Frank H. Cicerale
November 1, 2008
In an unofficial Part 2 of our unofficial series on the TVS blower, we swapped a Roush TVS on a Roushcharged 428R Mustang and were rewarded with some astounding results.

You Can call this an unofficial Part 2 of MM&FF's detailed analysis of the new Ford Racing Performance Parts TVS supercharger. Last month, we threw the TVS blower upgrade on a Shelby GT500 and made gobs of power, even more gobs of torque, and killed a bunch of mosquitoes with the ensuing tire smoke. This month, we throw a Roushcharger TVS blower on a 4.6L Three-Valve powerplant, and dig just a bit deeper into the TVS and what it offers enthusiasts.

It's common knowledge what a supercharger is and what it does. The obvious key to making more power is to supply the engine with more air and fuel. When you can burn the mix efficiently, you get greater cylinder pressure and a bigger push on the pistons. Increasing the flow of air and the accompanying fuel can be accomplished a number of ways-supercharging, turbocharging, and by the use of nitrous oxide. Matching the fuel to the increase of air is a matter of upgrading and tuning the fuel system.

The TVS (Total Vortices Series) blower and its predecessor, the M122 Fifth-Generation blower, are both designated Roots-style blowers. The Roots-style blower is the oldest design of the superchargers known to us Pony people. Other popular units are the twin-screw and centrifugal. The Roots-style was patented by Philander and Francis Roots in 1860. Used originally to ventilate mineshafts, the blower was first placed on a car engine by Gottleib Daimler in 1900. Since then, it has seen many different OE applications and versions, the latest being on the Shelby GT500, with another version of it on the various blown Roush cars (known as the Roushcharger).

In the past couple of years, there have been numerous advancements concerning blower size, rotor makeup, and the like. Obviously, going to a bigger blower, such as a 3.4L Whipple supercharger-like the one we installed recently on our in-house Lightning, The Fridge-allows the blower to process more air to feed the engine.

TVS Versus The World
In our last issue, we touched on the basic differences between the TVS supercharger and the Fifth-Generation Eaton huffer, the M122. While it may be a sin to utter these next few words, keep in mind that the M122 is the blower the GT500 is equipped with, while the new ZR1 Corvette from Chevrolet will have its LS9 showcasing the new TVS. We can't let the Bow Tie boys beat us up at the track, can we? While basics are good, details are even better. After all, it's your hard-earned cash you'll be plunking down.

"I will initially note that the blower on the GT500 [the M122] is actually a hybrid that utilizes a Fifth-Generation design with added rotor twist, that being 82 degrees," says Eaton Corporation's Global Sales Manager Arnie Dunai. "That being said, the physical differences [between the M122 and the TVS] are in the lobe count and the end-to-end twist of the rotor. The Fifth-Gen blowers have three lobes and a total twist of 60 degrees, while the TVS blowers have four lobes and a total twist of 160 degrees. The housing design is also different for the TVS versus the Fifth-Gen." These differences are seen in the inlet and outlet ports of the TVS, which are larger and smoother when compared to the M122s. In addition, the backflow slots that are seen in the M122 to decrease noise, vibration, and harshness (NVH) have been eliminated because they're not needed on the TVS.

"The outlet port has been redesigned for the new rotors, and we've also engineered the new front-inlet design where the inlet of the supercharger can be located on the same side as the pulley," Dunai says. "This allows for Eaton to design superchargers for applications previously though impractical due to air routing." For those holding the pink slip to a Mustang, the front-inlet design is not a concern, as the TVS offered by Eaton still retains the rear inlet configuration.

The swap was fairly easy, seeing as how the plumbing for the intercooler was on the car thanks to it already being supercharged. The only major parts we had to swap were the lower intake manifold with the intercooler, and the blower itself. The lower intake you see here was the new one ready to be dropped onto the Three-Valve mod mill.

In addition to getting Dunai's take on the TVS, we also checked in with Ryan Bunn, the marketing manager of the Performance Parts division of Roush Performance. Other than the obvious fact that the blower we installed in this article was a Roushcharger TVS, the one shown here in the photos is the same blower that Roush used on the 510hp P-51A Mustang. Additionally, Roush was heavily involved with the development and the construction of the TVS from the get-go.

