Sean73

Audis, Porsches and Saabs use the same OEM Bosch valve. So there are a ton of aftermarket valves that can replace that one without mods. Perhaps some of the aftermarket valves can be run open to atmosphere like you want. Also, try reversing the valve, plumbing it backwards and see what happens. Try searching on http://www.saabnet.com, also http://www.s4biturbo.com/art-dvtests.shtml has useful info on the bosch valve.[/url]

Did you check the start signal wire?

1) Without the O2 sensor, you're engine cannot ever go into closed loop mode at cruise and part throttle conditions. So, the ECU is probably defaulting to some type of limp mode or default program. So you have an A/F gauge? Although A/F gauges aren't accurate enough for tuning, one thing they do tell you is when your ECU is in closed/open loop. This information can be handy for diagnostic work. 2) Without the TPS connected, the engine is unaware that it's idling, and therefore, the ECU is probably reacting similar to #1, and explains why your not idling well. 3) You could be running too rich because the ECU is seeing start signal all the time. I've heard about this with many turbo swaps, where the start signal wire is hooked up to ignition positive, causing the the ECU to run rich all the time. Ok, you've said that the engine idles even worse with the O2 and TPS connected. Have you checked your CHTS? A bad CHTS could be causing an overly rich condition at idle, and then with #2 or #3, it gets even more rich, causing the engine to idle worse. First thing I would do is check the CHTS, and see if it's within spec. If so, hook it up. Check the TPS with an Ohm meter, and hook it back up. Check the O2 sensor for fouling, then hook it back up. Check wiring for proper start signal. Check all of your groung wires too. All of the tune-up stuff you've done is good, but with sensors disconnected, the ECU really can't, and won't do it's job. Good luck. Sean 73 240Z, L28ET, T3/T04E, NPR IC, Z31 ECCS

tbs When you say 14psi @ 4K RPM, what gear are you in? What's your gearing? I am running a T3/T04E w/ 57 trim compressor. I am not running 14psi yet, but I would say 3.5K-4K RPM is right around where I get full boost in first gear@ WOT. Usually, I am going too fast to have time to notice exactly when I get full boost. During normal driving and easy acceleration, sometimes I'll get no boost at all in low gears. In higher gears, the boost comes on sooner. I think it's a normal compromise of having a bigger compressor. If you're using a bleeder-type MBC, that could be causing some turbo lag as well. Sean 73 240Z, L28ET, T3/T04E, NPR IC, Z31 ECCS

In case any of you are tempted to use the Z31 CHTS instead of the 280ZX CHTS, I don't think it will work without mods. The Z31 CHTS will screw right into the L6 cylinder head, but it has a slightly shorter probe, and I don't think it makes good contact with the cylinder head (that's my theory, atleast). My car was running rough with a brand new Z31 CHTS, but when I switched back to the 280ZX CHTS, the problem went away. From examination of my Haynes manuals, it looks like the 280ZX CHTS and Z31 CHTS have the same (or similar) resistance values, so for now I will be using the 280ZX CHTS in my L28ET powered by 84 Z31 ECCS. Sean 73 240Z, L28ET, 8.8:1 CR, T3/T04E, NPR IC, Z31 ECCS Breaking in the rebuilt motor @ 6-7 psi.

Let's see, you need a custom manifold, custom downpipes, custom inlets, custom oil/water lines, and lot's of other unforseen engineering that will be required to make those used T25 turbos work. If you do all the fabrication yourself, I think you'll spend atleast 1-2K in parts and raw materials just getting it to run. I think a twin turbo L28 is cool, and I envy those setups, but I wouldn't try to build one on a budget.

You said that you wired the wastegate open, but I don't see any reason for that test, since you'll never get boost that way. Wire the wastegate closed and go for a very careful ride while closely monitoring boost. I recently had a bad wastegate actuator on my rebuilt turbo. It would boost to 6 psi, then drop into a vacuum immediately. I did a test with compressed air, and found that the actuator was not responsive and very sticky. I trashed it and installed a oem nissan actuator, and now I boost fine. Also, once the actuator arm is bent, I think you're in for a world of problems. The behaviour of the actuator is very sensitve to the tension on that actuator arm. If anything is out of alignment, loose, or too tight, you'll get unpredictable response. Sean 73 240Z, L28ET, T3/T04E, NPR IC, 84 ECCS

