The issue with out of the box manifolds is that I'll have no idea if they fit. Full Race is a local company so I guess I could see if they would let me try to test fit one but who knows.

 

Yep, won't fit in a 8

Your gonna need a custom manifold.

 

Say what!? Where do they put the heat? Coolant? Air cooled? Got a picture?

What if you do rear mount?

FC n.a's have a cooler fins in the header. It would be interesting to make them on the exhaust underneath the car.

http://docrace.files.wordpress.com/2011/10/dsc01028.jpg

 

Behr America Improves EGR Cooler - TopNews - Aftermarket - TopNews - TruckingInfo.comI thought i had remembered the new ones having this feture but cannot seem to dig it up at the moment. I did find a few aftermarket EG coolers specific for the 911. Like this one: Exhaust Heat Exchanger Set - PORSCHE 911 / 930 Turbo

Also seems to be common in diesels. Behr America Improves EGR Cooler - TopNews - Aftermarket - TopNews - TruckingInfo.com

 

Problem with a variable geometry turbo is heat from what I've read. Therefore they was used some 10 years ago in diesel engines on VW(and before that too probably) as diesel engines have lower EGT. I've driven one of these VW, and the result is good. Clearly better than a normal turbo.

But because of this heat limitation, its not a good match with rotarys, as I understand they have higher EGT's for some reason(witch I haven't looked into). Therefore a twin scroll would be a better option.

The question is what to do with the center exhaust. Splitting is difficult, therefore my thought was that bypassing turbo with this runner might be a good compromise?

 

Don't think thats a good idea. Are you putting the wg on the center?

 

Agreed A better idea that was mentioned above was to put the center exhaust on one side of the twin scroll and the other ports on another side. This may not be easy on a low mount set up however.

 

I think that would kind of defeat the purpose of a twin scroll manifold... the whole point is to keep exhaust pulses from the two rotors separate so they don't interfere with each other.

 

Right.

 

Which rules out the concept for a Renesis ..... unless someone can be bothered with the painstaking task of separating the center port . But doing that would probably make the exhaust more restrictive ......... which is counter productive.

 

Yeah it would take some fab for sure and who knows if that would even be beneficial. Only one way to find out.

 

The other issue, is even if you divided the center port and fed them into the larger exhaust port runners, there's no good way to know that when that exhaust pulse re-enters the main runner if it will be in time with the exhaust pulse in the main runner, or if it will cause issues. Again kind of defeating the purpose of a twin scroll setup.

I think for a renesis it's just not really viable, just like how all the turbo 20b guys run massive open volute turbos because they have three exhaust ports. Granted they are all timed differently but I think twin scroll on a renesis is more trouble than it's worth. Even if you get it to work, my guess is the results won't be stellar or anywhere near a 13b-REW or RE twin scroll setup.

 

This was my idea:

 

Why? wouldn't the much lower pressure of the center exhaust ports start taking more of the energy, reducing spool on the turbo? Seems counter productive.

 

That won't work at all, having a route for exhaust to freely bypass the entire turbo system will kill spool, if the turbo even gets going fast enough to make boost anyways. Exhaust gas will favor the path of least resistance and all of that exhaust gas going around the system is wasted energy that could be used to spin the turbine wheel.

 

you guys ever see this? Gasoline DualBoost Turbochargers | Light Vehicle Gasoline Engines | Our Technologies | Honeywell Turbo Technologies

 

My thought was that you could keep back pressure close to zero(or even adjust runner length to have it lower than atmosphere at certain RPM). Now, you would run very small exhaust area at slightly above idle, since turbo runners are more restricted, possibly having a better exhaust velocity for earlier torque, in the area between idle and boost. When RPM increase, center runner will be restrictive and pressure will increase at side ports to evacuate gases, turbo start spinning, with the advantages of a twin scroll, but with less gas going through the turbine. Therefore lower torque and HP, but flatter torque.

But this is just an idea, maybe the center runner would take all gases, leaving turbo with very little. My degree is in another field than turbo and exhaust design

 

There is no maybe about it ................. that is what would happen .

 

That looked like something nice. Good finding.

 

Allright then!!!

 

Wow ! that looks like very promising technology. Me want

 

Agreed. I would love to look into it more.

 

Everything always seems ideal on paper ..

 

^Well, if no one had tried to think new we would be stuck with the diesel engine. Or horse and carriage for that sake.

One of the ifferences between a good and average engineer is to get paper to match reality. It seems like they have done a honest try: http://turbo.honeywell.com/assets/pd...esentation.pdf

Sales people on the other hand....

 

There's a big difference between being practical and being a ****** with a dream unhindered by the concepts of reality

1. No (as in zero) aftermarket applications available yet
2. No information on fitment, but it should be obvious just looking at what is shown it won't be tight space friendly i.e. Low mount in an RX8 is not likely
3. Rotary turbo requirements are different than piston engines. There really isn't enough known about it's true capability to fulfill a rotary engines air flow demand over a very broad rpm range