What dyno/track tests quantify horsepower gains or losses from adding/removing windage trays on big‑block Mopars?
Executive summary
Published, controlled dyno or track studies specifically measuring horsepower change on big‑block Mopars when a windage tray is added or removed are effectively absent in the available reporting: what exists is vendor testing and decades of forum dyno anecdotes that report mixed results—claims of modest gains (often 5–12 hp) sit beside reports of no change or even losses depending on pan, stroke and rpm [1] [2] [3].
1. What the community says: scattered dyno anecdotes and no canonical paper
Enthusiast forums and vintage tech threads repeatedly call out the lack of a definitive before‑and‑after dyno on a big‑block Mopar; posters ask for “dyno sheets” and most conclude that either nobody has done a rigorous public test or the results are inconsistent, with some builders saying they never saw a loss and others warning of oil‑return or oil‑pressure problems [4] [5] [6].
2. The numeric claims: modest gains reported, but source quality varies
When numbers are quoted, they tend to be small and inconsistent: one discussion collects found dyno tests “ranging from 5 to 12 horsepower” for windage tray installations (no single published dyno sheet provided in that thread) [1], while vendors like Milodon and product pages from retailers assert that dynamometer and track testing verify increased power from their designs—but these are manufacturer‑backed tests and not independent, peer‑reviewed studies specific to every Mopar big‑block variant [2] [7].
3. Conflicting reports: gain, no change, or loss — depends on hardware and conditions
Experienced builders and racers warn that the effect is highly combo‑dependent: engine stroke, oil‑pan depth and baffling, crank scraper presence, rpm range, and tray design (louvers vs. solid) all influence whether a tray helps or hurts; some forum contributors say properly designed trays always add power, others say some factory or solid trays have cost power by interfering with crankcase gas flow or delaying oil return—evidence for all positions is anecdotal or vendor‑sourced rather than consolidated dyno studies [3] [5] [6].
4. What vendors and racers claim from dyno/track testing
Manufacturers selling Mopar Big‑Block trays explicitly state that they validated designs on dynos and at the track—Milodon claims extensive dynamometer and on‑track testing for its “Diamond Stripper” trays and Mancini Racing markets its trays as delivering increased horsepower at high engine speeds by reducing interior windage—but those pages do not publish the controlled before/after dyno sheets for the same Mopar long‑block, so the tests cannot be independently verified from the provided material [2] [8].
5. Reality check: what would a definitive test need to show?
A conclusive, transferable result requires controlled back‑to‑back testing on the identical big‑block Mopar short block: same oil, pan, crank, stroke and pick‑up geometry; multiple pulls across the rpm band with and without the tray (and with variations: scraper, deep pan, baffling), plus oil pressure and temperature logs; until such an independently published dataset appears, claims of a universal 5–12 hp benefit (or universal harm) remain unproven in the specific context of big‑block Mopars despite vendor and community assertions [1] [2] [9].
6. Practical takeaway for builders and racers
Given the available reporting, the only reliable way to quantify gains or losses for a particular Mopar build is a controlled dyno session before and after installing the chosen tray and related sump changes; general guidance from suppliers and racers suggests trays often help at high rpm or on stroker setups but can impede oil return in some combinations, so treat vendor claims and forum numbers as directional, not definitive [2] [3] [5].