My Z31 ECCS-powered 240ZT is running great now. At the wastegate setting of 6 psi, the power is phenomenal. Since I'm using flattops, acceleration is good, even off boost. Here is my dilemma- I have about 50 miles on the new engine now. I was planning on driving the car to MSA (about 500 miles from Tucson to OC). Can I effectively break-in the motor on the freeway, so long as I vary RPM and load? In other news, I spent a couple of days chasing a ghost in the ECCS that was causing some rough acceleration. Turned out to be the CHTS. I find out now that I was using an 83 CHTS, which is different from the 84 CHTS. It runs good with the CHTS unplugged, but I am going to try and install the 84 CHTS and see what happens. My boost problem was indeed the wastegate actuator. Some compressed air quickly revealed a faulty "rebuilt" actuator on my T3/T4 turbo. Lesson- test your wastegate before it's installed! See you at MSA Sean 73 240Z, L28ET, 8.8:1 flattops, T3/T04E, NPR IC, Z31 ECCS, Bosch bypass valve, custom intake, custom DP and 3" exhaust, 3.7 R200, Griffen Rad.

Afshin- I am using the 300ZX harness and ECU. I mounted the ECU on the driver side kick panel. This resulted in a huge excess length of wire, so I trimmed each wire to fit the S30 engine bay, and spliced in new connectors. I also deleted uneccessary wires from the 300ZX harness. I am using the factory 300ZX relays, and a Maxi-fuse block to supply power. Update: Took it for another test drive. Having problems with boost control, and I suspect it's a leak. When I hit 6 psi, it suddenly drops into a vacuum. So, it boosts, it just doesn't hold boost. Hopefully it will be a simple fix. Also, I can't tell if my Bosch BOV is working. I used the same BOV on my Saab 9000, and it made a nice smooth woosh sound. On my 240ZT, it makes more of a fluttering sound when I let off the throttle.

Well, it's all together and running. It was a comedy of errors to get this thing to start. Here are some of the mistakes that I made: Engine cranks, but no fire, and I found these problems: 1) The distributor was rotated 180 degrees. 2) I was using the wrong CAS 3) The CAS chopper was upside down. 4) I neglected to feed battery power to my fuse block for the ECCS (doh!) Engine fires but won't idle. 6) Swapped ECU, and that fixes it. Engine idles but won't rev above 2K. 7) Suspected MAF. Tried 3 different replacement MAFs, and the problem persists. 8. Bad connections found in MAF electrical plug - spliced in new one. And finally, after fixing all these things that I thought I triple checked, it runs and drives now. I took it for a spin, and it is SCARY fast! For the first drive, I kept the boost down to below 6 psi. At 6psi it feels incrediblly powerful, at least compared to my old SU-carb L24. The sound of the turbo spooling is out of this world! Next step- tuning and a little more debugging. I'll have some pictures of the completed install tomorrow. Sean 240Z L28ET, T3/T04E NPR IC, Z31 ECCS

The wastegate actuator is just stock-type, nothing fancy. I did buy a special bracket that is adjustable for mounting it on the compressor, and had to make a funny looking actuator rod. I have the whole setup installed now, will try to post pics soon. I did post a pic of the whole car in my gallery. Help me please, I can't get it started! I have 7 days till the MSA show, and only about ~1hour per day to work on the car. I've got fuel and spark. Firing order is correct. No codes from the ECU. It starts up maybe for a second or two on cranking. I definitely have more tests to do, but am running out of time. I am going to swap out the CAS next and see what happens. Are you guys with Z31 ECCS running the Z31 CAS or S130 CAS- does it matter? Pyro- I thought timing was controlled by the turbo ECU, so there is no mechanical or vacuum advance on turbo S130s or Z31s.

Yeah, I am using the stock head gasket. I took Corky Bell's advice, and declared the stock head gasket good till 15 psi (intercooled, of course). Since I'm going to run out of fuel at 12 psi, I don't think the head gasket will be a problem for this stage of modfication, but we'll see.

