http://money.cnn.com/2006/05/11/maga...mwm5/index.htm

I assume (hope) those are city numbers.

Maybe this could be a trick around CAFE for performance people. 17/27 400HP LS2 or with the press of a botton 500HP at the price of 13mpg city. Of course as many of you know, it isn't hard to gets low teens or even single digits with a small block if you really really want to .... and make your local tire salesman very happy at the same time.

I think a lot of people would be willing to loose 5-7 mpg to gain 75hp for at least a short period of time. Daily drivers don't need an LS7 (or LS2 really), but it would be nice to have LS7 power when you want or LS4 gas milage at the push of a botton.

 

I don't really know why the power switch should affect fuel econ outside of WOT unless you are really lazy when writing the engine management.

 

If they did that and it was literally just a flip of the switch for a bunch of extra cash you there'd be a 'hack' for it out in a matter of weeks and people would get their power without paying the manufacturer (or the government) a dime more.

That's interesting though. I knew the M5 was rated at 500hp but I didn't realize it required something other than a floored gas pedal to 'access'.

Lots of cars are getting these 'cheat codes' these days. The Lexus IS has a cheat code to disable its vehicle stability control and traction control system... a couple other cars have codes to cause their DSG-type transmissions to rev up and dump the clutch on the launch, which produces much better acceleration results but actually records the number of times it has been done and past a certain number of times will actually void the warranty. lol

 

The C4 Corvette ZR1's had a valet switch like that . Full 405 hp when off , when it was on the power was cut down to "if I remember right" 275hp . The vette switch needed a key though .

 

Exactly. Even if it was a matter of there being dual runners for dual intake valves or something, with tehe seocnd set held closed in low power mode, you'd still think they'd have them programmed for some amount of progressive opening in normal mode, and thus still not affecting 'normal' driving conditions, only opening when goosed all the way.

Maybe it leans it way out and puts the timing on the back bumper in low power mode, but again, what would be the point since you coudl still have full fuel and spark under heavy throttle anyway?

Hell, maybe they purposely did it just so the average snob who buys such a machine will feel that much cooler when showing the stats to his friends. I mean, cmon, what kind of 500+ hp engine is capable of V6 sedan fuel economy. Onlly some kind of chevy junk could pull off that kind of trick. BMWs little european horses know no such restraint on their appetite.

 

"The button" ought to be pretty easy to program, in this day of electronic throttle control, and continuously variable valve timing. Pull back 100hp? Just make 80% the "Full Open" setting for the throttle, and keep the cam from going all the way to the biggest lift/duration. Push the button to release these artificial limits. Done.

As to the mileage, I'm guessing that article speaks to the author's observed fuel economy. The vast difference between the 400hp and 500hp settings, is likely because he had his foot in it all the time on the 500hp setting. I'm betting more controlled testing in either mode would show little difference.

 

That's the only reason that makes any sense to me. The EPA mileage tests barely crack the throttle on most higher-powered cars.

 

Heh, good call. (I did not RTFA)

 

What about a dial like in indycars to control the power even more?