As a result of the worst marketing on Chevrolets part, the Chevrolet SS remains one of their best kept secrets. Otherwise known as the Holden VF Commodore in Australia, the Chevy SS is a bit of a two-faced vehicle. In the US, it is a stylish, four door sedan equipped with the infamous LS3 engine - no big deal. In Australia, the VF Commodore is the stock version of the V8 Supercar titans. If you have not heard of the V8 Supercars, open a new tab in your browser, and get to work.
Rich purchased this car knowing exactly what kind of reputation proceeded it. He happened to be strolling through a Chevrolet dealership looking for some work vans when he noticed it in a corner, covered in bird droppings and covered in a couple inches of dirt. After several months of waiting on recalls to be completed and negotiations with the dealer, he took full delivery of the vehicle and immediately started on his modifications list. The first step was to remove all Chevrolet badges and restore it to it's rightful Australian title.
First up on the performance modifications was a set of Kooks Headers and green catted connections. There is nothing quite like the sound of an LS motor with headers. Out of all the LS cars we work on, this one had the biggest gain from headers. With a baseline of 330hp, we saw a 44hp gain after installing headers. Prior to the install, we sat down with Rich and came up with a game plan oh what to modify and when. We initally planned for headers, then a set of CNC ported heads and finally a Magnuson heartbeat supercharger. However, no fault to Rich, he couldn't wait. He had a taste of the power drug, and now, he was all in.
With the decision to do all items at once, it took just about a week to get it all sorted. It was an early Christmas at the shop. Our work benches were covered with shiny new parts and one mean looking Magnuson supercharger. We are creatures of habit with the parts that we use, but that is only because we have tried many others and not had the same success. Along with the supercharger and heads, we would be installing a full compliment of Comp Cams springs, retainers, pushrods and trunion kit. This will provide us the longevity and performance we are looking for.
Let the teardown commence! With only 5,000 miles on this car, it was very easy to get everything undone and removed quickly. With heads off, and the entire front cover, it was surprisingly roomy inside the engine bay. We enjoyed the quick moment as we knew it would fill up quickly with the supercharger and all of its accessories.
Since the LS3's are a single bolt camshaft, we convert them to a 3 bolt style using factory GM parts and ARP hardware. The SS has the LS3, unlike the automatic Camaro's which house an L99 that needs the DOD and AFM deletion for a camshaft upgrade. That being said, the camshaft job was very straight forward. Comp Cams new microfinish polish on their camshaft was just released as a standardized option for LS cams, and this was the first one we have gotten to use. It looks like it should be more of a show piece than a car part, but we were still going to install it!
Alright! Cam installed, heads built and installed, now it's time to prepare for the supercharger installation. The Heartbeat kit is similar to the LS9 supercharger, so clearance is not an issue. Magnuson kits are always top-notch. They are great for the DIY people who are looking to do it over a weekend or two. With the caliber of this build, we added a couple aesthetic pieces along with a catch can from Elite Engineering, a local Colorado shop known for their amazing products.
Now that everything is installed from the supercharger, it was time for the final touches. Holden VF's come with an "OTR" intake (Over The Radiator) which is a high flow, low profile intake. Its a great finishing touch, but with the Magnuson kit, it is a tight fit. Remember that space I mentioned earlier? Ya, it's gone. In order to use the OTR that Rich had installed already, we had to get a different lid so it would offset correctly to the supercharger. In addition, we would no longer be able to use the factory Mass Air Flow sensor, and had to switch to a speed density tune. Speed Density tuning uses the MAP pressure sensor only - the MAF helps with low end driveability so there was alot more cell by cell tuning that was involved to get it just right.
The finished product, almost looks like it was supposed to be like this from the factory, and quite frankly, we think it should have been! After all was said and done, we saw final numbers of 586hp and 505ft/lbs on only 6psi!
I took some time to wait to publish this because, well I'm sure you are catching on by now, but Rich wanted some more power. As a man after our own hearts, we happily obliged and ordered up a couple smaller pulley's and a DSX Tuning flex fuel kit. DSX makes awesome kits for a lot of GM vehicles, making it as plug and play as possible. With a new set of Injector Dynamics 850cc injectors and the smaller Magnuson pulleys, we could really start to test the limits of the stock fuel system.
The SS Sedans come factory with the same fuel pump as the Camaro ZL1, so there was still some power left on the table that we could capitalize on. Unfortunately, unbeknownst to us, the Magnuson Heartbeat kit for the SS and the Corvettes are limited to an 81mm pulley as they sit over the snout of the supercharger. We put a 78mm pulley in the lathe and made enough clearance for it to work - one up'ing the engineers.
The 78mm pulley increased boost from 6psi to just under 10. With 91 octane, the SS made 650 whp. Not too shabby, but later it was found that the belt was slipping ever so slightly. Before finding that, we made the switch to ethanol which quickly led us to finding the limit of the fuel pump. Making 705 whp and 600 ft. lbs on ethanol, we noticed that fuel pressure was starting to take a dive over 6,000 rpm indicating that the fuel pump was not up for the task.
We always want to give our customers a car that doesn't have 'limits' per se with their driving. You know, the "Your car makes XXXX power but don't go full throttle over XXXX rpm". This isn't fair to them so ultimately, it was in everyone's best interests to put a slightly larger pulley on to make sure the car was safe and that Rich was able to drive it to its fullest.
Going back to the 84mm pulley and 8.3 psi, the SS still made 670whp and 564 ft. lbs of torque. It is definitely no slouch and now is faster than the highly acclaimed Hellcat, and cheaper too! Amazingly, the car still has excellent grip on the factory wheels and tires, partial thanks to its awesome magnetic controlled suspension. But for now, we think Rich will have his hands full with this monster.
Check out the video below!
2016 SS Details:
Kooks Headers and Green Catted Connections
Comp Cams Carz spec camshaft
Comp Cams hardened pushrods
Comp Cams beehive valve springs
Comp Cams titanium retainers
Comp Cams trunion bearing upgrade
GM CNC ported LS3 heads
Improved Racing OTR intake for Hearbeat
Magnuson Heartbeat Supercharger
Elite Engineering Catch Can
Moroso Billet Valve covers