Well finally I am posting some progress pics. Check out my gallery: http://hybridz.org/nuke/modules.php?op=modload&name=coppermine&file=index&cat=10218 Some info on my setup: L28ET, completely rebuilt F54/P90 Block with P79 flattop pistons (8.8 CR) T3/T04E Hybrid turbo Porsche/Saab Bosch BOV Jet hot coated stock ex. manifold with spacer to clear compressor. Custom 2.5" DP feeding 3" mandrel bent exhaust Isuzu NPR IC. Jet hot coated 2.25" IC plumbing. 1984 Z31 Turbo ECCS & flow tested injectors APEXI air filter and custom SS plumbing. Weber big throat TB Mallory low pressure fuel pump feeding custom surge tank Stock fuel tank modded w/ 3/8" feed Porsche 911 Turbo (Bosch) EFI fuel pump Bosch adjustable FPR Manual Boost Controller Griffin Radiator, 16" Permacool electric fan As of recently, I've installed the rest of the IC plumbing and intake. Amazingly, I managed to not make a single cut into the stock radiator support. I am making the final connections and hope to have it started soon for the MSA show. Will post more pics soon. After the break in period, I plan to max out the injectors at about 12 psi. I designed this swap to be easily scalable, and eventually I hope for 15-17 psi or more with programmable EFI. Sean

If I were you, I'd save your money for a better IC, that needs less mods to work with the Z. No matter what IC you use, chances are that you will need to replace the clutch fan with an e-fan. While you're at it, upgrade to an all aluminum radiator, because you're gonna need the extra cooling efficiency, since airflow through the radiator will be diminished by the IC. I'm running a NPR IC. I spent more money on plumbing, silicon connectors, and clamps, then I did on the IC itself (probably ~$300-$400). It took me atleast 4 weekends to successfully integrate the IC, radiator, and AC condensor into the engine bay, and build all the necessary bracketry. Had I known of all this trouble, I would not have hesitated to spend much more $$$ on an IC. Also, finding a place for the cold air intake was challenging, and required more plumbing, more money, and moving the grill forward an inch. I have a Z31 MAF, which makes plumbing a lot easier. With the flapper style AFM, I don't know how people do it. If you must use the GN IC, I would have both ends modified to run parallel with the core tubes. I would plumb it out from the J-pipe to the driver side of the radiator support, through the IC, then out on the passenger side of the radiator support., then finally to the TB. This plumbing arrangement isn't optimized for pipe length, but it does give you a little extra room on the driver's side to run a cold air intake. I'll see if I can post some pics of my setup tonight. Sean 73 240Z, L28ET, 84 ECCS, NPR IC, T3/T04E turbo, porsche fuel pump, custom surge tank, adjustable fpr, griffin radiator, 3" mandrel exhaust, R200, totally rebuilt suspension, stock brakes (almost ready to fire up).

I am almost ready to crank my L28ET w/ 84 ECCS and have a couple of questions. Afshin, can clarify how you hooked up the "burn off" wire for the MAF? I don't think that the S130 flapper AFM has a comparable function (correct me if I am wrong) , and I don't understand why your procedure calls for connecting the Z31 R/W wire to the S130 Y/L wire. The Z31 ECU also uses input from the speed sensor on the vehicle to run the burn-off function, and I wonder how to bypass or modify this to make the burn-off work in an S130 or S30 car. Also, has anyone experimented with all of the various flavors of Z31 ECUs (automatic, 5 speed, California, Federal, various years, etc...), and observed any performance gains by using one over the other? I have an automatic/turbo ECU from an '84 Z31, and I am stuck with it until a 5 speed turbo ECU shows up at the junkyard.

I need some 5/8" ID hose for my turbo oil drain, and need recommendations. The local industrial hose supplier has silicon hose (rated at 350 deg) for $6.00/ foot, and regular oil line (rated at 212 deg) for $1.75/ft. Both hoses seem inadequate to me, but I would like to hear your thoughts. My turbo is a hybrid T3/T04e, which is also water-cooled. The stock drain pipe is not an option for me. I need something that will work with a hose clamp. Thanks. Sean 73 240Z, L28ET, T3/T04E, NPR IC, Z31 ECCS (almost ready to fire up)

It might work, but I disagree with it in principle. Correcting a bad a/f curve with nitrous is just not good science. Fix the problem with your fuel system, then do the mods for high HP. You might have a leaky injector, bad sensors, bad AFM, incorrect wiring, etc.. etc..

yo2001 - what was your overall impression of the HKS S-AFR? I have one that I got cheap and I wonder if it's worth installing on the 84 ECCS and stock fuel system (except for adjustable FPR, and Bosch fuel pump). Did you use the EIDS? function that supposedly stabilizes rapid A/F changes and let's you run a BOV vented to atmosphere? Sean 73 240Z. L28ET, 84 ECCS, T3/T04E, NPR IC

