Hey guys, I've been on a build journey with my Evo 9, its now all fully rebuilt with new forged internals on an upgraded turbo running flexfuel via a new Link G4+ ECU, new COP setup, new IKH24 Denso plugs, new ID1300X I injectors . Broken in a correctly a few of months back and I have been weekending it without any drama but have been really babying it with a few pulls in 1st 2nd and 3rd to over 7,000 without any issues and 4th is going way to fast so anyway, I went to my first track day a week ago. Its pushing around 400hp at the wheels by the way.

Now here's the thing, after I did a couple of warm up laps and started to push it, suddenly I get this stuttering in 4th, 5th at around 5,500 to 7,000 revs,but for 1st, 2nd and 3rd, no issues to rev past 7k. So I've been doing some reading and there appears that some people have plug gap issues and some people have a fuel cut issues due to over boosting. Because it goes hard in the first 3 gears without issues, I am thinking this overboosting thing is going on.

So I have an appointment with the tuner tomorrow and he is going to plug in and check the ECU with me in the car and go through the logs. The problem is hard to emulate on the road as you need to be doing past 5k in 4th which means going fast, so I don't seem to get the issue on the road at normal speeds.

So what questions should I be asking him when I see him regarding the tune so I can nail this problem there and then?

Thanks guys for any responses.

 

Did you even check your plug gap? It sure sounds like that. Simple issue if so.