CivicX Basic Sponsor
Like I said without taking a look at some parameters its impossible to know for sure. And I understand and I have read all the comments, I understand why you guys would feel like that and if its a improvement for you then so be it. The open valve will flow through the center pipe only since its the path of least resistance.We're trying to tell you that multiple people (myself included) noticed some weird cold start behavior after keeping the valve open. When the valve is open a vast majority of the flow goes through the center pipe. You can see it for yourself if it's cold enough that all of the exhaust is coming out of the center pipe instead of the 2 side pipes.
I don't know what the root cause of the difference in driving characteristics. I'm just saying it is happening. You are arguing telling us it makes no difference or we are imagining it or something. I made the decision to my fuse back in and keep the car running as well as it can.
- Maybe they were forced to add the valve to comply with emissions as the cold start is monitored heavily by the government? How quickly the catalytic converters warm up is critical for complying with emissions so a change in exhaust flow could definitely have an impact.
- If the flow of the exhaust has changed and the software cannot compensate for it this may lead to the feeling of stalling or shuddering.
- Your theory of it canceling out drones at cold start is a good one - that could be part of it too.
There was a noticeable difference before and after. Maybe the ECU can learn around it but I wasn't willing to wait and see for no actual benefit.
I don’t have a Integra type S, but if anybody can confirm if it opens the valve in sport mode and it stays open on cold start and while driving? Please do chime in.
I’m not saying you are imagining it, never said that. Just said that it was probably not the valve that was causing it. Now on the testing front, if valve is closed and it did improve shuddering and hesitation. When it did act up was it colder or hotter? These are factors that we have to take into account.
Also on startup, even if flow is increased in the exhaust side. There should be no problems, how do other cars make it work? This is what points me to the software side specifically on the K20c platform. An engine is a air pump and almost all engines will perform similarly given conditions. There are some factors like airflow through the head and how well the intake and exhaust flow. But it should not cause a hesitation mechanically speaking.
If the integra leaves the valve open in sport mode and on cold start in sport mode it just further reinforces my point. Since they both have to meet the same emission standards and if it did cause a problem they would not install that function but we have to wait for confirmation of a type S owner.