The OE 2.5TFSI turbocharger INLET PIPE found on the 8V.2 RS3 and 8S TTRS is a significant source of performance limitation when looking at aftermarket tuning. Luckily, we have an ALL-NEW solution that releases significant performance potential…
In short, the Revo Inlet Pipe for this platform offers an increased 4-inch diameter, offering vastly increased performance potential. Our version maximises the possible gains while also offering a premium heat-reflective Zircotec coating. Allowing you to make more power AND drive harder, for longer.
It’s designed specifically for both RHD and LHD vehicles. Also supplied as a kit with all of the necessary components CLICK HERE.
If you want to know more about the extensive design process (some real test data numbers, facts and figures) and some of the decisions we took while navigating our exceptionally thorough development process, then read on.
OEM Restrictions
The restrictions in the OE inlet are due to two main reasons. Excessive heat absorption and poor heat rejection. This is even the case with only Stage 1 levels of tuning, too.
The 2.5TFSI inlet pipe is positioned near some of the main exhaust components mated to the engine head. Despite several OE heat-mitigation measures (heat shielding bolted to the exhaust components and a separate heat shield floating between the inlet pipe and the exhaust components), this placement causes typically high ambient temperatures in the engine bay region where the pipe is located.
Further accentuating this problem. The inlet pipe is placed in a location that essentially creates a “hot box” around the part.
This seals the inlet pipe off from almost all ambient through-flow that could cool the pipe. As well as creating an insulated “box” of heated components that reflect the engine bay heat back to the inlet pipe.
Both aspects serve to continuously increase the temperature of the pipe the longer the vehicle is operated.
2.5TFSI Extensive Testing
Testing has revealed that thermal management (specifically thermal rejection out of the engine bay) is of critical performance importance on these 2.5TFSI vehicles. As even Stage 1 software creates almost uncontrollable engine bay heating scenarios during aggressive driving.
Summing all the above characteristics together it becomes clear that the OE 2.5TFSI turbocharger inlet pipe becomes a significant source of performance limitation.
During the course of Revo software and hardware R&D for the 8S TTRS intercooler, 8V.2 RS3 intercooler and 2.5TFSI inlet pipe, the scale of the heat generation/retention issues discussed above were fully unveiled under tuned conditions.
During several testing sessions on the dyno, repeated dyno pulls in the Revo dyno cell (optimal fresh air/extraction ventilation) would result in metal pre-turbocharger intake plumbing parts becoming too hot to touch.
Dyno Testing & Results
The NEW, larger 4-inch Zircotec-coated Revo Turbocharger INLET pipe for this platform remedies the existing limitations of the OE part to provide the following benefits. All supported with thorough test data:
- Increased Intake Volume
- Heat-Reflective Inlet Pipe Coating
- Large Inlet Body maintaining LHD & RHD Fitment
- Cast Inlet Pipe Body
External, Heat Resistant PCV Solution
- +23.6 axle hp, +31.1 Nm max, +15.19 axle hp, +23.24 Nm average gain vs. OE intake system & turbocharger inlet pipe w/ Revo Beta Stage 1+ software, Revo carbon intake kit, Revo intercooler kit and Milltek de-cat downpipe
- 16.25% max, 19.75% average intake flow restriction reduction vs. OE 8V.2 RS3 intake system & turbocharger inlet pipe (via bench flow testing)
- True 4 inch inlet (4.25” OD, 3.94” ID) intake system connection, compatible w/ LHD & RHD vehicles
- Zircotec© proprietary heat-reflective coating applied to inlet pipe to address chronic engine bay heat issues on the platform
- External, flexible & heat resistant PCV vacuum system to maintain unobstructed internal pipe flow geometry & provide easier installation
- Included increased-diameter, flow-matched silicone coupler for Revo Carbon Intake back pipe
- Included grade 304 stainless-steel hardware for long-term heat/corrosion resistance
8S TTRS and 8V.2 RS3 2.5TFSI
We already have a Revo intercooler available on both the 8S TTRS and 8V.2 RS3 platforms, which manage this extreme heat entering the intake system. However, there is obvious room for improvement by extracting some of the thermal load from the pre-turbocharger intake air.
Fortunately, just as with the stock intercoolers on the 8V.2 RS3 and 8S TTRS vehicles, these heat absorption and rejection issues create several opportunities for Revo to develop an improved, performance-retaining replacement part.
It was determined that increasing the volume of the inlet pipe (from ~3″ to ~4″) would yield significant performance benefits, both in available airflow to the turbocharger as well as cooling.
Additionally utilising a proprietary, heat reflective Zircotec ceramic coating further reduces the impact of ambient engine bay heat in the inlet’s ‘hot box’.
This gives the Revo part the absolute best chance possible to mitigate the thermal issues at hand and retain the most power possible in the application.
We visited the Zircotec UK HQ to get a first-hand experience of the inlet being coated with their special heat-reflective formula. Very interesting and there will be more to come on the true merits of this coating at a later date.
