Hey everybody, I got my car rolling roaded a few weeks back and i'm not 100% happy with the results...

I have a 2005 fabia ASZ engine with the following engine mods:

a revo remap, pd160 air intake, forge fmic, allard egr blanking kit.

I made 144.5 bhp at the wheels and 275 pounds foot of torque at the wheels too. Does this sound about right?

horsepower at the wheels sounds about right but the torque seems low to me for a mapped car, im sure a fellow mapped fabia owner will speak up

Where did you go for the RR?

doesnt sound too bad, most quote the flywheel figure (guestimate) mines made 173bhp and over 300 lb-ft but dont talk much notice of an rr as there never accurate

I went to atspeed racing rayleigh. chers chaps

If you've got the spare cash, then go to another RR for a second opinion.

Agreed that power is about right, but i personally would've wanted a bit more torque than that.

If you're happy with the way it drives though, then i wouldn't worry.

Is it a custom map? Did they tone down the torque to protect your OEM clutch?

I went to atspeed racing rayleigh. chers chaps

You could always try Engine Advantages

They are quite good and give a true reading

Figures differ from dyno to dyno. For a Revo remap on Awesome-gti's rollers I would expect 160+bhp at the wheels but like I say figures differ from dyno to dyno. My standard car makes 125bhp at the wheels at its last dyno session at awesome.

If it drives alright then I wouldnt worry about the numbers.

I don't know the rollers in question, but the figures look plausible for wheels figures rather than flywheel guesstimates. What gear was that in?

the thing is that the rolling road setup they have is brand new, and i wasn't 100% sure of the way they carried out the rolling road.

For instance you watch a rolling road on youtube etc and the vehicle is allowed to run down on the rolling road. But the guy doing it was braking and making it lock up etc.

But the guy doing it was braking and making it lock up etc.

:eek: :thumbdwn:

the thing is that the rolling road setup they have is brand new, and i wasn't 100% sure of the way they carried out the rolling road.

For instance you watch a rolling road on youtube etc and the vehicle is allowed to run down on the rolling road. But the guy doing it was braking and making it lock up etc.

That's just plain wrong. The reason for doing the run-down is that that establishes transmission and tyre losses, which are where you get the base data for the wheels to flywheel corrections from.

Of course, that doesn't change my opinion that flywheel figures from a RR dyno are guesstimates, but there is some sort of science behind them.

what make of dyno?

the operator sounds like he did'nt have a clue tho

the guy doing it was braking and making it lock up etc.

:eek: :thumbdwn:

+1 :crazy:

What were you hoping for as those figures don't look too bad to me :confused:

I think you would be better to try and get a comparison against other cars, a RR day in Shoot Out mde would be ideal, then you would have a better understanding as to how your car compares.

Yeah I'm not completely happy.

I was hoping for 155-160 and was hoping for over 300 lbs ft of torque

Figures differ from dyno to dyno. For a Revo remap on Awesome-gti's rollers I would expect 160+bhp at the wheels but like I say figures differ from dyno to dyno. My standard car makes 125bhp at the wheels at its last dyno session at awesome.

If it drives alright then I wouldnt worry about the numbers.

What did the dynojet dyno say your power at the flywheel was?? As 125 @ Wheels seems high, you normally see about 20% losses.

We had 184 @ wheels and 205 at the fly on my mates dyno on a VRS fabia the other week.

hi

some places use a coast down test to work out flywheel losses. We do not do this because it is incorrect. how can coasting down equate to flywheel figures? it does not take a master scientist to work out that drivetrain loads under acceleration are much different than ones under decelleration, and its also carried out in neutral, so how can they be correct? the correct answer is they cant. that is why we do not use a coast down test.

anything carried out after the test was complete, braking etc, does not effect the final reading. in fact our dyno has an auto brake facility that stops the car for you after a test.

an inertia test measures the speed in which a known mass acclerates from A to B.

we know the mass of the rollers, and we know what the A to B its the rpm we test from. bhp and torque is worked out from there.

if the bhp is correct, then the torque is correct it CANNOT be wrong. its a calculation (bhp = rpm X torque / 5252) ANY car that revs past 5252 rpm, the power and torque lines will ALWAYS cross over at 5252rpm, if it does not then the calculation is wrong. anything we do to the rollers does not effect it.

not convinced? phone up mountune racing and see who they recommend for an accurate rolling road in Essex.

Our rolling road gives the same wheel figures as Ford motor companies chassis dyno.

so if your car doesnt produce what you expect it to, dont blame the rollers, try checking the car first.

what make of dyno?

the operator sounds like he did'nt have a clue tho

its a 2wd 1000bhp clayton chassis dyno. enclosed in a purpose built sound proof testing facility which is weather station controlled.

we have over 20 years rolling road experience. and combined 40 years motorsport experience.

perhaps you will read my other post and understand how an inertia test works and how our system works. maybe that will make things a little clearer for you.

:iagree:

if you don't like the figure just carry on driving round till you find one that gives you the figure your looking for

rolling roads do vary, and there are lots of variables to consider, tracking, tyre pressure, oil temperature, water temperature, air temperature.. the list is endless.

most properly calibrated dynos give the same wheel figures... its flywheel figures where problems begin.. many places ad higher and higher driveline losses to simply get higher results and big themselves up. the customer is happy because hes got a million bhp.. but in the real world, he still only has 100. we know of some places adding 40% driveline losses, one place constantly alters the flywheel figures until they get the desired reading. unfortunately there are too many dishonest people in the world. so for people doing the job correctly and honestly its difficult. we always test using wheel figures, its a no nonsense, no BS "what youve got" figure. i can enter any driveline percentage loss i like, how much power do you want? but we dont because we are honest, in reality a good calculated driveline loss is between 10 and 20% (10 for a racing box, 15 road box, 20 for a mini) end of the day it is physically impossible to give an accurate flywheel figure on a rolling road, if you want that go to an engine dyno. you can get a good guess as to flywheel figures, but its still only a guess.

i would far rather be regarded by professionals (such as mountune) as someone doing the job correctly. rather than an idiot thinking im doing it wrong.

you have to remember with these chip tuning companies,, they are in competition with each other "+ 50bhp, +80bhp" etc.. youve seen it before? you have to realise its so easy to lie about these numbers, and people beleive they are going to get the advertised power. but where they being honest when they tested it? most likely not. so for a genuine result, go to an independant rolling road... preferably an honest one!!

:iagree:

if you don't like the figure just carry on driving round till you find one that gives you the figure your looking for

WELL DONE THAT MAN!!

wheel figures are the only figures that count as thats whats actually going to the road, its all well and good having an estimated flywheel figure of 500bhp but if you've got 250bhp at the wheels it's no different to any other 250whp car other than costing you more in fuel

i have a 4x4, i know it loses more power thats obvious and just like anyone else i'd love to see huge headline figures but its the wheel figures that actually count

Thanks Atspeed. That just reconfirms what I've been told repeatedly down the years (and am getting tired of repeating, given the sort of sources I got it from).