[kaisen]

This past weekend was the Car Craft Nationals at the Minnesota State Fairgrounds. Among the many displays and events is the Dyno Competition. The top competitors are all running E85 in turbocharged or supercharged cars. The street-driven winner this year put down over 2,500 horsepower to the rear wheels. Many were over 1,500 hp. This is on readily available pump gasoline here in Minnesota. E85 is at most gas stations here. It's the cheapest 103-110 octane fuel you can buy.

Along those lines, I also spoke to a guy who owns a new 2014 Chevrolet Silverado with the 5.3L. He has been running E85 when towing, for the performance benefit.

The new GM Gen V motors now have direct injection, and they've upped the compression ratios accordingly. So the 5.3L V8 (L83) makes 355 hp and 383 lb-ft on regular 87 octane unleaded. But when running E85, GM has tuned the motor to make use of the higher octane, running more spark advance, more cam advance, and more fuel-events per stroke. The result is 380 hp and 416 lb-ft. That's an increase of 25 hp and 33 lb-ft torque with no other changes than the fuel. Run E85 when you need the extra power, run regular unleaded when you don't.

This gets me thinking of other modern direct-injected variable-timed motors and how they may benefit from this same "power adder". Especially force-fed motors like Ford's EcoBoost family. If Ford would tune the 3.5L EcoBoost in the F150 for similar gains it would yield 391 hp and 456 lb-ft (an increase of nearly 30hp and more than 35 lb-ft).

GM doesn't allow the pickup's 6.2L to run E85..... if it did, it would turn 450 hp and 500 lb-ft if it had the same impact as in the 5.3L.

Anyway, it was just interesting to me. A cheap power adder that you can run only when you want to. And many people don't know it.