-shock211-

iTrader: (1)

Search Is Down.
I will be rebuilding my engine and I'm starting to do research on mods i'd like to get for the rebuilt engine. ECU being my first item to research.

I'm looking to hear from 3rd gen VG drivers about their experiences with the jwt ecu or any reprogrammed ecu for that matter.
i've spoke with a few 4th gen owners that have the jwt ecu. they're not impressed with the gains at all. i've spoke to ppl with mevi and w/o. they both say the same thing.
but i'm curious to know how the 3rd gen reacts to the reprogramming. i emailed jwt with a few questions last week and haven't heard anything back from them.

if anyone can answer these questions for me it would be much appreciated.
what (average) gains can be expected from the ecu?
does the ecu reprogramming cause frequent maf issues?
how does it affect gas mileage?

i need to hear responses in regards to vg30e ecu experiences. all engines will react differently to being chipped. some get tonnes of power some don't.

custom maxima is offering a deal with jet performance chips at the moment. they claim 15hp and the job costs 350.00 + shipping. jwt costs 500.00 + shipping.

thanx in advance for any help you guys can offer me.

todamax

iTrader: (6)

I asked about the Jet ECU last week. The few responses I got completely blasted it, everyone said get the JWT. I don't think anyone here has the JET, although someone said it was good in thier Firebird.

90SEBlack

I programmed my ECU myself if your interested please let me know maybe i can help you out in doing it urself or i may be of some help doing it for you the rest of these guys on .org think im a bull****ter but if would like so help repro the rom i can help you out check out my cardomain site
www.cardomain.com/id/90SEBlack There is not verymuch info about the repro chip but if ur interested e-mail me Dilbert707@aol.com . The program on the chip is the stock VG30ett program with some minor changes to the fuel and ignition maps , U may need to upgrade injectors and FMU to run this program with the max fuel system.

90SEBlack

I programmed my ECU myself if your interested please let me know maybe i can help you out in doing it urself or i may be of some help doing it for you the rest of these guys on .org think im a bull****ter but if would like so help repro the rom i can help you out check out my cardomain site
www.cardomain.com/id/90SEBlack There is not verymuch info about the repro chip but if ur interested e-mail me Dilbert707@aol.com . The program on the chip is the stock VG30ett program with some minor changes to the fuel and ignition maps , U may need to upgrade injectors and FMU to run this program with the max fuel system. To remove the ROM u must remove the 4 screws from the ECU case thus revealing the circuit boards now there is a main board where the ROM is connected and a daughterboard which covers the rom u must remove this also but becarefull as it is connected with a small ribbon cabel , Our roms are not plug and play unfortunatly it must be desoldiered after i removed mine i installed a socket to recieve my rom so that i coult remove it without having to desoldier it every time, I suggest that after you put the socket in u leave the stock program on there and test the ECU to make sure that u soldiered everyting back in after ur sure that it works remove it again and begin burning ur new program our roms are not UV Sensitive (Or just really hard to erase with light) anyway i just flashed it after modifing a VG30ET Program reinstalled the repro ROM and alittle tuneing adjusting idle and upgrading to 92+ octane gas and the gains were not dramastic but there was an improvement , The main reason that i did this was to run my TT injectors because i am upgraing to a turbo in the next month or so.. If anyone is any more interested in my method e-mail me Dilbert707@aol.com

StinkyZ

As far as reprogramming a stock na I would probably invest in something else. Maybe get some cams or a better exhaust. Unless youre running a turbo I dont think there is going to be much gain from reprogramming the na ecu.

90SEBlack: I've got a jdm vg30et engine from japan that I might eventually pop some TT injectors in to. Are the TTs a direct bolt in?

Also, I'm planning on buying either an eprom programmer or a romulator and using it to reprogram my ecu as you have. I'm also going to get an ls-1 wideband o2 unit from innovatemotorsports.com so I can tune everything properly. What kind of programmer are you using and what software are you using? Did you modify the actual fuel and timing curves or did you change the K constant value?

mtcookson

iTrader: (2)

I believe the early TT injectors will fit right in our rail, but I'd hold out on those. For some reason with the reprogramming on my ecu (260cc injectors) it is still running quite rich which makes me (and the programmer) think that the injectors are actually bigger than I thought. I'm going to try pulling an injector to get a part number so I'll find out for sure what size they are. i should know this tomorrow.

