Yes, mod for mod, same psi, I think the intake manifolds, intake ports, and exhaust diffusers will hamper the N/A engine.

 

Your forgetting the fact that NA secondary ports are almost twice as big and have way more timming then T2 ports. The difference in the primarys isnt even close to enough to make up the difference in the secondarys, they only close 10 degrees soon then T2's..

 

exhaust diffusers arnt that restrictive, its just two "fins" and a bump,...

 

They are a restriction present that does not exist in TII engines, and the front hump I believe to be significantly restrctive.

 

The stock secondary/auxilary port combo and intake manifolds don't flow worth a damn, the increased duration just makes up for this lack of flow. We've seen this from countless engine builds; we're yet to see a 200 hp chassis dyno yet.
I have witnessed ported 4 port engines exceeding this number, running the stock TII intake manifolds and S5 N/A internals exceed this number, but don't have acess to the dyno sheets, so can't stake any real claims.

Because of this, and countless experiences in the dozens of engines I have built and tuned, I stand to believe that mod for mod, the TII engine would be a more powerful machine. Replace the intake manifolds with a custom system and get rid of that auxilary port system and it would be closer... but at that level of cost, you might as well just go with a custom periphereal port.

 

...this thread is old...

Jimmy sold his car and left the rotary world. I blew mine up and haven't had the time to get it going again; plus I ran across a gokart frame, a 175cc dirtbike engine, and am looking at t-25's.

 

I have Jimmy's motor. Let me telll you, he knows how to build a good motor. It is getting turbod right now as well. No exhaust diffusers!!!

 

Liquid great idea. U ever get that part made to test on my car?

 

nah; getting it professionally done was going to cost me about $260 for the first one, and $60 per after... not something I think is worth it.

as of now, I'm working on the 9.7:1 4Port N/A Dizzy'd MegaSquirt thing.

 

Hey Jim you still never sent me the rest of my payment.