5.7L Hemi Ram Header Upgrade: Long Tubes vs. Stock Manifolds & Real Dyno Gains
5.7L Hemi Ram Header Upgrade: Long Tubes vs. Stock Manifolds
There is nothing worse than knowing your 5.7L Hemi is capable of massive power, but feels choked by factory restrictions.
The Short Answer (TL;DR)
For 4th Gen Ram 1500 owners (2009-2018), replacing stock cast-iron manifolds with 1-7/8" Long Tube Headers is the single most effective bolt-on modification. Real-world testing shows gains of 0.6 seconds in the quarter-mile when paired with a custom tune. This upgrade also permanently fixes the common "Hemi Tick" caused by warped factory manifolds and broken studs.
The Community Question
Many drivers on the Ram Forum ask if upgrading to aftermarket headers is actually worth the cost and labor, or if it just adds noise. Specifically, users debate the performance difference between "Shorty" headers and "Long Tube" headers (LTs). Owners also frequently discuss reliability concerns regarding the 6-speed (65RFE) transmission when adding this extra horsepower.
The Mechanical Diagnosis: Why Stock Manifolds Fail
The factory exhaust manifolds on the 5.7L Hemi are cast iron "logs." While durable for basic commuting, they are engineered for strict packaging and emissions, not performance. These logs create significant backpressure, preventing the engine from expelling exhaust gases efficiently.
Furthermore, the thermal cycling of these heavy iron manifolds creates a massive problem: warpage. As the iron heats and cools, it expands and contracts, eventually shearing off the manifold bolts (usually on the rear cylinders). This results in the infamous exhaust leak known as the "Hemi Tick." Replacing them with another set of stock manifolds often leads to the same failure down the road.
The Engineering Solution: Scavenging and Airflow
Long Tube Headers solve the restriction issue through a process called exhaust scavenging. By lengthening the primary tubes, exhaust pulses are timed to create a vacuum effect that pulls spent gases out of the cylinder. This allows the fresh intake charge to fill the cylinder more completely.
Forum veterans note that switching to 1-7/8" Long Tubes (like American Racing Headers or Stainless Works) significantly alters the power curve. One user reported dropping their quarter-mile time from 14.1s to 13.4s just by adding long tubes and a tune. For maximum low-end torque, combining these headers with a 6.4L Truck Intake Manifold (Active Runner) provides "insane" off-idle throttle response.
Recommended Fix: Install 1-7/8" Long Tube Headers with High-Flow Cats and a Custom Tune.
Frequently Asked Questions
Long Tubes vs. Shorties: Which is better?
Shorty headers are essentially a direct replacement for stock manifolds. They are good for fixing broken manifold bolts without requiring a tune, but the performance gains are minimal (approx. 10-15 HP). Long Tube Headers require a tune but offer massive gains across the entire RPM range.
Do I need a tune with headers?
Yes. If you install Long Tube Headers, you will need a custom ECU tune (via HP Tuners or Diablo) to optimize fuel trims and prevent Check Engine Lights (CEL) related to the catalytic converters. Shorty headers generally do not require a tune.
Will the 6-speed transmission hold the extra power?
The 65RFE/66RFE transmission can handle the power if driven correctly. Avoid full-throttle downshifts (kicking it down a gear while flooring it). Manually downshift into the power band before applying heavy throttle to preserve the overdrive clutches.
