Which JWT?

Post by **Freakazoid** » Mon Dec 04, 2006 6:36 am

Hi GuysI am new here but have been reading every post with interest. Excuse my ignorance re the next question. Which of the different JWT ECU's are the correct one to use if my application is as follows. I am putting a VH45DE into a Nissan Patrol GQ. I don't need the ECU to talk to trans since I'll be putting in a manul tranny. I do though want full sequential on fuel and spark for the low rpm offroad work. I am not going to boost, just run NA. I don't want to run huge horses, am after reliablity and fuel consumption. Please keep in mind that I am upgrading from the 4.2l 6 that only put down 80kW last time it was on the dyno. I want to get it right and then will slowly increase to around 300hp, if that is easy to get, I'll chase another 50 horses or so. You'll know better what is possible.

Post by **T45** » Mon Dec 04, 2006 7:11 am

Welcome, you have come to the right place! I am also getting ready to swap in a VH into my frontier. I can't help you much but there are lots of people on here that can. Post a pic so we can see your beast.

Post by **elwesso** » Mon Dec 04, 2006 7:22 am

welcome to NICO!!!!

The JWT ECU is kind of overrated, we have another ECU that costs much less (500 vs 120 or so) and will do just the same if not more!!!!!

or you can buy the stuff and make your own tune. We are very helpful with sharing our ROMs so theres a good chance we could work together and burn a ROM.

Post by **Freakazoid** » Mon Dec 04, 2006 8:06 am

Hi Thanks for quick reply. Please tell me more re the other ECU. I can't get hold of original ECU, just engine. We ordered 4 from Japan, but no ECU's arrived.

Here is pic of my Patrol. Just recently fitted the 35" tires so need more power to turn them.

Post by **darinz** » Mon Dec 04, 2006 3:53 pm

I'd like to know a bit more about aftermarket ecu's. At present I'm looking at an Autronic SM4 but at about NZD$2500, it is hurting the budget a bit. I'm also fitting a VH45 into a GQ except I'm fitting a single GT3540 as well. I've been advised against a Link for offroad use do to the boards not handling it. With exchange rate it works out to about $1600 USD.As you can see my truck gets used pretty hard!

Post by **Mettler** » Mon Dec 04, 2006 4:02 pm

You don't need an aftermarket ECU. Make sure you research all you can about remapping the stock ECU before you automatically assume you need to spend over $2k.

Unwise move, seriously. My mate has an RB25DET with a massive Greddy T78 turbo, Q45 AFM, custom plenum, custom everything... insane setup, over 500RWHP, and he's about to sell his apexi powerFC computer in favour of his custom tuned factory RB20DET computer.

The VH computer is even more powerful than the RB one.

Post by **perana** » Mon Dec 04, 2006 4:31 pm

Speeking of "we" who are u refering to, and can i get 1 as well if thats what i need thanks.

Post by **elwesso** » Mon Dec 04, 2006 4:38 pm

Mettler wrote:
The VH computer is even more powerful than the RB one.

Seems ironic, but it really isnt!!!

Post by **Mettler** » Mon Dec 04, 2006 5:02 pm

According to JP, he reckons it's got additional onboard networking stuff... just upgraded circuitry or something. I have no idea myself, not having read into the tech info about it much, but I take his word for it since he's doing these things before my eyes. I don't see a logical reason why it would be more powerful, it's only running two extra injectors, two extra coils, a second knock sensor, a second oxygen sensor, and VTC... maybe it's just got additional functions to make it run more efficiently ?

perana: ECU tune with a wideband O2 sensor, custom ECU program written to a chip and installed into your ECU. Doing it with mine later this month... should be interesting

Post by **defrag010** » Mon Dec 04, 2006 6:26 pm

Freakazoid, I have the ECU from a 1991 Q45 that I'm not using. Cover the cost of shipping it to whever you are down under and it's yours.

Post by **darinz** » Mon Dec 04, 2006 8:56 pm

OK, what is involved with remapping factory ecu. I'm only going to run low boost with stock compression. Without running speacial fuel we reacon about 6psi will do the trick. The main goal is more torque but without restricting revs. How much dyno time are we talking?

