ToplessZ Posted March 18, 2004 Share Posted March 18, 2004 anyone posted a how-to yet. Id really like to do this swap for my 300rwhp on a budget Quote Link to comment Share on other sites More sharing options...
fl327 Posted March 18, 2004 Share Posted March 18, 2004 There will be one soon courtesy of Afshin. Im making up another harness that uses 87 z31t stuff. Afshins should be pretty good I think, his setup uses all the idle stuff off relocated z31 pins and he still has the fuel pump modulator and a bunch of other good stuff working. His setup is pretty good if you want to use all the stock idle stuff and what not, my stuff would be air fuel spark thats about it. Quote Link to comment Share on other sites More sharing options...
ToplessZ Posted March 18, 2004 Share Posted March 18, 2004 Cool please keep us posted. I really want to run the 370cc injectors though without having to go though jwt from reading this thread It doesnt really seam like its possible for me at this point as I cant modify the computer Quote Link to comment Share on other sites More sharing options...
turbobluestreak Posted March 18, 2004 Share Posted March 18, 2004 sleeper's doing it with a hacked mas. tbs Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted March 18, 2004 Share Posted March 18, 2004 I have no doubt that the Z31 setup on stock injectors would run better than the stock 280zxt ECU setup if you're running any increased boost or what not. Myself and a few other people have seen that with stock injectors on stock EFI, running ANY increase in boost, you tend to run way rich in the midrange, up to about 4000rpm, and then suddenly lean out pretty dramatically at anything above that. This is NOT a limitation of the injectors, as this happens at power levels much lower than what even the stock injectors should be able to support (theoretically they're good up to 250hp, but even at 200hp I made on the dyno, I was running WAY lean above 5k revs... this is VERY typical of all the 280zxt ECU setups I've seen dynoed). Whereas guys like sleeper, running the Z31 ECU get a much more even fuel curve, no super rich midrange, no leaning out above 4-5k. I think this is because the stock 280zxt AFM does reach it's fully open position at WOT at around 4k revs, hence it can't measure any increase in airflow past that point. I think past that point the ECU just switches over to a preprogrammed fuel map based soley on RPM and temps, assuming WOT, and stock 7psi.... therefore when boost is increased you start to run too lean at that point. I bet money the Z31 has no problems measuring air all the way to redline, and no problems compensating for increased boost, at least to a certain degree. I'm still very interested in switching over to the Z31... one day, one day By the way, there is either something seriously wrong with my setup (though it seems to be running fine to me) or I am just on the boost way too much... I'm averaging 17 mpg's..... Quote Link to comment Share on other sites More sharing options...
Guest ZmeFly Posted March 19, 2004 Share Posted March 19, 2004 HEHE, I get that driving threw the city, on the highway though I get fantastic mileage. Then again my FPR is shyte right now making me run pig rich at idle with 48psi @ idle Quote Link to comment Share on other sites More sharing options...
Bernardd Posted March 19, 2004 Share Posted March 19, 2004 Over the winter much testing has gone on. Any 88+ and some 87 turbo, not sure about 87NA ecu's, can be easily modified for larger injectors. Romeditor has a boost table that relates engine size, injector size and # of cylinders and other parameters and it is reasonable accurate in predicting where you will be in the fuel/ignition maps at a given boost. It is possible to move the resolution to where you need it by modifying the load scalars. It is possible to account for using a hacked maf to keep the airflow readings within the scale of the maf by adjusting the kvalue. I don't know yet where exactly the maf maxes out and have had no luck with modifying the ecu to work with the ford cobra maf. I've got two spare ecu's lying around looking for a good home......................... Quote Link to comment Share on other sites More sharing options...
turbobluestreak Posted March 19, 2004 Share Posted March 19, 2004 bernardd so are you saying you can increase injector plus as well? tbs Quote Link to comment Share on other sites More sharing options...