LHD & RHD Fitment
The increase to 4 inch presents challenges for fitment on both LHD and RHD while maintaining Revo hardware fitment standards. Largely because the main brake reservoir envelops a large amount of available design space on RHD vehicles.
The design goals for the Revo 2.5TFSI turbocharger inlet pipe were to maximise the air volume supply to the turbocharger via a significant part volume increase.
This volume increase is to be accomplished via a unique, cast pipe design that maintains a 4-inch cross-sectional volume area throughout as much of the pipe routing as possible while maintaining fitment on both LHD and RHD applications to Revo’s hardware fitment standards.
Finally, a turbocharger adapter is to be utilised to mate the Revo part to the turbocharger inlet. This allows for easy adaption and future-proofs the design.
The Revo 8V.2 RS3 Turbocharger Inlet Pipe Kit comes with 1 x inlet pipe assembly (with Revo PCV system pre-installed), 1 x stock turbocharger coupling ring, 1 x coupling ring o-ring, 1 x 90-110mm stainless steel, worm-drive hose clamp and 1 x silicone coupler (designed to couple the inlet pipe assembly exclusively to the Revo carbon intake back pipe).
Here’s how the Revo turbocharger inlet pipe satisfies the Revo design goals that we identified:
1. Airflow Increase
The main design focus of the Revo Turbocharger Inlet Pipe was to increase the internal volume of the part.
This data indicated that an increase to an inlet size of ~4” (and maintaining that internal cross-sectional area size throughout as much of the pipe as possible) would net significant performance gains on the 8V.2 / 8S 2.5TFSI platform.
However, this came with the requirement that a single pipe needs to fit both LHD and RHD applications. While this requirement was challenging, several areas of the engine bay volume around the stock turbocharger inlet pipe were markedly open to accommodate the geometry of the specially designed Revo pipe.
Namely, the area between the stock pipe and the firewall was plentiful, allowing for a ‘squished’ area of the pipe, which would expand into this area to maintain a cross-sectional area as equivalent as possible to the 4-inch inlet area. While simultaneously providing clearance to the master cylinder on RHD applications.
As with every Revo hardware part the design balances overall size increase (and subsequent performance increase) and fitment within the available engine bay volume given by the application.
In the 8V.2 RS3 / 8S TTRS application, the constraints considered when increasing the size of the inlet pipe were. 1. The main air conditioning line when increasing the inlet connection size and location of the pipe. 2. The exhaust manifold heat shielding and coil packs when increasing the width sizing of the Revo part. 3. The exhaust manifold/intake heat shielding and, tasty, RHD-placed brake master cylinder when increasing the depth of the Revo part.
The fitment/sizing decisions made to maximise the internal volume of the Revo inlet while retaining optimal fitment on both LHD & RHD vehicles are discussed below.
2. Height Sizing
The air conditioning line will serve to limit the amount of height added/size increase of the main pipe inlet. This constraint, however, was not realistically limiting when increasing the inlet size of the Revo pipe vs. stock, as the bottom/inner edges closest to the intake pipe heat shield bracket and the coil pack were simply maintained as current. The bulk of the diameter increase towards the main air conditioning line and firewall (where available space was more plentiful).
During the design process, it was also decided that the stock wastegate control line would be eliminated, with the Revo kit supplying a new, flexible & highly heat-resistant wastegate control line eliminating that dimensional constraint.
3. Width Sizing
Given the plentiful volume of available engine bay room towards the firewall, the Revo part was expanded into this area to achieve the internal volume increase required. As discussed above, the Revo part was designed to maintain a cross-sectional area as closely equivalent to the cross-section of a 4” circle (12.57 in.² or 8107.32mm²) as possible.
Using this design principle of expanding the volume of the inlet towards the firewall, the Revo part maintains this cross-sectional value until the middle of the part, when the internal area tapers to 4532.29mm² (a 44% internal volume decrease) for engine bay part clearance purposes.
The Revo part then tapers further to smoothly complete the internal volume transition into the turbocharger connection point. The innermost point of the Revo part maintains the same clearance to the nearest engine bay component (the exhaust manifold heat shielding), similar to the inlet connection clearance to the intake pipe heatshield bracket and coil pack, discussed above.
4. Depth Sizing
The most challenging design aspect of the Revo part, the depth sizing. Similar to the width sizing, the depth of the Revo part was strictly limited by both the exhaust manifold heat shielding and the master cylinder/reservoir of the braking system on RHD vehicles.
Again, the ‘squish’ design method was applied to both increases internal volume in the width axis, while maintaining appropriate clearances in the depth axis. The method of maintaining existing part clearances was also employed where the exhaust manifold heat shielding is closest to the stock part, to maintain an adequate air gap between the Revo part and the exhaust shielding, for thermal management properties (discussed below).
Dyno Testing
The Revo 8V.2 RS3/8S TTRS Turbocharger Inlet Pipe was tested on our in-house, UK-spec, non-GPF 8V.2 RS3 using Revo’s in-house Dynapack hub-based dynamometer.
