M150 Sequential Gear Shift Boost Drop

[Stephen Dean]

The cut pattern, plug temperature, exhaust manifold temperature and other variables will all play a part in the noise that the car makes on the shift.

I have two cars that I work on that both have the same engine/driveline combination (Subaru EJ207, Samsonas 6sp sequential, M150 GPR-P) and with the same shift settings, one is quiet, and the other pops and bangs on each shift. All of the changes that I have made to that vehicle to reduce the pops and bangs have not really made a difference.

[Lutek]

Well, it was easier than I thought.

https://www.youtube.com/watch?v=s3zyTRxG1XQ

If it sounds like there is no cut as I said it simply means there is no cut at all.

Now gear change is soft and smooth as never.

boost isn't dropping at all. love it and can't wait for paddles and big turbo

[David Ferguson]

So what was your solution?
Are you reducing torque with the ignition retard, or are you also cutting fuel before ignition?

[Lutek]

no cut at all. only retard. So my first thought was to cut for a very short period time on beginning of gear shift with speed limit function and target very little % of next gear and finish change with only retard. but before that I gave a chance and tried to work with retard only. Before I was thinking on it but I always used some % of cut. and it didn't feel so good, So I kept using ign cut. I don't know why I was afraid of it because it was simply and obvious. For me it even looks safer for engine but will see, only thanks to retard I get lil bit more boost but for me no problem I'm even happy.

What's the best of it. even if I had 20ms gear of ign cut in logs I could see lambda lean spikes. For now lambda is sitting on the target all the time. Simply great.