Could I custom tune my stock ECU?

[vwluv10338]

I was talking to a guy last night who said he made a custom harness for his 91 M3 so he could use a laptop to tune it. He said all you need to know are all the pinouts. Well I was talking to my computer wiz friend about possibly doing something like that for my car. Does anyone know if it would be possible? I mean isnt that just what Jim Wolf does? I believe I have the diagrams of all the pinouts stored on my computer in .pdf format. Could I make some sort of harness myself and have my friend work out something with my laptop? I know a lot of you out there are into computers so is it possible?

Eric

[Onizuka]

I think its definatly posible, but you would probably have to get your hands on some tuning software or get someone who knows how to program to do it for free.

[yellow_jacket]

If I remember corectly you actually have to remove the chip and erase it, then map in your new fuel curves etc. There was a post somewhere not to long ago on how to do it.

[IvoryJ30t]

yeah, you have to remove the chip from the ecu and replace it with an eprom or eeprom or a flash chip. also, i doubt the stock ecu contains the ciruitry to reprogram the chip on board.

your gonna need to be able to decypher nissan's fuel map from the binary data on the chip, alter the fuel map, convert back to binary [or hexadecimal] and rewrite the program.

its going to be alot more work than its worth unless you fully understand what going on in there.

[midnight brother]

get badbiki daughterboard and then the 931 tuning software. get the sr20det bin file and the address file. then tune and burn.

[BuudWeizErr]

I hope you know how to interpret and write hex!

[IvoryJ30t]

not only that, but the fuel map isnt straight forward, you have to know the algorithm that nissan used to create that binary data.

[midnight brother]

which are all on the internet

[dareo]

Bumping this post cause theres gotta be people that flash their own ECU's on here. Anybody at all burn their own chips?

I'd like a simple 550cc z32 maf no speed limit setup, if anyone makes chips id probably buy one if it was under 100 bucks.

If not i'll just have to be the first running my own ECU tunes but i doubt i am.

Anybody burning those eeproms out there?

[Phax]

Bumping this post cause theres gotta be people that flash their own ECU's on here. Anybody at all burn their own chips?

I'd like a simple 550cc z32 maf no speed limit setup, if anyone makes chips id probably buy one if it was under 100 bucks.

If not i'll just have to be the first running my own ECU tunes but i doubt i am.

Anybody burning those eeproms out there?

Try Fresh Alloy. That seems like the kind of board where you'd have the best luck finding people who do that kind of stuff. For your average person, pulling out a EEPROM reader/burner and busting out some A51 assembly on fuel maps and timing curves is kind of a sketchy proposition. Especially if the ECU is encrypted in any sort of way. The only guy who did ECU's that I ever knew of did them for Dinan. And those were encrypted by BMW at the factory. I wouldn't be surprised if Nissan did a similar sort of thing... even if it's only a few bits flipped.

[Phax]

This man speaks the truth!!

However, I wish you guys luck soldering all the connections onto the factory ECU. My soldering technique is not that good. I'll trust someone like JWT to solder their daughterboard (complete with dyno tuned fuel maps) to my ECU. I need it to work right the first time.

edit:

The following webpage has links to everything that you need, and even offers files for an S13 SR20DE(T) tuned with a Z32 MAFS and 550 injectors. I think that you have to guess how much boost the guy was running though. Probably best done by just cranking up your boost until it starts to lean out.

[mackdaddy240]

[QUOTE=Phax]

edit:

The following webpage has links to everything that you need, and even offers files for an S13 SR20DE(T) tuned with a Z32 MAFS and 550 injectors. I think that you have to guess how much boost the guy was running though. Probably best done by just cranking up your boost until it starts to lean out. [/QUote

What following wepage?? I need some roms that I can download to try out. I have access to a flash writer, and everything you need to program it I just need to see what setup works the best so if anybody knows where to download them PLEASE TELL ME EMAIL ME [email protected] HELP

[BaliLover]

The SR20 ECU does NOT use a rom chip, all of the fuel maps are hard coded to the ECU. You have to modify the ECU with a header and daughterboard to tune it yourself.

As of now, there isn't any way to do a real time edit of the fuel maps. You have to run the car and see what your setup is like, then turn the car off, pull the chip off the daughterboard, adjust the fuel maps and rewrite them to the chip, reinsert chip, and retest the car.

Without a wideband O2 sensor, this is pretty much impossible to do properly as you won't know where you stand with the fuel ratios. Its also not just about getting a perfect fuel ratio though, my car was setup to run slightly rich in some areas, and lean in others and I gained power over having it perfectly stoich.

I had my car custom tuned by Enthalpy (Scott) from TampaRacing.com and it took 14-16 dyno pulls and about 3 hours to set it up properly for 740cc injectors, a z32 MAFS, and the GT28RS turbo at 19psi.

It still cost me less than a JWT ECU, after paying for the ECU and dyno time, and its perfectly setup for my car on 93 Octane.

[240SXer]

Bumping this post cause theres gotta be people that flash their own ECU's on here. Anybody at all burn their own chips?

I'd like a simple 550cc z32 maf no speed limit setup, if anyone makes chips id probably buy one if it was under 100 bucks.

Enthalpy ([email protected]) Tunes ECUs. $500 bux. But you're not going to find any cheaper than that. Him and JWT are the only ones who have good reps for tuning well..

Good luck...

[robbbby]

I hear noting but bad things about JWT.

Bad tuning, bad turnaround time.

[240SXer]

I hear noting but bad things about JWT.

Bad tuning, bad turnaround time.

The tunes are more conservative than many people want. You need a FC to fine tune it with the JWT..

[SRdave240]

I have ROM tuned my own ECU and I am currently helping 2 of my friends do it (1 SR and 1 RB20). It isn't that hard if you just want to tune it for a generic set up (i.e. 550cc injectors, Z32 maf, limits adjusted to whatever you want).Ignition timing makes all the difference in the world!!!