Fishey

Odd, by that logic they should just run a 997 3.8L like RumBum since I know they make 430whp with that motor. I am sure the GTD car 4.0L makes identical numbers and the GTLM car that has the same weight and more drag which traps faster then the GTD car is also making identical numbers.

gophaster

This article among others I have read state that the reason for the switch was because using production motors would be cheaper and due to regulations. The Mezger has already proven itself over many years and Porsche tried to use it as long as they could. I think if they could have had it their way the Mezger would still be in at least the motorsport cars. I'm sure they will continue to perfect the new motor and maybe someday it will have the history and legacy that the Mezger does...Long live the Mezger!!

I'm going to change the oil on mine Monday, even though it's early... just because!!

Kevinmacd

To be exact the Gtlm car 911 and 912 make 470hp. Download the pdf for more in depth info.

http://www.porsche.com/usa/eventsand...gcars/911-rsr/

Carlo_Carrera

I was just thinking, lost in this is some really great news. Unlike in the M96/97 engine era Porsche is once again racing with standard production engine architecture in 9A2 engine.

Fishey

I don't think you understand how under rated all of the motors are in racing compared to the street. Do you have a rwhp dyno of the RSR? I have ran in those series those cars would be massively off pace with 470 crank hp. In 2011 our 500hp V8 Ford made "500hp" but in reality it made a nice number over *cough 580* at the rear tires like every other car on the grid. The fastest car that year was a Porsche DP car with a Mezger motor and it only made 470hp. Now, The Porsche was a bit lighter and had an extra gear but the TQ was much lower on those motors I don't think HP output was to much lower.

Kevinmacd

Rules are rules, not talking street, IMSA has their rules for each class, if the HP numbers were under rated then that means cars would well out do others in the same class. They use restricters to keep the power within the class limitations. In fact chevy had their GTLM corvette on display at the 12 hrs of Sebring this year, and it only produced 480hp.
Im pretty sure engines are rated at the crank since engines are swapable.

Fishey

Every car is under rated across the board.

Kevinmacd

Yeah especially in competition, keep thinking that, thats why they have to go thru an inspection before every race, and every pit stop and mechanical repair is supervised by an IMSA ref. to keep it in the GTE ACO regs.

z06801

I have always wondered about real life #s on factory built race cars, FIA gt3s ect. We had a shop who had purchased a former WC Audi R8 LMS and ran it in NASA ST1 class based on those factory numbers I think, when the car was capable of running 6sec faster than the track record for ST1. The car is now running GTSU. Think people would have had a fit if they tried to run it at nationals as a ST1 I didn't care enough to protest and make them throw it in a dyno. The thing with racing is its never fair. Lol