Well, we were all surprised apparently.
This carbon fiber wide body NSX, which was featured by SuperStreet in 2005, has passed through a few hands through the years. When the new owner purchased the car, he was looking for a power plant to match the aggressive body. Through many discussions, we eventually arrived at rebuilding the engine to the
ScienceofSpeed Stage 3 3.5L package we offer. The turbocharger system was an off the shelf
ScienceofSpeed Twin Turbocharger System with twin custom GT2871R turbochargers. These, slightly larger than the GT25s we use on stock engines, would allow the additional air mass to achieve the customer's goal of 650 whp on pump gas and give us some overage for an E85 fuel tune (E85 being an alcohol/petrol blend with an octane (R+M)/2 equivalent of approximately 95) - an alternative to more expensive race fuels. We made a few minor upgrades to the fuel system, including using Aeromotive's new 340 LPH fuel pump and a plug and play wire harness (soon to be released from ScienceofSpeed) to support the current draw of this new pump. We also upgraded the standard injectors from 750cc - 1000cc. Based on calculations and estimates of system efficiency we made, we (conservatively) calculated and had a goal of 800 horsepower at the crankshaft (the turbos at full efficiency will produce enough air mass for around 950 horsepower at the crankshaft - which rarely happens). 800 horsepower at the crankshaft would give us about 704 horsepower at the wheels on the dyno we use.
We were
blown away by the results.
819 horsepower and 679 lb/ft of torque at the wheels. That's 931 hp and 772 lb/ft of torque at the crankshaft. There was even a little more to go, but we had to stop there once we reached the maximum duty of the injectors.
All this power with off the shelf parts in stock at ScienceofSpeed. Even the engine itself, despite being a great package - is relatively factory with the addition of the 3.5L rotating assembly - including factory camshafts and factory cylinder heads.
We're very excited from these results - and it goes beyond just the numbers. First, we're excited to see that our new fuel system was up to the task of 900+ hp. Secondly, we're very excited that the twin turbocharger system has the efficiency to make nearly as much power as the turbochargers are theoretically capable of making (almost never the case). Lastly, and this I think is most important - while there have been some big horsepower numbers like this from single turbocharger systems, they all spool much later and the drivability suffers. With the larger custom GT2871s used, we only gave up 800 RPM of engine speed on this engine to hit peak boost compared to our smaller GT25s which some in at a very early 3500-3800 RPM. The result is a car that not only is fast, but is actually drivable with this level of power.
I hope you guys had fun with this, it was a nice way to end the week.
bruce91nsx - 873 hp - is our winner - even being 58 hp low! You guys should have thought more like Juice! I have a feeling that $25 will help out the project we are finishing for him next week!
take care,
-- Chris