The vehicle was tested with beta Stage 1+ software, a production Revo carbon intake, a production Revo intercooler kit and a Milltek de-cat downpipe. Only the pre-turbocharger intake system and turbocharger inlet pipes were changed for the tests described below.
Four back-to-back runs were performed to gauge the various metrics of both intake systems, as well as to evaluate the thermal performance of both systems. Below are the details and further explanations required for each graph. It should be noted that all four dyno runs were easily completed with both the stock and Revo intake setups (due to a Revo intercooler kit being utilized during the testing).
No significant thermal performance differences were uncovered during this initial testing, so the below graphs/explanations do not address this. However, further testing is scheduled with higher ambient temperatures (during summertime) to better highlight the increased thermal management properties of the Revo inlet pipe.
Additionally, the Revo Turbocharger Inlet Pipe was tested on a stationary flow bench machine to quantify the air restriction of the stock intake system, complete Revo intake system and no intake at all.
Three different configurations were tested; the complete Revo intake solution (production Carbon Intake w/Revo inlet pipe), the complete stock intake (w/stock turbocharger inlet pipe) and the stock inlet pipe with nothing attached (to evaluate the restriction of the complete Revo intake kit vs. the least amount of restriction to the stock inlet pipe possible).
Performance Graphs
Turbocharger Inlet Dyno Graph: This is a power measurement from testing both the stock and complete Revo systems. Several parts of this graph are quite notable, the first being the average gain of the Revo intake over the stock intake throughout the length of the run.
This average gain throughout the powerband of the engine is typical of intake modifications. Where gains are typically only seen towards the top end of the rev range (when engine airflow is at its highest and the engine can utilize the decreased intake restriction). This illustrates the effectiveness of the Revo inlet pipe (and overall carbon intake kit) on the 2.5TFSI platform, showing that these engines (coupled with software) have significantly increased airflow requirements and can benefit profoundly from quality intake upgrades.
Furthermore, the maximum power gained when utilizing the Revo carbon intake solution is also of note. These maximum power/torque gains are on-par with some of the most effective intake kits Revo currently offers, again illustrating the meaningful performance benefit of coupling both Revo hardware and software modifications on the 8V.2/8S 2.5TFSI platform.
It can easily be determined that the Revo Turbocharger Inlet Pipe is an effective intake modification, when coupled with Revo software, to reveal additional power gains from this platform.
Air Box Inlet Temperature
This is a metric used to confirm that the testing of both the OE and Revo intake systems were comparable. This data was retrieved from a thermocouple (temperature recording probe) placed in the entrance to the airbox during testing.
As such, this data confirms that the power gains shown were purely down to differences in the stock and Revo intake system designs. And not due to improper or purposefully misleading testing via test cell temperature fluctuations/manipulations). As can be seen from the graph. the temperature of the air being ingested by the vehicle throughout both testing setups remained similar (within 2°C – 3°C). with the only significant deviation occurring during the Revo intake testing (where the intake temperatures were higher for the Revo power testing (and putting the Revo kit at a slight disadvantage, as such).
Despite this disadvantage. The full Revo intake kit still produced exceptional power gains over the stock intake system. Solidifying the effectiveness of the Revo inlet pipe at increasing engine performance on a Revo-tuned 8V.2 /8S 2.5TFSI engine.
2.5TFSI Turbocharger Inlet & Intake Flow Restriction
This is another performance metric that is used to allow customers to understand how much more airflow can be passed through the full Revo kit vs. the stock intake kit.
As discussed above, the airflow capability of the Revo Turbocharger Inlet Pipe (via volume increases and design characteristics) was one of the main design foci of the product, in order to increase the performance of the engine.
However, this metric cannot only be quantified (fully) by dynamometer testing alone. It requires the supplement of bench flow testing to completely illustrate the performance advantage of the Revo system to customers. The graph further confirms this performance advantage. Illustrating that the complete Revo intake can pass more air to the turbocharger, per unit time, vs. the stock intake. thus resulting in the increased power output shown in the power graphs.
To further affirm this advantage, the graph also shows the Revo intake solution compared to only the stock turbocharger inlet. This is effectively demonstrating that the full Revo intake kit provides only a very marginal increase in airflow restriction to the turbocharger vs. no intake system at all.
This effectively confirms that the full Revo intake kit is providing the best performance possible from an intake system. Filtering the incoming turbocharger air while providing almost no additional turbocharger limitations while doing so.
2.5TFSI Performance Pack
Moving on from the pipe alone. This INLET now forms part of a full (Stage 2) REVO PERFORMANCE PACK for both non-GPF and GPF-equipped vehicles. Taking gains to ~525bhp on the non-GPF 2.5TFSI platform.
The Performance Pack is a full suite of hardware and extensively developed Stage 2 software. Safely and reliably maximizing the gains with the stock turbocharger unit. More on that HERE!