I agree w/ Tony regarding AFR at stock boost. Have you ruled out a problem with your stock fuel system? I would run a dyno at stock boost, and see what happens. You could be compounding problems by messing w/ fuel pressure, adjusting the AFM, adding fuel computer etc., if your stock fuel system is not running right in the first place. By running a dyno at stock boost, you'll be reducing the number of variables, and have a greater chance of solving problems correctly. Also, at 10 psi, your injectors are at the threshold of being maxed out (if not already). It's true that some people can run 10 psi or more on stock injectors, but not all stock injectors are perfectly equal, especially on higher mileage engines. I'd assume nothing about the injectors unless you have tested them. I have found a high degree of variability in the turbo injectors that I have tested personally. If you still run rich in the mid-range at stock boost, then you'll know that you need repairs, not mods. Good Luck Sean 73 240Z: L28ET, 84 ECCS, NPR IC, Custom DP, 3" Ex., 3.7 R200

I used the Z31 harness, and mounted the ECU on the driver's side kick panel. This created an excess length of wiring, so I had to trim to fit, and install new connectors everywhere. A formal write-up is just too long of a project. Basically, I got the 73 240Z wiring diagram, and the 84 ECCS wiring diagram, and taped them together. Then, it became intuitive how the two setups would be merged, with only a few wires connecting the two. I replaced the 84 ECCS fusible link box with a maxi-fuse block. After pulling the 84 harness, I spread it out over the living room floor, unwrapped it, and checked, and labeled every connection according to the wiring diagram. This was a good exercise, and learning experience. The wiring harness is installed, and trimmed to fit. It's so nice not to have to install that flapper AFM, which is a tank, and takes up too much space in the engine compartment. I am just waiting for my downpipe to be coated, and I can fire it up. I'll let everyone know the results. Sorry not to be more of a help, but this is really a mod that requires a full understanding of the wiring, not a step-by-step recipe.

By disconnecting the O2 sensor, the ECU has no way of calculating the proper fuel mixture in closed loop mode. That may explain your overly rich condition at mid RPMs. I think you have to get the stock fuel system to run right, with the stock components before tweaking things like the AFM. I would buy a half-way decent O2 sensor (Bosch, Nissan) then check the other EFI items.

Since I am in the process IC pipe plumbing, I'd like to explore Tony D's ideas about IC pipe routing a bit further. I wonder what the effects of routing the cool side of the IC pipe in front of the radiator would be. I can see why you would not want the cool air to be re-heated, that's obvious. But how much re-heating could actually take place? An argument to the contrary is that the charge air is moving at several hundred feet per second (roughly ~250 ft/sec for a 300 HP engine and 2.25" pipe). Therefore, a column of air inside 2.5 feet of IC pipe is only exposed to the IC pipe for .01 seconds. Additionally, only a small fraction of the charge air would come in contact with the walls of the plumbing. Add to that a ceramic coating on the IC pipe, and I wonder what the effects would be. Of course, whatever the effects may be, it would seems to be amplified in slow speed driving, where the air velocity is slower, and underhood heat can build up. I don't know what the right answer is, and I would error on the side of caution. However, in my situtation I can see that it's logistically easier to route the cool side of the IC plumbing in front of the radiator. It's not too late for me to re-route.

I'm looking for a gasket that goes between the turbine and the downpipe. The turbine has a 3-hole discharge flange. Does anyone know of an OEM source, or should I just make one? What material should I use if I decide to make a gasket? I have a sheet of exhaust gasket (paper) material, but I don't think it will handle the heat. Sean 73 240Z L28ET, T3/T04E, NPR IC, 84 ECCS, 5 speed, R200, 3" exhaust.

I created a 2.5" downpipe out of aluminized steel. I will have it jet-hot coated to withstand the heat and keep underhood temps down. I put in an O2 bung, and used a 2.5"-3" adapter at the end of it to bolt up to my exhaust. I have one of those 3 hole flanges on my T3/T4 hybrid. I had to get a weld flange from turbonetics.

I see what you mean. But with the air regulator drawing air from the j-pipe nipple, the turbo is forcing air into the air regulator at all times, and I wonder if this hampers flow out of the compressor by creating a turbulant area. That's why I wonder about the alternative; running check valve between the intake boot and air regulator to prevent boost leaking out of the intake during the rare occasion that someone would run boost with the air regulator open.