But wouldnt the change of airflow meter and ECU largely eliminate the potential for over-fuelling? Obviously the point here is to get more fuel in without it being too rich that things start going downhill.In any case it looks like I'll just be going ahead and trying it out. If it doesnt work out I guess the 2.0lt is going in. It was going to go in at some point anyway, but I was hoping to not have to miss an event.
If you get matching ecu, afm and injectors such as from GSR Galant, yes it would be fine fuel wise but you would not gain any power which would then be waste of money and time considering standard setup does the same. Putting just bigger injectors will definitely enrich your afr and reduce power output because ecu remains mapped for 210cc injectors instead of 240cc which is then just a waste of time again. The only way to put more fuel in and having the same afr is to get more air in as well, theres no other way. And ecu will put more fuel in for you when it sees more airflow. So your job should only be to get that engine to breathe better.
The standard ecu is mapped pretty well, has enough of timing(around 20 degrees in top end) the afr is around 13:1 all the way to 6000rpm and then it starts dropping towards 12:1. Even after few intake and exhaust changes it still remained the same but power output increased. I have played with my 4g61 for a while, I've tried few tricks here and there, bothered my brother many times to put it on dyno and see what works and what doesnt, saw what its capable of and then just did 63t conversion.
Heres couple of dyno graphs for you.
The first graph is of a freshly rebuilt 4g61 with everything else standard, 3-4 more degrees of timing was added from what is suggested by mitsi and 98oct fuel was used.
The second graph, unsure exactly of what the blue one is, but the red one had k&n filter, 60mm throttle body, extractors and 2in exhaust along with more timing and 98 fuel and it made what it made. My next step was to put some cams in but that was too much money for not so much power increase.
Ecmlink would work in your ecu but the problem is you cant run anything smaller then 450cc injectors with ecmlink. You could get single board vr4 ecu, get it socketed and play with tunerpro. With tunerpro definitions you can make changes for any size injectors and/or any mitsi airflow meter as long as you know their compensation values. Enable launch control, install knock sensor now that ecu supports it and play with many other features it provides. Only downside, it can be time consuming but with NA setup there is not much it needs a change other then a little bit in a top end. Another thing you could do that was on my to do list, put a dual runner intake manifold from a jspec vr4 galant to improve its midrange as they are flat a bit. For that you need some rpm related switch, or just wire it in to vr4 ecu if you end up using it. Another good alternative to do some of the above is haltech interceptor. These are some of the things you might want to look into if you want to get serious with it.
Anyway, I got a little carried away but hopefully you'll find at least something interesting and learn from it. And please do your self and your car a favour and replace your injectors with 4g61 items otherwise you'll just ruin the power and fuel economy unless you're going to take some action in engine management department. Yours were probably clogged up badly if it took 4 attempts to get them cleaned. Replace your fuel filter if you havent already done so and inspect your fuel tank as I've seen few of them having corroded tanks causing the injectors to clog up.
oh and dont play with intake pipe or airbox, just leave it alone
thats just my 2c lol
