ok ive read through quite a few posts and instead of taking over ill transfer here.

i know that some turbo kits have a plate to close the auxilary intake port because of the lag that is produced by more flow without more boost when the valves open.

MM mentioned in another post that you can adjust useing the acessport when the valves open to either keep them closed or make them open when the boost can readily recover.

another option was to remove the valves and keep all ports open.

So for aftermarket FI kits there are 3 options

use plate (easy and instructed by kits)
remove valves (used in many reciprocateing turbo kits)
adjust opening times of valves

obviously the majority of people have used the plate. has anyone done the other two? seems a shame to waste extra ports in such a fast revving engine.

 

whut?

most people do not use the plate. The plate is fairly "recent" addition, and is only there because it was a tuning shortcut. It's also only used on the greddy kit.

 

The correct solution to dynamic geometry intakes generally is to tune them to open at the proper times. They have variable geometry generally to improve volumetric efficiency across a broader range of RPMs. What people have done on KL V6 IMs which have a VRIS (variable resonance induction system or similar wording) is dyno consecutively with valves shut, valve 1 open, and both open. Then, the point at which one setup overtakes the previous is basically where you should set your opening points. I think this would hold true with the Renesis. I'm not sure, however, how far up you can run the Renesis with ports closed. The idea of variable intake capacity as you run the RPMs up seems like a nice system to have if tuned properly both as N/A and FI.

I had always thought that Greddy included the plate so that their undersized turbo could maintain boost pressure at higher RPM values rather than the engine sucking air faster than the turbo could push it and watching the boost creep down. The fact that they used such an approach is probably the first thing that turned me off of the Greddy kit as designed.

 

i didnt realise the plate was new. regaurdless, has anyone actually tried any of this other than what phyisics says is correct? just be nice to have some real life numbers

 

MazdaManiac is all over this.

My guess is that you want all the intake valves to pop open any time you're in boost.

 

I had and still have the block off plate in my aux intake port. Been dying to take it off but never got to it. I can't recall where I heard it from but the plate was originally designed for the greddy ems to prevent the car goign too lean. Correct me if I'm wrong. Looking to take out the plate, not sure if it's going to make a difference at all, but I am sure it will let the car breathe better. Didn't know that the AP can control when the valves open and close. Interesting.

 

no ---intake valves can get a little complicated. Now we do deactivate the vdi(supercharged folks) and recently i discovered a small thing in that the vdi plates do not really seal well--so i am modifing this. The question on the secondaries and the apv's as to the opening point vs keeping open--you also have to take into consideration as to what your fuel injectors are doing. Be sure you are getting enough fuel if you plan on keeping the secondaries open all the time. It may be a little harder to do than you may think. Not to say you cant open them before the oem setting of approx 3.6K. But to have them open all the time....good luck.
There is a little bit of work that can be done on the lower intake, valve timing is one.
What we really need is a heat soak fix--can anyone say custom water meth system for the rx8?
olddragger

 

Sealing on the VDI is unimportant. It is just a balancer and doesn't do anything until it is open enough to carry full flow between the primary intake runners.
The pressure on both sides is equal in all applications - it just acts as a resonator for port closing pulses.
If you are using the AccessPORT, any time you command enough fuel for the secondary injectors to turn on, the PCM will automatically open the SSV. (It does this in the OE tuning at 3850 or so at calculated loads above 68% or so.)
Having them open all the time (like the Int-X does) poses no problem, but it may negatively impact off-boost throttle response and mid-throttle torque.

"Custom" water/meth is redundant - all W/M installations are "custom".
Water/meth should not be used as an engine cooling system. It is just meant as a charge cooling device.
If heat soaking of components is an issue, there are better ways to address it. It is especially important to not have any system devices producing heat off-load.

Heat "soak" can be handled thus:
https://www.rx8club.com/series-i-tech-garage-22/cooling-mod-sorta-149246/#post2524379

 

MM the intx used to have the secondaries open all the time--not any longer from what i understand.
i understand the pressure is the same on both sides but flow is better without the irregularities--remember we deactivate the vdi. The vdi is not sealing well because it is not in the correct position at the normal oem dead stop. it is slightly cracked open.
The ports at the beginning of the lower intake can also be modified for a slightly better flow.
Water meth is never used for heat soak issues. But it doesnt hurt to use it when heat soak in unavoidable. We have a LOT of heat soak in regard to the intake..
olddragger

 

It still does. There is a option on one of the screens to decide when it opens.

???
Who deactivates the VDI? Its still there.
There is no reason to remove or deactivate it.
Same goes for the secondaries and the AUX ports.

 

The pettit guys deactivate the vdi and yes there is a reason to do this.
olddragger

 

And that reason would be?