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That illuminated z logo could work well for the s30 or any zcar for that matter.

That's actually what I once thought blow off valves were for. To me it seems that if you had a fixed wastegate, or none at all, aside from the turbo overspooling and blowing up given the right circumstances, consider that it would run very inefficiently. It might be okay for line racers, but having the turbo run at maximum capacity all the time only to blow the hot compressed air back into itself in a loop would be undesirable. Now because the bpv is releasing excess pressure, the turbo wouldn't necessarily be under a higher load, but regardless it would be spinning ridiculously fast and sucking in hot air from its own discharge and burning itself up. Also, the turbo would never shut down, as it would be spooling even at idle--to what pressure is hard to say; a balance between it's capacity at the current exhaust rate, and the load on the engine at which it would be caused to die. Does that make sense, or is it just 2am right now?

Andy: This is all relevant information, thanks. Sorry I haven't responded in a while, I've been having all kinds of side projects. We're still moving though. Well, I'm still waiting for my bpv, but the speed shop is making me a new throttle cable and the intake box is almost done (I really hope that works out, it's taking SO much effort to make!). It looks good so far though. Wondsparrow: Yes, the bov should recirc back to the turbo downstream of the maf, because if it goes upstream of the maf it is counted double and thus the ecu will overschedule fuel--ie. you might as well blow off to ambient. Recirculating back to the turbo doesn't really cool it or necessarily allow it to keep spinning, but rather to stop spinning on its own steam as opposed to spinning backwards from the backpressure created by closing the throttle plate suddenly and having pressure built up in the intake plenum. Once the air is downstream of the turbos, it combines and doesn't matter which bpv goes where--the only rule is that the recirculated air be evenly distributed between the two turbos so that neither stall. In fact, you don't necessarily need one bpv per turbo; the stock setup has two, but they immediately combine into one stream. The only thing I can't figure out yet is why there are two bpv's at all. For all we know, it's just to save space or have a common part between engine models. It's Al by the way. Al Gore. Now get off my internet!!

The ground wire probably goes into the loom to a common ground that is shared by many other components. The trail goes cold at the dash where the Y/G wire ends. I suppose if someone had the skyline gauges they could take a peek at the plug to find out exactly the color of the wire that goes to the trans.

When the cap broke off of mine, I saw that it was a magnet on a shaft, and the plastic cap over it it had a bunch of individual leads surrounding the magnet to generate a charge. I'm pretty sure one of the wires goes to the ecu (53?: At the ecu it is a different color), the other is ground.

If you're planning on going the route of an aftermarket ems, consider the fact that if it is going to use map sensors instead of maf's, you could easily just use an atmospheric bov which could make the change-over easier/simpler.

In essence there is a little gear driven generator that creates a voltage level based on the trans speed and I'm pretty sure in stock application it is connected to the ecu, which interprets it and sends a signal to the tach, but if you have a digital gauge you can skip the middle man because as it was concluded earlier in this thread, the ecu doesn't really need the signal to run properly (the sole purpose is function of the speed limiter, and who wants that anyhow?).

Can you explain your setup? I'm curious. Are you talking about the 240? That's a pretty bold statement, but as for me I'm really looking forward to sharing the experience. But yeah, I don't think 1.0bar would cut it. Are you talking about crank hp? From almost all the personal accounts I have read, the ceramic spool won't last very long at much more than 0.8bar. Even if it were ball bearing, you'd need the n1 version (GT25) with a steel turbine to feel safe running it that hot. I imagine the others who have done it will say that aside from everything else, you tires won't last long with that much power P.S. Spider=hijacking.

What, you mean the part about me making excellent progress? :'(

It's pretty fortunate to have the original recirc valves and that y-pipe to boot. I'm going to have to fabricate some sort of y-pipe for my universal bpv and find a way to install the two of them in conjunction. Yes, the the two control lines are vacuum operated. Will you be able to turn up the boost with these valves though? They don't appear to be adjustable. Unless the control lines also control the blow off pressure setting and can be hooked up to an aftermarket boost controller should you go that route. I take the lines for being more of an on-off switch though. Do the valves themselves say what pressure they blow off at? I'm still trying to figure out the hurdles, if any, involved with replacing two small valves with one bigger valve. I don't think it will be much, since Greddy actually sells kits for just that: one large bpv that replaces these two and keeps the stock plumbing (probably for the purpose of adjusting blow off pressure as I mentioned above). But again, I'm just speculating. It would be great if your valves could reveal some hard facts on the matter. I wonder if there is an "RB26 For Dummies" out there.

Did I hear you say ~550whp with the stock rb26 at 18psi? again.

