Bernardd

Boyd check out the post about the New megasquirt software in the turbo section. It's easy to control the timing now as well.

I've been too busy tuning my z31 ecu so I never even noticed when this came out. I'll have to read up on it. If I get you correctly we can now use our dizzy because we don't need the PITA sensor setup with the voltage going high 5* before max advance and going low 5* before tdc???? Has Magnus incorporated dwell control?? That would be the ticket. I guess it's not that hard to get a GM HEI module in there for dwell control. I'll race you to see who can get the M'S'S up first. Bernard

Which dizzy are you going to use for the M'S'S? You will also need to have some sort of dwell control for this setup. Gm HEI is supposed to work well. You could also modify the stock cas to provide the correct signal. Keep us posted and way to go. Bernard

I used both ecu's with stock injectors and stock turbo. BIG difference in the way the z31 ecu runs the car. I tried to extract the maps off of the stock ecu and would have been successful except for stupid operater error and pow no data on chip anymore. If someone wants to donate one I'm sure I'd be successful. Anyone with a z31 ecu can start burning chips for a very small investment. http://www.batronix.com has burners and erasers. Or ebay. Pick up a socket and a few chips. Get a local tv repair shop to remove the stock rom and install socket. Then start tuning. The stock z31 maps are available on the inflame ricetech page. I can send a text file of "performance" ignition maps for both the l28et and the vg30et to anyone who wants them.

Basically you take the fuel map and multiply the values in it by the factor of the larger injectors. 270/370=.73 This will only give you the factor. You have to calc the fuel map multiplier first then multilply that factor by the .73 factor, then reverse calc the factor to find the new fuel map value. This will give a stock fuel map with larger injectors. From there it's all tuning for the mod's you've got on your car. There are also warm up maps that should be adjusted based on water temp. It is easy to run whatever maf you want, just change the voltage quatifier map for the particular maf you wish to run. This will also change the way the fuel map is accessed so more calc's are required. The maf is part of the equation for the fuel pulses. I have to figure out how to lower the voltage at which the ecu sees the maf. That way the maf has a wider scale. The stock maf starts at sending voltage at 1.6v but the ecu will only start calc'ing at 2.2v. This is easy to do I just haven't done it yet. Next summer I will be using a cobra maf or z32 maf as I'm maxing out the stock maf by 3.8k or so. The ecu will calculate higher pulsewidths but you have to expand the load scalers. There is a way around this but that will remain my little secret. It is also possible to raise the hp value of the maf by allowing the ecu to use more than the standard 5.12 volts that the ecu uses as it's max. I'll be doing this on my ecu when I lower the activation point. It's a matter of changing the values of some resistors. The stock maf actually goes up to 5.69 volts (at least mine does) so it's not hard to do. I don't think there's an air flow limiter in the code but I'm not entirely positive about this yet. Test bench season will begin in earnest after this weekend. Ok so now I've given out some of what I know. I need some of you guys to get off of your northends and buy some equipment. Or someone with a background in assembly code for the 6802 mcu. At present I'm using an arrogant and PITA tuning company's code in my 87 ecu. It was very easy to tune and requires less work to get a nice idle and better top end. That's it. Comments, suggestions, flames....... Bernard

I've done that with three different setups. An 86 ecu with 370cc injectors, and 87 with 370cc injectors, and the 87 with 420cc injectors. I've also used a rather arrogant and PITA to deal with tuning company's code on the 87 retuned for 370's and it works fine. All for the cost of an eprom burner and eraser and a pile of determination (started out almost 4 years ago) and time. I've also fudged the stock afm with good results but all you can tune is the base timing and afm door. I've since found you could tune your accel enrichment by changing the values of the little resistors on the small board inside the afm. You would still have all the other little issues the stock efi brings with it, but you would have somewhat tuned fuel for a bigger turbo and/or more boost. SleeperZ setup is the way to go on the cheap. Mustang guys can actually buy recalibrated maf's for a specific injector size. There are many different ways of doing this. Now if someone where to get a burner (or get his going again) I'd certainly help them out in any way I could. I've thrown around the idea of selling chips but humans being what they are , expect the full dyno tuned chip for their car via mail. JWT can't do it, and I can't either. If I didn't know better I'd say that was almost a rant...........

If you're going to do a write-up I'd like to contribute. If anyone would be interested in a " what I know about the rom and where the data is located to modify for larger injectors, maf, etc etc". I could really piss off anyone that's bought a JWT ecu lately. ( They probably are anyway )

I still wanna know what the idle voltage is. 8) Please and thanx. Bernard

You should really post that somewhere on this site seeing that the conversion gets asked about fairly frequently. Nice time in your sig. When did that happen? With no boost increase??

