Radtec Drop In Intercooler Test & Results

[BlackBeast]

Radtec Drop In Intercooler: Volvo 850 & C/S/V70 Test & Results

Most Volvo owners may leave the modification of the intercooler (IC) as a last resort, due to the fact that intercooler research is limited on these cars and may not provide an instant increase in power. An air to air ICs primary function is to dissipate heat. Hot compressed air produced by the turbo flows through the ICs core, made of tube and fin construction. The heat dissipates to the outside, cooling the compressed air inside. This increases its density bringing more oxygen to the combustion chamber and therefore potential for more power. IC design is a vital component in producing a more powerful car. The data illustrated below compares the results of the uprated intercooler against a standard IC.

To allow a true 'on the road' comparison, a standard C70 T5 ('99 ME7) was chosen as the test vehicle, because the engines sensors can easily be read and data logged via the OBD2 port. To be able to compare the uprated IC to a standard IC, the test needed to be performed repeatedly, measuring the temperature of the IC when asked to provide consecutive wide open throttle runs. This would show how efficient the intercooler was at dissipating heat. The test was performed on a steady incline (hill) to put the engine under the maximum load, creating more heat than on a flat road. For this test, inlet air temperature (IAT), mass air flow (MAF) and RPM were logged at an ambient temperature of 13°C. Each data log starts at the bottom of the hill at 30mph in 3rd gear, where wide open throttle (WOT) is initiated up to peak RPM. The pull is repeated by braking hard down to 30mph and the sequence re-run two more times until, at the third attempt, 5th gear is selected and the engine allowed to coast down to 70mph.

Standard IC data log at 13°C ambient


Uprated IC data log at 13°C ambient


As shown by the data logs, there is a difference in starting IATs by 1 degree, even though the ambient temperature was identical and the car was driven at the same speed to each test. The peak temperatures reached by the uprated IC on the three pulls were on average 5 degrees less than the standard IC. The highest temperatures were seen, as expected, at the peak of the third pull. In both IC's the lowest temperature after each pull increases by a steady gradient throughout the test. A larger temperature change is seen between pulls of the standard IC (on average 3.5 degrees), where as the uprated IC shows a 1.5 degree temperature increase between pulls. The uprated IC was also closer to ambient temperature than the standard IC after the final pull. The MAF readings from each test showed an average of 1g/s difference between the two ICs, yet the peak readings were 5g/s higher with the uprated IC, showing that the uprated IC does flow more air through its core to the engine.

What happens if you decide you want more power? The easiest and least expensive modification on a turbo car is to increase the boost. A standard C70 T5 produces 12psi/0.8bar of boost. A stage 1 remap for this car increases the boost pressure to 18psi/1.2bar. A larger volume of air is passed through the turbo, causing the compressed air to be even hotter. IATs can easily reach in excess of 60°C at WOT even at low ambient temperatures, which is the threshold at which the ECU will retard engine timing. Turbo cars love cold temperatures. Ever noticed how much more powerful your car feels on a cold morning compared to a boiling hot day? With lower IATs comes a higher oxygen content, allowing the ECU to meet its ignition advance target values, therefore making consistent power. The higher the ambient temperature the higher the IATs; if IATs get too hot, the ECU has to retard ignition to protect the engines components, but will also cause a reduction in power. Boost pressure can also be reduced to protect the engine from damage, lowering performance even further.

The standard IC copes fairly well at a relatively low ambient temperature and standard boost, but as the tests have shown, the uprated IC reduces IATs even further. This will be even more evident at higher ambient temperatures and on modified cars producing more boost. Although these tests do not comparatively show the thermal efficiency of each IC (% difference to inlet, outlet and ambient), the IATs show that the uprated IC is at least 7% more efficient at cooling the air than a standard IC, allowing the engine to perform consistently.

Please click the link below to view the for sale thread of the Radtec drop in IC (for the 850 & C/S/V70 P1 models):-http://www.vpcuk.org/forums/showthread.php?t=41943

[Wobbly Dave]

I found about the same drop with the Nissens FMIC I fitted compared with standard. Good work there.

[Wobbly Dave]

Does anyone think that moving from 57mm ports on my Nissens FMIC to this Radtec with 63mm is worth the additional investment? I'd have to buy all new pipework to match.

[BlackBeast]

Does anyone think that moving from 57mm ports on my Nissens FMIC to this Radtec with 63mm is worth the additional investment? I'd have to buy all new pipework to match.

Only one way of finding out Dave. The setup is definitely good enough for the power you are after as has been proved by myself for the last year.

[Wobbly Dave]

I think I will wait to see how the IATS bear up with the current set up & if it proves to be restrictive I'll be in touch. Is there any time limit with the Radtec relationship?