Originally Posted by Phil

Surely as a rolling road tuner you'd know better than to start quoting guestimate flywheel figues though

On a more serious note, good debate lads

I've been out with Karl setting my own car up and I must say it is very difficult to test things on the roads, trying to keep grip and the pwoer down long enough to see all the revs before you brake to avoid hitting the back of someone etc..

With enough patience it can be done on the roads, but my personal 'money no object' preference would be to map it in a proper engine dyno cell for all the testing (at absolutely every possible load point etc) and then tweak the map at Brunters or somewhere similar to check everything is fine 'in car'

A question to the mappers, can you see things like ignition etc having to be altered between a dyno cell and road situation or is it mainly fuelling/charge temps that differ...

Originally Posted by Danny B

oh and tim will run 116 with said 270hp as its lighter, less power will mover lighter load



good night

Originally Posted by Danny B

what happened to your engine phil???

Originally Posted by dingy

The map says different phil

Originally Posted by RichardPON

I never thought I'd see the day that a "specialist" could register a 9.5 on my recently patented "bullshit-o-meter"

Originally Posted by WAYNE SCHOFIELD

I was directed to this thread by a collegue who thought I'd find it amusing...........

So you can map a car on the road accurately can you. Er no.

I do ECU mapping all day every day and my cars have won six championships last year alone including Brit Car, Belcar, Porsche Club, Rallycross stock hatch (won every single round), Rallycross modsaloons and BMW Khumo.

You don't win races and championships with cars that do not give good power and you do not win championships with cars that blow up.

You CANNOT tell on the road that your engine is running with optimum ignition values as the values are often short of the point at which det sets in. It is also VERY dangerous, for yourself and the general public, and if you are happy for a 'tuner' to run your car in excess of 100mph on the public road then you , by vertue of the fact that you know that it is being done, makes you jointly liable for any DEATHS that might occur from this outragous activity. I am sure that any insurance company would invalidate any claim and this would leave you paying out for the rest of your life both fiscally and with guilt. Go make your choice!

Plug ionisation equipment will tell you much better than det cans if det is occurring but even these, a snip at eight grand, do not tell you when peak power is being made. For this you NEED to use a dyno.

Fuelling is simple enough in either scenario. A combination of wide band lambda and a Gas Analyser with a high volume pump will tell you what you need to know. You all SHOULD know that there is more to setting up an engine than just fuelling.

'Dynamic pressure' is what is responsible for the potential rise in pressure at high speed. The equasion for dynamic pressure ( in pascals) is '0.5 x fluid desity(in kg/meter cubed) x the speed squared (speed in meters/sec). This does not take into account the fact that the airbox is not designed to make perfect use of dynamic pressure so, by that vertue, the pressure in real life will be lower and could even be negative.

So, in regard to the comments made about the rise in pressure in the air box, You do the sums. You might next consider that the atmosphere we sit about in is generally accepted to be 101,300 Pascals. Compare the numbers with atmospheric values and you will see that basically, until you are doing over 150 mph, it makes three fifths of sod all difference- even in a perfect world. You might also consider that on a Cosworth system, using a MAP sensor as a load reference, any such pressure is compensated for anyway! 'Mute point' I think they call it.

As for the Depression created behind the car causing scavenging behind the exhaust- OH REALLY! Show us a relavant equasion then! Just how fast do you think a car goes compared to the speed of the gas exiting the tailpipe? Why do you think the F1 boys have done so much work with regard to positioning of the exhaust outlets so that it increases downforce on an F1 Car? Why would this be so if it were not exiting rearward faster than the car goes. Hot gas is, of course less dense than cold so this reduces the effect. Hot gas is also more viscous which also detracts from the effect but still the F1 chaps, who I am led to believe do actually know what they're doing, use the high speed exhaust gas to increase down force.

They also use dynos, a lot, by the way.

Fact is that there is some importance to TRACK testing (I am off to Elvington myself with a 593 bhp F40 next week, all being well) but the vast majority of PROFESSIONAL mapping is done on dynos. Period. No point arguing, you will lose.

I expect that there will be a plethora of replies to this post, some with limited merit, and some with none.

I am very keen to separate myself from other 'engine mappers' who are getting the industry a bad name through poor, dangerous, practices. They can afford to charge less money for a job because they have not made the necessary investment to do the job safely and properly. It makes me wonder where else corners may have been cut with their practices that the customer might not be aware of. I hope I do not get 'tarred with the same brush' as some other people claiming to do a proper job.

I am here posting just the once only to try to put the record straight between the professionals, the amateurs, those who understand and the generally misled! I am not here to plug my services, sell my wares, have bits of flash or java running through what I offer onscreen before your eyes. I never advertise anywhere because I do not have to. Reputation keeps me busy enough for me not to have any spare time left to plug my stuff on any forum- let alone host one!

Have a nice argument boys!