more power

[ninjasteve]

I am wondering what would put out more power, turbo'd KLZE or KLDE. I know you can run higher boost with the de because of the lower compression ratio, but the ze has more power to begin with, so asuming that the engines have forged pistons/rods, upgraded fuel system, etc. which one would ultimately put out more HP without precombustion?

[mitmaks]

logically youll make more power with de, because by the time you spend modifying ze to handle boost you could've made more hp with de

[lakersfan1]

Originally posted by ninjasteve:
so asuming that the engines have forged pistons/rods,

Well, assuming you're already changing the pistons and rods, what the hell does it matter if you start out with a DE or ZE if you can change the compression when you replace the pistons anyways?

[goldsberry1]

Well when you take out the pistons and rods they are basicly the same engine. just depends on what compression pistons you put in it. the theres the cams. de cams are supposed to be better for boost,(less overlap). so i suppose if your going for boost go with the de.

[TsiMiata]

If you put the same pistons and rods in both motors the ZE will win. It has bigger intake ports and manifold runners. I think the larger lift of the ZE cams will more than offset the increase in overlap.

<small>[ November 15, 2004, 11:05 AM: Message edited by: TsiMiata ]</small>

[babyblueMX3]

cams would be better from the DE but like Tsi said..ZE has better flowing heads and intake..
my guess is ze would put more power..
you take the curve neck ze that already has the kl01 cams in it and you have the better from both worlds

[MazdaManiacMx3]

But the KLZE's have weaker head components. (retainers)

[mazdubber]

Originally posted by MazdamaniacMx3:
But the KLZE's have weaker head components. (retainers)

Aren't they interchangable anyways?

[lakersfan1]

Originally posted by mazdubber:

Originally posted by MazdamaniacMx3:
But the KLZE's have weaker head components. (retainers)

Aren't they interchangable anyways?

I believe it's jsut the exhaust are the same with 1mm different intake HLA and such.

[Kokiriwave]

KLZE=more power per PSI
KLDE=less power per PSI, but can handle more boost than the KLZE.

The KLZE engine can't handle very much boost untuned due to compression, but to my knowledge some of the fastest cars put out insane numbers with high-compression, turbo'ed engines.

You can boost both......my (hopefully correct) .02

Sidenote: babyblueMX3 what kind of times are you expecting with your project....??!?!

[ninjasteve]

what about the straght neck IM, is it possible to get to fit, and is it any better than the curved neck?

[ninjasteve]

would lower compression pistons with higher boost put out more power, or would higher compression pistons with lower boost?

[mazdubber]

Originally posted by ninjasteve:
would lower compression pistons with higher boost put out more power, or would higher compression pistons with lower boost?

The maximum power output would be roughly the same. But with a high compression low boost motors there is less emphasis on the turbo to make the power. So you'd have more power at the low end. Lower compression motors will give you more noticable turbo lag along with the more noticable boost when it finally gets up to speed.

[TsiMiata]

I don't think the compression ratio on the ZE is really a factor when it comes to boost. You'll bend rods or break pistons long before the higher compression comes into play. People are boosting 12:1 compression RSX motors with no trouble. 10:1 compression may not be the greatest turbo CR going but for the low 6-8 psi you can boost the stock motor it doesnt matter.

As far as the best CR for a turbo car there isn't one. To compare CR we have to assume that both the high compression and low compression engines we are talking about are identical except for the pistons. They have the same turbo, head work, rods etc..

Lower CR engines will generally have more lag but will tolerate more boost before pre-igniting. They will also make more ultimate power than a higher compression ratio. That's for two reasons. One is since the compression ratio is lower there is more space above the piston. That's more space to cram air and fuel into. The second and this might arguable is that you can run higher boost pressures. The higher boost pressure will make up for the loss in the static compression ratio that you get with a higher compression piston. So the air and fuel will get pack as tightly together as they would with a higher compression ratio if not more.

Higher CR engines make better daily drivers and racing that requires good low end power. It will give you better low end power and more linear power. The turbo surge won't be as pronounced. I'd rather have a high compression motor for say autocrossing where low end and linear power is better. My old talon had awful turbo lag. In city traffic you couldn't just on a whim cut some one off or pull out quickly. If you tried that it pull away like an 81 chevette until you hit 3500rpm.

For a car I was driving everyday I'd pick the higher compression ratio. For a full on drag car or highway screamer the lower the compression(to a point) the better.

[DavidOS]

ze
if your gonna forge the internals and turbo it well might as well go all out and buy an sds or haltech for it as well and keep compression the same so low end doesnt feel laggy at all.

then again i guesss it all comes back to that pain in the a$$ $ sign