Phyte Posted April 9, 2004 Share Posted April 9, 2004 I've got an L28et going in sometime around July, but the current L28 thats in my 74 260z is running kinda rough. I know the SU's are wearing out because they won't hold a tune for longer then a couple days. Since I'll be converting to FI with the L28et anyway, I'd like to go ahead and convert the current L28 to FI. I'm currently searching for a 75/76 gas tank, and I'll pick up a good fuel pump and run new lines. Basically what my question is, will a computer from a 75/76 work properly with my 74? I've already got a 75 intake, so I'll need a TB also. Anything else? I want this to be an easy conversion since I'll be replacing it anyway in a couple months. I just need my car to run better, and the gas smell is about ready to kill me. Damn carbs Phyte Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 9, 2004 Share Posted April 9, 2004 hmmm... but are you gonna be ready to completely swap the whole EFI system again when you get the turbo motor? While you CAN run a turbo motor on an N/A EFI setup, it's definately not the best way to go. You may want to think about finding a complete turbo EFI and swapping that in... though I have no idea how the N/A motor would run with that... I imagine that since it's still using an AFM to measure the air flow that it should easily supply the right fuel mixture for the motor... but once the AFM maxes out (somewhere between 4000-5000rpm at WOT, at least, that's where it happens with a turbo, probably not so early with the N/A since not as much air is getting sucked in) the motor would probably run rich as the ECU thinks you're running boost. I'm not sure but I dont think the N/A and turbo injectors are the same either... so you're looking at re-swapping a lot of stuff when the time comes. At any rate, you can wire any year EFI into your 260 or any carbed Z, up to and including the early 300zx Z31 EFI's. It's just a few wires you gotta splice for power, key-on, fuel pump and such. Quote Link to comment Share on other sites More sharing options...
Phyte Posted April 10, 2004 Author Share Posted April 10, 2004 Actually I'm not using the 83 turbo intake/ecu, etc. I've got a 75 intake, and if I get the computer from a 75/76 I should just be able to splice it in? I've already got a factory installed electric fuel pump on it, so I should just need the gas tank, intake, TB, and computer? Then when I swap the turbo motor in I'll aready have the gas tank and lines run and the only thing I'll have to "reswap" is the ECU. Phyte Quote Link to comment Share on other sites More sharing options...
mobythevan Posted April 10, 2004 Share Posted April 10, 2004 If you put something like Megasuirt in for the EFI you would learn all about EFI and be able to keep the same ECU/wiring harness/sensors when you swap the turbo engine in. Plus be able to program the ECU for either setup and any upgrades. Just another option. Quote Link to comment Share on other sites More sharing options...
Phyte Posted April 10, 2004 Author Share Posted April 10, 2004 If you put something like Megasuirt in for the EFI you would learn all about EFI and be able to keep the same ECU/wiring harness/sensors when you swap the turbo engine in. Plus be able to program the ECU for either setup and any upgrades. Just another option. Honestly man I work 90 hours a week with 3 jobs, and I don't have time to learn a setup like that. With my L28et I'm just looking at 10psi on stock everything else. Once I get this car done I'll just drive it around like that until my new business takes off then probably get a different daily driver and turn the Z into a track car. I've seen some pretty impressive numbers on hybridz with stock ECU. I can't remember who it was but they put down over 380 rwhp with the stock ECU. Phyte Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 11, 2004 Share Posted April 11, 2004 doesn't really matter which manifold you use, you should be able to use any EFI manifold on a turbo setup, though some would be better off than others. I am running a '75 intake manifold on my turbo motor as well, and am using the stock '82 Turbo EFI setup (with some '81 bits as well). Regardless of which manifold you run, all I'm saying is that the '75/76 EFI you're thinking of using would NOT be a great choice for running a turbo motor, though it can be done. And no offense to anyone but I highly doubt anyone was putting down 380hp on a stock Turbo or N/A ECU, unless we're talking a stock Z32 300zx twin turbo? I guarantee no stock '81-83 turbo ECU was able to make 300-anything hp to the wheels. And even less like than that an N/A ECU.... Who would bother with megasquirt or whatever if you could? Everyone'd be running the stock EFI..... Further, there are big differences in the different wiring harnesses, especially between N/A and Turbo setups. If you install the '75-76 ECU, you're going to be using an N/A wiring harness, probably from around the same year. With that wiring harness installed, you couldn't get away with just 'reswapping the ECU'. Your '75-76 wiring harness wont even plug into the turbo ECU (N/A computer has one plug on the ECU, turbo has three small plugs), hence you'd have to rewire in the later turbo wiring harness to run the turbo EFI. As far as I know you can't mix and match even the different year turbo harnesses (I think you can swap the '82-83's... '81's are different though). That's why I'm saying you should just wire in a turbo ECU and wiring harness right from the get go. Quote Link to comment Share on other sites More sharing options...
