standard power fig at wheels

[lew172]

What is the standard power figure at the wheels of a mk 1 172 please

 

[Rich-D]

If youre getting around 144bhp @ wheels youre pretty much spot on...

 

[lew172]

mine was rrd at 177.5bhp

with 128 bhp at the wheels



it has a magnex backbox

longlife centre section

pipercross induction kit







on the way is a group n ecu from hillpower

 

[RS-Steve]

128 @ wheels aint 177.5 at fly pal. Mine was RRd along with Boyos standard 172 an we both got <A target=_blank href= "mailto:144@wheels">144@wheels which is nye on 172BHP at the fly! ( ITHINK) Rich is the man for the calculations!!

As i remember

@ wheels figure X 1.2 = high at fly figure

@ wheels figure X 1.15 = Conservative fly figure.

Somewhere between an your about right i think but different people quote different transmission losses.

 

[007]

About 15% very very roughly off Fly to get ATW.

I got mine done at STAR and they seem to come up with the most bizzare figures ATW for everyone. Very similar to those posted origionally.

 

[RS-Steve]

Yeah to be honest i think it depends where you go etc as long as when you compare you work it out the same its not a problem really!

15% is good for me. Ive heard everythin from 15 - 20 % but 15 most often.

 

[lew172]

my figures read

norm power 177.5 bhp

engine output 170 bhp

wheel output 128.0

drag output 42.0 bhp

max power at 109 mph or 6350 rpm

torque 210 nm





max torque at 93 mph or 5450 rpm



hope these help



any suggestions on final fig with group n ecu

 

[RS-Steve]

Did you get a plot or just a number printout?

Your wheel out put seems low mate,Engine output looks spot on. Your torque looks impressive but im just lookin for my plots to compare!

 

[RS-Steve]

Its ok your torque is Nm mine was lb/ft thort it looked high!!

Where was that done out of interest??

As for the figures with a group N try lookin in either Meets or Ext.Power.Mech for Yorks RR day thread im sure 1 (was a cup tho) ran with the R-sport chip which is basically a Group N IIRC

 

[lew172]

it came with a graph

had it done in Abercynon South Wales on the 5th of this month

 

[lew172]

I was also wondering that the tyre pressure was down on the last rr run

also its fitted with 205/40/17s

which are slightly larger side by side to the original 195/55/15s

would that make a lot of difference

 

[Rich-D]

Quote: Originally posted by lew172 on 12 December 2003


mine was rrd at 177.5bhp

with 128 bhp at the wheels

Summat wrong there...

Theres no way on earth you have a 28% transmission loss!



My Cup has 147bhp @ wheels, so using your losses Id get 204bhp @ fly

 

[Rich-D]

If you use the standard 15% loss for a fwd...

(mailtoower@wheels">power@wheels / 85) x 100 = mailtoower@fly">power@fly

 

[lew172]

when tyre pressure was spot on and only a magnex back box and pipercross

power was 167 bhp ( it doesnt like it hot) and it was a hot day

power at wheels was 117 bhp

drag was 38.5 bhp

 

[Rich-D]

The @ wheels figures are just way to low mate...

Standard 172s kick out around 144bhp @ wheels, and my Cup has 147bhp @ wheels.

 

[McBunny]

well me at the last place 152 at the wheels

 

[lew172]

any suggestions at problems? what sort of drag output it says on your printout

 

[McBunny]

mine no dra print figure but i was getting a high one on my first rr day

 

[Rich-D]

Your @ fly figure is good, but the @ wheels figure is way to low...

Most likely the RR setup and at a different place I bet its different!



Losses should be about 15% as I said before

 

[lew172]

Quote: Originally posted by dogmaul on 15 December 2003

well me at the last place 152 at the wheels

what mods u got m8

 

[McBunny]

exhaust and decat

 

[Rich-D]

Yeah... a very LOUD exhaust!

 

[lew172]

Quote: Originally posted by Rich-D on 15 December 2003


Your @ fly figure is good, but the @ wheels figure is way to low...

Most likely the RR setup and at a different place I bet its different!



Losses should be about 15% as I said befor

any idea what it will make with my xmas present

a Hillpower group n ecu

or with this rr machine anyones guess lol

 

[Rich-D]

The Group N (aka R-Sport) ECU will give you little or no peak gains...

 

[Roamer]

Ok guys......

At The Wheels losses.....

The losses can be affected by a number of things, including the gearbox oil temperature - if youre car has had a good hard run to the RR and goes on soon after you arrive losses are less, but if youve sat around for ages and its all cooled down it doesnt flow as well, therefore higher losses, there are so many variables for these things that the only way to do it without having your engine out onto an engine dyno is on the rundown or coastdown, but that itself is affected by how quickly the RR operator can throw it into neutral, and of course as peak bhp is near the top of your rev range if he gets it wrong and comes off the gas before is bangs it into neutral this can affect the peak bhp readout for the flywheel

Sorry Ill stop rambling now.

 

[McBunny]

no carry on boss

 

[Rich-D]

Quote: Originally posted by Roamer on 15 December 2003


Ok guys......

At The Wheels losses.....

The losses can be affected by a number of things, including the gearbox oil temperature - if youre car has had a good hard run to the RR and goes on soon after you arrive losses are less, but if youve sat around for ages and its all cooled down it doesnt flow as well, therefore higher losses, there are so many variables for these things that the only way to do it without having your engine out onto an engine dyno is on the rundown or coastdown, but that itself is affected by how quickly the RR operator can throw it into neutral, and of course as peak bhp is near the top of your rev range if he gets it wrong and comes off the gas before is bangs it into neutral this can affect the peak bhp readout for the flywheel

Sorry Ill stop rambling now.

Hence why I am an @ wheels kinda guy...

 

[lew172]

as with all the other cars tested that day as soon as the graph started to dip he hit neutral



as you say the car was just waiting its turn with just a 2 min warm up

 

[Rich-D]

You got a copy of that graph for us to see???

 

[lew172]

">Quote: Originally posted by Rich-D on 15 December 2003


You got a copy of that graph for us to see???

 

[Rich-D]

Cant see that mate...

Just get this &gt;&gt;&gt; ">

 

[Ben j]

my valver has 127 at wheels with 154 at the fly - u must have big transmission loss. but hey - its french!