Sad to say this is becoming a yearlong project. Things still left to do that I can think of so far. fab/install intake box fab/install bpv flange and install bpv fab or buy exhaust system mount injector resistors, battery, boost controller, horn fab/buy/install throttle linkage buy/install odo linkage wiring... Months. It would take less time if I was set on doing everything myself or money wasn't as much of an issue, but on the plus side, going though my dad means that whatever we make ourselves or misc parts he can bring me home from work doesn't cost me anything. So far it's wait time v. spend money, and the former is winning. Still, I want my car back! I forgot what it's like to drive it! It's been non-op way longer than it ran. Probably the story of most of our lives though, right? When I finally took it off the jack stands I was like wow, I don't remember it being so low to the ground! The car looks so much smaller now. I was at Autozone today, looking for little parts even though I knew they never have anything I need, and I told the guy, who is an import lover, I was building a car to compete with the 2j and all he said was, "Good luck."

I am positive that the bov would route air actually just upstream of the turbo inlet, because you want to equalize the pressure on both sides of the turbo. If it routed downstream of the outlet, the bov would basically be feeding itself the same pressure i was under so nothing would happen. I guess in light of this information, I'll have to buy a bov and tap it into the elbow just before the collector. If I had known ahead of time, I might weld it right onto the collector itself as there is much more room. Nevertheless, there are two control lines on the original setup, and two valves, so it would seem that the pressure is bypassed on either of two conditions, but I'm not sure why. I can't figure out for sure where they are going but will post my hypothesis to see if it makes sense to anyone. Both valves according to the manual are set at the same vacuum control reading ~3psi. The lines at the arrow in the top picture are confusing. One goes right into or behind that T-pipe and to another hose towards the collector. The other is unknown. The arrow in the bottom picture is where I think one of the control lines ends up on the aac. I can't figure out where the other one goes or if it in fact goes right into the t-pipe, but even then I don't know why it would do that. The fact that there are two valves could mean there is just a redundancy or a fool proof type safety measure. On a side note, look at the bottom picture at [Point 7] The tube that the arrow is pointed to is described as the booster line, so that will go into my vacuum canister for the brakes. The tube directly in front of it is unlabeled and I have no idea what it does, so it's plugged for now. On the engine it sticks straight up just outside of the collector, while the other sticks up between a gap in the rear throttle bodies. Here's an alternate view of the aac with lines connected and the funny wording of the manual. I can't find anywhere in the manual that says what anything does, just how to remove and inspect it.

Andy: Why is your current setup venting upstream of the mafs? That seems kind of strange, I don't know if generating a lot of heat around the mafs is an issue or not. But like Daeron said, every time you close the throttle, the ecu is probably going to get confused because the excess air is still counted and in turn will run the engine rich until it is rescheduled on the lean side. And true, venting upstream of the intercooler would make it run through the turbo twice without being cooled and thus generate more heat, while running the air through the intercooler twice will only help cool it more. Although I'm not sure how little air we're really talking about here--it's probably almost a moot point. Still, you'd probably be better off venting to atmospheric than into the mafs. The recirculation system is designed for emissions regulations and to keep the air count accurate. Daeron: So basically I need both then? Again, I always thought bov's were to regulate pressure consistently, like if you had a fixed wastegate. But then I thought that would be wasteful because you're still spooling the turbo when you don't need to. However, it wouldn't be all that bad because if the pressure is dumped then the turbo isn't really under any load. Nevertheless... Anyway, the recirculation valve is just like a non-atmospheric bov, only not spelled the same? I don't want to wear out my turbos or anything by surging every time I release the throttle! My r32 doesn't have the ball bearing or the steel turbine, so I'd basically be screwed.

I figured the recirculation system should be just for emissions. I've never dealt with them before. It was the funny wording and vacuum diagrams in the engine manual that got me. My main curiosity was if what I speculated was true--like you said the ecu must calculate for this recirculation, otherwise the mas airflow count would be off. Do you mean however that a bov creates a rich condition rather? Since the ecu thinks there is more air going in than there actually is and schedules too much fuel. This would explain why it would be better to have the bov recirculate to the intake. Might it also be why people get map sensors instead of maf? I did more reading on bov's, which proves difficult because everyone uses the term loosely and interchangeably, but I saw that the main reason is to prevent compressor surge on the turbo, and recirculating the air should be the best way to do that. Plus it keeps the ecu more on point with the maf sensors. Also, I HATE turbo chatter! And bov hoots are disgusting in my opinion. In this light, I don't see how the wastegate could prevent a stall, it seems that they are for different purposes. I'm just thinking out loud here, I seem to have been misinformed about people installing a bov in accordance with a fixed wastegate. Still, most of the things people call bov's that I see look more like plain old dump valves.

