What is the advantage of making your turbo kit come w/ a 10cm housing rather than a 6 or an 7 cm? I was just wondering if there was any logic behind the HRC s16g.

I thought about this before I think that hahn probably wanted the power to be mainly in the higher rpms. He knew that our engines would spool it pretty quickly. With our engines at 9.6 compression and being fwd we wouldn't want or really need the power to start downlow anyway. I am running the low boost of 10 psi on my 20g with 7.8 compression and it takes awhile to spool up but this is on a 4g63. The 4g63 needs higher boost than a 420a to run with a good torque curve that starts low. On the 420a it was made n/a so it although it would benefit from having more power, it doesn't actually need it low. If you wanted you could do a smaller turbo than the 16g, you could use a t25 but everyone knows that turbo runs out of steam with more than 16psi. The super 16g is a good turbo that can run higher boost efficiently and even let our engine make nice power from it at low boost on the 420a engines. The bigger housing also lets the turbo move more air easier and we avoid having to fight wheelspin at low rpms a little bit by having the power start later.

13.4 @ 100mph
93 Eagle Talon Tsi Awd

It is probably to stop boost creep.

Dave
05 Ford F150 SuperCrew FX4

less restrictive turbine housing=more top end power, less chance of boost creep with internal wastegate.

:farfrommugen:
Yes I still own a 2gnt.
Damn right I've been here longer than U
klassic_liven@yahoo.com

From my understanding, I believe it was designed to minimize boost creep.

___________
Kon C

"Sometimes, a man has to do what a man has to do."

The number one reason is to completely eliminate boost creep which it does an extrememly good job of. This means you can get away with using an internal wastegate which is both less complicated and cheaper. The other reason is it allows the turbo have a higher flow on the top end where a standard 16G/20G would begin to fall off. A S16G flows 575cfm vs a big 16G at 550 and a small at 505. A S20G flows 680cfm vs a standard 20G at 650. The only downside is the increased lag, but that is not as large of an issue on our cars with the higher compression. A properly setup car can make boost well. Armond makes 18psi at 3500rpm with cams on a S20G and I was making 18psi at 3400rpm with stock cams and a S16G. He has more airflow and less restriction than me everywhere. My results are more expected of something a little more sane and real world.

05 Mazda RX-8
06 Lotus Elise