m_nettleship

7600 sorry wrong way round.

Milkybar Kid

hey taven , does the car drive nice and feel quick because if it does who gives a shit what anybody says .

plus all the people that are saying your wrong need to get a life , plus if they were that good dont you think they would be doing this sort of thing for a living .

C4llyT

So having a basic grasp of transmission losses means you should operate a RR for a living?
You two must share a brain or something.

fuzzy

ive got a basic grasp of what a peadophile gets upto. doesnt mean i want to do it for a living.

dojj

iTrader: (3)

6900 someone said earlier in the thread i think

Steven_RW

Out of interest - do you really have a basic grasp of transmission losses? If so what hp do u think is lost through the transmission and how have you decided this or proven this? If it is the difference between a dyno and a RR for a specific engine, that theory is extremely flawed. Tyre loss? Roller loss? Wind loss by the rollers? Gearing impacting the first two, in fact, impacting all three. Tyre pressures, binding calipers, the type of tyres the car is running and so on.

All these impact the variance between a figure from dyno to RR. Not just transmission losses.

RW

m_nettleship

hmm

Chip

iTrader: (3)

Without knowing any of that, M3s are meant to make 240ATW if they are 300bhp, M3's continually do make that power on standard engines.

So which of these do you think is more likely:

a)
His standard M3 makes 50bhp extra, and his gearbox just happens to have 50bhp more losses than a normal one

b)
The transmission figure he's been given is a nonsense





Does it not strike you as a bit of a co-incidence that his very reliable and dependable typical german engine has gained 50bhp at exactly the same time his reliable and dependable typical gearbox has lost the same 50bhp?

m_nettleship

Chip, Hows it gained 50? erm 320 standard, 340 now, erm that makes 20 duuur.

Chip

iTrader: (3)

They dont normally make 320 anyway, more like 300-310

With regards to the 350, was going from Jim's comment on 350, that was the last power figure I saw quoted.

Same question still applies though, do you really think you just happen to have an engine 20-30bhp better than all the other M3s at the same as having a gearbox 20-30bhp worse?


Surely its more likely the calculation between rollers and flywheel just wasnt very accurate?

EIL132

It is 7600rpm, there's a video somewhere of mine hitting the limiter and regardless of figures I can assure people they stick to an E46 M3s arse like glue and head to head with my own 3.0 M3 it pulled a fair bit ahead over 100mph even though they seem to make lower power? I never put mine on a RR, however I do agree those figures are wild.

Jim Galbally

just for a bit of reference, my sensibly modded 3.0 M3 (known to respond better to bolt on tuning than the 3.2) gained 10bhp over standard

that was with over a grands worth of "proper" exhaust, remapped etc.

Steven_RW

Chip, to state the obvious, I am not a believer that his car has made 350bhp at the flywheel. I seem to have picked up the vibe that we are not clear on that .

It is a fair statement to say that it isn't 60bhp lost through the transmission on the rollers that read 240 at the wheels for 300 at the fly. All the rest of the pointless arguments everyone has, is something I am not talking about.

RW

dojj

iTrader: (3)

the graph seems to drop off at 6900 rpm other than one that goes on past 7500 rpm

why would that be then?

hang on, let me read the tread again to see if its not obvious

dojj

iTrader: (3)

why does one graph only go to 7k when max power is above that?

SiZT

That was in 5th Gear which is closest to 1:1 ratio (apparently) but it hit the 155mph speed limiter before the redline

C4llyT

So go on an accepted percentage or formula which is tried and tested to give best 'guesstimated' figure.

Irrespective of having knowledge of the ins and outs, a blind person could see what's wrong here.

Thing is the ATW figure is spot on for what it is, so it's relatively safe to assume all is as should be.
It's the human part after this that's at fault.

m_nettleship

how u assume the wheel figure is accurate? How how How.

Duffrent size wheels, tyre pressures, blah blah blah.

Look i no my moter isent 345bhp, winding the beemer lads up is funny as fook, But anyway,

If i did a run in 3rd 4th an 5th, witch i did, but 3rd was lossin traction on the rollers, all the wheel figure lines wud read diffrent thats proven, So how come in anygear you run it, the flywheel figure will stay the same no matter wat??????????????

dojj

iTrader: (3)

but, from my limited knowledge of the subject, the rollers take the torque figues and then do maths to them to get the bhp figures

if you are producing more torque than the rollers can handle in the lower gears then you are going to get an -F in your maths, whereas if you are doing it in a different gear then you could be looking at a potential A* (assuming you've gone for the higher grade paper which doesn't limit you to only get a C when you are using 5th gear, no matter how perfect your answers were)

m_nettleship

only u dojj, lol

C4llyT

What's Mark Shead got to do with this?

ballin

iTrader: (1)

probably about the same as a GCSE maths exam

m_nettleship

nothin really me old cocker!!!! he only viewed the graphs.

dojj

iTrader: (3)

ok, it may be a bit too vague to understand where i'm coming from, but i think it makes sense

the rollers measure torque
they someones does some maths
and a power figure is worked out

so if you are trying to measure the torque and the wheels spin on the rollers, does the reading mean you are getting more or less power due to them not reading the correct figures?
so, in an attempt to get rid of the 3rd gear wheelspin, you try it in 5th, being that 5th is the closest to the 1:1 ratio
unfortunatly, in 5th, it's too fast on the speedo in the car so you never see the full potential
so, as a compromise, it's run up in 4th, where it hits the limiter and doesn't smoke the wheels on the rollers
nfortunatly though, the gear ratio's aren't those of the 1:1 you would expect so some fudging of the figures gives you an incorrect reading at the wheels, which then means you have an incorrect reading at the flywheel when you work back

so you either get a fail for not doing it right
a C because you've done everything right but you can't get any higher
or an A* because it's impressive enough to make everyone go "ooohhhh! look at the pretty numbers"

C4llyT

What did he say?

m_nettleship

Looks spot on,
But that only mark lookin at a graph.

Im goin to get another graph same rollers and see wat they were loosing on tranmission, I no another did 226bhp, but i didnt look at the wheel figure so i will have a look friday.

No one can say right or wrong until its put next to other cars on same rollers on the same day really.

C4llyT

Well they can because that engine won't do that power without serious mods.
Thought you were on a wind up....?

m_nettleship

yeah, hopin it hits 320 ish! after mods. hope so.

i couldent resist though, ive never known a forum like it, reply after reply it never went quiet.

C4llyT

I replied a few times too....
Thought it must be a wind up, no one could be that stupid, even a ford driver

Be lucky with 320, depends on mods.
As you may have found out they're lucky to hit their 316 standard figure, as rhd has worse downpipe layout.
Also I think at the time they used top fuel they could for the magic 100ps per litre.

WD Pro

I seem to remember max power at 7400 & limit at 7600.

Was the 321 not just a marketing ploy to get 100 bhp / L in a production car ?

C4llyT

Or the ps figure which the Germans use, which would give them 100ps per litre...

m_nettleship

isent it cos of the steering rack,


is this the uk one




and this american

C4llyT

Well steering being on other side.

American was 240 brake or something equally lame, glorified 2.5 I think.

Jim Galbally

indeed, the american M3 had more in common with the 328 enginewise

m_nettleship

oh