15. Like the TFS R, the inlet...
15. Like the TFS R, the inlet on the Holley did not measure a full 75mm. The Holley was slightly larger than the TFS R at 72.5mm, but still a few shy of the specified 75mm.
After removing the GT-40 and cleaning our sealing surfaces, a fresh coat of silicone was applied to the front and rear valley rails and the TFS R lower intake was set into place. We had previously swapped over the various sensors and injector hardware from the GT-40 lower. Once the lower was torqued into place, the upper was given the same treatment. Then came the 75mm (Accufab) billet throttle body and we began to connect the engine harness, dyno wiring and fuel system. The Pro-M meter was the last to get plugged in and as distributor removal was not necessary to facilitate the intake swaps, the timing was left in the same position for the remainder of the testing. We were anxious to see the first of the big three intakes run on our test motor, as we had high hopes for the rpm potential of the TFS R.
16. Similar in external appearance...
16. Similar in external appearance to the TFS R, the Holley SysteMax II demonstrated theeffectiveness of its longer runners byproducing significantly more torque thaneither of the other two intakes. The Holley alsoposted impressive peak power numbers at474 hp and 436 lbs.-ft.
After the oil and water were brought up to temperature, we saw just how much extra power was available from these larger manifolds. After some playing with the adjustable fuel pressure regulator to bring the air fuel mixture in line, the TFS R intake posted peak numbers of 475 hp at 6400 rpm and 422 lbs.-ft. of torque at 5100 rpm. The intake swap had netted a 25 hp gain over the GT-40 baseline, but the added top-end power came with a price. The TFS R intake was down on torque compared to the GT-40 to the tune of 25 lbs.-ft.
17. The inlet of the Victor...
17. The inlet of the Victor 5.0 was the only one of the three to actually spec out at 75mm.
In a nutshell, the larger intake traded top-end horsepower for low and mid-range torque.
Even before the motor had a chance to cool, we ripped off the TFS R intake to make room for the Holley SysteMax II intake. If you can look past the brilliant flash plating (shiny exterior) the Holley and TFS R intake look similar on the outside. Both upper intakes feature a large V-shaped upper intake aft of the throttle opening that extend back to the plenum. The plenum then arcs into the runners that connect the upper intake to the lower intake.
18. Unlike the other two upper...
18. Unlike the other two upper intake, the design of the Victor allowed access to the runner for porting. Of course this is irrelevant if the intakes are to be Extrude Hone ported.
Internally, the TFS and Holley intakes differ substantially. The Holley features not only longer (by about an inch) but also odd-shaped intake runners. Unlike the TFS R and Edelbrock Victor 5.0, which utilized traditional rectangular ports (the mating surfaces that join the upper and lower intakes), the Holley featured odd-shaped runners that resembled distorted rectangular semi-circles. Though the shape of the runners were somewhat unconventional, the results were what counted and odd shaped or not, the Holley posted some pretty impressive numbers especially in the torque category. The Holley was the most difficult of the three to install, with a time-consuming center bolt (under the throttle body) making life difficult, though by no means impossible. The plating made the Holley the brightest of the bunch, which might make it a favorite to those inclined to show off what's under the hood.
Installation difficulties aside (what's a few extra minutes?), the Holley showed that the time was well spent as it easily out-torqued the TFS R intake and missed the peak output of the TFS R by a mere 1 hp (474 hp vs. 475 hp).
19. The Edelbrock intake was...
19. The Edelbrock intake was not without its faults, as it refused to go on ourtest motor. Installation required grinding edges of the lower intake.
Though 1 horsepower is really splitting hairs, the extra 14 lbs.-ft. of peak torque is anything but. The longer runners in the Holley SysteMax II intake no doubt contributed to the added torque, but the extra grunt did not cost any peak horsepower. Generally there is a tradeoff with horsepower and torque. The Holley intake design bolstered torque production over the TFS R without any sacrifice in peak power.
As with the TFS R, the Holley lost out to the torque-champ GT-40 down low, but bettered the tubular intake as the revs increased. The added torque production of the Holley intake (over the TFS R) is evident in the fact that the Holley bettered the GT-40 baseline at 5250 rpm, some 250 rpm sooner than the TFS R. Note the two humps (not quite a dual torque peak) in the torque curve of the 347 equipped with the Holley intake. This is a function of the efficiency of the long runners in the intake and the motor coming up on the cam.
20. These small protrusions...
20. These small protrusions on the AFR 185 heads stopped the Edelbrock from sliding into place. Once treated to some simple grinding, the Edelbrock went right on.
The Holley SysteMax bested the GT-40 by 5250 rpm, much earlier than the TFS R intake. Though the Holley offered a better torque curve, the additional torque production did not cost any top-end power. The Holley was only down by 1 hp compared to the TFS R intake. Like the TFS R, the Holley was down substantially to the GT-40 in the low and mid-range.
The final intake to be tested in part one of our "Super" intake shoot-out was the Edelbrock Victor 5.0. Designed as a step up the performance ladder from the Performer and Performer RPM, the Victor was designed for high rpm power production. Unlike the other two 5.0 intakes in the Edelbrock stable, which share a common lower manifold, the Victor is a clean sheet of paper design that incorporates a dedicated lower manifold with raised runners that mate to the short runner upper intake to produce a high-rpm EFI intake worthy of the Victor name.
21. Like the Edelbrock shown...
21. Like the Edelbrock shown here, all of the intakes received the various sensors, fuel rails and injectors prior to testing.
In looking through the Edelbrock catalog, the pages are full of the trio of intakes, heads and cam components. Edelbrock has done extensive research (both computerized and on the dyno) to come up with components that work best as dedicated packages. For a significant improvement over a stock intake, look no further than the Performer. The next step up the performance ladder is the Performer RPM. As the name implies, the Performer RPM is designed to produce better breathing (usually from larger and shorter runners) than the standard Performer to promote better power production at slightly high engine speeds. For a maximum effort, the Victor is the next logical step.
During our testing, the Victor 5.0 lived up to its performance namesake by besting the other two intakes with the highest peak horsepower reading. Where the TFS R and SysteMax II intakes signed off near 475 hp, the Victor 5.0 kept on pulling to reach 481 hp at 6600 rpm. The Victor 5.0 out-torqued the TFS R intake by posting a peak torque reading of 426 lbs.-ft. at just 4900 rpm (lower than the other two). Like the TFS R, the Victor 5.0 fell prey to the torque of the Holley manifold and lagged behind the Holley until 6150 rpm. From 6150 rpm to 6700 rpm, the Edelbrock demonstrated what short, high-flowing runners can do by besting the other two manifolds. Oddly enough, the Edelbrock was the only intake of the three to give us installation problems. The lower intake refused to go on past the small ridges in the AFR 185 heads (see photo).
The problem did not occur with the Holley or TFS lower intakes. Some minor grinding on the edges of the Edelbrock got us back under way, where the upper intake was the easiest of the three to install.
As with the two other "Super" intakes, the Victor 5.0 lost big torque down low to the GT-40, but picked up big time once the revs reached 5500 rpm. With our three intakes out of the way, you'd think we would be satisfied. Wrong. After running these three (four including the GT-40), we grabbed another trio and subjected the 347 test motor to even more abuse. Check out the results in part two of our "Super" intake shoot out.