Saner

iTrader: (1)

I've been toying with the idea of going single turbo for quite some time. While researching I noticed that most people who went single did not use anything lower than a .82 hot side in fact found that most were running a 1.0 or higher turbine for street.

A lot of my friends were criticizing me saying that using anything over a 1.xx hot side would be incredibly laggy on the 1.3l rotary. Mind you they are all piston engine owners, mostly 4cyl, who have no experience with the rotary. Me on the otherhand have never even been in a single turbo FD, so I didn't have an explination as to why these motors can run something so large yet still be streetable.

Your thoughts?

Chaotic_FC

rotaries don't have valves, therefore they breathe very freely. especially with a high overlap port.

ScorpionT

iTrader: (3)

A 13B is rated for 1.3 liters, but thats for 2 combustion chambers, 1 per rotor. A rotor being triangle shaped actually has 3 faces. Per 360 degree rotation of the eccentric shaft you actually have 3.9 liters (100% VE) of air being moved. You need a much larger hotside because you are moving much more air than 1.3 liters per rotation.

Tell your friends to start reading before talking about things they dont know haha.

Chaotic_FC

this is incorrect.

a 13b does in fact move 1.3 liters of air per rotation.
the rotor moves 1/3rd a revolution for every revolution of the eccentric shaft.
it is the equivalent to a 2.6 liter piston engine, for a 1.3 liter piston engine takes 2 full rotations to make 1.3 liters.

Evil Aviator

That number is a ratio, not a physical size. You can't directly compare A/R ratios unless the turbochargers are otherwise the same size.

Anyway, the rotary engine's exhaust is very powerful, and is therefore able to swing a turbine wheel pretty well. Plus, as explained above, the 13B is more comparable to a 2.6L 4-stroke piston engine.

ScorpionT

iTrader: (3)

Doh! I realized I explained it differently than I was thinking. Long day

Let me fix my explanation. Each rotor of the 13B has a complete cycle(intake, compression, ignition, exhaust) per rotation of the eccentric shaft. In a piston engine, the crank rotates twice to do the same thing. Like Chaotic said, the valve-less system also accounts for the air requirements. The combustion chamber is cleared more efficiently with a rotary than with a piston engine, which means higher airflow requirement.

Saner

iTrader: (1)

Thanks for the input, guys! If anyone else has any more info feel free to chime in. I'm a sponge and need to understand this before I actually act upon it. I want to make sure that single turbo is the route I want to go.

Thanks again

kenn_chan

try this one on for size..... a rotary engine has about 3 inchs or less from the combustion chamber to the start of the header and its a straight shot, no valves or anyting in the way.

each housing is in time with the other so all of your exhaust pulses come out (think the combustion chambers...3 per rotor, 6 total) in synch with each other. its a natural 3 into 2 header before it even enters the actual header, this creates a much more "orderly flow" for the exhasut gasses resulting in a more powerful "pulse" and a higher efficiency in the exhaust track. Higher efficiency allows a smaller displacement engine to spin a larger turbine with a larger a/r and still spool at a relatively decent rpm. the same as a higher compression piston engine can spin a larger turbine quite well

remember we have not discussed the relationship of the compressor here just the turbine.

kenn

Saner

iTrader: (1)

Great explanations from everyone, thank you.

My goal is to choose a turbo that will be fun to drive around town and still put down some good numbers at the strip. I will only track this car MAYBE 2x per year so my main objective here is to have a street car. I plan on using a PFC and my motor will have stock ports. I understand that porting will open up the ability to produce more power, however, I haven't been able to enjoy this car for several years because of the ongoing problems the sequential system has been giving me. I want to do the best I can with what I have.

I've been researching to find out what turbo would best suit my needs, however, everyone has a different definition of "streetable". Is anyone in or around the CT area who has a single turbo, stock port FD that can take me for a ride? It'll give me a better idea. Shot in the dark, I know, but it's worth a try.

In the meantime, what are your thoughts on your definition of a streetable turbo for the FD?

Thanks

ScorpionT

iTrader: (3)

Streetable turbo, GT35R or Precision 6262. My first two picks.

Chaotic_FC

if you want it to be REALLY streetable, you can always go with twin equal sized turbos. you probably wont even feel lag. Also, such things as dialed in intercooler piping, and a v-mount setup will help with lag. As open of an exhaust as you can get away with also helps.