subzero plenum questions

[RIPS]

Throttle body.......

[RIPS]

Or this.......

[RIPS]

Or this......

[Cool Hand Luke]

What sort of power gains with a correctly tuned RB20 and decent turbo over the standard plenum?

[T0nyGTSt]

The standard plenum has no issue with high power.

A lot of 550-650hp cars use the OEM plenum.

T.

[Steve]

And RB30 heads have been used on 8 sec cars. Just because it is capable doesnt mean its the best.

With higher hp applications, the stock throttle body may be restricting airflow, and a larger TB would be useful. the stock plenum flows very well, but esp if you put on a larger TB, fitting a properly designed front facing plenum will help increase throttle response as the intercooler pipework is greatly reduced.

Sub zero originally designed their plenum because they found that they got to a point where for every extra pound of boost they wound in they werent getting the expected rise in rwhp. Their findings state that when chasing higher hp, their plenums flowed better than stock - which is always a good thing.

About the only time this becomes relevant (apart from reduced pipework) is when you are winding the boost up and not getting the expected gains at the wheels, ie, the stock plenum is creating restriction to air flow.

As mentioned, you can get more power out of a stock plenum, but its efficiency is reduced.

[GTS-t VSPEC]

There aren't any huge power gains to be made from the different plenum design in my opinion, but the improved throttle response, reduced piping, and improved look of the engine bay are well worth it:D

[RIPS]

Thanks gtst v spec, Thats why we do them, as you know most people are not in the 500hp+ zone but just want the response, less intercooler plumbing and the looks....Rob