SleeperZ

Just to be argumentative, and not leave Oltmann all alone here... EFI vs. carb, if you are taking in the same amount of fuel, the same amount of air, and completely vaporizing the fuel, you will have cooled the air the SAME amount, regardless of the position of the piston as it starts the compression cycle. I know, I have no amazing or irrufutable credentials, but I did pass a college thermodynamcs class, so I believe I have a clue about what I'm saying (but no experience with carbs - and experience counts for a large amount, I know that). In addition, if the vaporizing fuel is cooling your intake manifold, you are actually gaining heat in your intake charge, and the EFI will in fact be cooler than the carb system. We may agree to disagree, and in the end it won't matter, but I think it's a good arguement.

I as well am doubtful about a cooling advantage the carbs are claimed to have. If the air is cooled by the evaporating fuel in the venturi, one would expect the same from an injector spray (even if it is closer to the cylinder). Once the "stuff" gets into the cylinder I would think it's all the same temperature, as there is no net heat gain or loss - the only exception is an intercooler on a turbo, where you actually are removing heat from the intake charge. If my thinking is in error, please correct me.

I agree with Lockjaw on the hard pipe thing. My IC only has 2" inlet and outlet, so to minimize pressure drop and length, I ran 2" from my turbo to the inlet, the the outlet expands from the 2" to the 3-1/4" on my TB ASAP. Here is a picture of my install: My throttle response seems even better than before the IC install. BTW, I used steel - it was cheap - and I just got the pieces back from the plater with a black anti-corrosion oxide finish - they are not going to rust on me.

I used the cheesy 1/8" pipe, but there is no flow in the tube, so SIZE DOESN'T MATTER (in this case )

Twin turbos on THAT!!! No shadow could stick to a car sporting that powerplant!!

Ron - I am still using the stock 280ZXT fuel system (injectors, pump, regulator). I am running a V trim T3/T4 hybrid, intercooled, at 12 psi with no indications of leaning out. As soon as I can get out to the strip, I will be inching the boost up and find out where the fuel system limit is. I don't intend to just throw fuel at a stock ECU - just adding injectors or changing fuel pressure will screw up the drivability and my fuel mileage and emissions. When I run out of fuel (injector), I will first try adding unmetered air to balance the extra fuel, and fine tune it with the MAS. Ultimately I intend to reverse engineer the ROM code in the ECU and write my own fuel and ignition maps (I'm cheap - why pay JWT $600 for something that is close but not quite right?).

I cut my 280ZX harness to shreds, but I didn't crack the case of the Z31 ECU. Different path, same result - that ECU really knows how to stroke the L28ET the right way.

As for myself, I'm brand-blind. When stock don't cut it, for me, usually Nissan stuff bolts in better, as the car was originally Nissan. As for an Infiniti swap - that would be way cool - but I wouldn't go out of my way 'cause it sounds like a real bear of a swap. And I'm with you Lockjaw - it is way cool to kick around the V8s with a "stock" 6-banger (at least the heavy V8s, a V8 Z is a tough one to beat).

IMO, if you are really stuck on that POV (POS), the best way to make it work is put more spring in it, not washers. Every washer you put in there will limit the travel of the plunger - I found with mine it would not keep 12 psi, the boost would rise as RPM did (hybrid turbo, not stock). Also, it was quiet so I couldn't really tell when it was venting. The spring from a 200SX turbo POV worked very well, and if you need a little more margin, the POV can tolerate 1 or 2 washers.

Exactly, cold, like I noted. There is about a 0.002" difference hot to cold, and hot clearance is 0.006" for intake and 0.008" for exhaust.

Assuming you have spark and fuel , the timing is all it can be. Check the cam timing (cam mark lines up at TDC with #1 valves both closed) and the distributor timing according to the FSM (engine at TDC, oil pump mark lines up with the dizzy shaft, dizzy half moon at 11:30 to the left). Are your plug wires attached to the cap in the right order? I just got my swapped motor running, and followed these guidelines and it fired right up. MOF, my ignition timing was DEAD NUTS on, I had no dizzy adjustment at all. BTW, your valve adjustment is quite loose, but it will not keep the engine from firing. Cold, the exhaust should be 0.010" and the intake should be 0.008".

