KL_03 pistons in a KL_ZE

[VizualXTC]

I know the KL_ZE has a 10:1 compression level and the KL_03 has a 9.1:1 compression, which makes the KL_03 a "better" engine to turbocharge. I have taken alot of slack becuz I want to turbocharge the ZE but I've not backed down. I'm still on track to turbo the ZE. My question is how much HP will I lose if I put the 03 internals in the ZE? I'm guessing with only the lower compression I would only lose about 10-20 HP which would still keep me around 180HP with the lower "turbo friendly" compression. Tell me if my theory is off, of if you have better ideas other than just going with the 03. I know I could get the 03, intake, exhaust, and ecu for about the same amount as the ZE and maybe more HP, but I still want to turbo the ZE. Any help would be appreciated. Thanks all.

[pelado]

One of the things you could do other than lowering your compression ratio is to use water injection. Go to <A HREF="http://www.aquamist.co.uk" TARGET=_blank>www.aquamist.co.uk</A> for a look at their system. If you decide you want to purchase one, then the best price I've found is at <A HREF="http://www.flyinmiata.com." TARGET=_blank>www.flyinmiata.com.</A> <P>Oldsmobile (believe it or not) was one of the first to turbocharge a production car. They used their 4-v aluminum V-8 (the descendent is used in Range Rovers today) with a CR of 10.25:1. This gave the Olds Jetfire good pickup at low rpm while waiting for the turbo to build intake pressure (max of 5 psi). How did they keep the pistons from melting when the inevitable pre-combustion occurred due to the increased cylinder temperatures? Water injection. The old Olds water injection was complicated, the new system from Aquamist is computer controlled.<P>You asked for alternatives, there's one.

[VizualXTC]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by pelado:<BR><STRONG>One of the things you could do other than lowering your compression ratio is to use water injection. Go to <A HREF="http://www.aquamist.co.uk" TARGET=_blank>www.aquamist.co.uk</A> for a look at their system. If you decide you want to purchase one, then the best price I've found is at <A HREF="http://www.flyinmiata.com." TARGET=_blank>www.flyinmiata.com.</A> <P>Oldsmobile (believe it or not) was one of the first to turbocharge a production car. They used their 4-v aluminum V-8 (the descendent is used in Range Rovers today) with a CR of 10.25:1. This gave the Olds Jetfire good pickup at low rpm while waiting for the turbo to build intake pressure (max of 5 psi). How did they keep the pistons from melting when the inevitable pre-combustion occurred due to the increased cylinder temperatures? Water injection. The old Olds water injection was complicated, the new system from Aquamist is computer controlled.<P>You asked for alternatives, there's one. </STRONG><HR></BLOCKQUOTE><P>Sounds like a kewl idea, but a little too advanced for me right now. I'm too lazy right now to learn about the water injection systems. Plus I'd like to run more than 5psi boost in my application. Thanks for the input man. Any additional info, or suggestions, or comments are welcomed, and encouraged.

[pelado]

I wasn't implying that you could only run 5 psi boost if you used that water injection system. I was just stating the Olds turbo setup from '62 was limited to 5 psi.<BR>If you're considering going higher then I see a change of pistons in your future.

[VizualXTC]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by pelado:<BR><STRONG>I wasn't implying that you could only run 5 psi boost if you used that water injection system. I was just stating the Olds turbo setup from '62 was limited to 5 psi.<BR>If you're considering going higher then I see a change of pistons in your future.</STRONG><HR></BLOCKQUOTE><P>The thing is, that price is a big issue for me right now. But then again so is power. I'd rather pay the extra for the ZE than save money and have a slower car. If I can find proof that the 03 indeed will produce more power than the ZE under turbo applications, then I will go with the 03. Otherwise the ZE is still in my agenda. The water injection is something that I am too lazy really to learn, and prolly a little more money than I want to spend right now.

[Smokin mx-3]

I believe that youu can run 10psi on the kl-ze of intercooled boost that is stock everything

[VizualXTC]

Hmmm......I still havn't gotten my question answered. Please, can someone tell me if the 03 pistons and rods will fit in the ZE, or will I be ok with just the rods? ANY help would be MUCH appreciated. Thanks all.

[Esper]

what are the differences in the two engines besides higher compression and a different ECU (in other words, fuel & ingintion curve)? if that's all there is, then i would assume that the pistons would swap. but then you'd have a low compression engine with the fuel and timing and spark all running at higher levels. this would hurt performance when naturally aspirated, and if you turbo'd you want to retard the timing even more (i'm not sure how the ignition would be different, other than maybe colder spark plugs). my whole theory could be completely off if the engines have a lot less in common than i'm assuming...but if i'm right then all you're gonna end up with is a KL-03 with a ZE ecu for price of a full ZE. hope this helps.

