All RR will be different...U can only go along with the ones you've been on....

Should use same one all the time too...Might get a better over all view from not modded to modded engine.....I know you have take other facts into account..Temp etc...But it's your best bet to standardise the results..

[Edited on 10-09-2003 by mav]

You will find that most rollers are inaccurate. The idea of accurate rollers is hard to see as loads of different rollers give different results, depending on various conditions. I know someone that had there Astra Gsi rollers twice in 2 months on different rr's with no engine changes and there was a difference of 14bhp, thats on a pretty much standard engine.

If you buy a car and it reads under then Vauxhall will just say the rolling road is inaccurate. On brand new massed produced engines, its got to be fairly easy to standardise engine outputs.

what does a 1.4 16v sport put out at the wheels?

My graph from star


Corsa 1.6 16v sport
Full magnex zorst
Decat pipe
Induction kit wi cold air feed/ heatshield
Full service day b4 with plugs/leads/oil/oil filter/ engine flush etc
Car was running well..

So 12bhp......over standard..Think this is achievable......Maybe a wee bit optimistic.

well tollerances can be measured more or less accurate..... they are called race tuned :P

yes nassua ur right i was at peugeot ecosse rolling road day an all 106 gti's were putting out 128bhp an thats standard book says 120 bhp i think it is so the manufacturers can cover there backsides if ur car under performs then big trouble for vauxhall/peugeot etc etc an other brands

my old 1.4 16v produced 94 bhp standard on rollers

my 1.6 16v is yet to be dyno'ed plus no engine is the same there is a small percentage that engines will run to as nothing mechanical is perfect an cannot me measured perfect so variances will occurr this is why we have tolerances on dyno's an engines equipment etc

this link has a good wee write up on the different rating standards for power, it's references are for american motors but theory still the same....

http://neptune.spacebears.com/opine/horsepwr.html

think along the lines of trade descriptions, if they say the engine is 110 and you get it tested at 90 then they either have to rerate the car, not good pr, or spend time/money to bring it up. however if it 'appears' to over perform then we're happy customers !
I've always thought in the past that vauxhall engines perform better than quoted, certainly all the novas and corsas I've had have run really well, I'm not totally convinced about mine at the moment though....
I'd certainly recommend getting a car on the dyno before doing any major mods the you have a baseline to work from.

Do other manufacturers give out 'minimum' figures too?

(comparing my mates 1.2 16v punto with my 1.2 16v corsa :P)

I've never heard that they are minimum. They will be true.

aye, i was a bit taken aback, like i said it was running crap as well. only thing is the figures quoted by vauxhall are supposed to be 'minimum' figures i believe, whether or not they are really 8 or so horses less who knows.... i'll get the graph scanned and post if anyone is interested.

I'd say thats one optimistic rolling road!

had the car (2001 corsa c 1.4 16v )up to star performance on saturday morning on the rolling road, 98bhp and 95lb.ft at 6000 and 4200 respectively. cant complain coz thats with nothing done to it. and i thought it was running crap.... any other confirmed figures for the 1.4-16v ?
new plugs, modified the air duct going into the airbox and it's running better again. got some more to do and will take it back to see what the difference is later in theyear.
definitely recommend changing the standard air intake from behind the grill, it doesn't let in enough air, especially at higher speeds. I've changed it to 3 inch piping from the box to directly behind the grille between the radiator and the headlamp. lotz more air coming in now. engine slightly more responsive and pulls better at higher rpm. new panel filter on the way too....