1 wire is enough.

I am using the strut bar from Top End, that connects the strut towers together and to the firewall. It is very rigid and lightweight, and required only a little bit of fab to connect to the firewall. I was a bit concerned with the thin material that forms the lip at the top of the firewall, so I took a 3' length of bar stock, 3/4" x 1/8", lays almost perfectly in the top channel, and drilled through it to the tabs of the strut bar. It seems very rigid now to the firewall - no complaints on this one. No heim joints, no stainless - it has a nice black powdercoat, but it's not show quality, suits my application.

Just my $0.02 -- you definitely don't want to thread into aluminum unless you heli-coil it, and I'd still hesitate considering the application. You have to have it machined anyway, so use a good steel for the disc.

The remaining wire has to go to the coil - probably the minus, the typical place to hook the tach and measure RPM.

BTW, I think the swastika wheels are 10mm offset, like the 6 spoke 14"x6" ones.

i believe they are the same as any L series head. 0.008" cold/0.006" hot for the intake, 0.010" cold/0.008" hot for the exhaust.

With Scotties link to the Excel program, and my timeslip ('78Z, '83 L28T, 12 psi), my 0-60 is 5.36 seconds. Not too shabby for street tires!

Pretty sure you won't like 3" on an N/A, and guaranteed when you get a turbo you will have to redo the exhaust anyway, because the downpipe is in a different location than a header. I use a 2-1/2" exhaust on my turbo (T3/TO4, 12psi intercooled, 13.6@102) and I have no spool problems whatsoever.

So....how about the rubber boot between the AFM and the turbo? I had a big leak there and it ran like crap, but it wouldn't idle either. Your issue can only be caused by one or two things (already mentioned), so swap an ECU and see if that fixes it, as the TPS signal could be messed up inside the box.

Very interesting stuff about the stock turbo cams. The one I'm using now with intercooler and 12 psi really seems to run out of breath over 5000 rpm, especially compared with the cam in the P90 I ran last year. The turbo cam (Schneider) would pull hard to redline - I hit the fuel cut on the ECU many times. BTW, the specs on the Schneider I used last year (and will again, soon as I swap off the head) is 114 degree lobe separation, with intake/exhaust duration (0.050" cam lift) of 240/230 with valve lift of 0.460" (intake and exhaust). I'm really happy with the cam now that I've compared it to factory. Of course the cam needs special lash pads and springs along with valve geometry re-setup.

You will have quite a bit of tuning to get the stock Z ECU to run the turbo motor. It is used to spraying some pretty weak injectors, so you will have to swap in some turbo injectors (or bigger), then somehow get the ECU to back off on the duty cycle so you don't foul your plugs when you are not WOT. You will run PIG RICH until you get that under control. IMHO, swapping in the turbo ECU and harness is not that big of a deal, and the result is a smooth-running factory turbo system that is ready for upgrades. A better platform.

The flapper will open more under load than not. The engine is consuming more air under load (producing power) than when you are not moving the car, so you will get more deflection as more air is drawn - it is not particularly RPM dependent. Still sounds like a shorted idle TPS contact to me, either at the TPS or in the ECU. The reason you can run the RPM past 2000 RPM is the engine is not loaded and is not consuming the fuel - I believe the TPS at idle will limit the fuel to a small amount, and this is enough to propel an unloaded engine to any RPM, but under load - cough! pop! sounds lean and no power. The Z31 folks will tell you AFM, but the flapper ECUs are different, and may not exhibit the symptoms, but I don't know that. Disconect the TPS connector and leave it off. You can also try measuring for continuity through the open connector.

If it's a T3/T4 hybrid, you have the stock exhaust housing. I don't know much about A/R on the compressor side but I just researched my compressor -- knowing it was a T4B, I took off the snail of the compressor and measured the inducer and exducer diameters and compared them to the dimesioned wheels on the turbonetics website. I was able to positively identify my hybrid as a T4B with the V1/V2 trim.