Bernardd Posted March 19, 2004 Share Posted March 19, 2004 bernardd so are you saying you can increase injector plus as well? tbs Injector Pulse? Yes. I can tune the fuel and ignition to exactly what I need. My 46lb injectors will be a new challenge. Haven't tried anything that big, but I don't think it'll be a problem. Bernard Quote Link to comment Share on other sites More sharing options...
fl327 Posted March 19, 2004 Share Posted March 19, 2004 Had to re think my z31 conversion wiring, at one point I was going thru a lot of MAFs. My z31 stuff is really bare bones, running fuel pump off a simple relay setup, basically just maf and ecu would be big changes. I do have a lot of those 370s though... Afshins writeup should be pretty good, he has every stock function that the ecu controls running with z31 stuff, very nice I thought. Two weeks I should have z31 running, again , messed up Im only doing the wiring work so I can drive it 14miles round trip to the shop... Quote Link to comment Share on other sites More sharing options...
Afshin Posted March 21, 2004 Share Posted March 21, 2004 I just posted a "how to" for the swap in the turbo section as promised Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted March 22, 2004 Share Posted March 22, 2004 If that's yo2001 from zcar then I'll trust what he says. I've talked to some of the brightest from that site and he was always right. I am almost finished installing a z31 turbo computer on my L28ET. I just need to wire the fuel pump relay up and figure out the speed sensor. I really didn't consider it to be a proformance enhancer. Just a suplement for the original. They are 2 different systems. That is you can't swap computers or harness back and forth between the 2 systems. I spent a great deal of time finding wire diagrams and tracing out the entire engine harness. I ended up making my own wire diagram. I have done a few other mods to the engine like machined the inside of the manifold and fit a KA24E throttle body on it. I also used the 300zxt AAC valve with idle adjuster and idle up solenoid. I plated off the old AAC valve. I am trying to get a MLS Cometic head gasket for the car as well as an intercooler (prol. large NPR). I guess I should say I have a 71 240z. I placed the ECU on the passenger side kick panel. Then I drilled a 2" hole next to the original engine compartment hole only slightly lower because of the fan unit. I am pleased with the way it looks so far. I just don't have a cover for the ecu. I may just leave it that way. If you check out my web site you can sort of see the mock up of what I have done. I will be making changes soon and show some of the current state that I am at. right now the pictures take a while to load even if you have broadband. Quote Link to comment Share on other sites More sharing options...
frank280zx Posted March 22, 2004 Share Posted March 22, 2004 i can only say one thing... MEGASQUIRT It works like a charm, gets better milage, and gets rid of any restriction, if you can wire in a mass you are good enough to go megasquirt Quote Link to comment Share on other sites More sharing options...
frank280zx Posted March 22, 2004 Share Posted March 22, 2004 i can only say one thing... MEGASQUIRT It works like a charm, gets better milage, and gets rid of any restriction, if you can wire in a mass you are good enough to go megasquirt Quote Link to comment Share on other sites More sharing options...
Afshin Posted March 22, 2004 Share Posted March 22, 2004 I have no doubt that the meqasquirt set up is great and certainly has the very significant advantages of tunability. However, the Z 31 set up has pratical benefits such as : total cost $100-$120 for the full set up, can be easilly up and running within a day (with instructions), does not require programing, laptop, dyno time, will be more reliable, passes emission easilly, has self diagnosis mode. Also, with an MAF as opposed to MAP system it can fine tune itself to changes in altitude, exaust, boost change...which usually require reprograming with a MAP based system. I think when the ultra megasquirt with wide band O2 sensor and direct coil ignition comes out and proves to be reliable like the current set up I will switch over. That just sounds to damn good Quote Link to comment Share on other sites More sharing options...
turbobluestreak Posted March 26, 2004 Share Posted March 26, 2004 Bernardd could you burn me a chip for 35 lbs injectors as well as some new timing curves, just let me know how much if you are willing to burn one. tbs Quote Link to comment Share on other sites More sharing options...
Bernardd Posted March 26, 2004 Share Posted March 26, 2004 No problem. Check your pm's. Quote Link to comment Share on other sites More sharing options...
Afshin Posted March 26, 2004 Share Posted March 26, 2004 Hi turbobluestreak Where you the one I contacted thru Chris and sent those nice diagrams for the Z31 MAF connector and for the fuel pump relay? I lost my old emails and contacts a while back. If that was you thanks again, it certainly helped me work out the Z31 swap. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.