Rolling Road Results FAO; People In the Know!

[Mat-CooperS]

Basically as title says really, I went to a rolling road on saturday, just wondered what people on here thought of the results, as in what do you make of the readings?

The guy who did the rolling road said that the torque curve is very strong and everything seemed to be running properly. Is he right in saying that?

Mods are, GTT17% pulley, reduced belt, spark plugs and a JCW Motorsport air filter.

Results were;

Engine output = 196bhp
Wheel Output = 157bhp
Drag output = 41bhp
Max power @ 107mph or 6730rpm
Torque = 154 lb/ft
Max Torque @ 63mph or 3970rpm.

Max speed 112mph
Max rpm 7040rpm.



Any opinion welcome,

Thanks.

[MINIAC]

Quote: Originally Posted by Mat-CooperS (original)

Engine output = 196bhp
Wheel Output = 157bhp

This represents a drivetrain loss of about 20% which is too high. The figure used in the US is 12%.

[Mat-CooperS]

Thanks for that, any idea what it could be down to??

[madmac]

How old is your car? Face lift? If it is not then this seems about right to me. The pulley is obviously doing most of the work for you, plugs are stopping detonation ( i presume they are colder ones). The BHP figure seems ver close to the standard works figure for a pre-face lift car. I think this goes some way to answering my initial question about ecu upgrades, thank you, although what i am now doing is looking at the throttle resonse and wondering wether an ecu upgrade would improve that in the part to mid throttle openings. For reference to other people who have not fitted colder plugs, (my own personal experience has been) with the standard plugs my cars ecu would retard the ignition, this would then reduce performance. With colder plugs this dosen't happen although i am not sure if it has taken a small something away from the resonsiveness of the accelerator in the low to middle rev range. I am now wondering if the fuel mixture needs to be slightly weakend at this point.

[Mat-CooperS]

Thanks for the reply.

My car is an 03 plate, so pre face lift. Yes I have fitted colder plugs, the GTT iridium plugs to be exact. The pulley does seem to be doing alot in terms of power, if the car was 163bhp standard then the pulley and the air filter have increased bhp by 33, so I'm quite impressed that this is close to an older JCW. Although I didnt notice any difference after fitting the JCW M'sport air filter so again the increase is all down to the pulley.

I certainly noticed a big difference after having the pulley fitted, both in terms of extra power, better torque right through the revs and of course more "whine"

Sorry I cant help more on your ECU query, but I have noticed Roland from GTT has mentioned that most cars dont require a remap as the standard ecu is very adaptable.

[Gabbagool]

Quote: Originally Posted by Mat-CooperS (original)

Thanks for that, any idea what it could be down to??

Typically a supercharger does sap a lot of power from the engine.

More importantly in this case though, the power output was measured at the wheels rather than the flywheel so the at the wheels figure is the most accurate.

The figure for the flywheel is effectively scaled up to represent the typical drive train losses. Without removing the engine you cannot measure the true horsepower at the flywheel.

[OneDriver]

Could someone let me know why the top speed figure seems so low? Is this common on a rolling road? My MINI One tops out just over 120 on a flat bit of road (with light mods).

I though Cooper S's were good for 140 ish with those kind of mods?

On the flipside though you seem to have seen some great HP increases over standard with those Mods... seems like money very well spent.

[uncle albert]

Quote: Originally Posted by OneDriver (original)

Could someone let me know why the top speed figure seems so low? Is this common on a rolling road? My MINI One tops out just over 120 on a flat bit of road (with light mods).

I though Cooper S's were good for 140 ish with those kind of mods?

On the flipside though you seem to have seen some great HP increases over standard with those Mods... seems like money very well spent.

That'll be max speed in 4th gear - the gear in which the test was performed.

James

[OneDriver]

Wow.. I never knew that. I thought dyno runs were ocnducted in all gears.

Thanks James

p.s Looks like you S drivers will still be leaving me in the dust then! (Unless you stay in 4th!)

[Paul@1320]

Our pre 04 engine has registered 152whp on our rolling road and achieved 157rwhp at Santa Pod running 93mph at 2456lb, when we put a 15% and a ex manifold and cam it showed 197whp on the dyno and we run 99mph at 2546lb in Jan this year which equals 197rwhp

TunerCalcs - Calculate Wheel Horsepower from 1/4 Trap Speed (mph)

Customers stock 05 /06 teflon blower cars we have seen 160-167whp

The customers 167whp turned into 196whp with a 15% pulley a Alta CAI and JCW manifold

None of the above parts we supplied, we just love seeing the before and after results.

