Entering the world of "Hybrid"

[Ben's Z]

Greetings, I believe this is my first post. I own a 77 280z and I am probably going to purchase an '83 280ZXT tomorrow for the motor. Presently the owner said he cannot get the engine to run, but it did turn over last time it ran. (6 years ago). My goal is to get the car running decent then pull the motor to put in my '77. I am going to pull my stock motor when the car goes to paint in January then place the Turbo engine in after paint. I think ultimately my goal is to have around 250RWHP from this engine. From browsing the net it seems the best way to achieve easy power, is to up the stock boost to around 10psi with a manual boost controller, 3"inch exhaust a T3/T4 hybrid turbo. I know with an IC higher boost levels can be achieved to around 12psi, but then the ECU and injectors start to become the limiting factors. I know about the brown top Ford Injectors and it seems like the z31 or s31, whatever it is ecu is a nice upgrade over the stock 280zxt ecu.

 

Presently the parts cars has no starter, so I am crossing my fingers I can at least get it to turn over.

 

Any other suggestions before I take on this task?

 

Here is my car. BTW the parts car has Swastikas with what I am told is good tread, they will replace my awful hubcaps.

Edited June 18, 2011 by Ben's Z

[Gollum]

For 250 wheel HP, you can certainly get away with the stock EFI setup, but just as long as you know that you'll be leaving some power on the table, and also leaving some economy on the table as well.

 

I'd leave the turbo stock unless it's needing to be rebuilt, then you might as well find a T3/T4. The stock T3 will make all the way up to 300 wheel hp when forced with a decently sized intercooler and plenty of fuel.

 

My recommendation though, is to leave the injector stock so that you can still get good economy, warm up, and low end driveability. Use a rising rate fuel pressure regulator, and don't buy one that's a fixed 1:1 ratio. Buy one that can be adjusted via adjustment washers, because you'll most likely want something more like 3:1. Running just 10psi can get you to your goal if everything is running right. It'll just be a matter of getting it on a dyno with a O2 sensor so you can tune the RRFPR for full boost conditions.

 

Don't **** around with adjusting the air flow meter, or adding resistors to the coolant temp sensor. Those are good ways to just get everything out of whack and turn your EFI system into a crude digital carburettor. Both of those can be used as tools to fine tune, but for such modest power goals, I see no reason to go screwing something up.

 

And also, if I recall correctly, the ECU for the L28ET has maps that go to 10psi stock and won't hit a brick wall, so to speak, with injector duty cycle, when going beyond 7psi. The main reason you'll be wanting to dyno tune with some adjustability is because prolonged duration of 10psi might require more fuel to keep the engine from detonating, and with modified exhaust on the stock T3 you might be hitting 10psi much sooner than the ECU would expect, which could cause some tuning issues. Overall it's a well designing map for it's day and can take some abuse. You just want to make sure it doesn't blow up.

 

Also, just plain don't use the knock sensor. Pretty much all of us with the stock ECU just leave it unplugged.

[Ben's Z]

I got this information from a member here and over classiczcars.com

 

Do you concur with this suggestions?

 

The stock fuel system (other than the pump) can supply enough fuel for 270rwhp, (around 12-13 pounds of boost) However, to flow that much fuel in the stock system, you need to cheat and get the fuel pressure to rise as boost rises. The Begi regulator, and the Walbro fuel pump can do it reliably. The beauty of this setup is that is runs EXACTLY like a factory bone stock car, until you get above factory (7psi) of boost. The Begi regulator does nothing until you get into higher boost. I climbed my fuel pressure up to about 65psi of fuel when the boost hit around 12psi. I actually set it up with a bike pump. With the car at idle, the fuel pressure just sits at factory spec. I pumped air into the Begi (12psi) and observed the fuel pressure rise to 65psi. It's adjustable. You fine tune the fuel pressure rise with a screw and you adjust how fast the fuel pressure climbs with a bleeder screw on the unit. It's very mechanical, low tech, reliable, and runs like the factory car.

 

The ECU upgrade is more elegant and has more tuning potential. But the Begi way with the stock ECU is set it-forget-it reliable. You will not be able to extract much more than 270rwhp with the stock ECCS though. That's about all the injectors can handle. Your torque will fall in the 300ft-lb range with that setup.

[Gollum]

Yea, that's basically the advice I just gave you...

 

But what I said regarding power and economy are still true. With a fully programmable unit like megasquirt you'll end up getting more power per PSI of boost and better economy off of boost. Either way, you'll want to tune your RRFPR on a dyno once you've gotten it into the ballpark. Last thing you want is to have it running a bit lean under boost and think it's fine, but then have a severe detonation meltdown first time you go racing on a hot day.

 

And I personally believe that an aftermarket pump isn't necessarily a "requirement" for your goals. People have made 300 to the wheels on the stock pump.