CSF announces The “O” Series

All-aluminum radiators w/ built-in oil coolers

It’s been a productive 2015 year for CSF’s Racing & High Performance division, and one of our most innovative product lines so far has been our innovative “O” Series line of race-spec all-aluminum radiators with built-in oil coolers!

**PRODUCT UPDATE for CSF #3076O & #7042O**
We have switched to using the Mocal compact, lightweight, high-flow M20 x 1.5 filter sandwich plate (Mocal part #SP1F) instead of the ones made by Greddy. Apparently, there were some internal issues that prevented us from purchasing the Greddy sandwich plates from their USA distributor so we had to source this part from another manufacturer.

* 2006/2007 WRX has a much tighter fitment due to different factory oil cooler and exhaust manifold combination. To make this work with these model years, you will either need to remove the factory oil cooler and cap off the coolant line coming off the water pump and at the block and/or run aftermarket headers (as it’ll have less of a fitment issue).*

**PRODUCT DISCLAIMER for CSF #3076O & #7042O**

The CSF radiator/oil cooler combo has a liquid-to-oil heat exchanger in the bottom end tank of the radiator, which is used as the engine oil cooler or can also be used as a transmission oil cooler in vehicles with automatic transmissions. Because of the compact size of the oil cooler, the cooler has been designed to be extremely efficient in relation to the size of the cooler and compared to a typical air-to-air oil cooler. To make this type of oil cooler as efficient as possible, we have inserted turbulators into the plate-type oil cooler to keep the oil in the cooler longer and agitate the oil inside the tubes for better surface area contact, which results in more efficient heat exchange. This oil cooler results in a significant pressure drop of approximately 30psi compared to using no oil cooler and approximately 20-25psi compared to using a traditional air-to-air oil cooler. 

Before this product’s release in 2015, we had done extensive testing with highly respected Subaru engine and motorsports specialist, LIC motorsports (when they were still in business) and we determined that this part was safe to release to the market. Our prototype unit was ran for months on a test vehicle, where we tested for any damage or engine degradation – once we were comfortable with the results, we released the cooler.

Some customers have reported concern regarding the pressure drop being too high and the operating pressure being too low for comfort using our product (both the oil cooler as well as the radiator). For this, we recommend a traditional style air-to-air oil cooler in conjunction with our manual High-Performance 2-Row Race Radiator (CSF #7042) or 1-Row High Performance upgrade (CSF #7028).

With that being said, we have sold close to 500 of these combo unit coolers with zero reported engine failures or issues related to the longevity of the system – including pro-am global time attack cars and more.

SUBARU WRX / STI 02-07 (#3076O)

SUBARU WRX 08-14 / STI 08-20 (#7042O)

The 1st models of this new “O” Series is for the Subaru platform: 02-07 STI/WRX (CSF #3076O),  08-14 WRX and 08-20 STI (CSF #7042O). These 2 applications were developed alongside industry leading Subaru engine builders & race tuners, LIC Motorsports from Northern California. CSF also reached out to one of our closest race teams, Subaru tuners, and dealers; Snail Performance, to help with fitment and performance testing in the hot Arizona desert they are regionally located in.

Technical Specs:

  • These radiators utilize a 2-row 42mm core that feature CSF’s exclusive B-tube technology, as well as an ultra-efficient 6.5mm multi-louvered fin for maximum surface area contact, heat dissipation, and extreme performance capabilities.
  • Equipped with an all-aluminum racing style drain plug for quick and reliable fluid changes
  • CSF 1.4 Bar (20 psi) radiator cap
  • Engineered and designed to be a complete “drop-in fit” install. Works with all the OEM brackets, fittings, AC condenser, hoses, and fan shrouds (only minor trimming needed at fitting locations)
  • Featuring a robust 4-plate liquid-to-oil plate-type oil cooler built into the bottom endtank. A liquid-to-oil cooler is much more efficient than a conventional air-oil cooler. Lab tested in CSF”s ISO certified in-house lab testing facility to reject heat better and at a faster rate than a 10 row air-to-oil cooler. In addition, by being placed in the bottom endtank, the oil temperature is regulated by the thermostat of the cooling system. Never have to worry about operating temperatures not warming up fast enough in cold weather climates.
  • Complete with 2 AN-10 male fittings and is compatible with many popular aftermarket engine and exhaust manifolds.
  • This kit comes complete with a machined thermostatic sandwich plate made by Greddy and forged right angle -10 fittings made by BAT.
  • Topped off with the industry’s finest 1 hour hand polish “mirror finish” for a look that matches the performance.
  • Installation of this unit will require an additional 1/4 to 1/2 a quart of oil

No expense spared with CSF’s included kit. Complete with a machined thermostatic sandwich plate made by Greddy and forged right angle -10 fittings made by BAT.