"Roush's Erin Dmytrow helped Eaton with the development of the TVS, and Roush is the company that is technically making the blower," Bunn says. "Eaton supplies us with the internals, and we cast the case, assemble the blower, and then bench test it.

"The differences between the M122 and the TVS lie in the virtual efficiency of the four-lobe TVS design. That design compares very favorably to other boosting technology out there. The key advantage the TVS has, though, is that it supplies a higher volume of airflow with better efficiency and less heat."

"The internal air velocity management allows for much greater thermal efficiency, which means less work is being done to the air during compression," agrees Dunai. "The Fifth-Gen has maximum thermal efficiencies in the 60-percent range, while the TVS sees maximum thermal efficiency in the 70- to 75-percent range, and over a much larger operating range of pressure ratios and flow. However, peak efficiencies don't tell the whole story, because true improvements from the TVS are evident in its dramatically increased operating range. The TVS still has 70-percent thermal efficiency in regions that a similarly sized Fifth-Generation can't even operate.

"The TVS has a higher pressure ratio capability, and the combination of the higher lobe twist and the larger inlet ports allow for much greater volumetric efficiency, especially at higher speeds. Volumetric efficiency is actually the highest at maximum rated rpm, and this shows that the flow capacity of the TVS is orders of magnitude greater than anything prior in terms of flow versus displacement. It does not die off at high rpm. To say it simply, if a Fifth-Gen and a TVS were at equal displacement, the TVS will flow more air at lower temperatures."

With so much emphasis being placed on the differences in the rotors and their respective lobes, are there differences in the composition of the rotors? "The TVS rotors maintain the reliable material and mechanical properties of the Fifth-Gen units, including our patented abradeable powdercoating," Dunai says. In layman's terms, the blower rotors are made of the same stuff, but the TVS rotors and the lobes are designed for better power with less work. The TVS sounds like a winner when compared to the Eaton M122, but how will it stack up against a twin-screw?

"The twin-screw has internal compression, which the TVS does not, as it is still technically a Roots-style blower, though with many improvements," Dunai says. "Contrary to popular belief, internal compression created by rotor lobe profiles and speed ratios are not as important to thermal efficiency. There are many other factors that contribute to thermal efficiency that are more important and, as proven with the TVS, internal compression is not the deciding factor of thermal efficiency. I will, however, state that the laws of physics and thermodynamics still do apply. The TVS just capitalizes on them in a slightly different manner to achieve its results."

So, what does this mean in terms of blower speed, boost level, and horsepower levels? "We have bench-tested the blower to 15,000 rpm, which creates about 8 psi the way we have it pullied for sale to customers," Bunn says. "Honestly, though, we see no limits in terms of the blower. We feel the blower is fully capable of feeding 1,000 hp."

The Roush Connection
We headed to JDM Engineering to cover the Roushcharger TVS install on a Roush 428R Mustang. Before we get into the details of the installation, we chatted with Bunn about the specifics of the kit Roush offers, and some things of interest that we had questions on. "We offer three different versions of the Roushcharger TVS kit," Bunn says. "The kit that we sent to JDM Engineering for the installation was a kit we have for naturally aspirated, Three-Valve engines. It comes with everything needed to install the blower on a naturally aspirated engine, from the blower to the intake manifold, hardware, intercooler, and more. The second version of the kit is the one we sell to those who already have a Roushcharger on their car, such as the 427R, 428R, or the Stage 3. This is a bare-bones kit that replaces the blower and intake manifold with the TVS pieces. Nothing else is needed because the car already has all of the other paraphernalia associated with the super-charger. The last version is actually a complete short-block with the blower kit. This is essentially the same package that we installed in the P-51A Mustang, and allows you to run higher boost levels with the TVS due to the P-51A's specific engine components. With the P-51A, we change the components to forged pieces, and lower the compression ratio from 9.8:1 to 8.5:1."

One thing that Bunn noted was the fact that a tune is needed with the TVS installation. "We currently don't offer a calibration for the naturally aspirated or swap kits," he says. "When we sell these kits to our customers, we tell them that they must take the car to a professional shop, such as JDM, to be tuned. We also suggest that they go through the bottom end and beef it up, though Jim [D'Amore of JDM Engineering] seems to have a good handle on making a stock bottom-end motor live with a TVS making a respectable amount of boost. As for the P-51A short-block kit, we do offer a tune with that one."