I'll try the photo again!

Post by **Freakazoid** » Mon Dec 04, 2006 9:38 pm

defrag010 wrote:Freakazoid, I have the ECU from a 1991 Q45 that I'm not using. Cover the cost of shipping it to whever you are down under and it's yours.

I am in Cape Town South Africa. I am very interested, pls let me know how you want payment. I'll cover cost no problem, or maybe even get courier to pick up from you.

Just so I sound stupid again. Am I correct in thinking that the JWT is standalone, or is it a piggyback or is it a reworked ECU from the vehicle itself. I mailed them and they want an exchange unit, couldn't figure it out.

Is there anywhere that somebody has put down info on the different aftermarket ECU's and if they are actually up to the task of running a modern day V8. There are mountain loads of ecu'S around for the little 4 cylinders, but nothing really that can run a V8 properly and that is fairly priced.

Post by **SuperHatch** » Tue Dec 05, 2006 3:36 am

Freakazoid wrote:Just so I sound stupid again. Am I correct in thinking that the JWT is standalone, or is it a piggyback or is it a reworked ECU from the vehicle itself. I mailed them and they want an exchange unit, couldn't figure it out.

JWT is a remapped stock ECU.

Post by **Freakazoid** » Tue Dec 05, 2006 5:03 am

Thanks, figured it would be something like that. So the best is to get hold of original ECU, spend a couple weeks rewiring the entire thing as the engines just gets cut out, and then start with remapping once it goes.

Post by **Mettler** » Tue Dec 05, 2006 9:44 am

Remapping factory ecu:

1. Open the casing & desolder the 28 pin eeprom chip.

2. Solder in place a 28 pin socket.

3. Plug romulator into the socket.

4. Figure out beforehand roughly what you want to do, advanced spark etc... keep it close to standard.

5. Run romulator into a laptop, and edit map settings using rom editor or live edit, while the car is actually running on the dyno with a wideband O2 sensor. Should take an hour or two to get a mint tune!

6. Save the edited rom as a bin file, and burn a new 28 pin eeprom chip with the pocket programmer.

7. Unplug romulator, and install your new custom tune 28 pin chip.

8. Reassemble casing & put ECU back where it belongs.

Viola, you have a totally custom tuned engine, suitable for your requirements. The factory ECU can work with turbos too, just requires more extensive remapping.

It's not quite as easy as 8 steps... first you have to learn what the hell you're editing, what settings you need to do etc, but all that can be learnt by reading up on the net about it. Here at Nico, we have shared around all the bin and address files for VH ECUs, so those are easily obtainable. The rest of it is just learning, which you'd have to do with a more expensive aftermarket computer anyway.

Post by **Freakazoid** » Tue Dec 05, 2006 10:55 am

I assume you need ALL the original engine sensors or are there any you can change or edit out so you don't use them? Same goes for controls like EGR?

Post by **elwesso** » Tue Dec 05, 2006 10:58 am

Freakazoid wrote:I assume you need ALL the original engine sensors or are there any you can change or edit out so you don't use them? Same goes for controls like EGR?

Yeah mostly.... You can get rid of sensors easily, or trick the ECU so it doesnt throw a code... The old ECU rae pretty simple, so no matter if you were runing a stock ECU or a standalone, youll have to have basically the same sensors...

Im not sure if anyone has used a MAP sensor on the stock ECU (im sure its been done somewhere), but the stock MAF can handle 600HP or something like that (dont quote me on that number, but its enough for most people)...

OYu can also ignore the MAF if you wanted and just have the fuel and air based on throttle opening (using calculated air volume values, not as accurate but if your at WOT most/all the time it probably is good enough).

Post by **Mettler** » Tue Dec 05, 2006 11:40 am

Wes, it's possible to transplant the AFM sensor into a pipe with double the cross-sectional area and halve the resistance output (or something to this effect) to double the capacity of your AFM. JP did this with a regular green sticker AFM for an RB30DET running a massive turbo, and it works quite effectively.

