?
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Post Thu Nov 09, 2006 10:24 am

I was chatting to a ex-touring car driver who runs a race car team and he was explaing how they use certain types of grease in the wheel bearings to reduce friction!!

I replied: " bollocks to that, if I want to go faster I just turn up the Boost!"

but thats the diff between a track car and a road car I suppose!
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oldroydsr4
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Post Thu Nov 09, 2006 10:37 am

Different oils/greases through the transmission, straight cut gears etc
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Post Thu Nov 09, 2006 10:53 am

oldroydsr4 wrote:Different oils/greases through the transmission, straight cut gears etc
Having driven a Mk2 escort with straight cut gears, I doubt anyone could live with them day to day, sounds cool to start with but far to loud for a daily car and at full chat they're jsut abusive to your ears! Track only really unless you fancy phoning your passenger to have a chat on the way!
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blingsta
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Post Thu Nov 09, 2006 1:47 pm

I agree Mark.... Turn up the boost mate!!
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Post Thu Nov 09, 2006 2:23 pm

You could switch to front wheel drive and mount the engine sideways.....but I'm happy to live with higer transmission losses and RWD rightness! :D
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Jon_Bmw
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Post Thu Nov 09, 2006 5:02 pm

Straight cut gears are cool for a few mins as mark says, but after about 10 mins, bloody boring. All you can here is whining, no engine noise at all :(
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Post Thu Nov 09, 2006 5:46 pm

Hi

You clould try micropolishing the gears in the box & diff, only a couple of hundred more on top of a box rebuild.

Jason
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Post Thu Nov 09, 2006 6:52 pm

or you could just bolt the actual lump straight onto an engine dyno and get an accurate readout of the true power output, rather than spending your money to get lied to with power losses of up to 25% attributed to trans losses :x

as long as the oil in diff, and gearbox is clean and fairly new, and the bushes are new and firm, then there isnt too much of a loss.

TBH you cant really feel a drop of say 15bhp on the butt-dyno
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Post Thu Nov 09, 2006 7:23 pm

or you could just bolt the actual lump straight onto an engine dyno and get an accurate readout of the true power
Think Morat was probably refering more to not wasting power that could otherwise be propelling you along rather than how much WHP figures get added to them.

Be interesting to know what a Veyron makes at the wheels as it's immensely beefy transmission must waste SO much power!
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