After hearing the news that the ZCG 370z made some pretty nice power gains, a new customer came in and wanted to do the same for his blue 370z.  To up the ante a bit he also ordered a set of Berk high flow catalytic converters (HFC’s) to replace the stock units and hopefully make some more power, let’s find out.

We knew exactly what to expect from the install and everything went off without a hitch.  We obviously had to perform a few minor tweaks with the Stillen pieces just like we did on our shop car to get the fitment to be acceptable.  After all parts were installed the car was strapped to the dyno and we went about our business to get some numbers.  After all was said and done the car picked up 27whp and 14wtq for a total of 302whp and 247 ft/lbs of torque.  Which means the Berk HFC’s add roughly five to six horsepower when you compare the numbers of the ZCG 370 which goes without the HFC’s, for now….

The really nice thing about these simple bolt-on modifications is that the performance of the engine is increased over the entire power band.  I don’t know of anyone in their right mind who would turn these gains down for the price.  300+ whp with THREE bolt-ons, not too shabby for a couple hours work.

Special thanks to Ken at Roost Billet Products for making those killer ZCG plates for all of our show cars and cars without plates.  You rule Ken.

Here are the results from this morning’s plenum swap.  The results are… ummm… about what we expected.

This car is a 02/06 350z with an automatic transmission.  There is an extensive list of aftermarket components on this car ranging from a carbon fiber diffuser to a custom painted roll cage, but this post has nothing to do with any of these mods, it is about the before and after dyno numbers.

The plenum install went off without a hitch and the car was back on the dyno in no time.  This mod was a straight plenum swap with no fuel or timing changes made (the owner did not want to install a Uni-Chip or other tuning hardware at this point.)

Run 003:  Stock Nissan Plenum (BLUE)
Run 005:  Cosworth Plenum (RED)

On to the dyno graph you can see that the Cosworth plenum LOST a healthy amount of horsepower and torque through the entire rev range except between 5,800-6,000 RPM where it gained two, yes two, horsepower.  The design of the plenum just doesn’t seem to work on lightly modified normally aspirated cars.  Unfortunately this is a loss that will really be felt when driving the car.  This plenum is so beautiful that we really wanted to make a ton of power with it so that we could improve the looks and performance of the engine.  At this point I would find it really hard to recommend this to a customer.

Mind you that this is the first normally aspirated car that we have installed the Cosworth on.  My full post with all of the boosted car tests is still to come this week.  That post will include all of the dyno results and all other pertinent test data.  Very, very interesting….