No replacement for displacement?????

[typhoone]

i was thinking about something earlier, and i was wondering:

 

if there is no replacement for displacement, why is the rb26det so much better than the vg30et?

 

rb=racing bred 26=2.6 d= dual overhead cam e=electronic fuel injection t=turbo

 

vg=.... 30=3.0 e=electronic fuel injection t = turbo

 

the vg has more displacement, but i am sure there are plenty of reasons why the rb26 is better. I am not trying to be a purist or anything like that, i was just wondering, that's all.

[280zwitha383]

It should be:

"(all other things being equal) there is no replacement for displacement"

 

A bigger SR engine WILL make more power. A bigger VG will make more power (than the VG30). Just because a smaller engine makes more power than a larger engine doesn't negate the old adage. The smaller engine probably has (a) better flowing head(s), intake, exhaust, piping, more advanced timing and A/F controls etc.

[76s30]

a 500 hp 3.0 is more drive able than a 500 2.0 (sr20) any day anywhere.

more displacement means more torque period. more torque means more hp at lower rpm.hp= torque x rpm / 5252. your also talking V vs's inline. which is kinda apples and oranges.

more displacement spools the same turbo sooner.

[alexideways]

RB26DETT = DOHC twin turbo

 

VG30ET = SOHC single turbo

 

+ since the VG30ET came out, there was a lot of advance in internal turbine aerodynamics. RB = newer = more efficient. Compare it to a VG30DETT and you're already way closer...

[Scottie-GNZ]

"No displacement for displacement"........BUNK! You cannot make generic statements like that.

 

Do not confuse displacement with HP. It's not how much displacement you have but how much you can stuff in that displacement. Perfect example: early 80s Corvette 350ci had 202hp, early 00s Corvette 350ci had 354hp, 07 911 215ci (n/a) has 355hp!

 

There absolutely is a replacement for displacement - efficient components or forced-induction. Dont forget that a turbo engine has the potential to stuff an additional equivalent of its displacement into the original displacement for every 14.7psi boost. Sound confusing? That means an RB26 at 14.7psi has the potential to stuff 5.2L into its 2.6L displacement. At 29.4psi, it is up to 7.8L packed into 2.6L displacement. Obviously, the 7.8L intake charge is compressed, then the compression stroke compresses it even more. Ignition, BANG, big HP from smaller displacement.

 

So, like I said, its not what the displacement is but how much you stuff into that displacement before you light the candle.

[Evan Purple240zt]

I agree with scottie fully.

 

Just an FYI, rb does NOT stand for Race Bred. Thats an internet rumor.

 

Just wanted to clear that up.

 

Evan

[Careless]

Do not confuse displacement with HP. It's not how much displacement you have but how much you can stuff in that displacement. Perfect example: early 80s Corvette 350ci had 202hp, early 00s Corvette 350ci had 354hp, 07 911 215ci (n/a) has 355hp!

 

you make a good point. but i think you also hit the nail on the head when you mentioned both 350's, while missing what the phrase really means, altogether.

 

the whole message in the "n r f d" quote is in regards to the SAME engine. Not completely different engines.

 

Sure the porsche engine is almost half as small and makes 1 more horsepower. But what happens when you take the dynamics of the 215ci engine, and make everything bigger? you're allowed to stuff more air, and more fuel, and you then create more energy due to a larger combustible area.

 

the saying doesnt apply to cross-platform or totally different engine designs due to the fact that certain engines have different heads that would allow better combustion chamber design, therefore increasing possible compression ratios. i.e. - a replacement for displacement. this is apples to oranges.

 

now, apples to apples, you'd have the same engine, only stroked, or bored out, and with the same compression, everything updated to provide for the new parameters, and you'd make more power if your calculations are correct.

 

a honda head flows much more than a nissan head. just look at the b16 or b18 head, and compare to an RB25 head, by not counting 2 cylinders. So if you make it bigger, it doesn't mean you're creating as much energy.

 

you can read about the immense flow ratings of a stock honda head on endyn's website. i'd like to replace the "n r f d" quote with "the more you can ram, the more it can WHAM!" but that sounds a little...