GSC Power-Division Camshafts S1 Grind ( Part Number:GSC 6025S1)

GSC Power-Division Camshafts S1 Grind

Part #: GSC 6025S1
MSRP: This Item is no longer available.


Brand: GSC PowerDivision
Cam Exhaust Duration: 266
Cam Exhaust Lift: 10.4mm
Cam Intake Duration: 268
Cam Intake Lift: 10.8mm
Location: Intake and Exhaust
Machining Required: No
QTY: 4
Springs Required: Yes

Mfgr. Warranty: No Warranty
Condition: New Product
Return Policy:

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Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.

RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.

The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.
GSC Power-Division S1 camshafts for the USDM 04-07 STi. These will not drop any low end power, but actually cause faster spool of the turbo, creating more power and torque across the entire rpm range. Good for stock turbo or up to 500WHP(GT35R) upgrades. Upgraded valve springs are required; Beehive valve springs are recommended but not required.

Intake Exhaust Duration 268 266 Peak Lift 10.8mm 10.4mm Duration @ .040" Valve Lift 225 225 Centerline @ Peak Lift AVCS 113 BTDC
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  • Q: do I need upgraded valves also?  rosstitute 2 years ago


    I just got done with pulling my engine apart and shipping heads off the machine shop. It says that the springs need to be upgraded but do the valves also need to be upgraded as well or are the oem valves more than sufficient enough to get the job done?

    • A: Upgraded valves are not necessary with these cams and you can use the OEM valves with upgraded springs.

      Zach G. 2 years ago
  • Q: Enlighten Me  RIBahler 2 years ago


    I am having a reputable shop build my motor, but I was doing some research on GSC cams and springs which I order, and it has come to my attention that the GSC cams are failing. As you can imagine I am scared of this happening and cannot afford failure. How true is this, how can it be prevented, or should I retern the GSC Cams and stay with my stock cams? Here is my build thread:

    • A: We have great experiences so far with GSC cams and we have not had any failures reported to this point.

      guest57853c642a8d25b5018c44a7 2 years ago
    • A: RIBahler, Any EJ Camshaft is susceptible to the type of failures talked about in the thread that you posted. The root of the cause of failure is inadequate supply of oil to the cylinder heads. Oil volume will always follow the path of least resistance. The oil supply of the EJ cylinder head, AVCS components, and Turbo feed are all shared. The internal head components are on one side of a 1mm restrictor the other side will feed the AVCS and the turbo feed. If you are having a reputable shop perform the work on your engine request thorough cleaning of the cylinder head oil galleys. When reassembling the AVCS request the use of NEW OEM AVCS screens and thorough cleaning of the lines. If you are using an aftermarket turbo oil feed line it is suggest to reroute the turbo feed line to the one of the cylinder block ports. If these items are paid special close attention you will not have an issue with our product or any aftermarket cam set and you can enjoy modding your Subaru EJ engine.

      Greg @ GSC 2 years ago
  • Q: valve lash  thomasperry 3 years ago


    Do these cams tell you what valve lash to use?

    • A: There will be a cam card in the box which has the recommended lash specs along with the suggested break in procedure.

      Greg @ GSC 3 years ago
    • A: Valve lash specifications are not included, but you can refer to the factory service manual for those specifications.

      Zach G. 3 years ago