There's not enough data here to really answer your question.

It could be that he's not actually at a higher RPM. Except in sixth gear, he might be in a higher gear with the 4.77 car than he would be in the stock car.

Another possible explanation is that in the stock car he drove with the engine in a less-efficient part of the power curve than he did with the 4.77 car.

What you have to remember is that "mileage" basically equals "energy consumed per mile X the efficiency of the powertrain".

To get better mileage you can either reduce the energy consumed per mile or you can increase the efficiency.

The engine does have certain RPM bands for which it has the peak efficiency.

 

If you use an inertial dyno, you can tune at any speed and at any throttle under load.

You essentially set up the tune to reflect n/a values while below boost at wot and then fine tune it at partial throttle. They do this by feeding in the exact weight of car and driver so the inertial dyno reflects true load and then use your cruise control.

Works great. I was at 20 mpg before this type of tune I'm at 23mpg now if I don't stick my foot in it too hard. I also picked up a some more ponies at lower rpms.

fltsfshr

ps hey scott...that was you I gave that helmet too wasn't it?

 

wow. You must drive like a bat outa hell all the time. I get 30 mpg highway and 26 mpg average on commutes with a few lights and traffic.

 

I'm boosted with bigger injectors. Before boost I got 27 city but that was a long time ago.

I do put my foot in it however, don't you?

fltsfshr

 

i have 4.77's and a supercharger also.. my mileage is also the exact same as when my car was stock too. only if i drive like a supreme asshole will i notice my gas gets guzzled quickly.

 

why do you drive with 2 hands on the wheel?..that ain't cool..

 

Yes sir, that's me. She sees use almost every month too Thanks again.


And for the record... for me "Boost = Stock Comptech SC"

I do get on it a little bit. It's a rare trip that my car doesn't see 9000rpms, multiple times.

I'm actually suprised to see the geared + SC guys are reporting stocklike numbers. I thought that combo would result in a decent drop in mileage. Makes me really want 4.57's now

 

This is good information. I'm surprised that the mpg did not drop that much.

 

Why did that guy have painters tape all over his front end?

 

It's magical. If you put it on your car at a track day or an autocross, when you come home your car will still be "just out of the detail shop" perfect.

Or at least, some people think so.