I have twins, hx35, needs some work but has worked very well. I d like to slow down the over speed issue with the 35. So I have some choices, rebuild the hx35, or

1. 35/40 hybred, 60 mm compressor with larger compressor housing.
2. super 40 from pdr.

I like the super 40 cause it uses a 16 housing and 4 inch outlet, but will it spool slow on twins, my large turbo is a ht3b 26.

Im adding a coated and ported manifold, and a spacer with a 50 mm waist gate to bypass the small turbo.

 

I'd go with the super 40 if I were given those two choices. Yes, it spools a little later, but it gives you something in return...

jh

 

I have a Dodgezilla 14cm WG turbine housing. I believe that is with a 62mm compressor 8 blade wheel. Tyically 6 blade wheels are used from my understanding. City Diesel said the 8 blade would be better for towing so I kept it.

Running as a single I had issues with the DZ. It basically built boost too fast. I don't mean that the way it sounds. I mean too much boost at too low rpm. I did have light surging at 16-20 psi of boost below 2000 rpm and barking issues that could make shifting a challenge. I don't know how a 6 blade compressor would have changed things because I installed twins. I saw drive pressure roughly equal boost until about 30 psi. The sweet spot (for my altitude of 4200') is about 26 psi of boost.

In my case, for towing the DZ/s400 works very well as well as general hot rodding. I seldom concern myself with EGT. All of the DZ's (running as a single) bad manners vanished. Making 55-60 psi of boost is nothing that is very hard with drive pressure just a little higher. My pop offs are set for around 55 psi so measuring drive there is difficult, but otherwise it hangs with boost fairly close. The spool seems to be most efficient at 1800 rpm and above. Below that it can struggle a bit. At 1500 rpm it can still make boost, but it is also fairly easy to overfuel and to have a nil power coal train especially in 5th gear.

I can only guess that the super 40 would spool at even higher rpm. I would find that out for sure. So, if it were me, I would make my decision depending on if I wanted more on the bottom for towing or open up on the top for max Hp.

Jim