Quote:
Originally Posted by Sami Aaltonen
Here is an other "more or less" easy question.
First place; I just want to clear this out for me, have I understood it right.
Racecar Engineerin 1996 vol 6 No1:
Gordon Murray explains the Engine side:
"I know people don't believe us, but the engine that won at Le Mans was internally an untouched road car engine. Nothing was changed on it.
It was re-mapped, but that was it...".
So, the engine was untouched, but the re-mapped word gets me interested. What he precisely means about this word?
-> The engine was race tunned, more power and torque,
setuped for the racing? Like LM engine has compared to basic F1?
->The engine's computerbox, electronics was changed more race format?
Did I understood this right? 
And what comes that Racecar Engineering article of 1996 GTR, it's absolutely suberp story. All the developing work 1995 to 1996 and even 1997 plans and changings have been mentionded. Very very good story! Exactly that information which I have been looking for specially from GTR's!!!!!
Defenitely worth of 8€ what I payed that on EBAY! 
If you find this magazine, do not hesitate to buy it!
And Thank you for the answers to my question! |
As for the basic architecture of the engine being as a standard road F1 that won LeMans, I would totally believe Gordon on that. What he does not add in the article is the main fundemental changes that had to be made, to make sure the engine ran reliable for 24 hours. I can elaborate further if anybody wishes to know.
On the remapping side of things, a race car engines fuel requirements are totally different to the road car. The road car has to be fuel efficient and emissions friendly, remember it had surpassed the most stringent Californian emissions regulations at the time it was introduced.
The road car fuel injection system runs two injectors per cylinder, ie it runs on a lower fuel requirement in its lower rev/load range, switching to the second injector at higher engine rpm/load thus covering its requirements for emissions, driveabilty fuel economy and over a 100bhp per litre at maximum power.
The GTR spec engine did away with the second injector system, running with its own specified single injectors. This, with the air restrictor requirement plus a free flowing exhaust system and the need to run in the higher rpm/load range. led BMW to work diligently on the engines fuel/ign mapping, the result was an increase in torque, around 527lb/ft @ 4500 compared to the road units 479lb/ft @ 5600. So a more powerfull and driveable engine as a result, but with poor fuel economy compared to the road car engine.
So its "HORSES FOR COURSES"
Sami, when you hear a GTR engine going up through the gears, its the engines torque being produced that makes that wonderfull engine sound
