LS1LT1

Oh ok, I'd figured as much.
And 'best guessing' is fine just as long as people don't misconstrue/misinterpret it all and start quoting some of this stuff as actual fact or reality LOL.

MitchAlsup

I have a friend that builds and tunes motorcycle engines that go into some kinds of "small cars" for racing purposes. He is getting 220 HP/litre NA from his most resent efforts (1.0 and 1.1 liter sizes; pump gas, 93 octane). But more than the peak power, his goal is to keep the power band as broad as possible to make the cars more drivable.

This is the point everyone is forgetting. 7 gears over 6 gears means that one can position the engine in its powerband easier (even it it takes a bit more rowing. Only the 7th gear needs to be selected for fuel economy. 1st will/should be chosen for 7% tire spin at FT acceleration out of the hole, 6th gear chosen for top speed; allowing the other 5 gears to be closer spaced.

1985 Corvette

I love them. By blow the dust off, I meant a redesigned version of the C4 seats. So all the great fit with improved support. That would make the performance enthusiast happy and shut up the mags complaining about them.

Racer X

No offense, RPM has a lot to do with fuel efficiency. Friction goes up with the square of the speed of the engine. So on any given engine configuration raising the RPM at which operates increases friction which means more fuel used to overcome the friction. BSFC is the appropriate measure of fuel efficency of an egine and it is not at peak operating RPM. Show me where a engine that produces peak power at 8500 RPM and one that produces the same power at 6500 RPM and look at the BSFC at their peaks. There is a reason the Corvette gets better mileage that others cars with smaller higher RPM engines of the same power.

Friction means lost power. Higher RPMs means more friction. Higher RPMS means more wasted fuel to produce the same power.

Yes I know there are many factors to fuel efficiency. Other factors the same higher RPM means less fuel efficiency at the same power.

Denise85

I for one am not too concerned with size. Just overall performance.

JustinStrife

LS1LT1

hig4s

Then you are saying two engines using the same technology, the one with more displacement will not have the potential for the most power?

McGirk94LT1

90% of the time you are correct. However, its an unanswerable argument as every engine is different. You want to use the same technology to be fair, but that isn't fair. For example, if you bored an ls1 out to 6.0 there's no guarantee it would make more then the ls6's 405 if you used the ls1 intake, heads, and cam. Using 100% stock components swapped over yes, you'd almost always make more power. But its not that simple, as the ls7 and even ls3 proved. The ls7 required a total valvetrain overhaul to hit its targets. The ls3 heads/intake can only fit on gm 6.0 blocks because of bore size requirements. Now, destroke the ls2, rev it higher, and could you make more then 400hp, on stock intake/heads/cam? LS2 intakes are mediocre, but I don't doubt you could by revving high enough. On stock valvetrain, I dunno. But again, what's "equal" when you're making these comparisons?

Not to long ago, a certain few viper fanbois claimed the 8.7 in the new viper would make 700hp days before its reveal. I was called an idiot when I said that a production 8.7 wouldn't make 700hp, and look what happened. To me, that was law of diminishing returns in action. So instead they revamped almost anything they could on the 8.4, making it a far better overall engine then an 8.7 based on the heavier valvetrain of the older 8.4.

No replacement for displacement is generally true(except its not, boost) but not so much when rules are involved aka production ready engine.

JoesC5

How about a 5.3L in your C7.

http://media.gm.com/content/media/us...01_copo_camaro

Might get hit with a gas guzzler tax, though.

BlueOx

Oh no! No replacement for displacement...unless I can do a 9 second quarter with 5.3L, of course.