FAQ
All Koyorad Racing radiators with welded-on billet filler necks will use Part # SK-C13 (Red Label) Deep plunger style cap. SK-C13 is a common radiator cap style that will is compatible with many Japanese vehicles. NOTE: Our alternate radiator cap, Part # SK-D13 identified by Blue top label is the shallow plunger type that will not fit Koyorad all-aluminum radiators, but will fit BRZ, 86, and some OEM Honda and Toyota vehicles.
Please contact any of our authorized warehouse distributors to assist with your Koyorad purchase.
50/50 coolant antifreeze mix is mandatory. Use OEM manufacturer’s recommended coolant. Note: Coolant additives do not contain the necessary anti-corrosion properties as 50/50 coolant antifreeze mix. Coolant additives should not be used. Prior to installation, a complete cooling system flush (including heater core flush) is mandatory in order to eliminate any old coolant, contaminants, mineral deposits, and previous additives. Dex-Cool is not to be used with Koyorad all-aluminum radiators. Follow vehicle factory service manual for proper filling of the cooling system after a Koyorad all-aluminim radiator has been installed. Reference vehicle owner’s manual for coolant capacity, then 1 additional gallon on-hand to top-off.
We are always accepting applications. Please send your formal sponsorship proposal to: race@koyorad.com
All-aluminum Koyorad radiators will accept genuine replacement drain plugs (include rubber gasket), Part# PI1186. This can be purchased from any Koyorad dealer. Thread size M10x P1.25. Recommended torque specification is 7-8 ft./lbs.
Mail us a Self Addressed Stamped Envelope (SASE) including paid postage on the envelope inside to receive your free Koyorad sticker pack. Sorry, no special requests or phone calls. Allow approximately two weeks for processing. USA residents only.
Mail SASE to:
Koyorad Racing Dept.
15 Doppler
Irvine, CA 92618
Strategically placed aluminum partitions that are positioned in the end tanks of a radiator create a dual or triple pass configuration. With the ability to direct coolant 2 or 3 times within the radiator core, improved heat transfer and performance can be achieved within the same space. In most applications “NFLO” will be triple pass, however in some applications NFLO indicates a dual pass configuration. NFLO radiators can be identified by the “N” following the Koyorad part number.
We recommend seeking the work of a professional mechanic for any cooling system work including: maintenance, installation, repair or diagnosis. Prior to any radiator installation, a complete cooling system flush (including heater core) is mandatory to eliminate any remaining contaminants, mineral deposits, and left over additives. Follow all procedures found in your manufacturer’s factory service manual. A comprehensive post-installation inspection including: pressure testing and testing for electrolysis is mandatory.
Unfortunately we do not build one-off radiators at this time, but we are always expanding our race product line, please email your request to: race@koyorad.com.
1/8 PT sensor provisions are provided on select Koyorad radiators (supplied with matching plug) and allow most Japanese branded water temp gauge sensors (APEXi, HKS, Defi, Pivot, and GReddy) to thread directly into the top radiator tank, eliminating the need for an upper hose adapter. 1/8 PT is a Japanese standard thread pitch, also known as 1/8 BSPT, but should NOT to be confused with 1/8 NPT (Autometer style thread). 1/8 NPT threaded sensors are not compatible with 1/8 PT/BSPT Koyorad thread provisions.
Koyorad compatible 1/8 PT (1/8 BSPT) sensors:
- Apexi
- HKS
- GReddy
- Pivot
- Blitz
- Defi
- STRi
- Autometer
- Innovate
- AEM
- ProSport
- Revel
- Turbosmart