Dyno Test Results – Part 2
We already proved what the Jackal Motorsports Stage 1 tune could do on a stock RS6. This time we added one thing the ARM C8 4.0T Downpipes and went back to the dyno to see where the hardware picks up where the tune leaves off.
ARM Motorsports 3 Downpipe Runs Stage 1 Tune
Test Setup & What We Changed
In our first RS6 dyno test, we established that the Jackal Motorsports Stage 1 tune on a completely stock 2021 RS6 added 68 wheel horsepower and 77 wheel-torque , entirely through software, with zero hardware changes. If you haven’t read that post, start there.
For this session, we kept everything identical , same car, same Jackal Motorsports Stage 1 tune, same Dynojet dyno, same 93 Octane pump gas , and added only one variable: the ARM Audi C8 4.0T Downpipes. Three pulls in this configuration to confirm consistency.
Test vehicle: 2021 Audi RS6 – EA825 4.0T V8 Twin-Turbo
Dyno: Dynojet
Fuel: 93 Octane Pump Gas
Tune: Jackal Motorsports Stage 1
Hardware change: ARM Audi C8 4.0T Downpipes – all other hardware stock
Total runs: 3 (Stage 1 + Downpipes)
Best Run – All Three Configurations
Stock – Best
556 WHP
587 WTQ
Stage 1 – Best
624 WHP
664 WTQ
Stage 1 + Downpipes – Best
647 WHP
654 WTQ
Downpipes gain over Stage 1
+23 WHP
647 vs 624 WHP
Total gain over Stock
+91 WHP
647 vs 556 WHP – +16.4%
Full Dyno Data
| Run | Configuration | WHP | WTQ |
|---|---|---|---|
| , | Stock (reference) | 556 | 587 |
| , | Stage 1 (reference) | 624 | 664 |
| 1 | Stage 1 + Downpipes | 638 | 650 |
| 2 | Stage 1 + Downpipes ★ Best | 647 | 654 |
| 3 | Stage 1 + Downpipes | 642 | 654 |
| Downpipes gain over Stage 1 | +23 WHP | see note | |
The three downpipe runs were highly consistent , all within 9 WHP and 5 WTQ of each other. That kind of repeatability across three pulls tells us the hardware is doing its job predictably and reliably.
Where the Downpipes Actually Make a Difference
The peak numbers only tell part of the story here. To understand what the Downpipes actually do, you have to look at where the two curves diverge , and that story starts at 5,000 RPM.
Below 5,000 RPM, Stage 1 alone and Stage 1 with Downpipes run nearly identically. The power and torque curves track each other closely through the low and mid-range. The Downpipes aren’t adding anything you can feel down low , and that’s expected. At lower RPM and lower flow rates, the stock downpipes aren’t the limiting factor.
But above 5,000 RPM, the story changes. The Stage 1 tune on stock downpipes starts to lose ground as exhaust flow demand increases. The stock downpipes begin to build backpressure at higher RPM, and the power curve reflects it , it begins to plateau and taper off earlier than it should. The ARM Downpipes remove that restriction, and the result is visible on the chart: the power curve continues climbing through 6,000 RPM while Stage 1 alone has already started to roll off. Above 6,000 RPM, that separation grows to as much as 35 WHP and 30 WTQ in favor of the Downpipes, a gap that only widens as the stock exhaust runs out of flow capacity.
Note on peak torque: Stage 1 alone showed a slightly higher peak torque figure (664 WTQ) vs Stage 1 with Downpipes (654 WTQ). This was a narrow spike at a specific RPM point , not a meaningful difference across the torque curve as a whole. The broader torque band between the two configurations is essentially identical below 5,000 RPM, and the Downpipes clearly pull ahead on power above it.
The V8 Finally Sounds Like a V8
The dyno numbers are compelling, but there’s another reason RS6 owners install Downpipes that doesn’t show up in a chart: the exhaust note.
The stock RS6 exhaust is heavily suppressed from the factory. Audi builds these cars to be refined and quiet , which is impressive engineering, but it also means the 4.0T twin-turbo V8 under the hood is almost completely muffled. You know there’s a big engine in there. You just can’t hear it.
The ARM Downpipes change that. By replacing the restrictive stock units, exhaust gases exit more freely and the character of the engine comes through. The result is a deeper, more authoritative exhaust tone that opens up under load and lets the V8 breathe the way it was meant to. It’s not obnoxious , it’s the sound the engine was always making, finally given room to be heard.
On a car with this much power and this much engineering behind it, the sound should match. The Downpipes get you there.
Stock to Stage 1 to Stage 1 + Downpipes
Taken together, these two dyno sessions tell a clean and complete story about how to build power on the C8 RS6 platform in the right order.
The tune came first , and it delivered immediately. Jackal Motorsports Stage 1 added 68 WHP and 77 WTQ on completely stock hardware, transforming the powerband from 3,500 RPM all the way to the rev limiter. That’s documented in full in our original dyno post.
The Downpipes came second , and they picked up exactly where the tune ran out of room. Once the ECU is extracting maximum effort from the engine, the stock exhaust becomes the next constraint. Remove it, and the top end opens up. The result is 91 WHP and 67 WTQ over the stock baseline, a 16.4% power increase on a car that already came with 591 crank horsepower from the factory.
For a full list of our RS6/RS7 Upgrades CLICK HERE.
If you would like us to help you with your EA825 build, let us know and we’ll be glad to assist you!
The ARM Team