Duke

That manifold is probably designed for low end torque with its stock-like long runners and small plenum.
Aftermarket ones tend to do the otherway around to get better high end breathing.

macnewma

Ya think so? I would think a race motor would want more high end breathing than low end torque. I am certainly not an engineer or engine builder though.

The engine was once a 3 liter engine so I don't think lowend was a problem. Maybe there is a compromise between the longer trumpets and the smaller plenum? Maybe this is a more optimal design?

Max

Duke

I agree. But as far as I can see that intake is designed exactly the same as the stock one. But it can still have better and more even flow than stock of course.
But long runners promotes torque.

toddk911

I thought the best design for our cars is a big plenum with longer runners, for quicker spool up and good low end response.???

Also, I would not want to persue this if John is as he is the tuner and I would not want to step on any toes. I would be more than happy with some joint venture; i.e. someone handles the R&D, and I take care of production.

Tomas L

Our cars has long runners to give them better torque an drivability in the low rpm range before we get boost.
The purpose of the plenum is to act as a buffer for the pulsating airflow to the individual runners. A big plenum reduces the risk that the plenum isn't able to supply enough air to the runners, a small plenum gives better throttle response, smaller volume to fill when you crack the throttle open.
A way (partly) around the disadvantage of a big plenum is to put the throttle valves after the plenum, then the plenum is always at least at atmospheric pressure. You still have longer time to fill a larger plenum with presurized air when the turbo spools up but the effect of plenum size on that should be smaller.

Tomas

toddk911

Ok, so longer runners with a smaller plenum??? Sounds good.

Asarus

For your information, i asked some information to Porsche about this carbon fibre intake manifold. After some research and calls to Porsche Motorsports, they said this part was not produced by Porsche and the part number was unknown...

Lark

Here is another pic. as you can see the runners are quiet different from the stock one.

Part number

Brett

It also apperars that with this configuration there is much more room to fit a larger turbo under there

Darius Juca

To me it looks like the runners are actually shorter.....actaully they are if you measure them from beginning of runner till head(not by much)...and it looks like the plennum has actually more volume than the stock wich makes sense..this is a well designed manifold!!!!

Konstantin

well I did the same BEFORE I post here.
If It would be that easy I wouldn't ask on Rennlist. I not only called them but I also have been IN the Porsche Motorsport parts department and searched for all 968 Turbo Parts. It is not allowed but with the right conections it is possible.
Of corse they can not find it since it do not exist any longer it is not registered in a computer or in acatalog and it was a special part and not a Motorsport production part.
same as the Portotype Turbo in my 968 Turbo S or the special heads for the cup cars (not the one listed on their catalog) and so many other parts.
so If someone has one or seen one or know where to get one let me know.

I did my homework and just ask Porsche if I can buy one is not the solution here. It is not that easy
I am also looking for the central Locking system from the 968 Turbo RS. and the wings on the yellow 968 Turbo RS on my web site

Konstantin

toddk911

"and it looks like the plennum has actually more volume than the stock wich makes sense."

For a track car.

toddk911

I'm getting a stock intake this week, We will start with that to make sure temps and fitting are ok. Then we can make improvements from there, i.e. extend the length of the runners and smaller plenum, for more low end and quicker throttle response.

My buddy jsut found out there is a hot rod shop right down the street from his fiberglass shop. They have flow bench, dyno, etc. Might be able to work out some free testing time.

Konstantin

let us know how it performs. Be sure to make dyno before and after so that we see the difference.
The Intake above make true 40+ HP. If you can get 20 HP more it would be worth the money

Konstantin

Duke

To make it gain low end torque I'm afraid it will lose high end HP.
I'm not sure of the market, but judging from the other products already on the market it seems more people are interested in gaining high end HP instead of the opposite.