Twin Turbo Idea
 

This is more of a theory thing, and im not planning to actually put this into real time, as in make a setup like this, or ever want one. By answering my question, you'll help me understand turbo systems a bit better, thats all, so please, I'd appreciate it if people would not tell me how retarded this idea is. thx


With the rotary engine, a 13B, using a twin turbo setup, how would running one turbo PER intake rather than combined compare?

So you'd have two throttle bodies, with two intake manifolds running into the engine with a twin turbo system (obviously not in sequence) where one turbo forces air into just one rotor, and another turbo for the other rotor. The intake charge is NOT combined.
Would you get better throttle response? How would this be beneficial, why would it not be? Lets put costs aside and just look at overall performance over running two turbos with one intake charge per two rotors, and two turbos per two intake charges seperate for each rotor?

thx guys, its always fun to play around with ideas on here.

Too much fabrication/piping. You;d need 2 intercoolers, and 2 pipes running all around the engine bay.

omg, thats just what I was trying to say in the first couple sentences. Im not talking about costs or fabrication, becuase I realize the work involved. This is just strictly on a discussion level and not implementation. thank you.

As far as 2 intercoolers, you could run one intercooler, dual inlets/outlets. Since you have 2 throttle bodies, you'd need to rig up 2 throttle cables. Then if you still wan't to retain your cruise control, you'd have to rig up another cable to control both throttle bodys. Of course, as you already stated, you'd need a custom intake manifold, and you'd have to find 2 throttle bodies, or find a twin throttle body. Other than that, it would be just like any other twin setup.

Now that you know all of that, it would be pointless. With a normal twin setup, you have 2 turbos that feed both the primary and sec. runners all in one. No matter which way you do it, each rotor will receive the same amount of air. There's not much of a restriction with both turbos feeding 2 primary and 2 sec. runners all-in-one. If there was a better throttle responce, it'd be so small, you probably wouldn't even notice the diffrence.

What i'm doing with my twin setup is running an intercooler with dual 2" inlets, and a single 3" outlet to a Mustang throttle body. Then it will flow from the TB into a custom intake manifold. I'd say this is pretty much the best way to go.

-Alex

Keeping the two intakes devorced from one another is a bad idea. The two turbos will NEVER be pumping in the same amount of air no matter how good your wastegate system is. One or the other rotor will always be getting more air and unless your engine management can handle individual air/fuel ratios independanly you'll hear a BOOM soooner or later. Even if you did run independant spark and fuel, it wont be a smooth running engine. Balance is one key to power and longevity. Thats why you should combine the turbos output together to what ever in-balance is going on they cancel eachother out so both intakes see the same amount of air regardless of rpm,load etc. You can combine both turbos output via a merge collector before the intercooler, after, or use the intercooler itself as TT Rex 7 is discribing or even a simple crossover pipe. As far as the intake, twin throat throttle bodies are a common thing used on rotaries.

~Mike............

I got to the two throttle cable parts... and stop reading but.

That setup just leaves too much room for error. Its one more throttle cable to get stuck, and one more coupler to blow off. It just makes the car more unreliable.

-- Is it a cool idea yes. Is it practical--- NO.

Yeah, what he said... This would be a tuning nightmare.

Don't think you would necessarily need two cables.. You could use an intake such as the TWM or the Tweakit's Individual throttle body setup. Only one cable, TPS, with two injectors per TB. Hardest part in my eyes would be tuning the car.. You would have to factor in compression numbers, or in other words, if you had a stronger front rotor than a rear rotor, i think it might make things a little more difficult. Neat idea though.

-Justin

How would this setup say compare to a single setup with the same CFM being forced in? In terms of high end HP and say like boost times? would the true twin turbo spool up faster, the same?
How would a true twin turbo setup idea like I mentioned, compare with the stock twin turbo setup if say the CFM of the intake charge were the same with both setups?

thats what im really getting at. thx for your time. ;)

i think you would almost have to look at it as two seperate motors as far as tuning and everything. You would be able to flow alot of air though but im not sure it could spool well with only on rotor because of less strokes of exhaust flow. Even if they were sized well it wouldnt be a smooth spool

There was some guy that ran two 13B's into a single trans (7Stock 5&6 possibly 7 too), I bet he got worse numbers than a single 4 Rotor. Why ? Because Mechanically nothing is totally equal, so you have to tune / compromise for the lowest common denominator... that's why tuners on piston cars have to start adjusting when the first (hottest) cylinder strarts knocking, and not when the last does...