SleeperZ

I've been there, have an account. Sorry, the knowledge and experience pales in comparison to here. And the purists there run rampant.

That's a good idea Garrett, and that's how I knew my old pump was not providing enough flow at pressure. If the regulator is stuck open, you'll not see much fuel pressure at all. More likely it's just not responding to manifold pressure. You should see fuel pressure rise with boost, exactly 1 psi per pound of boost over your baseline pressure. Yes, for a factory ECU that measures the air. All that is needed is to match the mass of the air with the appropriate amount of fuel. Anything else is a bandaid. An AFM "swing door" approximates the air flow, and with preset corrections, it is calculated to an equivalent mass. It's not very accurate, but it works to a certain degree. The Z31 unit measures air mass, and fuels dead accurately. That's exactly what I explained above. Maybe you need to re-do your math; it's the real world results that count and the math's job to explain it. There are more than 5 people on this forum that have made 300hp with stock injectors and fuel pressure, and safely, so you telling me it can't be done carries no weight.

Good one DAW! Had me going there for a second!

Search. This topic has been extensively discussed, and the answers are all in previous threads. Even Zcar.com has most of the answers on his topic.

Lol! With those "small" injectors I ran a 13.2 @ 104. 14 psi boost, better known as 12 psi at sea level. The factory stuff is great for moderate performance levels, and you don't have to be rich or a genius at rewiring or tuning a stand-alone.

Is that real? Frightening!!

The chain tensioner easily has 1/2" of travel, if not more. You are saying it cannot tolerate 0.080" of extra length in the chain? I bet the chain "stretches" that much from old to new.

No, please don't turn Jesse onto the Z car. He'd probably make something stupid out of it, like a boat or a lawnmower.

No, because it's on the other side of the throttle from the potential leak. The engine will pull the vacuum it needs, regardless of whether the air is metered or not.

You can see from my sig I am putting 419 torque through mine, and I run drag radials. Shane (a racer local to me) ran a T5 with slicks and high 11's for several years. That 240 was running 400+ hp. The only issues with the T5 seem to be shift fork related, and that can be remedied with a good shifter with hard stops.

Why not bolt up a starter motor to it and carry in a fully charged battery? It's the bell housing that has the starter threads, correct? Just get some nuts and attached it. Make sure the engine has oil in it, and do a compression test...

Is that the basis for the Supra joke: "What do 400rwhp, 600rwhp and 800rwhp Supras have in common? 12 second time slips!" It's a fine theory, but everyone knows the Supras suck at launching. And some of it may be that peaky power band.

Yeah, I don't think taking a vacuum reading will tell you if you have a leak. The engine is going to draw the intake down, regardless of where in the intake it is. The only place you will see a vacuum leak from a measurement is if it's after the throttle, as it's the throttle that the engine works behind to create the vacuum. Double check the all the connections between the AFM and the throttle, especially after the turbo compressor -- that's what will cause the engine to run lean off-boost and rich on-boost.

Search the threads in this forum with your goals in mind. All the answers for your questions I guarantee are here. If your goals are a modest 300hp (crank?), you don't need any fuel system upgrades except perhaps a pump. Stock turbo, and a modest intercooler, maybe a bigger exhaust.

Now I won't get to see Terminator 4 anytime soon.

All I can say is "good luck", and I hope it turns out like you want.

That's how I would initially adjust it. as you are using a boost controller to drive it. You can always go tighter, but keep in mind you don't want to lose the full travel of the wastegate flapper (at least where you would get boost creep).

Looks like the exhaust flange is different. How will you bolt up a downpipe?

Yeah! That is a bada$$ Z31.

You'll know it. It sounds like gravel. And I got it with a heat-soaked radiator, 200*, at 16 psi. No way will you have it at 8psi, unless your FI or fuel system is not performing.

My impression was this "keep the valve open longer" trick occurred much later following the intake stroke, where you would lose the inertia from the intake, and actually have flow back out the valve. Correct me if I'm wrong, but that doesn't seem to be flow efficient - and for maximum power out of an engine, you simply try to put in the most air (and fuel). I'm looking at my turbo cam spec card, and the intake valve actually closes 52* ABDC (at 0.050" camlift). And I know that flows up high - it loves to spin 6000. If it made more power by delaying the valve closure even further, wouldn't they have done it, instead of stopping at 52*??