Test 1: Stock vs Comp 273 Cam Test in a 5.7L Hemi
Test 2: Small vs Big Cam Test in a 5.7L Stroker
Test 3: 260H vs 268H Comp Cam Test in a Mild 5.7L Hemi
Test 4: 260 vs 273 Comp Cam Test in a Mild 5.7L Hemi
Test 5: Stock vs Comp 260H Cam Test in a Mild 5.7L Hemi
Test 6: Comp Cams 273H vs Custom Cam in a Modified 6.1L Hemi
Test 7: Comp 273H vs Blower Cam in a Supercharged 6.1L Hemi
Test 8: Stock vs Comp 260H Cam Test for a Turbo 5.7L
Chapter 4: Headers and Exhaust System
Test 1: Stock Exhaust Manifolds vs Long-Tube Headers on a 5.7L Hemi
Test 2: Exhaust Manifolds vs Long-Tube Headers (KB SC 6.1L)
Test 3: Shorty vs Long-Tube Headers on a Mild 5.7L Hemi
Test 4: Shorty vs Long-Tube Headers on an IR 5.7L Hemi
Test 5: 1¾-inch vs 17⁄8-inch 5.7L Hemi Headers
Test 6: Effect of Header Collector Length on a 5.7L Hemi
Test 7: Stock Manifolds vs 1¾-inch Headers on a Modified 5.7L Hemi
Test 8: Truck vs SRT8 Manifolds for a Stock 5.7L Hemi
Test 1: NA vs Paxton on a Modified 5.7L Crate Engine
Test 2: NA vs Kenne Bell Supercharger on a 6.4L Challenger
Test 3: NA vs TorqStorm with 9.9 psi on a Modified 5.7L Hemi
Test 4: NA vs Procharger D1SC (9.6 psi) on a 5.7L Hemi
Test 5: NA 6.1L SRT8 vs Vortech V3 (8.9 psi)
Test 6: Effect of Boost 19 vs 22 vs 24 psi (KB SC 6.1L)
Test 7: NA 6.1L Hemi vs Magnuson TVS2300 (6.0 psi)
Test 1: NA 370-ci (5.7L) Stroker vs Turbo (10 psi)
Test 2: 5.7L Hemi: NA vs Single Turbo with 8.1 and 10.4 psi of Boost
Test 3: 76-mm Turbo Test: CXRacing vs Precision on a 370 Stroker
Test 4: 6.1L Hemi-Effect of Boost (7 vs 11 psi)
Test 5: 6.1L Hemi Stroker-Gains from Boost (9 vs 11 psi)
Test 6: NA vs Low Buck Turbos 7.3 and 13.3 psi on a 6.1L Hemi
Test 7: NA vs High Boost on a Modified 5.7L Hemi
Test 1: NA vs Zex Nitrous (75 hp) on a Modified 6.1L
Test 2: NA Modified 5.7L vs NOS Nitrous (125-hp Shot)
Test 3: NA 6.1L Hemi Stroker vs Nitrous (175-hp Shot)
Test 4: NA Modified 5.7L Crate vs Sniper Nitrous (100-hp Shot)
Test 5: NA 6.4L Hemi vs Zex Nitrous (100-hp Shot)
Test 6: NA 6.1L SRT8 Hemi vs Zex Wet EFI (200 hp)
Test 7: NA 426 Hemi vs NX (175 hp)
Test 1: Stock 5.7L Crate vs 5.7L Hemi Crate Update
Test 2: Stock 5.7L vs 370 Stroker
Test 3: 6.1L Hemi-Effect of Timing (20 vs 27 vs 33 Degrees)
Test 4: Stock 5.7L Crate vs Upgraded 5.7L Crate
Test 5: High-rpm 392 Stroker
Test 6: 5.7L NA vs Zex Nitrous (250-hp Shot)
Test 7: 6.1L NA vs Vortech Supercharged
Test 8: Modified 6.1L NA vs Twin Turbo
If you look closely, the three major competitors, Ford, Chevy, and Dodge, all offer powerful engine combinations, but only one has the name Hemi. It is arguably the most recognized name in the high-performance automotive kingdom, there is just something about the name Hemi that screams performance. Never mind the power numbers, would you rather have a Ford Coyote, Chevy LT1, or an honest-to-goodness HEMI? Even the guys from Ford and Chevy have to agree that the Dodge Hemi is every bit a worthy successor to the original. Sure, the Blue Oval and GM boys are jumping up and down about the efficiency of their little 5.0L and direct-injected LT1, but nothing from the other two look or sound as impressive as a Hemi.
The four-valve 5.0L Ford lacks displacement, while the Bowtie boys have not re-embraced the new LT1 as they did the previous LS engine family. Toss in the fact that Dodge offered up the Hellcat and Demon, and you can see that Hemi performance is alive and well. Back in the muscle car era, it took 426 ci to eclipse the 400-hp mark, and that was with the old gross power rating. Today, a modern 6.4L (392-ci) Hemi offers 485 (net) hp, and does so while offering a combination of mileage, reduced emissions, and drivability that were only a dream back in the 1960s. This book is all about how to take an already impressive Gen III Hemi and make it even better!
The Hemi engine family has naturally evolved since its introduction to keep Dodge owners one step ahead of the competition. The original 5.7L was rated at 345 hp, and was a solid step up in performance over the previous Magnum engines. The conventional V-8s just could not hold a candle to the power output of the new Hemi. To keep pace with the LS engine family offered by the power mongers at GM, the Hemi saw increases in displacement, first to 6.1 liters then to 6.4 liters. Each step up in displacement brought further power gains, but the Dodge engineers also threw in improvements in efficiency.
The 5.7L featured a 3.917-inch bore combined with a 3.578-inch stroke. The larger 6.1L offered in the SRT8 performance versions stepped up the bore size to 4.055 inches while retaining the same 3.578-inch stroke of the 5.7L. The latest 6.4L altered both the bore and stroke by combining a 4.09-inch bore with a 3.724-inch stroke. The hybrid 6.2L Hemi used in the Hellcat combined the 4.09-inch bore of the 6.4L with the 5.578-inch stroke of the 5.7L and 6.1L.
In addition to the increase in displacement, performance Hemis also received improved cylinder heads, revised camshafts, and even new intake manifolds to further improve performance. This becomes obvious when you measure the respective specific outputs of each factory Hemi. The specific output is a measurement of how much power the engine makes for each liter (or cubic inch) of its displacement. The 345-hp 5.7L produced right at 1 hp per cubic inch or 60.52 hp per liter. Stepping up to the 425-hp 6.1L resulted in a specific output of 1.148 hp per cubic inch or 69.67 hp per liter. The 6.4L iteration offered 485 hp, which equates to 1.237 hp per cubic inch or 75.78 hp per liter. The steady increase in the specific output means that Dodge did more than just add inches to its performance engines, it also improved the efficiency. This was accomplished with increased static compression ratio, improved cylinder head flow, and revised intake manifolds. On the SRT8