A buddy of mine has been working on a M62 supercharged L28E for the past year and a half. He went overseas to work for a year so that's why it's taking so long. If someone knows how to post pix I can fire over a pic of the blower/engine setup on the stand. He's finishing up the brackets right now along with suspension and still deciding what's he gonna so for engine management. I'm thing stock turbo injectors and the z31 ecu would be fine for the 200 hp or so that it'll be making.

When I removed the POS idle control system to vcm it left me with enough spare wires to convert everything without cutting or splicing except for under the hood. IIRC you have a - and + to the coil added as well as the self clean to the maf. I also ran an extra wire across the dash (underneath of course) for the fuel pump circuit. I can't remember why tho. Someone was nice enough to provide me with a nice spreadsheet that made it a snap.

I'm going to hang on to the maxima tranny for a while and see how my rebuilt tranny holds up. I will probably use it myself down the road. Unless you want to trade me for a certain abused 4sp auto that has lead a tough life in a twin turbo 240. After the swap is completed of course.

So, you're back to the turbo 350 trans, or the 700r4, 2004r???? I finally seemed to have my tranny hooking up. I'm still very interested in any conversion info you get. And I've got a Maxima 4spd auto for cheep as soon as I can get free to pick it up.

pin 31 at the ecu and pin D at the maf, does your setup have the .5 volt step? If you have to add timing doesn't that mean it's rich? Have you got the right o2 sensor for your ecu? Does it cross from about .2-.8 vdc or so? I don't think the o2 is used at idle but if it's warm enough it'll tell you what's up with the mixture before it cools down.

What is the maf voltage at idle? Does it flucuate a lot?

Is your tps adjusted properly? When I switched to the z31 ecu and removed all of the idle control stuff, I had to re-adjust the tps. What was happening was the tps was too close (100-150 rpm would cause it to open) to opening at idle. Sometimes it would idle high if the engine was gently idled down, and sometimes it idled perfectly. Sometimes it hunted up and down. I adjusted it to open up 300rpm above idle and that fixed the problem. Bernard

How does the N/A setup control dwell? Is it in the ignition module? If it is, it would be simple to tear out the module and make the megaspark'n'squirt work. I have no idea how the wiring goes in the module but you could make a custom chopper wheel with proper sized windows, adjust the dizzy so the signal goes high at the proper time (I forget what the spec is) and goes low 5 degrees before tdc, and send out the signal to the ignition module which can send it to the transistor and voila, we have ignition. Does this make sense? I've got the parts sitting in the garage if someone can confirm this might work. I've got two megasquirts that can be installed in short order. Please bear in mind that I haven't slept for three days due to someone in the family loosing her teddy bear. Bernard

That is impressive!! I chose to reprogram the rom. Easily done, but you need to have the equipment to do it. I'm also running 370cc injectors but will be moving up 450's next summer along with a better intercooler/turbo setup. Bernard

Do you have an upgraded fuel pump (you should if you don't)? Does the voltage look steady? Is the Maf in the same spot as the afm is supposed to be? I believe Jeffp had a similiar problem with his when he first converted. Might wanna talk with him about this. You can also reclock the maf to see if it makes a difference. A buddy of mine did this with his 450hp setup on is 300zx to get rid of a crappy idle. The mufstank guys do this all the time in custom setups. What do the wonderful folks at JWT have to say? Bernard

You could have a z31 ecu reprogrammed or do it yourself like I did. The entire cost of my fuel system along with 370cc injectors was 300 dollars. That include the eprom burner and eraser. Bernard

Thanks James, I'll pick one up next weekend and try it again.

I took my car to the track this weekend and managed to run one 12.9 pass. I've had my tranny rebuilt and done the modifications as per 240z Turbo's modification info. While it does shift better it still slips between 2-3 when the tranny gets warm/hot. I'm also going to move the cooler to a better spot and try again. Smoking the tires is not a problem. This is with a heavy 83 2+2 turbo. I would not be afraid to use the auto for drag racing however for autox and road racing it's garbage IMO.

Turbo ecu should work for now. I don't think there's much of a difference btwn the two. If you get a non turbo ecu it can also be reprogrammed to work with a turbo setup.

Any chance you swapped out the fuel pressure modulator? It's tied into pin 18 at the ecu. Not sure how it works other than it controls the fuel pump in some fashion. I don't have many straws left to grasp anymore.

I've been fooling around with my timing the last few days and have noticed that the only time my advance doesn't activate is when the tps is disconnected. Have you checked btwn pins 18 and 25? The harness could be shorted together. Or grounded together. Tps opens up at 900rpm or so? The only other thing I can think of is the transistor or capacitor at the coil may be having some effect. There's a small tab on the bottom of the dizzy beside the harness plug with a grounding tab. Is it grounded? Doubt that will have anything to do with it. When you tried the other cas and stuff did you try your stuff on the other car as well?