Quote Originally Posted by teh_mugen18 View Post
Everyone says that the sleeves on Honda bottom ends are only good until about 300hp. The only question that i have is, it seems like the vtec turbo engines make a whole lot more power up into the 300+whp range with the same amount of boost that non-vtec engines run on and only seem to make in the 220 - 230whp range...

Now my question about the sleeves is, is it safe for these vtec/turbo engines to be running in the +300whp range with no sleeving due to the way vtec reacts to the same amount of boost? or is it something else?? Because it just cant be "safe" to run like this, right?

Its just something i've been wondering about...
vtec motors make more horsepower (with the same size turbo/boost) mainly because the compression is higher (10:1 as opposed to 9:1) and the heads flow better. basically the vtec motor is more efficient. you'll notice the the torque will be about the same though because the displacement is pretty much the same. you have the same scenario when you look at both motors NA too.

remember it's not about the amount of boost, it's how much power you're making. both motors can handle 300whp, you just have to run more boost to get the non-vtec one there. but what i've seen though is with both motors at 300whp, the non-vtec motors make more torque, as a result of that extra boost it has to run.

i've seen ppl run 350-400whp and higher with no issues, and i've also seen folks crack sleeves at 350-400whp too. 300whp seems to be that magic number where you can be confident it'll run all day and not have to worry about it. i'm making about that much on my db8 with pistons/rods and stock sleeves and i've been driving it every day for almost 4 yrs.

just my - someone more knowledgeable could prolly break it down more