SleepeR1st

iTrader: (1)

http://www.youtube.com/watch?v=VK0uy...eature=related

Just skip ahead to where they get to the skyline. The tuner talks about making a highly responsive skyline, instead of a huge numbers monster. Not sure what that means, faster spooling turbo or what?

In terms of rotary performance, is there a road to go down in terms of responsiveness, or big numbers?

rxforspeed

iTrader: (3)

The "responsiveness" they're referring to is torque. Torque is what moves your car, not horsepower. Torque is much harder to squeeze from rotarys or smaller four-cylinders than big gas-guzzling V-8's, but it can be done. If you're looking to build a torque monster of a rotary, you might want to think about running more than just two rotors...

For a good streetable car, whether it be a rotary or piston-powered, you really need a good mix of torque and horsepower. The more efficient your engine is, the more power and torque it will produce. I'm building a nice streetable 13b, and I'm not expecting much torque from it. It'll be turbocharged, but will retain ports small enough to assist in low-end torque production. I don't even expect to hit 300HP (but I'd like to), but my concern is the "responsiveness", or the low-end and mid-range torque that pins you in your seat when you stomp the gas pedal...

In terms of building for "responsiveness", be realistic. Don't buy the biggest exhaust system, turbocharger, or throttle body you can find. If you don't know what you're doing, ask a reputable engine builder for assistance or have somebody else build your engine for you that knows what they're doing. You have to build with the entire "package" in mind, not just individual parts. When you have a system that's engineered to perform together, you'll get better results than you would running a 4" exhaust system and a monster BOV and wastegate on an otherwise stock engine and turbo...

diabolical1

iTrader: (3)

i think you can retain/create a great torque curve from a rotary (or reciprocating) engine by sizing the turbo correctly. the problem that i see many guys put themselves into is trying to copy someone else's setup with no regards to the details that make it work. so they'll go out and get a huge turbo that works great with a bridgey and try to put it on stock ports.

port your engine for the application - sometimes that may mean settling for smaller ports - whether intake, exhaust or both. for exhaust, i think you should buy the biggest exhaust system for it as long as it's the biggest for "your" setup - however, that may not be very easy to decide. on the induction side of things, careful porting to clean up the airflow in the manifold and throttle body or simply switching to an aftermarket system that is proven to have better response to throttle inputs would be a good idea.

Viich

iTrader: (1)

Well, sort of. Bear with me for a second. Torque is twisting force. Power (Horsepower) is work done / time. With a rotational force, work is torque*angle rotated. Power is therefore torque*angle/time. Angle/time is commonly known in automobile circles as 'RPM'. Power, then, is torque*rpm.

The upshot of that long explanation was that yes, torque is what moves your car, but if your engine is spinning at higher RPM, your engine is applying that torque over a greater angle, thus generating more power which is used to push your car forward. It's the whole argument of why the small engine reving higher is better, but you can only get so much that way. Obviously, twice as much torque reving at 2/3 the speed is going to be more power.

No argument with this. You can adjust how you drive to compensate for a higher power band, but a wider power band is way more fun to drive, and you get what you want by designing a whole system to do what you want.

slo

iTrader: (1)

You will get the greatest responsiveness with the largest most free flowing exhaust possible and medium to large street ports for a turbo. Bigger ports and less exhaust restriction will spool the turbo faster.

A turbo sized to make 300 WHP on a 13B should make near full boost a hair over 3K RPM, it would start falling off over 6K ibut would still make for a very responsive car with a real wide power band.

RETed

They are probably talking ditching the ITB's on the stock intake system.
You can make bigger power by going with a big single TB and removing all those little ITB plates.
Removing the stock ITB plates decreases response, but it increases power potential.


-Ted