Any thoughts on the new GSC S1 Billet cams folks? Most online stores don't seem to have them in stock.

Any dyno sheets, or experiences?

Please share.

 

I have the gsc s1's on my evo 8. I absolutely love them. They do lope a bit at idle but very good street manners. On the stock cams the turbo felt like it was out of breath by 6k rpms. Now from 5-7k rpms the car pulls strong all the way through. I'd recommend them if you do not want to upgrade your valvetrain.

 

I personally liked S1 a lot.

- Enough performance increase for stock or near stock sized turbo
- Trade-off response / power using adjustable cam gears
- Stable idle / no stall
- Can use stock valve springs / retainers (with not too excessive boost / rev limit)

But the reason why it is not popular is that most people would go S2 for more HP.

One local guy also got S1 after a bit of waiting, but he moved on to S2 about a year later, but even with new springs / retainers / S2 cams, his turbo was not making more power, so he said S1 was a better choice for his setup.

I saw even S3 or aggressive cams can make nice dyno curves (not much sacrificing low / mid range), and add a few more horse power even for stock turbo, but for overall stress-free street driving, I prefer S1 over more aggressive options as long as you do not have a short term bigger turbo upgrade plan.

 

They are the same as the precious, out going "cast" or whatever S1's, I think GSC went to billet for core availability. Obviously billet is better, but GSC hasn't really had a quality issue in a long time anyways. They're definitely a good choice.

 

If you have an Evo 9, I suggest S2's. They make more power everywhere compared to stock. There is no downside to them for drivability on and off boost. Springs and retainers are required though.