RR comparison N/A v S/C
Turbo Mini Forums

Here:

http://www.mini-performance.co.uk/images/sprite/book1.mht

2004 and 2006, same rollers so valid comparison, same engine apart from Vmax kit.

Rich

Here for the craic..

Supercharged Arden powered

hmmm, nice bit of extra curlywurly at the bottom end there,

Uhmmmm, how come the sc lines don't cross at 5250rpm? Am i missing something?

dunno, unless i cocked up the chart?
will go and check printout..

Here for the craic..

Supercharged Arden powered

Chart is correct as near as we can get to the printout.?

Here for the craic..

Supercharged Arden powered

TD is right, that 2nd curve is funny.

alex

AlexF

Can't really understand why though - as it looks 'right' as regards the shape of the curve.

Always, always check that the torque and HP cross at 5250 rpm before you leave the dyno. If they don't - ask why!

Did he use a spark reference for the RPM for both, or try doing the RPM through the rollers?

Edited by turbodave16v on 18th Aug, 2006.

[quote=TurboDave,18/08/2006 22:06:37]

Always, always check that the torque and HP cross at 5250 rpm before you leave the dyno. quote]

please explain, why at 5250?

i have no idea!
I'll have to check the readings I've put into excel versus the lines on the printouts.
in case theres an error somewhere.
I did notice we have a lot more drag than mini Sprocket's recent RR at the same place 37.5 and 40 as opposed to 24.5.

Here for the craic..

Supercharged Arden powered

       torque * RPM

BHP = -----------------

              5252



Alex

Edited by AlexF2003 on 18th Aug, 2006.

AlexF

http://auto.howstuffworks.com/horsepower.htm
http://auto.howstuffworks.com/question622.htm

ok - it's meant to be 5252 rpm, not 5250, but I always just remember it as 5 1/4 K rpm... It's the way my simple mind works....

Dave , are you sure that crossover thing works on every engine , i read somewhere on the highpower board some viper owner s engine made so much torque from very low down the torque curve was always above the hp curve,

think about these 16 cyl oil tanker engines that make 1,000,000lbs of curly wurlies but only make 100,000 bannanas, how will they ever cross.let alone reach the dizy hights of 5252.rpms

carl

Edited by fastcarl on 18th Aug, 2006.

WWW.FORCE-RACING.CO.UK PLEASE CLICK HERE

If they DO cross, then it has to be at 5252rpms surely????

I know what you mean - and you're totally right about truck engines - but these have usually called it a day by 3500rpm's?

Now heres a though, slightly off topic but relevant.

On the rundown to calculate drag, my transmission sucked up 24bhp. ( forgot to stick more air in the tyres)

Tell me this. 1hp is worth 0.746KW, so there is a loss of, for arguments sake, 18KW. where does this go? Physics states that the lowest form of energy is heat. So why is my gearbox not melting on a long journey. You'd need another rad bigger than the one fitted. Thats 6 three bar electric fires permanantly on (for a visual image) or a domestic central heating and hot water boiler for a decent size bungalow.

Just my fuzzy logic on all this thats all.

24 hp in a transmission? Christ! Did you put a couple of torque converters in there aswell???

What can i say

Other than MINISPORT

like i said, this energy just doesnt dissapear, it has to go some where. It doesnt add up to me.

TBH i think i need to overhaul the brake calipers, there might be some drag on the brakes and the soft tyre pressure didnt help either.

Edited by Sprocket on 19th Aug, 2006.

Here for the craic..

Supercharged Arden powered

That is ludicrous, 30KW, im sure the gearbox would be glowing and the oil boiling.

Please some one tell me, where is all this energy magicaly dissapearing to, it cant be right.

Still Ive all ways been one of those who only uses the @wheel figure for any sort of comparison. the flywheel figure is just a big up figure and realy means nothing, like it did in the old days with the analogue rollers when the operator would whack on about another %20 without realy even trying to calc it.

SC transmissions should have less losses, as should freshly built helicals, soft tyres dont help and niether does binding brakes, a car not sat quite true on the rollers, drag on the roller itself, could all play a part.

Edited by Sprocket on 19th Aug, 2006.

Please some one tell me, where is all this energy magicaly dissapearing to

oil churning

Metro turbo weekend driver,Mini turbo in the making again!

I have personally found from experience that the "run-down" type rollers do give a flywheel horsepower reading that is a good indicator of what an engine would be "expected" to produce, this is for near standard engines with quoted power outputs from the factory.

AlexF

The difference between SOUND and NOISE being??????????

Ok so sound is generated, but say for arguments sake in the case of Richspec's transmission it was 10KW, Equivelant to a turbojet engine, 160db, VERY noisey, so noisey infact that youd damage your ears in seconds. http://en.wikipedia.org/wiki/Sound_power , that leaves 20KW to the transmission and tyres, thats still a shit load of heat.

Edited by Sprocket on 19th Aug, 2006.

so i dont mean to hijack the thread but just looked at my print out and it looks like mine cross at about 4800 revs. so does this indicate a problem or something wrong. how do you go about fixing it.

no longer a series, but still 1.3 turbo.

5252 is a theoretical number and judging the quality of RR operators and calibration, anything goes.

Theoretical in that, that is what you should have. the equipment can be the problem, not necisaraly your engine

My print out was prety dam close

Edited by Sprocket on 19th Aug, 2006.