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….

It’s Tuesday here at Z Car Garage (and everywhere I guess) and we have another busy day ahead of us.  We are still working on getting some ‘real world’ results on the Cosworth plenum and the full results post will be up in a couple of days once we finish testing and tuning on the dyno.  So far the results have been interesting…

We were able to do a small amount of testing with the new Cosworth plenum at the end of the day on friday and we were showing some nice gains.  Now we are back on the dyno and will be swapping the plenum around to a few cars to see how it performs with different modifications.

Cars to be tested today:

2003 350z: Stock engine, aftermarket cams,  APS Twin Turbo

2005 G35:  Built Engine and APS Twin Turbo

2003 G35:  Stock engine, JWT cams, APS Twin Turbo (ZCG G35)

2005 350z: Stock engine, Vortech supercharger

Testing later this week:

2005 G35: Stock engine, JWT Twin Turbo

All of these cars have other modifications (exhaust, cams, etc.) that will be gone over when I post the full Cosworth report here on ZCarBlog.com.  More good things are coming friends…. Happy Monday

Christmas came to Z Car Garage today as we finally received a pair of the much-anticipated Cosworth plenums.  The new design was created to maximize air flow and to make sure that it is distributed to each cylinder as efficiently and evenly as possible. For right now they are made to fit the VQ35DE, non Rev-Up and Rev-Up, engines.  I’ve been told that there is no plan to build a system for the VQxxHR engines yet.

The main body is made of cast aluminum with machined gasket surfaces for a quality seal and partially machined runners for improved flow.  As you can see form the pictures there are two carbon fiber end caps, one on each side of the manifold, to direct incoming air into the boldly pronounced air horns which lead down to the cylinder heads.  These carbon caps are extremely thick and look to be able to stand up to the abuse that any boosted VQ engine can put out.  They are a far cry from the thin, and almost flimsy, original caps that we saw at SEMA in 2007, could this redesign be part of the 16 month delivery delay?

We will be fitting the two plenums that we received on to a pair of turbocharged G35’s by next week, one with a stock VQ35 engine and a JWT (Jim Wolf Technologies) twin turbo kit and the other on a fully built engine with an APS twin turbo system.  I will have more photos and installation impressions by early next week as well as dyno numbers as soon as we get them fitted to the cars.  Maybe the ZCG G35 will be getting one as well…..  Have a great weekend!!

If you are interested in purchasing a new Cosworth plenum please contact Rob Fuller through email at Rob@zcargarage.com

For those who purchase locally there is even a chance that you could see your car’s dyno results right here on ZCarBlog.com