[Custommx3]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by VizualXTC:<BR><STRONG><P>The thing is, that price is a big issue for me right now. But then again so is power. I'd rather pay the extra for the ZE than save money and have a slower car. If I can find proof that the 03 indeed will produce more power than the ZE under turbo applications, then I will go with the 03. Otherwise the ZE is still in my agenda. The water injection is something that I am too lazy really to learn, and prolly a little more money than I want to spend right now.</STRONG><HR></BLOCKQUOTE><P>Here...<BR><A HREF="http://www.naplesnews.com/staff/fortier ... lcome.html" TARGET=_blank>http://www.naplesnews.com/staff/fortier ... me.html</A>

[David Coleman]

Yeah, the KLD pistons will fit in a KLZE. Same with the rods. Swapping pistons isn't a job for the faint of heart however. As far as I can tell, the pistons are no stronger or weaker, and the rods are identical. They will both hold the same amount of boost, the question is how much octane you can get. Sean is the man to talk to about that, but I'd wager that with cold enough plugs and a bit retarded timing [under boost], you could get away with 7-8psi on 94 Octane. Sean was running 5-6 with a small intercooler on pump gas for quite a while. I'm not certain what he's up to now though..

[VizualXTC]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by David Coleman:<BR><STRONG>Yeah, the KLD pistons will fit in a KLZE. Same with the rods. Swapping pistons isn't a job for the faint of heart however. As far as I can tell, the pistons are no stronger or weaker, and the rods are identical. They will both hold the same amount of boost, the question is how much octane you can get. Sean is the man to talk to about that, but I'd wager that with cold enough plugs and a bit retarded timing [under boost], you could get away with 7-8psi on 94 Octane. Sean was running 5-6 with a small intercooler on pump gas for quite a while. I'm not certain what he's up to now though.. </STRONG><HR></BLOCKQUOTE><P>Sean Matthews said that a Ford Rod/Supra Piston combo would fit in the KL_ZE. Isn't the Supra a 3.0L I6 engine? Does anyone know what he may be talking about? I'd ask him but he's in Japan right now.

[pelado]

It doesn't matter if the Supra is an inline engine, for that matter any piston/rod combo you can find that works within your engine is OK.<BR> <BR>Rod lengths need to be pretty close.<P>Rod big ends need to be an exact match.<P>Piston bore needs to be pretty close or at least on the larger side and within the allowable diameter your cylinders can be bored (there's always sleeves, too).<P>The combo of rod length and piston pin to piston top surface needs to be evaluated so the piston doesn't contact the head or make compression ratios sky high or too low.<P>The supra piston is for a turbo and turbo pistons are usually dished so you don't have to worry about the piston crown matching your valve arrangement.

[David Coleman]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by VizualXTC:<BR><STRONG><P>Sean Matthews said that a Ford Rod/Supra Piston combo would fit in the KL_ZE. Isn't the Supra a 3.0L I6 engine? Does anyone know what he may be talking about? I'd ask him but he's in Japan right now.</STRONG><HR></BLOCKQUOTE><P>He's talking about the SVO rod/ supra piston combo. The supra pistons are 86mm, up from 84.5mm of the stock KL pistons. It would drop your compression a good bit, but a guy who did it on probetalk said it was so much machine work to get it all to fit that it's not worth it. You could just get custom overbore pistons and rods and not have to worry about resizing rods etc.

[VizualXTC]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by pelado:<BR><STRONG>It doesn't matter if the Supra is an inline engine, for that matter any piston/rod combo you can find that works within your engine is OK.<BR> <BR>Rod lengths need to be pretty close.<P>Rod big ends need to be an exact match.<P>Piston bore needs to be pretty close or at least on the larger side and within the allowable diameter your cylinders can be bored (there's always sleeves, too).<P>The combo of rod length and piston pin to piston top surface needs to be evaluated so the piston doesn't contact the head or make compression ratios sky high or too low.<P>The supra piston is for a turbo and turbo pistons are usually dished so you don't have to worry about the piston crown matching your valve arrangement.</STRONG><HR></BLOCKQUOTE><P>Yes I know that the placment of the pistons has no affect on interchanging them. I should have stated it as a 3.0L 6-cylendar rather than I6. I was just comparing the 3.0L to the 2.5L of the KL_ZE.

[mx3gsr]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by David Coleman:<BR><STRONG> Swapping pistons isn't a job for the faint of heart however. As far as I can tell, the pistons are no stronger or weaker, and the rods are identical. They will both hold the same amount of boost, the question is how much octane you can get. Sean is the man to talk to about that, but I'd wager that with cold enough plugs and a bit retarded timing [under boost], you could get away with 7-8psi on 94 Octane. Sean was running 5-6 with a small intercooler on pump gas for quite a while. I'm not certain what he's up to now though.. </STRONG><HR></BLOCKQUOTE><P>For the guy swaping his rods, I wouldn't waste your time "changing" to the KL03 pistons. Here's why.<P>Assume a relatively simple intercooled turbo system installed onto the Mazda V6.<P>On a stock KLZE, you're maxed out at 6-8psi because that's the limit before you start to have pre-detonation problems (knocking) due to the higher compression, and you'll also be breaking the 300hp limit which even without detonation will be the power limit where you'll risk bending the relatively weak factory rods.<P>On a stock KL03, you're maxed out at 8-10psi by the weak rods. But due to the lower compression, you're still at about the same power output (300hp) so you're beat either way.<P>Realistically, without large dollars to spend to go past 300hp, it doesn't matter which engine you turbocharge. And if you have the time/money/desire to change the pistons you might as well go to some forged custom built units like Dave suggested since a rebuilt bottom engine is going to set you back $3000-5000 anyways. That should be good for 15-20psi.