Rotary Development

[NoDOHC]

Originally Posted by GravityFed

i still want to see some dyno charts

Unfortunately, now it will have to wait until spring, as dyno season is nearly over.

The charts that I have so far are posted under intake manifold modifications.

Originally Posted by classicauto

A custom intake with less porting (and presumabley revs) won't net an extra 40% increase in peak power, assuming 200 to be the practical peak benchmark for a well done streetported 4 port.

I think that 200 WHp is selling a well done 4-port drastically short. As I have posted before, I am convinced that mine will make 250 WHp just as it is with a better ignition system that allows it to make full use of the VE curve that is already has. (The explanation is posted in the intake manifold modification thread and need not be repeated here).

Don't forget that I am running 8.2:1 Rotors, a far cry below the 9.7:1 rotors that most race cars run.

Even assuming that I have eeked the last horsepower out of my engine (no improvements to be had with better ignition), I still make 216 WHp using low-compression rotors and a TII manifold (No RE builds here). My intake was piped to the front of the car (cold air intake in the fender), I had stock Racing beat headers and presilencer with dynaflow mufflers and stock y-pipe. I was also running a stock mechanical fan with a bad clutch (stuck in engaged position), Turbo drivetrain and stock tires (more losses on a dyno than low-profile tires on larger wheels). Neither was I running royal purple or some fancy oil to minimize drivetrain loss.

I think that many would argue that I have left a lot on the table there too.

I think that the torque numbers speak for themselves (160 Wlb-ft @ 6100 rpm), The stock port timing will make more torque than the typical streetport as it allows for a more complete intake stroke.

I have long argued that bigger is not always better, I will continue to hold that position. Most streetports are designed for turbo cars, where the late port close allows the car to run more boost. This does not help with a naturally aspirated engine, which needs all the intake charge that it can get.