Nissan ECU Tuning

tryskriel · Joined: 15 Aug 2004 Posts: 36

I want to make a anti-lag program to launch on drag strip

Skyline GTR with GT45

I did make my tune that i put on the second part of eprom and i did my anti-lag program that i will put on the first part of my 512 eeprom but i want to switch it on the fly, and i think that to do that, i need to have the same checksum in my two program. I did try to change a value at time during 20 times to see if i can get the same checksum but cannot get it

My antilag program have the timing retarded to 0 all the way and add more fuel with a rev limiter of 5000rpm

Do someone can help me to get the checksum i want ?
Thanks

openloop · Joined: 22 Dec 2005 Posts: 81

For antilag I would do ignition retard + lean out to heat exhaust gazes and send energy to the turbine

tryskriel · Joined: 15 Aug 2004 Posts: 36

All Anti-lag i have seen add more fuel and retard the timing to do the explosion in the exhaust !!!!!

openloop · Joined: 22 Dec 2005 Posts: 81

tryskriel · Joined: 15 Aug 2004 Posts: 36

I think its the same, you cannot run leaner, you have to add more fuel !!!!

I found a way to adjust a lot my checksum by going in winhex and change my FF values that are not utilised and put 11 and my checksum will change a lot so i will be testing the next weekend !!!!!!!!!!

tryskriel · Joined: 15 Aug 2004 Posts: 36

It works !!!!!!!

We can build 6psi on neutral with a GT45 on a stock RB26.
Just waiting some slicks to go on the track !!!!!!!!!!!!!

kl4s · Posted: Thu May 01, 2008 1:09 pm Post subject:

Nice!

I guess you set your rev limiter lower in the anti-lag map?

to what rpm are you limiting it?

and how do you switch from one map to another?

with some kind of a chip select on one of the eeprom's terminal?

if so is it a mechanical toggle switch or electronic?
_________________
2.2L RB20DET 1989 R32 Skyline GTS-T

stinky_1 · Joined: 11 Feb 2007 Posts: 15

I would "guess" the simple way to do this is just tie a line off your clutch switch. Then use that to toggle a relay that would switch between the high or low address on the chip.

He just has a lower rev limiter set on one of the maps, and it looks like he played with the timing and fueling as well. Depending on how that was done it may create issues. I would "think" that just lowering the rev limiter would be enough.

After a few trial runs you should be able to get a proper idea what RPM is perfect for the most boost + still maintain traction. After that you should enjoy perfect launches every time.

On a similar note, the Honduh guys are running something like this that has been coded right into the chip itself. No need to run a larger chip either. The ecu know if the cluitch is in, and then they watch the vehicle speed sensor as well. If the speed is lower than 8 km/h AND the clutch is in, it forces a manually set lower rev limiter. This creates the same effect and does not require you to wire in switches and relays.

I am very curious to know exactly which method you went with. And if anyone is currently working on making a hard coded version? If you dont want the info public I would LOVE to get a PM with at least a "hint" as to what you have done.

OT: KL4S: Arent you on GTRC too? Your skyline specs in your sig, and name similarities are a bit too much to make me think otherwise.

kl4s · Posted: Tue Jun 17, 2008 5:15 am Post subject:

yes I am
I'm Klys there...
_________________
2.2L RB20DET 1989 R32 Skyline GTS-T

stinky_1 · Joined: 11 Feb 2007 Posts: 15

I was pretty certain it was you. But you never know.

I have seen some other GTRCers kicking around here, and on a couple other forums as well

kl4s · Posted: Tue Jun 17, 2008 5:24 am Post subject:

yeah I've been putting off tuning my car for a long time since I lost my old EEPROM programmer

but now I bought another and and got my friend's Wideband sensor..

so I gotta do it! I'm running WAY too rich in some areas and kinda ok for most of the power part.

It seems I'm currently around 14.7 at 120km/h crusing...

which I think is way too rich
_________________
2.2L RB20DET 1989 R32 Skyline GTS-T

stinky_1 · Joined: 11 Feb 2007 Posts: 15

I know I lean it out at crusing speeds as much as I can get away with. It allows you to save a little bit of fuel. Plus, as soon as you step on it to overtake someone you are no longer in the "crusing" area on the maps anyway. So nothing bad should happen leaning way past that.

From what I have seen most people are only tuning for WOT performance anyway, and only do slight leaning on ALL maps at every other point. Not enough to make a difference.

But you are not quite "stock" anyway.

I wish the OP would confirm what he did for sure to get his launch control sorted out. I know how I would do it (as posted above). But thats still a hardware aproach to something that could be entirely done in software from within the ecu.