Roush also offers everything in the kit to make the installation a snap, though a few fuel-system and ignition upgrades are recommended. "We recommend it, but make it a point to almost tell the customer that a GT500 fuel pump is needed," Bunn says. "The content of the kits are unique in that most everything is there, including a dual 60mm throttle body similar to the one seen on the GT500, as well as a more durable and better flowing cold-air kit. As for the ignition system, we recommend a one-step-colder plug for '07-and-older cars, while the '08-and-newer vehicles can retain their stock spark plugs. In 2008, Ford went to a 5/8-inch plug, which is smaller than the '07s'. The smaller plug seen in the '08 is more resistant to detonation under boost than the '07-and-prior plugs due to the design."

Price And Performance
So what does this all mean in terms of price and horsepower? Let's get the pricing out of the way first. For the full-on kit (such as the one we installed), the TVS and its related components will set you back $5,899 and can be found in the Roush catalog or online under PN 403994. For those who already have a supercharger, such as the Roushcharger, the kit checks in at $4,999 (PN 403995), minus all of the unneeded components that the big kit comes with. While that's a good chunk of change, based on our before-and-after dyno and track testing, it's well worth it.

The car on which we performed the swap was an '08 Roush 428R Mustang equipped with a five-speed transmission. It was probably better we tested it on a car that already had mods done to it, as most of you out there don't hesitate to throw the bolt-on speed parts onto your S197s. Regardless, our test subject showcased a full-on Kooks exhaust system, including long-tube headers, as well as adjustable rear shocks, instant center brackets for the control arms, 4.10 gears, a one-piece aluminum driveshaft, and 15-inch Bogart rear rims wrapped in 275/60/15 Mickey Thompson drag radials.

"The swap was fairly easy to perform," says JDM's Jim D'Amore. "This car was a bit easier because it already had a supercharger on it. If we were to install this on a stock Three-Valve, it would take one full day. For a car like this, with it already having the intercooler installed and plumbed, it would probably be three hours less."

With the original Roush blower and the added bolt-on parts, and stocked with a custom JDM tune, the Roush 428R thumped out 386 rwhp and 366 lb-ft of torque, also measured at the rear wheels. After spending the day swapping over the blower, D'Amore revised the tune to his liking and strapped the beast to the dyno rollers. When the computer spit out the numbers, we were all duly impressed. The blower increased power by 160 hp to 546, and torque by 183 lb-ft to 549 lb-ft at the rear tires. Also, if you look at the torque curve on the supplied graphs below, you'll see that the boost curve for the TVS blower is smooth and linear, while the same curve for the Roushcharger on the car dipped badly early on and was choppy throughout the entire dyno run.

So how does this translate to the track? Before the blower swap, the quickest this S197 made its way down the quarter-mile was an 11.84 at 119 mph at Epping Dragway in New Hampshire. That was before we got hold of it, however. With the blower on, the car tuned up, and the M/Ts ready to go, MM&FF editor and resident car jockey Evan Smith slipped behind the wheel for a couple of stabs at the Old Bridge Township Raceway Park quarter-mile in Englishtown, New Jersey.

The temperature showed 90 degrees on the thermometer, humidity was at 80 percent, and there was a 10-mph headwind-obviously not the best conditions in which to go for low elapsed time and top speed. The first two runs resulted in high-1.9-second 60-foot times, and an 11.73 on the first run and an 11.85 on the second at close to 124 mph. Obviously, Revvin' Evan knew there was more in the car, even on this sweltering summer day. "The Roush had wicked throttle response and was blowing the tires off badly, on launch and in Second," he says.

After cooling down the blower, Smitty lined up for the final three runs the car would make that day. The results were astounding. The next two runs showcased 60-foot times in the low-1.8-second zone, and a pair of 11.58-second elapsed times. The trap speed shot up to 122.93 and 123.62, respectively. The final run of the day saw the best short time so far, a 1.76, but a bit of heat soak set in, and the car slowed to a respectable 11.66 at 119.96. Smith feels that with a drag suspension and favorable weather, the Roush would be a 10-second machine.

While the quarter-mile testing didn't show the true potential of the car, we can chalk that up to the tight suspension and poor weather conditions. Still, with horsepower numbers like that, there's no question as to the benefits of the new TVS supercharger. Welcome to tornado alley!