They have + or - 10 degrees of adjustment in either direction. Because we start with a stock cam gear the belt engagement and hardness is all OEM. No additional noise, no problems with wear on the gear surface. Because we use five hold down set screws there is minimal chance of slipping. The stock cam gear is steel, not aluminum so there is also less chance of stripping out one of the set bolts. Adjustable cam gears are mandatory when using HKS cams. We found over 50 rwhp on Warren Joe's blue 91T by tuning the cam gears on our dyno. Typical settings on HKS 264 cams are 4 degrees of advance on the intake and 8 degrees of retard on the exhaust.
The graph shows the effect of ATS Cam Gears on a 2.1 3S-GTE with ATS TD06 turbo kit. Run number 23 was with stock cam timing set to true zero and run number 25 is with the exhaust cam retarded 6 degrees. A increase of 15+ hp and 15lb ft. of torque! Remember this was with stock cams. HKS cams show even bigger gains.
You get $50 back when you send us back your original cam gears! We just added the option to the website so you can purchase the gears and send your gears in advance. Because these are machined in batches we cannot gurantee you will receive your exact cam gears back.