Phyte Posted April 12, 2004 Author Share Posted April 12, 2004 From Member "J Taylor" from this thread My z made 388rwhp running the stock ECU, larger injectors with a modified stck turbo AFM. This was very lean and definately not safe but never the less it did make it. The car made 340rwhp for several years fairly safely with the same setup. It also obviously had other parts such as the larger turbo and intercooler to make the power but was made with an untouched 160k mile shortblock straight out of the junkyard, ported p90 head with stock cam, stock exhaust and intake manifolds. You can make decent power from the stock stuff but if you can afford a stand-alone I would definately recommend it. JT I didn't say stock turbo I said stock ECU. I'm going to use the 75 intake on my 78 L28 with an 75/76 ECU. The wiring only seems like a few wires, and I've already got a factory installed electric fuel pump. Phyte Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 12, 2004 Share Posted April 12, 2004 hmmm... "modified stock turbo AFM"? Okay, I correct myself then. That's pretty impressive. I still find it hard to believe anyone was making that kind of power on a stock ECU under any circumstances... but considering that the ECU gets most of it's data from the AFM, and that the AFM supplies more data to the ECU than other component of the EFI, it would be helpful to know exactly how the AFM was modified. The way he says 'modified stock afm' makes me think it's more than just adjusting the spring tension. I also wonder exactly what size injectors he was running? I suppose large amounts of power are possible on the stock ECU... the injectors are the biggest limiting factor of the factory EFI, so once you throw bigger ones into the mix, it's just a matter of 'tricking' the ECU to get it all to run effectively. But I think most would agree it's definatley not the best way to do it. Ah well, I'm stuck with a stocker for the time being myself... at least now I know what's possible, I guess I have something to strive for now though, huh? As far as which ECU to use and all that, use what you have and whatever works for you. I was only trying to save you a little bit of time. You are right, there aren't that many wires involved in getting the EFI into a carbed Z. There were only 6 wires on my turbo setup that needed to be spliced into the 240 wiring to get it running. Since then, my friend that did the work says he's found a way to only do 3 or 4 wires. So it's not that big of a deal, really. I just wanted to make sure you knew that you would have to change out the harness as well when you went over to the turbo ECU. Quote Link to comment Share on other sites More sharing options...
Phyte Posted April 12, 2004 Author Share Posted April 12, 2004 hmmm... "modified stock turbo AFM"? Okay' date=' I correct myself then. That's pretty impressive. I still find it hard to believe anyone was making that kind of power on a stock ECU under any circumstances... but considering that the ECU gets most of it's data from the AFM, and that the AFM supplies more data to the ECU than other component of the EFI, it would be helpful to know exactly how the AFM was modified. The way he says 'modified stock afm' makes me think it's more than just adjusting the spring tension. I also wonder exactly what size injectors he was running? I suppose large amounts of power are possible on the stock ECU... the injectors are the biggest limiting factor of the factory EFI, so once you throw bigger ones into the mix, it's just a matter of 'tricking' the ECU to get it all to run effectively. But I think most would agree it's definatley not the best way to do it. Ah well, I'm stuck with a stocker for the time being myself... at least now I know what's possible, I guess I have something to strive for now though, huh? As far as which ECU to use and all that, use what you have and whatever works for you. I was only trying to save you a little bit of time. You are right, there aren't that many wires involved in getting the EFI into a carbed Z. There were only 6 wires on my turbo setup that needed to be spliced into the 240 wiring to get it running. Since then, my friend that did the work says he's found a way to only do 3 or 4 wires. So it's not that big of a deal, really. I just wanted to make sure you knew that you would have to change out the harness as well when you went over to the turbo ECU.[/quote'] Ya those are some pretty impressive numbers! I'm not looking for nearly that much HP anyway. Is there anyway you can put me in touch with your friend about the wiring? I'd like to know what he means by only 3-4 wires on the turbo setup. Thanks! Phyte Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted April 13, 2004 Share Posted April 13, 2004 I haven't talked to him in a while... actually we've had kind of a falling out, as I had some major problems with some work he did for me after that, and really felt ripped off. I don't imagine it being wired much differently than the N/A ECU, as far as which wires you need to splice into the 240's wiring. Just need power for the ECU and fuel pump, couple wires for ignition, that's about it. Quote Link to comment Share on other sites More sharing options...
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