just wondered how accurate there rolling road is ?

 

They weren't too bad when I used them a couple of years ago, more or less in line with somewhere else I went down South. Nice lads too

 

I think this is the Rollers than NMS use for there power runs so if its good enough for them then it must be good.

Sorry if this is wrong but im sure i have seen Daz with the Dolomite use these.

 

im 99 per cent sure you are right mate.

 

this could start an interesting thread

 

i'm sure that the measured torque on a power run is spot on

whether the engine speed is accurate that affects the power figure is another thing, and forget any measurement of losses to give an 'at flywheel' figure and you won't go far wrong (provided there is enough cooling air to let the intercooler do it's job properly)

 

Derbyshire RSOC use Nobles for their RR days - quite a few NMS cars run on these days

I think they seem quite consistent and haven't seen any strangely high readings from cars from there

 

Didnt Dingy use these the other day?

 

Other than a 125bhp transmission loss on Dinglie's car .

Power at wheels (as Nick says), seems pretty honest .

 

What are u looking for?

A r/r that tells u the wheel bhp "that it sees" from ur car?

I'm sure they are perfect at nobles for that.

"Is it accurate" - well thats too open a question as each rolling road will measure different power at the wheels for a variety of reasons.

What do u seek from going on the r/r? To compare ur at the wheel power to another r/r? or to tune your car or something else.

Nobles read my rsturbo at 170ish at the wheels and around 220 bhp fly. AVA measured it at 195 wheels and estimated around 220 fly.

Which is accurate?

If you go by the wheels figures then its impossible to say which is better as it is purely the r/r telling u the figure that it sees. Larger rollers mean lower roller RPM at the same wheel speed. Lower roller RPM means lower loss - thus higher reading.

Just use a r/r for what its for. Seting up your car - giving a consistant reading before a mod and after a mod. Otherwise ur probably going to cause urself headaches trying to compare figures from one r/r to another

gl

RW

 

Mike you make me piss at times....

You claim the engine dyno is most accurate yet it has so over inflated figures known to man...

You could run at ava - bigger rollers, less loss so more at the wheel figures...

You could run at a DD for a third gear run, so less top speed, less losses so more at the wheel figures.

Meaning the faster you go the more the loss's

Mine @ scs dyno made 405 say, made 320 @ wheels @ ava and 365 @ fly at nobles.....

The cooling at nobles is fine...

Nutters made 4bhp difference at APT to nobles @ flywheel.....so its pretty consistant with both those two rollers.

The algorithm's for working out at the wheels, the gear speeds and the roller size are all different on the 3 rollers mentioned so its impossible to say which is actually correct.

RR are no where near as accurate as it being on the road IMHO, stick your arm out the window @ 150mph and see how fast the air is moving, no fan at any rr feels like that and thats just one factor...

I use nobles cause is a measure on how the car is changin, same rollers.

I am going to use a dyno Dynamics rollers on sat with the same boost so lets see how much the rollers differ.

 

Oh and i don't actually give a fuck on figures cause the car goes like fuck

 

make up your mind

 

Why ?

I stated the cooling at nobles is fine (for a rolling road)

And

The air on the road is hard to mimic

2 difference scenarios - not a comparision.

 

You complete donkey, so you're telling me YOU believe the 125bhp transmission loss?

If you read the rest of my post, you will see that I agree that the at wheel figures can be pretty much trusted .

The dyno figure is a GROSS figure without ANY ancilliaries, so it WILL differ dramatically from any in-car figure - ESPECIALLY if you go and strangle the car with a restrictive exhaust .

This was why I started dynoing my own engines with both the airbox and exhaust on the engine that it would be using in the car - in order to minimise the differences between in-car and out of car .

 

why bring them up in the same post about the accuracy of a particular rolling road then?

the air on the road is hard to mimic on a rolling road - very true. but why would you need to mimic it on a rolling road?

 

Mike, what i meant by this was dingy and i have been to a RR day before where the 2wd cars were getting about right readings, but when the 4x4 cars went on, there were some unusual outputs for specs

 

My exhaust doesn't seem to be the bottle neck mike.

foreigneRS - sorry, i bow to your greatness.....it was just a comment.

 

So 125bhp transmission loss for a 2wd car is considered "normal" on Noble's rollers?

 

Have you actually measured the back-pressure then? If so, cool - what was it?

 

hi all thanks for comments. so do we think nobles flywheel figures are fairly accurate then.

 

what you got a bag on for mate? i'm just asking you some questions

NO a flywheel figure cannot be measured on a rolling road, only estimated.

the ATW figure will be accurate as measured at the time though - although this may not be the same as you would get on the real road or on another rolling road with different sized rollers, different temperature, different air pressure, tyre pressures, air flow and so on.

why is this so hard to understand?

 

No mate - missed off my

Sorry

 

Mike your car made 518 @ dyno and made 396 @ wheels at AVA...and that would be about 350 @ nobles....

Seems quite a loss to me

 

My car made 515.4bhp on the dyno and made 395bhp @ wheels at AVA . BUT, it was on a restrictive 3" exhaust, an inadequate intercooler (ACTs in excess of 55°C) and had mega tall gearing meaning 4th gear at 8k = 168mph. ALL of which has huge effects on the at wheel figures (ESPECIALLY the gearing) compared to a car properly set up (which mine now is). Obviously I didn't know what I know now then .

I bet if I went back with the same engine, knowing what I know now, it would make 440bhp @ wheels NO bother and even more with standard gearing .

 

Sadly mike the roundabout fucked your saff and that was that LOL...

I would take it to ava but its to fucking far

 

So when you bringing the escort up to ava then mike

 

You have a short memory, it was reshelled and sold to Justin .

 

When I can be arsed to drive the million miles .

 

i suppose the onlyway to know for sure is ive got to drive to nobles and r/r there again. fucking long drive though

 

And you are retarded cause it wasn't YOUR saff then was it

 

Well apart from the shell, EVERYTHING from my car was used , even the identity, so it is still G888 GCL - my old Sapphire .

 

i only had a 60bhp loss through transmission on dastek rollers...(4x4)......

 

but like i've said on another post...if the car dont perform on the rollers like it does on the road,then whats the point.......i lost 3psi

 

U monkeys - all ur doing is winding each other up

Whats the definition of "accurate" at the wheels readings?

Both readings for my rst were accurate - 170 odd at nobles 195 at ava - its the figure that the rollers see. The effort they have to put in to stabilise the rolling road. Due to higher losses created by the EFFORT just to turn the rollers (without adding extra resistance/retardation (is that a word?)) at a higher speed if u are in a higher gear or on a different roller size, the extra effort put on by the rollers to stop the car accelerating differs.

Just put the car on the same rollers and use it for comparing before and after results of modifications.

GL HF

RW

 

nobles i fine mate like dingy&linsay said we use them for club rolling road days

 

think thats the only way im gona know mate. fucking long way to chesterfield for me though.

 

nobles are fine exactly same reading on my old engine as of powerstation 412bhp slight difference in torque of 10 ft/lb,365 at nobles 354 at p/station ,im at powerstation 2moro with latest engine will be interesting