XTCoX

This section of this post was a total engine identification fail on my part. Im editing it out because I feel like an ar-tard now... I can only ask that you document it well and keep us updated. Keep up with the through work and awesome care that you're giving that S30.

Nah, I was just giving you a hard time . And I agree with everything you are saying.

Well then its not N/A then is it? LOL

Well yeah..... but who wants a JZ without a turbo, I ask you?

With your power goals, I would have to agree with grtiz that going with the 1jz might be a bit more cost effective. At SupraStore.com, there are more parts for the 1jz, and they are less expensive than their 2jz counterparts. Not to mention that the 1jz internals are good up to (according to some other posts on Hybrid Z) 500hp. But if you're set on a 2jz, more power to you, its a great build.

The speaker draws power.... hmmm. That never occurred to me, but it makes sense and clears up a lot of the logic gaps. And you guessed right, 2 ohms in bridged mode . Again, thanks

You, my friend, deserve a medal for taking the time to write this. Thanks a million.

That's great news. Thanks for putting it into terms that I understand Oddjob. Thanks for the correction on the LPF/HPF. Now that I understand just what kind of conversions the power is going through, I gather that the "load" you are referring to is the Impedance of the speaker (2-8 ohms) which is the division factor for the amp's max power. That's going to show me what is the total max power being fed into the speakers, which is further modulated by the potentiometer on the input side of the amp. So a speaker with a high impedance is going to reduce the wattage of the signal being fed into it, making it "safer", right? (correct me If I'm wrong, but doesn't basic physics dictate that this high impedance translates into a lot of heat?) So this is the equation then: (AmpWatts/SpeakerResistance)/PotentiometerResistance=TotalPower ....or something to that effect. Close enough though, eh? ^That's mostly just for me to get a handle how the power fluctuates in the system, as long as its close. And the link is close, but my amp is about half that thing's length, all the same features, looks exactly the same in terms of style, but it's not the same. I don't know why, but mine has ceased to exist on the net.... Anyway, thanks again for all the advice. Oddjob, you have helped immensely. Edit: This is the system I was looking at: http://www.sonicelectronix.com/item_2481_Rockford+Fosgate+Punch+P1692S.html

The amp im going to be using is a Phoenix Digital amp, and it says that its 2 Ohms stable, and it has two crossover modes, LPF and HPF (low and high pitched frequencies) it also says that it has a bass boost. Im pretty good with electronics and units of electrical measurement, but it makes me wonder how the gain is turned down...is it just a big rheostat that reduces the amps... Whatever its not really important. The amp says that it should be used with a stereo with a suitable resistance level 2-8 ohms. Now that falls within the 4 ohms range, but I don't see how to adjust it, or is it automatic, or does it not even matter? Sorry the information is so vague i've been looking for the amp online in hopes of not having to post these questions here, but as of late I am SOL.

Hey Dhp, I was planning on running a pair of 6x9 composite speakers with a 240w peak/ 120w each side with 1000w amp I've had just laying around. Bad idea or could it work by just taking the gain down way low?

I'm interested in how you plan on putting those speakers in the doors. You gonna slice out some of the metal inside to door to make room for the speakers, or what? Also, I'd like to know what kind of stereo that you're using. The PO of my car had removed the center of the dash and the console, and I never got it back. So I am thinking about having the middle of the dash fabricated, from an aluminum billet or something of the like, but could you think of any other options that may be easier or more practical?

Thats an interesting way of setting up the system, Oddjob. The speaker panel doesn't seem like too much work, so I'll give it a shot this weekend most likely. Thanks for the insight.

Great! Thanks Bob. Ill probably end up doing that. One more thing...any idea where to mount a subwoofer in the car? I was thinking about either mounting it magnet-up in the spare tire well, or making a sub box. The problem is that I have no ide where to put a sub box, and I haven't seen it done before, so i'm not sure if that' even a viable option. Thoughts?

Yeah ive got those. Mounted face up, or pointed at the back of the seat?

Well, the car came with 2 speaker holes cut behind the seats of my 260z. Im a little concerned about the obvious here... I think the sound might be muffled if mounted behind the seats, but I REALLY don't feel like kicking down an extra $140 bucks for an MSA speaker panel, or running wires all the way to the very back of the car, plus I'm not totally sure if that's even a reasonable concern. They are good, 6x9 speakers (does that even make a difference? I don't know). Has anybody mounted the speakers behind the seats, and had it be decent, or should I just bite the bullet, not be lazy and get the damn speaker panel? Feel free to speculate, but I feel that first hand experience in doing this is the only way to know whats really going to work and what won't (not sure if that's even relevant, but hey ).

thanks for the info Bob . BRAAP, the piston rings are far from new, so those don't need the break in, but a reground cam and reconditioned rocker arms would. So how long before they are broken in? zedsn, the vapor problem went away. Thanks for the quick response guys.

Well, Im not getting any backfiring or popping, so that's good news .... But that term you used...Lapping...Im not sure im familiar with that one. Sorry for the ignorance, I've just been on a car-rebuild-crash-course for the past couple of days. The guy that we bought the head from said that we had to keep it under 3000 rpms for the first 50 miles or so, bcause "the valves weren't properly seated yet"...Is that correct?

Got the E31 on today. Runs like a champ with the Stage 3 MSA cam in it. No more steam either. Side question for you guys: There was some extensive machine work on the head, which included a new 3-angle grind, and 280z valves. So, how do we know when the valves are properly seated? 50 miles or so?

how much water could accumulate in the system that it would take 30 min to clear out? Im not disagreeing, just a little surprised that it would take that long to clear out. There was steam billowing out of the exhaust, when we revved it, when it idled....you're saying that this could be just from accumulation alone? Ill give it a shot, but that seems like it would have to be a liter or so of fluid stuck in the exhaust for that much steam to be coming out of the tailpipe.

No, I didn't do a pressure check personally, but they guy we bought it from said he did. I guess you can't trust anyone. Anyway it's good to know that this is a common problem...now I can stop feeling like the world is ending . Thanks guys. I'm getting an E31 with a stage 3 cam, heavy machine work and N42 valves tomorrow. That's going to be fun.

Well, I'm stumped. We just replaced the head gasket, head, and everything else that connects to the head, and this engine is billowing steam out the tailpipe. Could the water jacket be busted in the head? The head had been restored to a clean, polished finish, with all reconditioned equipment. The only explanation I could come up with was that the water jacket was cracked somewhere. Anybody have any other idea's what's going on here?

This is just a side question: I was under the impression that the P90 and E31 had the half-moon shaped quench chambers, and the N47/42 had the full circular chambers...... Ill have to do some research on this, now im really confused!

Well, I called MSA and they said that the N42 block has flat-top pistons, so i guess that that wont be an issue. I know that the P90 is the best flowing head of any of the S30 heads, which is why I want it, albeit a slightly lower compression ratio. I could compensate for the loss of compression with a lower-profile gasket and adjustible cam sprocket, or I could grind it down, but then it wouldn't be suitable for a turbo application. Its something to think about. I am just going to throw it on stock and see how it works. Then i'll go from there. If i dont like it, Im more than positive someone will buy it.

Yeah thrustnut, thats a good point. I have an N/A L28, but I wanted to get the P90 ported, polished, with a huge cam and a valve job..... I pretty sure that the lower compression wont be a problem, and i plan on putting a turbo on the car, so this is a must. Unless, someone knows something about comp ratios that I dont, and would advise against this N47 to P90 swap for N/A applications???

You want one for a cam project? huh.... Now why's that? wouldn't you rather have a P90 or an E31?