The IMRC will work no one said it wouldn't but is it really needed? What is the purpose of the IMRC and dual runner intakes??????
So you figure with an oval port converted to split port there is a potentially better mixing? How do you figure its not worse? Have you gone through the countless hours of the testing the factory does?
Your entire idea of how the oval port converted to split port is all fine and dandy but you are really forgetting the lack of separation between the air with different velocity and the enormous port size which just kills the velocity...
I do really think its easier to fabricate a fuel line than to come up with an entirely new head port design don't you think?
What is the big deal about EGR except emissions care to enlighten me? EGR is an emissions control device nothing else, if your so worried about emissions why not keep the precat's too?
1. Yeah I say potentially because I don't know for sure. I can tell by the driveability that it is NOT worse than stock. Qualitative assessment, driveability equal to or better than stock. You on the other hand cannot prove that it is NOT Better now can you?
2. I am not forgeting the lack of separation as the air exits the primary valve.
YOU are forgetting that the primary runner is what causes the air to increase it's velocity, not the number of valves. YOU are forgetting that like a train, once that air is moving it has Momentum. It doesn't just suddently lose that momentum because it opens into the wider "pre-chamber" where two valves are instead of right into the cylinder. There is no instantaneous reduction in speed and that means it will take a while for the air to slow down. It will probably still push most of the air through the valve port that is right in front of the air stream coming out of the primary runner.
Therefore the air still has enough momentum to enter the cylinders at a greater speed than if it were traveling through a much bigger ovalport the whole way. Is it better than a full split port all the way down to the cylinder itself? Probably not but the more evenly distributed fuel carried through both valves probably makes up for it IMO. (for another through provoking example: think quasi-dual exhaust versus a single exhaust of the same diameter; the quasi-dual restriction is determined by the single pipe portion not the dual portion)
3. 'easier to fabricate a fuel line....' Not really, at least not for someone like me. I'm not creating a new design I'm adapting two designs. That was relatively easy. Same as adapting two fuel rail designs together. The time involve differs, not the difficulty. In that case you would have to evaluate all the remaining time to hack anything else up and fit it as part of the final assessment to complete the job.
In my case everything that can be operational should be operational was my goal.
It doesn't mean that your method is wrong. If your goals differ from mine then we cannot compare easily.
EGR operational. In the tuning code there are sections that have a timing multiplier based upon EGR flow rate. It is there because the engine can tolerate more timing under those condtions....or so the descriptions say. That seems to me that it could possibly be usefull in other ways too.
Emissions are important to me and they should be to you too. You ask why not keep precats then? Well you've heard of planning and prioritization right? I prioritize making more power as my #1 goal, my #2 goal is driveability, my next goal might be reliability, or emissions operation depending on my state, my #4 might be fuel economy, my #5 might be maintenance costs....you get the idea.
These values are like slider bars, you can't increase one without decreases somewhere else. I would not increase power so much that I couldn't live with the driveability so I set mygoals a bit lower. I also want it to be somewhat reliable though not as reliable as stock may be acceptable.
Pre-Cats are most usefull on cold startup and not necessary beyond that but nice. The car still meets emissions requirements without them so that makes it an easier choice to get rid of them. I kept the main cat because it wasn't that much of a drain on power versus the majority of the emissions work it does.
etc.
So unlike some, I approach this thing logically, with goals and plans and such. Consequently I have had a lot of successes in all the areas I've chosen to stick my fingers into.
