The TXS single-plane is designed...
The TXS single-plane is designed as a high-performance street/strip manifold. Thanks to the two-piece configuration, we had the two-plane off and the single-plane cinched down in under five minutes.
AFR currently has three spider assemblies available for their Titan series of small-block Chevy manifolds, including the Titan DPR, a dual-plane street/strip layout, the street/strip TXS single plane, and the TXR high-rise race single-plane. Any of these manifold configurations can be swapped on a common baseplate, and the swap can be completed in just minutes since the baseplate (and distributor) can remain in place on the engine. To aid sealing, The Titan manifolds took a cue from the latest OEM sealing technology and feature molded rubber seals rather than conventional gaskets. These seals fit in precision-molded retention channels in the manifold, and are crush-limited by the fastener configuration for a perfect seal every time. The system virtually eliminates the potential for fuel, vacuum, coolant, or oil leaks.
We had a chance to run all three of the Titan manifold configurations on a 372ci street small-block equipped with AFR street 195cc heads. These three configurations are designed to cover the needs of most conventional small-block Chevy engines, from street to serious race. The dual-plane DPR showed the broadest torque curve while retaining excellent power production into the higher rpm ranges. With the single-plane TXS, we saw the textbook trade in low-end torque for higher rpm output that would be expected when swapping from a single-plane to a dual-plane manifold. This would be the ticket for combinations where top end power trumps low-end torque requirements, such as applications with high-stall torque converters that never see the lower end of the rpm range. The TXR high-rise single-plane is designed for serious engines, and the moderate power of our street/strip engine wasn’t really at a level that would demand an intake of that capacity. Interestingly, the TXR race did show a power gain compared to the smaller TXS, even with our moderate combination. On a serious big-inch small-block, we’d expect even bigger power gains with the TXR.
As might be expected, we found...
As might be expected, we found the single-plane required a minor jetting adjustment to optimize the air/fuel ratio. Westech’s Steve Brulé stepped up the jetting at the rear of the carb by three sizes.
We did find that the Titan offered unrivaled ease of installation compared to conventional small-block Chevy manifolds. On the dyno, we worked through the three manifold configurations in record time, without the hassle of draining the coolant, or pulling and retiming the distributor. The sealing system performed as expected, without spilling a drop of messy liquid on our stout small-block. We have to hand it to AFR for taking the lead in technology with the Titan, breathing the newest in manifold technology into the familiar small-block.
While 372 ci might seem like an unusual combination, the bottom end of our engine is based upon a Dart SHP short-block assembly, offered with a bore and stroke of 4.125 inches and 3.480 inches. Featuring all forged internals, this big-bore, short-stroke combination is virtually bulletproof, and it delivers a compression ratio of 10.5:1 with the AFR 195cc street heads on our motor. Valve action is provided by a COMP 242/248-degree duration at .050 hydraulic roller cam. While the cubes are moderate compared to some of the common longstroke
combinations, the power output and willing rpm make this a standout piece.
Back against the pump, the...
Back against the pump, the single-plane showed a textbook trade of low-end torque for top end power. From 5,200 rpm up to the redline, the single-plane made more power, showing peaks of 484 lb-ft and 537 hp.
Last on deck was the TXR high-rise...
Last on deck was the TXR high-rise single-plane. This intake is designed for high power with more radical combinations, bigger heads, and big cubes. With a moderate 372 ci and the 195cc AFR street heads on our engine, our combination was less than optimal for this intake.
We questioned whether the...
We questioned whether the TXR would show any improvement on our moderate small-block Chevy. Surprisingly, we found a modest improvement throughout the rpm range with this manifold configuration. Peak output was now recorded at 489 lb-ft and 540 hp, though the peak torque came in at a higher rpm than with the dual-plane.
AFR Titan Manifolds 373ci small-block Chevy