Price ~ $649 MSRP/MAP, currently offered at an introductory price of $599 (with kit included)

Both of these new Subaru applications are now in stock, and are available through CSF’s global distribution network and select list of exclusive dealers.

Click here to read the press release from LIC Motorsports.


Exclusively for Jackson Racing

This has been one of the most challenging and difficult products for us to design. A truly collaborative effort between CSF Radiators and Jackson Racing spanning the course of more than a year in development. Our 1st prototype debuted at SEMA 2014, and we’re very excited to be able to showcase the 1st production unit at SEMA 2015 at the CSF booth in central hall (#21555). With over 5 prototypes, countless design changes, and many hours of discussions, both of our companies are very proud to have the world’s 1st true “drop-in fit” all-aluminum radiator with a built-in oil cooler for the ZN6/ZC6 platform. This new model works with all OEM components, including the fan shroud, AC condenser, and mounting brackets. It requires no modifications or trimming to install.
This new model will be available at the end of 2015 or 1st part of 2016. Contact Jackson Racing for pricing, availability, and ordering details for this highly anticipated cooling solution for the Scion FR-S and Subaru BRZ. CSF #7050O

Got an idea or specific need for another application in our “O” series? Let us know! Contact info@csfrace.com

Speed Academy utilizes the CSF O-line radiator for their project STI

28 thoughts on “CSF announces The “O” Series

  1. Would definetly be intreseted in something like this for the 370z. Email me if you guys need a car for R&D. If not I’m still very likely to purchase if something like this is released for the 370z.

  2. sc300 would be a fantastic seller! Just a note it would be straight forward enough to offer the same design to fit the gs300 also by adding a second set of fan mounting points. using sc300 hoses.
    I have both chassis available for R&D

  3. Jackson Racing does not seem to carry the Miata radiator CSF #2863O. Any chance of buying one through you directly?

  4. Can you provide information for fitment with expansion tanks? Does the OEM expansion tank for a 2013 sti need to be relocated? Have you done a fitment test with the killer b dual washer coolant reservoir?

  5. What a great addition your tank would make to the E36 and E46 M3 world, who use both a radiator and oil cooler for the S54 engines. A common radiator and oil cooler would be a weight savings for racers and much simpler to mount. So when can we have a “o” series E36 and E46 radiator?

  6. Is the oil cooler thermostat setting between 75 ~ 82 +/- 2 deg Celcius, and if so can a 115 deg C or so thermostat be installed instead?

  7. Re. CSF #7042O
    Kindly advise following:
    – GReddy thermostatic sandwich plate – size of thread for oil filter;
    – air-to-oil cooler – size of female thread of radiator.

  8. I have a 2007 STI with a closed deck, ported heads and Aviad 2 stage scavenge sump with 9 qts of 15w-40 oil. Power is 500 WHP on E85. I’m running 235 F oil temps in 95 F weather. I already have Koyorad but using stock STI cooler/heater for break in. Before I buy a large external oil cooler that displaces 40k to 62k BTU’s and having to run it in front of my radiator I am curious if this is enough or what BTU equivalent. Basically is this enough for track use?

  9. Kindly advise whether the All-aluminum radiators w/ built-in oil cooler CFS #7042O with fit in my 2011 Subaru Forester SH9 (S-Edition)?

  10. 2020 sti. Im going to buy it, i just want to know if there’s a specific oil line kit recommended as i understand this doesnt come with any.

    • Hi Ryan,

      Because of different manifold set-ups. we’ve opted not to include a line kit.
      This will have to be measured and fabricated by yourself or the shop you choose to have install the kit.

  11. Why did you switch to a NON-Thermostatic sandwich plate? I just received my order of the 3076o and realized the Mocal part is non thermostatic.

    • The radiator itself is thermostatic therefor having 2 thermostats is unnecessary and cause another point of failure. Furthermore sourcing the Greddy sandwich plate became unavailable

  12. Would any of the “O” Series fit an RX-8? I noticed there are applications for the NA and NB Miata (CSF2862O & CSF2863O respectively). Would either of these fit? If not, is there any possibility of developing one for an RX-8 application? Rotaries are notorious for their higher temps and could really use something like this!

    • Hi Stanley,

      We do not have an RX-8 application in our O-Series, but we do have an all-aluminum upgraded radiator (with no oil cooler) for 04-08 RX-8. Its part number is CSF #3164.

      Thank you for your interest.

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