90SEBlack, which file did you use to program your ecu, the VG30DETT from the Z32 or the VG30ET from the Z31? The guy that I had program mine did it using the VG30DETT map and since its running rich he's not sure if he should have used that map or the VG30ET. Any info would be great! Thanks!

StinkyZ

Are you using the stock maxima afm? From what I've read the easiest way to compensate for larger injectors or a different afm is to change the K constant. The K constant acts as part of the equation the computer uses to find the injector timing. If you change the K contstant it changes the injector timing across the board. Let us know when you find out about those injectors.

-shock211-

iTrader: (1)

well here is my plan.
i'm getting a free vg30e in august 04. i already have the aftermarket exhaust system on my current vg. i will be rebuilding the engine and pumping up its juice. i've already started to research cams. it will get a port/polish and i'm thinking forged pistons. and lastly ecu upgrade.
i wish i was gutsy enough to do the vg30et swap like mtcookson but this is a free engine and a direct bolt up.
90seblack - what mapping did you use for your ecu? vg30dett or vg30et?
and what kind of gains did you see? how has it affected your mileage?
does anyone know what mapping jwt uses?
i have no problems upgrading the fuel system if it's worth it.
how far is north tonawanda from buffalo?
i'm in toronto and if we were to go ahead and reprogram the ecu. i'd be willing to drive down and meet up.
we'll talk about this ecu thing for sure man. thanks for the info.

StinkyZ

As far as I've ever read JWT modifys the stock map to work with the changes you tell them youve made. I've never heard of using a map from another engine like a vg30dett on a vg30et. I dont see why it wouldnt work but it also seems to me that it would be better to modify the stock map. I can only imagine that JWT starts with the stock map and then changes the K constant and does some small tweaking to the fuel map in certain areas.

The general concesus on z31.com (we all have vg30e or vg30et engines) is that its not worth your time and money to try to rebuild a vg30e if you are trying to make power. My suggestion would be to rebuild it and in the process prep it for a turbo. About the only thing you need to change on the engine would be the compression ratio. If you lower it a tad and stick bigger injectors on it like you say you would have a great turbo engine. Once your done with that just figure out how to bolt a turbo to it and you're all set. It will require some additional work and money but I think you would be much happier with the end result. I'm sorry if I sound so negative but I really feel that for the work you put in to an na engine you're not going to get that much out of it. Dont forget some sort of headers if you plan on sticking with the na.

Chris91SE

iTrader: (1)

haven't read the whole thread but if you're building up (injectors, nos, turbo etc) then JWT can program the ECU to whatever you need. Their "stock" reprogram is what i have and what you can get through them cattman or whereever.

I only track tested mine a couple of times and knocked 1/2 second off my 1/4 mile time. Gas mileage improved slightly.

90SEBlack

Its a program from the VG30ET Z31 , The TT program fuel curves were much two high for just one turbo and out intakes , The Injectors are from a 1991 Twin Turbo 300ZX they are running at 71% Duty Cycle if my calculation are correct anything over that and it will be the great flood , I mod the Z31 fuel and ignition maps with only the K constant do deliver more fuel at each injectors pulse did not change the hole delivery method.


CHRIS91SE : But it is really worth it to send it out for a week or 2 of downtime when the equiptmrnt that i bought only cost me 250.00 including shipping and i can program whatever i want as many times as i wish , If i remember when i looked at JWT it was $500 , Not saying that the stuff that Jim writes isnt good code but its rather expensive

-shock211-

iTrader: (1)

hahahaha
i have a spare ecu to send out

i wonder if anyone has any before/after ecu dyno runs? anyone?

basically...i just need to determine if the ecu is worth reprogramming. i'm definately not willing to pay 500.00 for it seeing as no one really raves about the upgrade. or at least that is the way it seems to be. but if the jet one or some of you ppls reprogramming skills are up to par. i'm definately gonna do the mod. i just need to do a lot more research.

90SEBlack

i can show u a dyno sheet after the injector upgrade and new ROM program, It wasnt stock before the dyno but u can still see the baseline change over the old too the new, Ill ppost them 2night around 9 - 10 when i get home ill scan the sheets in and host umm on my cardomain, if ur still interested, It went from 167whp too 178 whp on a VG30E still n/a

StinkyZ

What kind of programmer and which software are you using? How did you go about tuning the new injectors? So you just calculated the new K constant and thats all you had to change?

davebond007

Wow, that's more than most stock VE's (and some mildy modded ones).
How much torque did you have at the wheels?

