engine life of raced production engines

[Roninho]

Hi,
a few days ago i started a topic in the sportcars/gt segment of this forum on what changes OEMS/manufactureres make to the racing engines that are production based engines. Such as the engines that are used in GT3 (which if i am not mistaken all need to be based on a production model engine).

Basically the conclusion from that discussion (for me at least) was that the OEMs do change a lot to these production engines.
The only racing car that i know that used a non-modified production engine is the Reiter prepared Lamborghini Murcielago (http://www.lambocars.com/murcielago/...p670_r-sv.html)

So my question is, if these manufacturers change that much to these engines are unmodified production engines not capable of being raced without modifications?
If i take a Mercedes SLS AMG or Nissan GTR (both over 500 hp), have it raced by a professional driver and have that guy race it for 45 laps (a F1GP distance ) at Spa-Francorchamps will the engine then fail?
Or if the same driver goes to the oval @ lausitzring or Rockingham UK and runs it for 500 miles on the oval? Will the engine then fail?

[Ospi]

In your examples, no, they'll be fine because those cars have been developed with the knowledge that their owners will track them and potentially spend a lot of time at the track and around the high rev range of the engine. Generally if they decide to enter these engines into professional racing however then some mods are likely. For example the engine may be solid mounted and dry sumped (if not already) and generally they will run a gearbox and diff with higher ratios to improve acceleration performance compared to a road car and as a result a race engine will spend more time at its limits so it has to be factored for.

They also are aware where gains can be made through the power curve with some minor mods, even with air restricted engines and so they'll chase those when possible.

So it's not so much that the top end production engines can't be raced but more that they can make gains within the allowed rules by making modifications.

[Roninho]

Thank you for your reply, that makes it a bit better for me to understand.

So if you'd take such an engine, put it in a open wheel chassis/Formula car (i'm ignoring the part that this actually has to fit ) and race it in a event like BOSSgp or an hobby/amateur race then this should have a chance of sticking together for an hour?

[EfiOz]

We won the Bathurst 12 Hour with an off the shelf 458 engine. It had about 4500km on it when it passed the finish line.

[Roninho]

Wow, quite a remarkable performance! What made you decide to pick a production engine, and were you guys confident that it could work?

[Roninho]

Does anybody else have an example of production engines straight from the car into the racecar?

[EfiOz]

GT3 is mostly production engines. At best they have a couple of freedoms to "blueprint" and upgrade the cooling system but everything else is standard road car in a Ferrari, even the ECU's.

The Lambo is similar except they use a proper motorsport ECU. There was talk of a Reiter car that had done over 18000 racing km on one engine. Even with the 430 we would see at least 9000km before any measurable performance drop off.

The Audi is almost all road car.

We chose it because we didn't have much choice.

[Roninho]

thank you.
is that the case for all gt3 engines, or just the ones you have experience with (Ferrari)?

As for the Audi, you say it is almost road car. To your knowledge, what are changes to this engine that makes it ''almost'' road car?

[EfiOz]

Inlet restrictors, bigger radiators/oil coolers.

I've had experience with Ferrari, Lamborghini, Mercedes and Audi, all are built like this.

[Mr_A]

I am new to this forum, and I see that this is an old topic. Long time since last post, but I'll add my input.

All these engines that are mentioned above from sportscar producers like Lambo, Ferrari, Mclaren etc with big engine dispalcements can head out on the track pretty fine and take a lot of beating. With no problem.

However, engines with smaller displacements that need modifying to keep up with lambos/ferraris and that league, need to be looked after. My main message is that there is a BIG difference between sports cars right out of the factory engineered to go fast, vs cars that are being modified/tuned to go fast. YES, engine life is long on those production engines from Porsche and the makes I mentioned above.