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

I’ve been away from the blog for over a week to concentrate on a few other things around the shop but do not worry, WE ARE NOT GOING ANYWHERE, in fact we are doing everything we can to make our customer cars the best they can be.    I’m going to try to get all of you back up to speed on the recent shop happenings today.

I also have a ton of new, and AMAZING, parts for the Behemoth 240z with the RB28 stroker here at the shop.  This will deserve it’s own post so look for that either late today or tomorrow.

Let’s see… where did we leave off?

We installed a Vortech supercharger on  350z last week.  The blower assembly in this project was a sealed unit from Vortech which means that all the fluid required to lubricate the supercharger is self-contained and does not use the engine oil what-so-ever.  This reduces the install hassle greatly on a Z and there seems to be no performance difference.

The only annoyance with this setup is that you now have to change the supercharger oil separately from the engine oil every 7,500 miles.  The normal Vortech kits use engine oil for lubrication so you end up servicing the supercharger every 3,000 miles when you do a standard oil change.

We also installed gauges to monitor the engine vitals and one of our custom ZCG oil cooler systems to keep things in check.  The car has a few other bolt on modifications such as an Apexi exhaust, upper intake plenum, etc. and the new power curve is right where it should be for an early VQ35DE with a Vortech.   The best part about this car was the customer’s face after he came back from the test drive.  He had an ear to ear grin and kept saying to himself that he needed to be careful while he adjusted to the new power.  Awesome.

Another car that we have been plugging away at is a VERY SPECIAL 300zx Twin Turbo.  This car is pristine inside and out and out and has enough one-off modifications to make your pocket book wince.  The engine let go awhile back due to an ignition system failure and over the past few months we have been building the power plant that this car deserves.  The old engine made over 600 wheel horsepower and the new engine should make a decent improvement over that.

This car has so many cool little (and big) things about it that I wouldn’t be doing it justice to leave them out, so there will be more pictures, info, and dyno graphs once this phase of the project nears completion.  We can’t wait!

And last but certainly not least is the Red 280zx restoration….

The interior parts that we have been waiting to get back from the dye shop were picked up last week and they came out great!!  We are planning on clearing part of our week out to focus a generous amount of our attention on finishing this car for good.  As it goes together I’ll be adding pictures right here on ZCarBlog.

I know… I know… Many of you have been waiting patiently to hear what has been going on with this 350z project car.  Now I am here to feed you a just a teaser of what is to come!   From the graph below you can see that the car made 500whp and almost 500wtq at 15lbs of boost on our terrible CA 91 octane fuel.  Remember that this car has a built automatic transmission, with a drive train loss of over 20%.   That puts the crank horsepower rating at or above 650hp!!!

If you are wondering why the car hasn’t made more all you need to do is consult the dyno graph again.  Just as the torque converter locks up the numbers seem to go flat.  This is because the car has a mere fifteen degrees of timing in it.  When fully tuned this car will run close to 18 or 19 degrees of total timing which will smooth out the graph and bring this engine to life!

REMEMBER THIS WAS JUST THE BASELINE RUN WITH THE NEW TURBO KIT

After more timing is added and the air fuel ratio is adjusted, we expect to see the graph continue to climb into the atmosphere.  Only time and tuning will tell, and for that you will have to wait just a little bit longer.  Drool away.

Yesterday we installed a set of Stillen high-flow catalytic converters (HFCs) onto the 350z that received the Injen Intake system and the Unorthodox Racing lightweight pulley last week.  We’ve seen how these HFCs have improved the power band in the past on other cars but it’s always nice to back up good results.  Again, this car is equipped with a Nismo exhaust system, unlike the other car with these mods which has a Bassani exhaust.

The Stillen high flow cats are a high quality piece but as with all exhaust modifications where the stock catalytic converters are removed we were interested to see if there would be any increase in exhaust rasp.  As you remember this was a small issue that we had to resolve on the red HR car that had the Bassani true dual system with an x-pipe.  The Nismo system is much different, it comes from the cats into a 2.5″ to 3″ Y-pipe (stock is 2″ to 2.5″.)  From there is a single 3″ pipe, with resonator, back to a factory style (but larger diameter) rear muffler.

This car with the HFCs installed exhibited almost none of the rasp that has become associated with the dual exhaust cars.  While the exhaust note was very nice, you can see from the dyno graphs that this car was a few horsepower short of the Bassani 350z.  The cars were dyno’d on different days but all the results are SAE corrected to get them on as even a playing field as possible.  In their uncorrected forms, both of these cars are putting down over 300hp to the wheels. Very impressive.

Below you can see the run comparison with and without the HFCs.  The Stillen cats gain around 10hp and 10lb/ft of torque at the wheels throughout the rev range.  That’s certainly power you will feel on the road which makes this change almost mandatory from a performance aspect.

Here are the graphs that show this customer’s entire power gains over the past week or so and the comparison between the this car and the earlier Bassani equipped car.

We are trying to get the ball rolling with a header and camshaft comparison for the HR engines and maybe an turbo install in the near future to show all of you what is really possible with all available modifications.  We can’t wait to make more “RELIABLE” power from the HR series.

Link:  Other HR related posts