rapidcossie

Where do I say rolling roads are gospel?

Im saying rolling roads, used correctly can produce very accurate power figs.

pani_k

iTrader: (1)

No machine in the world is 100% accurate mate. You can only calibrate it as best you can and have a workable error margin but as for it being an inaccurate measure of BHP I don't think that is fair.

Please tell me a better way of measuring BHP that is as pratical and convenient as a rolling road.

Edmund

Im saying they cantAs said we have all got our own opinion,mine based on truth LOL.

Back to the M5,yes i think you may be right,hold back and see what happens Mr Brannan,hopefully in a couple of months a good one for under 30k

Edmund

Hi mate,a dyno is obviously the most accurate measure a rolling road is great for getting an idea on bhp especially for comparing to others,whoever Rapid works for he obviously is trying to advertise that his rollers are very accurate,yes for a diagnostic tool.

rapidcossie

Can see the headlines now!

Dyno Dynamics goes bust beacause the can measure the power of an M5

rapidcossie

Boo lol

foreigneRS

a hub dyno is not as convenient, but eliminates the tyre/roller interface to reduce the error.

no rolling road can give you an accurate measurement of engine power, but it can certainly give you an accurate measurement of 'at the wheels' power (bit of a misnomer if you ask me, as that is what a hub dyno will give you. rolling roads give what i would call 'at the road' power)

Saaamon

iTrader: (2)

lol a very entertaining discussion,, edmund although i can understand what your trying to say, rolling roads are a very useful tool when increasing power and tuning an engine and yes power fiqures can vary from one to another as well as room temp etc but you are ment to use the same rolling road when tuning an engine to keep everything as consistent as possible

dovboy

officer-"mr begbie can you tell me why you are doing over 180mph on the m8!".

mr begbie "well officer its like this,the rollers are not acurate enough above 100mph windspeed so........."


imo rollers are the most acurate way of doing it bar mapping it on the road or at a private runway.but i dont think there is a replacement for new air passing over the car at the speeds to match the wheelspeed.

SapphyMike

Hang on, arent you guy who was moaning in the other M5 thread about saying that Stu shouldnt be singing the praises of an M5 on a Ford site, yet here you asking advice on its costings.

sounds like double standards to me.

RWD_cossie_wil

iTrader: (9)

Having seen a few E36 M3's on the rolling road, neither made decent power, and both had problems due to the traction/stability control not understanding the front doing 0 Mph and the rear doing 120+ Mph in 4th gear ... IMHO *( limited to cossies), you can't beat a road "live mapped" mapped car by a true expert, having driven a number of RR and "real world" mapped cars, the ones where the car has been mapped on the road has felt a damn sight better each time...

EIL132

How the fuck does a post about buying a car turn into rolling road wars? Driving one is completely different to sitting in one surely!?

The E60 M5 is a fantastic car, but it will continue to depreciate like a bomb lowering the value of the E39, as will/have all M cars, just to answer the original question

Edmund

I was just trying to put my point accross that a well sorted Cossie could spank an E39 after it was said that one was spanking alledged 500bhp cossiesCall it double standards but the E60 is surely a completely different argument.

SapphyMike

Theres a few ~300bhp cossies that have run quicker 0-60 times than the "book" figure for an E60 M5. Doesnt mean they will spank it though does it?

Anyway, its all been like comparing chalk with cheese. I love Cossies, but for the money, i'd rather have an E39 M5. Theres no point doing a gazillion mph in this day and age.

foreigneRS

that's true of most cars with ESP though - as said before, you can disable it by removing fuses or simply unplug the large connector on the ecu normally located with the ABS pump/block

Mike Rainbird

iTrader: (3)

Euan,
What has been posted about the V10 BMW on the rollers is correct. Unless some fuses are pulled (I think the ABS being one of them), then it's electronics don't allow the full power mode to be used, as it is detecting a HUGE disparity between the front (stationary) and rear wheels (100+mph). This is quite common with a lot of cars with sophisticated traction control systems.

Edmund

So a big to euan

Benni

This is why I said I thought Euan was taking the post out of context. I went to a rolling road day and all the Focus ST's where showing around 180bhp which is 45bhp down.

Benni.

Mike Rainbird

iTrader: (3)

That's because they have REALLY shit intercoolers as standard . So the second it comes on boost, it hits the retard map on the rollers . Even on the road you can do this . This car benefits HUGELY from an uprated version .

TurboShed

AlexF

Back to M5s.....

The E60 is a simply stunning machine - it shouldn't be possible to use 500 bhp in the wet BUT IT IS!

I would also recomend you try an m6 (not that much more) as the car has a completely different feel to it. The weight distribution is slightly different but other than that its the same car underneath - BUT - it feels so so different. I think its a better car

In regards to the prices - any thing will drop in price if you wait! So using that theory no one should buy anything as it will always be cheaper next week :s If you want one - buy one, just dont winge about how much money its loosing!

Happy car buying.

gingeRS

you do understand that a rolling road, chassis dyno and engine dyno all work on the same principles, and therefore produce just as accurate results

the only factor in the measurement discrepencies is the car itself.....tyres, transmission etc.

you could argue that the M5 engine makes its 507Bhp in an engine test cell, and nowhere else, but how much 'use' is that to joe public who buys the car??? precisely F-all