D/R 725 Front Mount Intercooler System 
 

 

 
   

"the fastest car ever recorded by our Correvit, pulled 1g in acceleration off the line, quicker than a $300K F355 Ferrari!"

Motor Magazine  

 

 


DR725 system shown with prototype intake manifold

New APS D/R Series 725 Front Mount Intercooler System
 
APS DR 725 FMIC - P/N APSWRX-FMI/R4
Professionally engineered performance for 500 - 725 horsepower applications utilizing 50 - 75 lb/min turbochargers.

The legendary APS front mount intercooler has quickly become the benchmark for all front mount intercooler systems for the Impreza WRX. Extremely high flow rates and massive temperature reduction - a level of performance that other manufacturers can only aspire to achieve.

APS has now upped the ante even further with the release of the D/R 725 front mount intercooler system, specifically designed for very high horsepower Subaru WRX and STI engines.

Unlike other systems that require cutting of structural components at the front of the vehicle, APS has designed the D/R Series FMIC with a truly bolt-on replacement unit that not only maintains the structural integrity of the vehicle, but also forms the perfect mount to accommodate the largest FMIC available for a WRX and STI.

Another bonus for the Subaru performance enthusiast is that the APS D/R Series FMIC maintains the stock fog lights!

In the case of intercooling, where bigger is better, APS shoehorned the largest intercooler core possible into the WRX for maximum cooling capacity and engine performance. With intercooler core dimensions of 9.5" x 28" x 4.5" (24.1cm x 71.1cm x 11.4cm) for a surface area of over 266 square inches and a total intercooler core volume of 1,197 cubic inches (19,600 cm3) (the largest by far of aftermarket WRX and STI intercoolers) that's over 4.5 times the size of the standard top mount intercooler.

The APS intercooler core is of internally finned construction and offers significantly enhanced flow and heat exchange performance over the standard intercooler and other front mount intercooler systems, particularly at high charge air mass flow rates. Also, unlike other manufacturers of WRX intercoolers who reduce cost by using deeper cores of small frontal area, the APS D/R Series intercooler is designed with the optimum ratio of intercooler core surface area (over 266 square inches!) to intercooler volume (1,197 cubic inches). The result is an intercooler system with outstanding flow and cooling performance, particularly at high engine horsepower levels of 500 - 725hp.

However, there is more to intercooling than size alone. Fully engineered light weight, cast aluminum end tanks ensure optimum charge air distribution throughout the entire cooling core for maximum charge air cooling and minimum pressure drop. 

The reality of intercooler excellence in terms of performance equals:

  • Largest intercooler surface area possible
  • Optimal intercooler internal passage volume
  • Lowest possible pressure drop
  • Highest possible intercooler core efficiency
  • Matched to the turbocharger air delivery in lb/min

In other words the greatest possible charge air temperature reduction with the lowest possible pressure loss at the rated flow of the turbocharger - Whilst maintaining good throttle response.


DR650 Intercooler above available in Stealth Black or STI Silver

An intercooler drops the charge air temperature, which enhances the combustion of the air/fuel mixtures. This more complete combustion of air fuel mixtures produces higher engine power. 

Intercooler performance is measured by the amount of energy (temperature) the intercooler can remove from the inlet charge air as well as the pressure drop across the entire system. It is important to consider the entire intercooler system and not simply the intercooler core itself.


Pressure and Temperature Data

The following table details pressure and temperature reduction data at various horsepower levels. Note that turbocharger specification will have a significant affect on temperature and pressure data.

Turbochargers with a smaller capacity compressor for example will discharge compressed air at a higher temperature. This results in increased charge air volume (hence gas speed) through the intercooler system to achieve an equivalent mass flow of compressed air. After all, the mass of air available for combustion is the overriding factor when it comes to producing power from an internal combustion engine. Conversely, a larger turbocharger will supply cooler air for the equivalent mass flow of compressed air.

Flywheel Power
325 hp
425 hp
525 hp
625 hp
725 hp
Pressure Data
Pressure Drop Across Core Only (psi)
0.4
0.7
1.0
1.5
2.0
Pressure Drop Across Core and all Ducting (psi)
0.5
1.0
1.5
2.2
2.9
Boost Pressure in Manifold (psi)
10.6
18.4
26.1
27.0 (1)
32.0 (1)
Temperature Data
Ambient Air Temperature (deg F)
70
70
70
70
70
Temperature at Compressor Discharge (deg F)
230
300
415
430
475
Temperature in Intake Manifold (deg F)
75 (2)
90 (2)
105 (2)
110 (2)
120 (2)

(1) Intake, head, exhaust manifold etc. flow improvements utilized
(2) Vehicle Stationary on Chassis Dynamometer

Never before has such an outstanding production intercooler system been made available for the WRX/STI performance enthusiast. For high horsepower applications, the APS DR725 is the clear choice.


The APS D/R Series Front Mount Intercooler system is supplied complete including every nut, bolt, bracket etc. for easy fitment. DR725 Intercooler above available in Stealth Black or STI Silver

Note 1: Not supplied with APS logo on intercooler core.

NOTE: Available in Stealth Black or STI Silver

The APS D/R 725 FMIC system includes a nickel plated flange for direct bolt-up of the stock blow off valve.
For applications utilizing a larger than standard turbocharger, APS recommends the use of a high performance blow off valve.
Please note that intercooler fitment requires the APS high flow air intake system for hose clearance.

Click Here for information on how Dyno-Comp relies on this precision crafted APS product to build what is arguably the ultimate Subaru high-performance sports car.

 
INSTALLATION INFORMATION

Click here for APSWRX-FMI/R4 Installation Instructions

WRX and STI enthusiasts will be delighted to know that the D/R Series Front Mount Intercooler system has been designed as a do-it-yourself installation and we are sure you will find the experience personally rewarding. With a basic tool kit and enthusiasm you will find the installation a breeze - For '01 to '05 models around 5 hours depending upon what other non stock parts are already installed, or need to be installed on the vehicle and for '05 - '07 models, around 8 hours depending upon what other non stock parts are already installed, or need to be installed on the vehicle.

Of course some may find the trimming of the front plastic air dam time consuming, though special trimming templates are supplied with the system to assist you in achieving an accurate trim.