Post by **elwesso** » Tue Dec 05, 2006 11:44 am

Good info... So basically, taking then 90mm VH MAF, you would take the electronic guts out and transplant it into a 180mm tube, and cut the voltage the ECU sees in half.... Brilliant...

Ive also seen on twin TB setups where they run one MAF but double the voltage...

Post by **Freakazoid** » Tue Dec 05, 2006 11:59 am

Cool, now I just need to get the ECU. I think that concludes a lot of my homework re the engine. Now I need to learn how to do it all. Fortunately one of the local tuners is taking one of the 4 engines we brought in so we have some knowledge there with a vested interest, although I think he might run an aftermarket ECU.The next 2 weeks will be about measuring and drawing up an adaptor plate to make the 350Z box fit to the VH45.Thanks again for all the info

Post by **Mettler** » Tue Dec 05, 2006 2:00 pm

elwesso wrote:Good info... So basically, taking then 90mm VH MAF, you would take the electronic guts out and transplant it into a 180mm tube, and cut the voltage the ECU sees in half.... Brilliant...

Ive also seen on twin TB setups where they run one MAF but double the voltage...

Almost

It's not double the diameter, it's double the cross sectional area. Twice the cross sectional area can literally fit only twice the volume of air through it at the same pressure/vacuum... which is the aim, to double its volume capacity & mod it to be able to measure it accordingly.

A 90 diameter circle has an area of 6361.73 square mm... so if you're going to halve the voltage the ECU sees (or by whatever percent), then you have to increase this area accordingly. In this case, we're doubling it to 12723.46 square mm.

Since we're working with real materials and using only that which is actually available to us, a 127mm I.D. pipe (5 inch) will provide an area of 12667.69 square mm, which is pretty damn near perfect... it's the best you'll get at a size which is quite likely a stock size pipe.

There's margin of error built in to the ECU anyway and one of those ****house apexi safc fuel controller things will allow you to perform any fine tuning adjustments if necessary, but with a negligible difference of 55.77 square mm, I don't think it'd have any effect on the reading.

The great thing is, I'm pretty sure the yellow label 90mm Nissan AFM provides the greatest resolution with air volume readings (compared to other Nissan AFMs), so doubling its capacity will still allow it to be a pretty accurate, high volume AFM. The most important thing if you ever do this, is to ensure you transplant the sensor in the exact center of the pipe, getting it wrong will more or less render your AFM inaccurate, and if it's too far out, it'll be useless!

Freakazoid: Here are some links that you and others may find useful in learning what you need to do to remap ECUs... note, these pages are in regards to other Nissan motors, but the principle works the same way with the VH ecu:

http://www.redz31.com/pages/fuel/romula ... mwise.com/

Post by **Freakazoid** » Tue Dec 05, 2006 10:34 pm

Thanks very much, that was going to be my next question, where to get the necessaryn info to do the whole rom thing. But I thought I'd leave it till I need it, so thanks for posting it now. I'll get my head around it in the coming weeks, maybe then I can ask some more informed questions.

I have a question re the MAF vs MAP but will start a new thread on this.

Post by **slownslurious** » Tue Dec 05, 2006 10:52 pm

since we are sort of on the subject does anyone have maybe a half cut harness that came with a replacement motor that they don't want? I'm wiring up mega squirt on mine and having the harness plugs and wire routing in the engine bay would be a huge help, and I know most ppl just toss the half cut harness when they order a JDM engine and use their stock one, so Id rather avoid buying and cutting up a stock one if possible.

Which JWT?

Which JWT?

Re: Which JWT? (Freakazoid)

Re: Which JWT? (T45)

Re: Which JWT? (elwesso)

Re: Which JWT? (elwesso)

Re: Which JWT? (elwesso)

Re: (Mettler)

Re: (Mettler)

Re: (defrag010)

Re: (Freakazoid)

Re: (SuperHatch)

Re: (Mettler)

Re: (Freakazoid)

Re: (elwesso)

Re: (Mettler)

Re: (elwesso)

Re: (elwesso)

Re: (Mettler)

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