Bernardd

I'm Mtcookson's program guy. I've used two methods to reprogram an ecu for larger injectors. Firstly I've used only the fuel map for my own z31 ecu powered L28et. Changing the k value did nothing or the address for the k value is wrong for the vg30et rom. Secondly, I've reprogrammed a few z32 ecu's that required the k value be changed. Along with that the load (tp) values for ignition and fuel have to be changed to keep the fuel map scaled properly. The on time of larger injectors has to be accounted for as well. When changing the maf sensor the maf table needs to be changed as well as the k value adjusted. K value changes allowing for a maf change are opposite to the injector k value adjustment. I reprogrammed Marks ecu for 260cc injectors under the impression that the stockers were 180cc's. With the problems an engine swap presents we (Mark and I) have not been able to determine if the ecu behaves like the z32 ecu or like the z31 ecu. I'll gladly reprogram anyone's ecu if they send me a socket and a few eproms.
Bernard

StinkyZ

Haha. Thats cool. I was wondering who was doing the programming for him. Couldnt you simply pull the z31 turbo fuel maps or maybe even the entire eprom and swap it into the maxima. The engines are identical except for the idle control unit. I doubt any of the vg30e maximas will have anything to do with the z32. Just for the hell of it why dont you try swapping in the vg30et bin that you sent me. Doubt it could hurt much since its already set for the 260cc injectors. Wish I had a pic of the maxima ecu to see if the pins are the same. I cant imagine they are much different from my Z.

Bernardd

Unfortunately the two ecu's (z31 + Maxima) are completely different in everyway. The connectors are totally different, the harness wiring is different and the layout inside the ecu is different. The code inside closely resembles the z32 ecu but uses the dizzy cas and single coil vs coilpacks. I'd like to try the z32 code on a maxima ecu but I don't have a maxima handy to try it on. (volunteers?????) Currently a buddy of mine is trying to get the sci option for the processor (6303) to work with gm ecu software so that realtime data logging can happen and to watch sensor info. The fuel map that 90seblack has posted on his cardomain website is a screen shot of an 86 turbo rom that he's found on one of two sites. This fuel map will not work very well in a Maxima ecu to say the least. It may work somewhat with larger injectors but the top end would be lean and the bottom end would be rich, unless the maxima ecu is able to cut out more fuel via the o2 sensor than a z31 ecu. Like I said before I'd like to reprogram another ecu for someone.
Bernard

90SEBlack

No thats a screen shot off my desk top yesterday afternoon , I opened the .bin that i burned, and i am running TT injectors currently with Vortec FMU andh High Volum Fuel pump and Apexi SAFC II to richin at the top end, the bottom end runs very well with no trouble at idle! I also have my heads ported / polished and with 3 angle valve seats , and Motorsport 262/256 .420" lift cams believe me this program will run on a max ECU and its a 88 VG30ET bin file. Ill send you a spare ECU or just a ROM chip with the same program on it and u can see that it runs just like new throwing now codes and running the larger injectors.

DA-MAX

iTrader: (10)

are you sure thats your own map? cause this is the one from that autoserve site-->


you sure you didn't just copy and paste this onto your website from this site(http://www.autoserve.8m.com/vg30et-fuelvals.jpg) ?? just wondering cause it seems strange you said you made changes but the fuel values are all the same

and also why are you still using an FMU and AFC?? the whole point of remapping and ECU manipulation is to eliminate the use of FMUs or any other outside devices that would interfere with ECU->injector operation.

Chris91SE

iTrader: (1)

Bernardd

It's entirely possible that the code runs on a Maxima ecu. That I cannot dispute, but that's not a 88 vg30et fuel map. That's from my 86 turbo. The binfile used to be up at the inflamericetec site. I sent it to Matt. The screen shot is used by the autoserve guys along with a bunch of other info Matt and myself have collected over the past year and a half or so. They took it off after a nasty email from Matt. Why don't you send me a copy of the code you used in the Maxima ecu and I'll be able to tell quite easily what year it's from. If you guys show me how to post pix I can show you fuel maps for the Max, 86-88 turbo and z32 or most any other Nissan. If I understand you correctly you're running a vg30et binfile in the maxima rom? Z31 ecu = HD 6802 cpu, Maxima ecu = HD6303 cpu. That's interesting.
Bernard