Real Differences Between Turbo Flanges

[ozzimark]

I thought with the bigger one (i have the 7cm^2 in my garage lol...seems huge) your actually more at risk for spikes etc, since you have a small turbo that's a fast a spooler with less restriction which can now spool out of control w/o proper tuning/Boost controller? Atleast that's what i was told about the dangers of the 19t with it, although i imagine that it's affects at 17PSI are not going to stand out and w/ the tune will likely be even safer.

Personally i would switch to angled if you've got it out etc...the DP from OBX for angled is >>> then the straight pipe version as well, incase your tight on money.

Larger nozzle area is the same as a larger A/R, it will cause the turbo to spool a bit slower, and flow more at the top end.

If you look at them side by side there are noticeable differences in the size and smoothness of the flow paths.

I was under the impression that the change to the A/R of the housing was the only real difference, though I could be wrong. I remember Hussein having a picture comparing the two housings around somewhere

Edit, found his old straight flange vs. angled, not quite. Still digging :lol:

[jschaefer7406]

They're the same "size" afaik, the difference is in the turbine nozzle area, 6cm² vs 7cm²

Right. Inlet and outlet sizes are the same (same DP), but the "choke" area for the turbine is larger on the 7cm. As said, this allows for better overall flow up top, but slower spool and less bottom end boost.

On another note, anyone have any experience swapping between OEM actuators? Wondering if the actuator was originally chosen based on the turbine housing characteristics or compressor character?

Here's what I mean. 16T originally used a 218/60 actuator with a straight housing (M4.4). When ME7 and the angled turbine came along, a 275/60 actuator was used. Compressor was unchanged, only the turbine housing and management system. Why the stiffer wastegate?

Why I ask is this. I am running a 15G with 6cm angled housing and ME7 management on my 2000 (WothRLine custom 14 psi tune). I have been going back and forth about what actuator to use. Like the feel of the 218/60 unit and HD TCV, but was seeing some high part throttle spikes (to 15+, then falling to 10 and holding). Loved this setup otherwise, but don't want to risk my otherwise stock LPT engine. That in mind, i swapped back to a new 150/40 actuator and new OEM TCV to experiment and boost is slightly erratic and the car feels more sluggish. Thoughts?

Sorry for so much info (and possible thread-jack ),

Joe

[Bah]

Oooo makes sense now that i read up on it a bit hah..

But(sorry i know im still off topic) does that mean with the larger A/R that your less succeptible to bend rods? Or am i thinking about this wrong? I never really researched on it, but i figured i'd ask some knowledgeable guys before i put the flange on =p

[TRACStar]

But(sorry i know im still off topic) does that mean with the larger A/R that your less succeptible to bend rods?

IMO yes, when I swapped to an angled housing the large hit of torque that always scared me almost vanished completely. It smoothed out the transition into boost and made much more linear power development (on the butt dyno, but feeling of delivery usually matches). With the straight housing it sometimes would almost feel like a nitrous hit when the boost came in.

I swapped to an R manifold at the same time but in theory of operation I would think the housing had the biggest influence.