When Bell Intercoolers set out to design the Volvo S60R/V70R Front Mount Intercooler System the goal was straightforward, improve performance and performance capacity over the factory intercooler system. To do this we focused on increasing thermal efficiency, decreasing pressure drop and improving thermal inertia, the standard performance benchmarks for an intercooler. We also focused on providing considerably more structural integrity at high boosts levels as the factory system utilizes plastic intercooler tanks and tubes, which are prone to cracking and failure under prolonged exposure to higher boost pressures and the accompanying heat increases.

Before examining the technical details, let take a quick look at the performance figures. The following data was gathered during testing sessions* utilizing a 2004 V70R with the following modifications: 18.5 psi Boost Pressure, ECU Upgrade, Low Restriction Exhaust.

Pressure Drop
(Measured pre-intercooler inlet and post-intercooler outlet, averaged across six test runs)
Factory System: 1.67 psi pressure drop
Bell Intercoolers System: 1.04 psi pressure drop
Improvement: .63 psi, a 38% reduction in intake air flow restriction

Thermal Efficiency and Thermal Inertia (Intercooler Outlet Temperatures)
(Measured post-intercooler outlet, averaged across six test runs)
Factory System: 86 °F @ 69.4 °F Ambient
Bell Intercoolers System: 70.8 °F @ 68.5 °F Ambient
Improvement: 15.2 °F drop in intake temperature

Horsepower Gain
18hp increase over factory intercooler system (measured at wheels). Good pressure drop and thermal efficiency numbers provide excellent details on where improvements were made, but the horsepower number is the one that easiest to translate to real world performance. This improvement in horsepower is the direct result of the increased thermal efficiency and lower pressure drop of the Bell Intercoolers system.

These numbers quantify the improvements found at the testing pressures of 18.5 psi boost, a pressure selected because it is representative of the average boost pressure range for most modified S60R/V70Rs. The Bell Intercoolers system safely and efficiently handles the mass air flow of 18.5 psi, roughly 340-350hp (at crank), with little effort. This is because our intercooler system is designed to remain efficient up to the 450hp level. Tthe factory system is only designed to accommodate 300hp. The Bell Intercoolers system was designed to provide maximum performance benefits to all modification levels, from stock to track-only racer. This power capacity means the Bell Intercoolers system expands with your forced induction modifications. So, whether your plans involve increasing boost pressure or installing a larger turbocharger, the Bell Intercoolers system will meet your intercooling needs.

So how did we improve on the factory system? The Volvo engineers designed the factory intercoolers (yes there are two – one large, primary intercooler and one small, secondary intercooler) to work well at the factory boost level (14.7 psi) and at ambient air temperatures of approximately 75-80 °F and cooler. These intercoolers do a good job if you remain within those constraints. However, if you are planning on raising the boost pressure or if you do most of your driving in places where you see ambient temperatures over 75-80 °F then you are going to see the efficiencies of the intercooler system dropping off, reducing performance and increasing the risk of detonation.

The Bell Intercoolers S60R/V70R Front Mount Intercooler System is designed to replace the factory intercoolers and tubes with a high performance, high efficiency intercooler system. A system capable of providing substantial decreases in intake air temperatures and pressure drop, even at high ambient temperatures and higher than stock boost pressures.

Intercooler Core
To improve on the factory design we started where we would with any of our racing intercoolers, at the core. The factory intercooler system utilizes a Tube and Fin core design and while this type of intercooler provides a cost efficient intercooler, good from a manufacturing standpoint, it does not provide the best performance. The Bell Intercoolers system uses a Bar and Plate type core designed for higher flow rates, less flow restriction (lower pressure drop), higher thermal efficiency and higher thermal inertia. The cores we use in the S60R/V70R Front Mount Intercooler system are the same US made, high performance Bar and Plate cores we use in our custom racing intercoolers.

As mentioned before, the factory intercooler system is a good design, as long if you do not intend to raise boost pressure beyond the stock setting or you do not drive where the ambient temperatures are above 75-80 °F. The Bell Intercoolers system picks up where the factory left off. By using a large 3” x 13.6” x 18” Bar and Plate core, sized specifically for the Volvo S60R/V70R, we simultaneously increase thermal efficiency and reduce pressure drop. This core size is designed to safely, efficiently handle up to 450hp while delivering low restriction flow and high thermal efficiency.

