whiteEJ8

What exactly is compression?
Why is low compression good for turbos and high compression good for N/A.

which would be faster:
Turbo B18C1
Turbo B20z (not CRVTEC)

assuming they have the same tranny, ECU, intake manifold, and are running the same boost.

Thanks for the help.

qtiger

Compression ratio is just what it sounds like... the amount (in a ratio) your engine compresses the intake charge when the piston comes up.

So, for example, a 10:1 compression ratio would compress the air to 1/10 its volume.

Between those engines... the b18c1 would definately come out ahead, but one of the points of using the b20 is its lower compression ratio (lower compression ratios are more boost-friendly), so you'd be able to nudge the boost higher on the b20.

After taking that into consideration... it would be very close.

VtecApprentice

OK let me try this

HmMmM . . . if you know how a four stroke engine works, you will know the compression happens when the piston move up from bottom deck center (BDC) to the top deck center (TDC) of a compression stroke. This compression stroke compress the air/fuel mixture in the cylinder hence increase the pressure of the mixture. During the compression, temperature rises.

For N.A = since air is not precompressed, you can compress it more without it being ignited by the high temperature which is call detonation which may cause knocking which is bad

For T.C = since the air is precompressed by the turbo charger which has high pressure hence high temperature :dunno: . If you compress it alot in the cylinder again, it will cause it to pre-ignite by over heat and cause detonation.

did i missed out anything lets wait for the expert here to fill things out :naughty:

for N.A. B18C1 will be faster then B20Z (stock to stock) and B18C1 have higher compression ratio :dunno: As its natural for a bigger displacment engine to have bigger torque . . so which is faster actually ? ? ? expert please ? ? ? heehee

for Turbo Charged, B20Z allows more boost as it has lower compression ratio :dunno:

dubcac

The b20 also has a stronger stock sleeve, and thicker stock rods, not to mention .2L more displacement, so you'll be making more torque. As for which is faster, that depends on a lot of things.

MrFatbooty

Dude VtecApprentice, you're goin a lil overboard with the smilies there eh?

TeHJuSTiN

lol :thumbup:

Watertick

Thats what i was thinking.....

VtecApprentice

heheh sorry about it . They makes the posting looks more lively thats why i post them I will try not to include soo many smilies in next time

-KangaRod-

BDC = Bottom Dead Centre
TDC = Top Dead Centre

Thought you might like to know

inspyral

B20 sleeves aren't that much stronger than other B series sleeves:
http://honda-tech.com/zerothread?id=280870