Which is better and why? I know the copound turbos are earier but which set-up is best for what or are they the same?<br>Any help would be greatly apreciated.

 

Just guessing ,but I would think compound has to be better. To do parrellel it seems to me you would have to use smaller turbos, because they are gonna see half the driving torque of the exhaust, once you split it. Smaller turbos would spool faster, but with less on top. Hey I'm guessing!? ??? Do you have access to a manifold that's divided 3 and 3?<br> Tony

 

For guys that need higher boost pressure, compound is the answer. Most turbochargers are not able to go over 3.5 or 4 compression ratio. So you are limited to about 50 psi. With compound turbos you can 2 stage the charge of air to make the turbo go to values over 50 Psi and stay efficient.<br><br>True twin turbo setups will be limited by the pressure ratio, but will spool quicker as smaller turbos have smaller inertia. <br><br>FWIW the manifolds on the CTD are already split front to back and port together at the turbo connection.<br><br>I hope this helps out.<br><br>J-eh

 

I actually know someone that is parraleling two HY9's but he is gating the exhaust and compressor side to run one up to 5-10psi and then open it up to run both. It should be interesting to see how it performs when he gets it done.

 

On a compound setup, is the smaller turbo the one that is directly attached to the manifold, or is the larger one the one that is attached to the manifold? Which one is the main turbo and which one is the secondary turbo?

 

The smaller turbo (secondary) is bolted to the manifold and the larger primary slides underneath it

 

Thanks. I was curious.