Oh, I wasn't sure which way the line flowed, I just new it led to the turbo controller. I took a guess and figured it used venturi to get a live relation between how much the turbos were taking in versus how much they were putting out. My chart looked like it said "vacuum sensing line" but it could have been overlapped because all I was looking at was the overhead view of the engine. So that Y shaped hose in the center there leads to the front of the front turbo and the hole in the air hose of the rear collector? Then the hose I have going to the turbo controller comes off the needlepoint on that tiny hose just above center in your picture? One question about the recirculation system though. Does having a recirculation valve mean that the wastegates don't unload the turbos completely and subsequently there has to be a blow of system downstream to dump excess pressure? I was under the impression that I wouldn't need an inline bov until I increased the boost or went to aftermarket turbos. I'm still very new to the concept...

It's kinda hard to tell from these pictures but when installed that fitting connects to a vacuum line rail that wraps around the back of the engine. That particular vacuum sensing line is one of two lines connected to the turbo pressure regulator, which is labeled PCM Valve. The valve itself seems to have evaded the camera in all my pictures so far, but I can take one of it tomorrow if need be. Originally, I believe there was likely a plastic or rubber hose that went where the plug now goes which bridged the intake lines between the two turbos. (If you saw my modification of the front turbo inlet into a straight pipe, the original inlet pointed off to the side and out of the top was a port about the size of this aluminum plug where the other end of that hose connected as far as I can tell from the engine vacuum diagrams.) Somewhere on that hose was an outlet to this vacuum line. For some reason I only got a piece of the hose and insulation foam with the engine where it was cut and have yet to see anyone else's pictures with it still intact, most likely because they go with aftermarket intakes altogether or at least an aftermarket boost controller that makes this line obsolete. I figured at least for now it would suffice to have the line go into one turbo and assume both are operating at roughly the same capacity. If anyone has any insight into the matter, chime in! Are there any skyline owners in the forum?

I have pictres, too many, they probably explain themselves. Some of it has been discussed previously but I didn't have time to add pictures until now. I'll rant more in the final writeup.

I've always been curious how long track tires would actually last on the street with mostly nondestructive driving, ex. burnouts in front of in-n-out... Soft tires are kinda like invisible horsepower too, and both good tires and lighter chasis add all kinds of fringe benefits. Who wants to help me make a carbon fiber/titanium 240? The one thing I hate is when ricers completely gut the car to outrun people. Now THAT's cheating. Having a lightweight spaceage unibody is sweet, taking a 1985 POS with a 1.6L and removing everything down to the mirrors and antenna is just bootleg. A car without a passenger seat isn't exactly what I call streetable. ...But is a car with drag meats in the back and dimes in the front technically streetable? Hmm, where to draw the line...

LOLZIES!

Those louvers I like. I want some. Locking?

I thought it was just further weight and balance adjustments. I could be wrong. Still though...

I haven't been around in a while so just a quick pathetic update. I drew up the plans for my air cleaner box off the styrofoam model I carved up using the 6x10 filter I ordered. It was $45 but I got 10% off and a $15 rebate. Just waiting for my dad to get the free time to tig it. Other than that, I have pictures, but there's not much to see, I connected all the fuel lines finishing that part up. The radiator is finally connected but I still need to get a new overflow box (smaller--the one I had was already a generic replacement) and find a spot to mount it. I might do that tomorrow. The intercooler is disconnected one last time for the placement of the air box. It will pretty much go right in smoothly (I think) with a few more silicone hoses which I'll order after double checking with a fitting of the real box once it's made. Also my dad is going to seal up a 6" aluminum tube to make the vacuum bottle for the brake booster. I'm really saving some money on all this welding of scrap pieces. Plus it will all look pretty nice together anyway, so I'm happy with the progress, just not the speed at which it is going. I want my car back! I'm already planning all my interior work with the money I made fixing another car, plus that little tax break, and a website I'm working on. It's going to look niiiiiiice! Eventually. Cheers!

Wow. I should have taken a trip to NZ. Yeah, don't know about that l20 though... It the aftermarket parts follow the same trend, the RB30 is definitely worth the extra $200, or you'll regret it later.

Are rb20s cheaper over there and have more aftermarket support? Again the situation over here is that the sr20 makes loads more sense because it actually produces more torque and can rev higher. The only thing the rb20 is probably better at is long term potential, but that's thousands of usd away anyhow. That is unless of course they are a dime a dozen in nz... Careless' idea makes more sense, find an rb30 block in the same condition and do just like you said, forget salvaging an rb20 block.