Another design we are now looking at for our intake plenum. The parts below the plenum (dual injector manifold and individual TB's) would be very different.

This manifold has been flow tested at over 700 cfm with all runners delivering near identical flow. Notice the buld kidney shape at the first TB's and how it gradually necks down towards the final ones. Kinda reminds me of the same principles applied with good intercooler tank designs described in A. Graham Bell's book, Forced Induction and Tuning.

 

is that the WC plenum?

 

The WC Plenum is in post #3140 above. The plenum in post #3146 is a custom designed and matched flowed plenum.

 

I really like the new plenum and the flow rate. Interesting info on the other plenum mentioned above though. Nice talking to you the other day Chad. I'm looking forward to this beast come alive, c'mon already.

 

Art,

Enjoyed talking to you also. Again, tell your mom I said hi and let her know we all all praying for her.

I suspect the motor will be assembled by the 15th of this month. This plenum thing threw a monkey wrench into getting in on the engine dyno before the end of the year.

I do not believe the WC plenum would cause damage being our tests flow air in and then measure air out each individual runner. They are all open at the same time which is not what occurs in a turbo charged motor's operation. The plenum actually flowed about 75 cfm more than the 997 GT2 plenum. Like I said the difference is the balance of each individual air flow at each leg. The 997 GT2 is relatively balanced at all legs using the same parameters on the flow bench.

Probably would not hurt the motor but I have to ask what could we be leaving on the table response wise if everything is balanced. I'm sure Porsche could tell us but they are not going to say a thing. Could this be the last undiscovered frontier of the 996tt motor? Nah, Porsche already has direct port fuel injection. Not sure if I want to smile or cry?

 

I can't believe all we are waiting on now is for Swain to return our pistons. They were sent out to them two weeks ago.

 

While we are awaiting the return of our pistons from Swain, we are turning our attention towards the intake from the wye pipe to the heads.

We will not be using the Mustang MAF so this area will be straight tubing. The same for the old location of the 90 mm throttle body. The piping will run from the wye pipe to the splitter on the intake in the above pic. We are in the design stage once the charged air leaves the bottom of the above plenum.

We have to incorporate the individual throttle bodies (and linkage and servo motors) with the dual injector manifold. The tricky part will be the funnel design part that goes immediately following bottom of the plenum to the throttle body so as to accomplish balanced flow from the plenum to all six throttle bodies. We will also have to come up with a fuel rail to work with the dual injectors.

 

looks sick man

 

Not really sure yet. I wasted about 5K with the WC manifold before I decided something different may be better. I suspect no one on these forums have flowed all the different manifolds before. I have spoke to different tuners and none that I have spoken to have. It took looking at what Porsche was doing with the different year model turbo's and GT3 along with many flow studies to come up with what we believe is an understanding as to the dynamics involved.

It is very possible that we will be wrong and our concerns really will not matter. More study will tell and hopefully others will start to take their own look. This is an area the aftermarket has followed only up to the splitter. The plenums after the splitter to the heads have been a no man's land. By that I mean people have taken what Porsche has to offer on different models and mixed and matched, without any real studies or significant modifications. Our gut feeling is there is really something to be gained here.

Furthermore, eliminating the MAF and the single throttle body is entering into two areas that not many have ventured with the 996tt type motor.

 

Chad make sure you calculate the volume of that intake. There is a formula related to the size of the motor that needs to corrispond to plenum volume. That one looks great but small.

 

Those rods look beautiful, Chad. The process involved in making them that you described really goes to show how much technology is going into this motor.

Do you already have all the chassis parts spec'd out?

 

You brought up an excellent point.

Yes, the motor in it's entirity has been mapped out for flow and volume. Frankly we did not expect the issues we encountered with the parts we are addressing now. Neil was the one who said everything we have done to date could be a waste of money if we didn't map the intake to determine if it in fact was matched to the rest of the motor.

Funny thing is ......... we looked at the turbo's and glossed over the plenum and injector manifold in the beginning.

To directly answer your question ........ volume is also being blueprinted. The above is what we are looking at now, it does not mean it will be what we finally use. Heck, I thought I had the answer with the WC plenum. I am simply keeping people up on how things are pregressing at this time.

 

I wonder if the new Porsche expansion type intake manifold would work on such a high power build.

 

I am not sure exactly what manifold you are referring to. We are using GT3 RSR heads which have been slightly ported. The 996tt and the GT2 plenums will not work due to their much smaller ports.

 

All the parts have been determined. Many have already been installed. Cary Elsinlohr of ERP will be handling this for me. He has parts that have been on his rack for years (that have been paid for), however he has not been able to install due to the lateness of this dam motor assembly.