SleeperZ

Initially, you won't need a BOV. When you add an IC is when you may want to add a bypass valve if you are still running the stock ECU. The DSM unit works well. You can get 250 to the wheels with the stock ECU and injectors. If you are shooting for 300, consider an aftermarket (standalone) ECU. The stock injectors and pump will not be adequate at that point. You cannot push the stock turbo past it's capability - it just becomes a hairdryer at that point. If he's getting only 250 hp at 20 psi, he needs a better turbo - I get that with a hybrid T3/TO4 running at 14 psi (12 psi at sea level) and an intercooler. That's my next point. Get a good one. Don't skimp. At the very least, an NPR will work, but if you are serious, get a Spearco or a Bell.

I was wondering what the heck this thread is all about. Has someone P.M.'d Stony to let him know? That really sucks there's so many jerks out there who have to present a ripped-off image as themselves...

Oh man, I love those late '60s early '70s Chevy trucks. I drove my Dad's '72 shortbed to high school occasionally, and my first street race was against a friend who thought his 4 banger Capri was the $hit. Needless to say, he lost bad...

Heavy, you make some compelling points, and articulate them well. Guys, this is an excellent example of a highly polarized, yet extremely disciplined discussion. I am rarely disappointed by these off-topic (of Z cars) discussions.

I believe the pump is mounted where the AC compressor mounts.

That is so funny. Those turbodiesel trucks can be very fast for their size. I drove my Z to work last week, and one of them tried to race me. He actually was pulling very hard - I'd floor it and pull a few lengths and let off, he kept coming, I'd pull on him again, probably got up to 90 in the 55.

Sure they did. 4 banger, L16.

Is your flywheel a 2+2 or a turbo? I remember Lockjaw saying something about having to remove material from the inside of the bellhousing to clear some version of a pressure plate, like a Z32TT unit? Maybe I shouldn't second guess here, as I've always used stuff specifically for 280ZX turbo, and have not mixed parts from anything.

You can remove the valve on the intake with a plate, but don't forget to block the hole in your exhaust manifold too.

Yeah, the ignitor thing, sounds right. That's the nice thing about the Z31 ignition though, just pick up another at the pick-n-pull for $10.

Sounds like a sweet little swap!

Are you sure you aren't talking about an EGR valve? When you say dump pipe, are you referring to the exhaust?

I've wondered that myself. When I was using the stock turbo manifold, I never had it hooked up, and never gave it a second thought.

It sounds like you have the right equipment to do what you need to do. I think you can probably implement what you are proposing without a lot of trouble. I would still be cautious about using a fuel cut, and would look into cutting ignition as well, like a Nissan ECCS. I highly doubt you will overspeed those turbos - single T3, yes, twins, no way - it sounds like a good match.

The computer has no idea what manifold pressure is (I'm assuming factory ECU?) And fuel cut is extremely dangerous, especially at high boost - you could get instant detonation if an injector does not cut off cleanly - killing ignition is safer. If you really feel uncomfortable with your boost controller, modify the popoff valve. I added a 200SX spring inside my existing popoff, and got a full flow popoff at 12 psi.

I got charged a good amount. I got rolled for new turbo rockers, and I sprung for a new cam and valve springs (Schneider turbo cam, single spring). New lash pads, reground the valves and seats, new guides and seals (I believe), resurfaced the head, and just the minor valve unshrouding work set me back about $1500.

Sounds to me you are looking for an L28ET, stock. Just add intercooler. Easy to install, not very expensive.

My head builder did some valve unshrouding around the exhaust valve.

It's a sad state of affairs - I heard the Lynch story was staged on the BBC, and I never heard that from any US news source. I heard the timing was perfect to coincide with waning US public support for the war once we engaged and became bogged down going to Baghdad.

I think I'm the one who coined that. I'm operating under a few assumptions here: Turbo motor, ECU that measures airflow directly, and a lean condition under maximum boost/maximum RPM. I'm also assuming the lean condition is a result of maximum injector duty cycle reached (which may not be the case - the airflow meter may also be saturated.) Under that condition, a RRFPR is installed to correct the lean condition at maximum RPM/maximum boost. Since your fuel pressure will be boosted higher according to manifold pressure only, and not RPM, at lower rpms and maximum boost, you will be too rich. From my own experience, and most street turbo setups, maximum boost setpoint is reached by 3000 or so RPM. Redline is 6000-6500. Result - you will be slower from being too rich just to save your motor at the topend (not that saving your motor is a BAD thing...) And it will last the whole time you are trying to go fast once you hit boost. My recommendation - turn down the boost slightly until you can tune the car properly with bigger injectors.

The Weber throttle body is an excellent item. Why would they sell a breather if it wasn't the right thing to do? The answer seems obvious, so they can make money, and if it works for you that's fine. But the fact of the matter is the factory ECU was not designed to operate with large vacuum leaks, such as an open breather, and you may not get a satisfactory idle or off-idle response. Other than that, and your state's emissions concerns, I'm sure it's no big deal.

Setting the timing is easy. Just make sure you are at idle, and the TPS contact is closed. Then loosen the distributor and turn it until the timing light shows the TDC mark at 20*BTDC. Tighten the dizzy down and you are done.