Why is this reduced pressure drop important? If you are producing 14.7 psi boost at the turbocharger and your intercooler has a 1.5 psi pressure drop, then you will only see 13.2 psi of boost pressure after the intake air has passed through the intercooler. Of course you can turn up the boost pressure at the turbo to 16.2 psi and be back to 14.7 psi at the intake manifold, but in doing so you have compressed the air to a higher pressure and that introduces more heat. This is additional heat that your intercooler then has to remove. This increased resistance also increases the work load of the turbocharger, increasing spool up response time. So, a low pressure drop provides higher boost pressures to the intake manifold with lower levels of adiabatic heating. A lower pressure drop also provides less resistance for the turbocharger and allows for faster spool up of the turbo for reduced turbo lag.

This larger core means more than just improved turbo response and a high power capacity, it means dramatically improved thermal efficiencies at higher ambient temperatures. While the factory system is only efficient at ambient temperatures of 75-80 °F or below, the Bell Intercoolers system can provide high thermal efficiency up to ambient temperatures above 100 °F. This improved thermal efficiency translates directly into increased power. One way to convey the effectiveness of an upgraded intercooler is to think of the performance difference of a turbocharged engine at 75 °F versus 60 °F, a 15 °F temperature difference. Your R will have noticeably stronger acceleration at the cooler temperature of 60 °F as opposed to 75 °F. This 15 degree temperature difference is exactly what we found during our comparison testing between the factory system and the Bell Intercoolers system (at 70 °F ambient).

Intercooler Assembly
While the intercooler core is the primary component of the intercooler assembly there are other important pieces to consider, starting with the intercooler tanks. The factory intercooler system uses a cost effective plastic tank design. These plastic tanks and tubes, while acceptable for the 300hp design specs of the stock S60R/V70R, are not a reliable material for increased boost pressures. This is a cost-saving measure by the factory and if you never plan to increase boost pressures then you should have nothing to worry about. Our Bell Intercoolers system features high strength aluminum intercooler tanks and inlet/outlet fittings. These are designed to withstand temperatures and pressures up to 50psi boost pressure.

Our intercoolers are also designed for the higher air low levels found with higher than stock boost pressures. With larger inlet and outlet fittings, 2.5 inch vs. 2.25 inch for the factory, and high flow tank designs, our system presents less flow resistance for increased power and faster turbo response, even at stock boost levels.

Each intercooler assembly is anodized (Type II Color, MIL-A-8625E) in your choice of Clear (natural aluminum finish) or Low-Visibility Black (matte black finish). This standard coating provides a corrosion protection for the aluminum intercooler while offering a choice of color options.

Intercooler Tubes
Our high strength, high flow approach also applies to the intercooler tubes. Again, as a cost-saving measure the factory designed their system to use plastic and rubber intercooler tubes. As with the plastic intercooler tanks these will work well if not subjected to the higher thermal and pressure loads seen with increases in boost pressure. The Bell Intercoolers system uses high strength steel (2.5 in. and 3.0 in. diameter) intercooler tubes with TIG-welded construction. These tubes will easily withstand the elevated temperatures and pressures associated with higher than stock boost levels and feature oversized hose beads to provide proper hose retention under high boost levels. Each tube is then treated with high temperature powder coating to ensure a durable and maintenance free finish.

The Bell Intercooler tubes include all factory sensor and vacuum line mounting points. They also include, as standard, a mounting port for the Aquamist water injection system.

Every component of the Bell Intercoolers system is designed for optimal performance up to 450hp. From the Bar and Plate core to the high strength, high flow tubes, it is all designed to deliver the highest efficiencies possible. For a final comparison, how would the factory intercooler handle 450hp? Simply put, it couldn’t. At the pressures and temperatures seen at that power level, it is likely that the factory intercooler system would have suffered a structural failure in the form of cracking or rupturing of the plastic intercooler tanks and intercooler tubes. If it did remain intact the intake temperatures would be too high and the pressure restrictions too great to allow the engine to function properly. Keep in mind that the factory system is designed to work well within the scope of the factory engine settings. The engineers were not designing for higher boost levels. We suspect that the factory engineers, if given an open budget and higher boost targets would have designed something similar to our system.



* Test Notes
Vehicle: 2004 V70R
Protocol: Vehicle was tested first with the factory intercooler system, then tested again with the Bell Intercoolers system. No other modifications or alterations were made to the vehicle between tests.
Dyno: Dyno Dynamics AWD dyno


Test Conditions:
Factory Test
Temp: 69.4º F
Humidity: 88%
Pressure: 30.04 in.

Bell Intercoolers Test
Temp: 68.5º F
Humidity: 71%
Pressure: 30.29 in.