You might noticed that I've used whp for the above dyno measures simply because with run down losses like that you cant compare like for like, where as whp the variable maybe not as much.

The drivetrain loss you are seeing there seems to be normal with that make of dyno

All the above was acheived with stock ecu's

I would of expected yours to make at least 170whp on our dyno, how many miles has you car done? do you know what the compressions are like?Did you buy Rolands upgraded bypass valve? What fuel did you have in the tank?

[roland2003]

Hi Guys, you can't just assume a percentage loss (eg 12%) .It has to be measured and added on to the WHP figure. If for example you did a run in 6th gear on 19" wheels, with 15psi tyre pressure and the tracking towing in/out miles and a slightly binding front brakes ,the WHP on a stock MCS may come out at 110bhp! BUT if you then measure the losses (which in the example will be huge) it should come out at circa 60 bhp .
110+60 =170 flywheel horse power.
If you took the same car did the run in 2nd gear on 16" wheels with 40psi tyre pressure, perfect tracking and no binding brakes the WHP figure will come out at around 160. If you then measure the losses they will come out at circa 10bhp ie 6% loss! So 160+10=170 bhp (the magic number again)
It is totally wrong to measure whp then not measure the losses. It is the Flywheel HP figure which is by far the most relavent-See the thread I put up a while back;- ' Flywheel Horsepower V Wheel Horse Power '(or something like that)
Yes the losses are on average are circa 12% ,(which is 15% added on to the whp figure btw) .
The power sounds about right tbh, though we have never seen or worked on the car.
Best Regards Roland GTT

[Paul@1320]

So if you take Mat Cooper S 157 whp figure and plus 15% losses equals 180.55 bhp

So the rolling road is calculating that its got 15.45bhp more or is that a Maha rolling road gives totally false whp fiqures, maybe Mat Cooper S should of been reading 170ish whp

If you go here you'll see more Maha figures for Cooper S and Coopers;

MINIaddiction :: Log in

As you cans see the drivetrain losses are even more though the whp figures are similar

I suppose really the only way I can make comments is by dynoing the Mini on our dyno then go to Maha rolling road and have a go, I had planned to have a try on some hub dynos like the Dyna packs as DMH reckons run down losses are 10.9%.

What various dynos have you been on Roland and have you seen a big difference in whp figures or bhp figures??

[roland2003]

Hi, rolling road results can carry huge errors, miscalibration, faulty (worn?) ,operator error, slippage , brand /type of RR etc.
You need to measure the losses (which are high here I know , but then the whp figure is low too). The flywheel figure tbh seems somewhere handy to what you might expect for the mods done, which illustrates the importance of measuring & adding on the losses figure. In this instance I'd be looking to establish why the losses were high. ie Are the brakes binding? Is the tracking out? Am I running 22" wheels? What gear was it done in. Is it an early MCS where the gear are higher (gives lower whp figure).
Ive seen RR figures (wheel & Flywheel) vary by such huge amounts that it begs the question can you rely on the results atall? -

Best Regards Roland GTT

[Paul@1320]

I suppose we're lucky to have Chris as an operator and a machine at the moment which seems to come up with the same results as the Pod.

I always say to people it just a big tool that you cant fit in the tool box, and really you should use it to compare deltas as you add on parts and not compare dynos to dynos(though thats what I was doing earlier) but It'll be intreasting to see what the others read.

I was meant to be going to that MA rolling road day but unfortunatley it clashed with the Mini2 Top Gear run.

[Mat-CooperS]

Hmmm, you professionals have lost me now!

A bit of further info on the car, on that particular day;

1. Its been run on Shell Optimax (or V-Power as its now known) since December 06 (when the pulley was fitted)
2. I check the tyre pressures every week, they are always iro 32psi.
3. Its running on standard 17" s-spokes with Pirelli run flats.
4. Its the pre face lift, so higher gearing.
5. No tracking issues.
6. Brakes definitely dont bind.

I didnt realise there was so much to it tbh, I'm gonna have a re read of your comments.

Thanks for now!