Hi,
I'm writing using my brothers account and had a quick question(s):

How do rotaries run such huge horsepower numbers on lower boost levels? (I'm coming from an EJ20 background so forgive me)

Also, the single upgrade turbo kits seem to use huge turbos (72s, 78s etc) Putting one of those on my car would be insane lag. What are the lag characteristics of these single turbo kits?

Is it that the rotary engines produce an unusually high exhaust velocity as compared to inlines and boxers, thereby alowing the use of larger turbos?

Thanks

 

Yes--velocity and thermal energy. Also, a 1.3L rotary engine is not comparable to a 1.3L piston engine. I'll let others speak more on the subject, as I don't want to give you bad information

 

It produces high exhuast velocity, heat, and volume, all which help to move the larger turbines...

 

The stock boost of about 11-12 lbs. maximum is not really all that high of boost levels.
For a street car that is decent, but look at Toyota's GTP cars of the '80s....they ran about 55 lbs of boost on a 1.5 litre engine to get over 700 hp, if memory serves....

 

Rotary engines are completely different from pistons, as you already know. Therefore, numbers are going to be very different also. Take a look just at the size of the engine, 1.3l, and then take a look at a civic that is turboed, with their almight 1.8l if they don't swap it. Look at the number differences, its the way the engine was built and the workings of it that allows for the numbers to be high even with a lower boost.

 

i don't understand exactly what you mean about the civic comment. the largest engine they (honda) has put in a civic thus far was a 1.6L b16. but if you turbo'd a b18 like you were saying at teh same boost levels you would likely produce more hp than a 13b at teh same levels

1.8L@10lbs
http://hondata.com/dynoericksracinggm.html

1.8L@10lbs
http://hondata.com/dynogsrturbo.html

and just for ***** and giggles heres a 2.0@12.5lbs see 372hp
http://hondata.com/dyno372turboimportbuilders.html

turbocharged hondas ain't no joke man

 

Yeah, but look at the extensive mods the engine has. With 11-12lbs, we have been known to push anywhere between 300-330 (or so) RWHP with only bolt on mods.

Let's use Adam Sawatari as a good example. The guy was running about 17lbs with a single, he dynoed somewhere around 550hp, and the guy ran mid 9s. To get anywhere near 550hp, a honda motor will have to at least run somewhere around 25psi or so.

 

Where did you get this info? 550 sounds high for only 17 psi. I'm not saying he didn't do it but it would take a hell of a port job and a hell of a turbo to pull those kinds of numbers.

 

The main reason why a rotary makes so much hp is related to VE AND to a free path into the "combuston" chamber. Typically, 70% of intake restrictions on a piston engine are located in the head alone. We have no cylinder head, no valves, etc...It's a much straigher and less cluttered shot in AND out. Piston engines require higher boost levels to overcome those restrictions. This info comes from a head engineer at Ford, btw...
Michel

 

Damn you make me pull out my archives
"Turbo Magazine" March 1999 P.82
Oh, I was a little bit off my figures

17.5lbs . He dynoed 548RWHP

The article states the 13b was extensively ported. No mention of the type of port job it is. "The main power adder is a one-off hybrid turbocharger from FasTrax Turbochargers.......the unit is a custom one off. A T4 turbine housing is joined by a diesel-based compressor housing that has been modified for rotary duty. A custom back plate is used to register the wheel which has been re-contoured for improved flow."

That's his secret sauce.

 

I like the smell of that sauce!!!

K

 

you guys are all wrong!!! the rotary engine creates so much power with such little boost because of its high amount of "mojo". it is a scientific fact that "mojo" has radical effects on many things. it makes ugly men attractive (austin powers). women usually cant bear the sight of a man with green "cavemanesque" teeth, but with the proper mixture of mojo into the bloodstream that same hygenically incorrect man can have the best of the best. its simply that simple. this equation can be related to the rotary engine and boost. lets say that the rotary engine is the ugly man with no chance in hell to succeed against the other more popular engines. . . oh my, here comes the boost. the boost is the rotary engines mojo. by adding this mojo directly into the bloodstream (bloodstream=fuel/air mixture) of the rotary engine he is now the hit on the street. . . now he is out on the road ready to eat everything up!!!. . . . . . . . . .. and maybe even get some head. . . . . . . . . .. . . . . . . . . .. piston head that is!!!

paul

 

 

the first engine was not extensively modified, it says in the write up that it was a sotck GSR engien and tranny. it also sates that it makes 260 hp at the wheels and 300 at the crank, all at only 10psi! and to top that it gets 30mpg on the highway. a stock FD only gets 255 at teh crank and something like 20mpg?
regardless i would still rather have a FD, im just saying that turbo'd honda's can creats some serious power. they are great engines.

 

You are forgetting one thing. What was the compression ratio on that first GSR engine? If it was a stock engine then I am sure its compression is higher then the stock FD engine's.

The FD has a 9:1 compression ratio. @ 10lbs of boost that is a simulated compression ratio of 15.1:1

If someone can find out the compression ratio of the GSR engine I can find out it's simulated compression ratio @10lbs of boost.

 

High exhaust gas energy and very straight exhaust ports (no valves in the way) allows us to use very big turbines so we can move more air (what the other guy said). Thats why we have big turbos on small engines and still don't have much lag. With big turbos you don't need as much boost to make power.

 

A few things about rotary engine propensity for boost.

1. Turbo is 4-6 inches away from exhaust;
2. Exhaust pulses are once every rotation of the crank even though the rotor runs at 1/3 the speed of the crank; and
3. The exhaust port is not a peripheral meaning it's a straight shot into the turbos.

 

the 1.3L rotary displ rating is based on 1 crank rev, the 4-cycle piston eng displ is based on 2 crank revs.

13B should be compared with a 2.6L piston eng, not 1.8L. that's what's done in road race competition regulations.