also take into consideration the fact that you really should do the springs and retainers if you go with the S2's. I went through the same dilemna and contacted Greg at GSC. For the stock turbo there really isn't any "negative" to going with the bigger cam, just as long as you do it the right way. If cost is a concern then realize you're going to at least double your cost by going with the S2 over S1.

 

Big cams little turbo.. i ordered s2 for my 71 hta. Coming from hks272's after a lot of recent tests showing awesome gains.

 

S2s and my 8 turbo have been a good combination. I do not have any loss of spool, just a significant amount of more mid range and top end power.

However you must upgrade the springs. The stock retainers are good.

 

I have not seen any loss in Spool on S2 VS s1 vs Stock on stock turbos. S3 yes loss in spool. Stock turbos spool so dam fast its real hard to see what cam does what on the Dyno.

For pump gas power the S2 are the way to go for sure. I love my S1 on E85 but on pump gas I know I could push alot more hp with S2's

 

Just did the ER gsc cam special incl springs retainers. Proof being gsc cams being back ordered!

 

^^ I know the feeling took about 2 months for mine to show up when I had mine installed. But hey a good mod is worth the wait, I never regretted swappin my old school hks 272 cams for those.

 

This is comforting information in my search for an EVO since most have aftermarket cams. My original thoughts on cams coming into the EVO world was sacrificing reliability (idle/startup) for power.

 

^^ not necessarily a good tuner, can tune your idle to be pretty consistent, its still a lopey idle, cant get around that. But can tune it to where it doesnt fluctutate at idle rpms, mines good. But all around the cams are good, compared to running my old hks 272 cams, I lost no spool up rpms, still hits right around 4000-4100 same as with previous setup.

 

So if i was to ask: why does GSC offer S1 cams,it sounds like: for people who dont want to upgrade the valve-train and don't want lopey idle.

I remember reading though the S1 have TQ come on quicker in the mid range, but sounds like to a meaningful amount.

 

Lopey idle makes your car sound super fast, so you can tell everyone else their cars are slow. but never race them or drive fast, i always do the speed limit. Ive gotten two speeding tickets, speeding isnt worth it for me anymore.

E85 makes cams sound less aggressive from what ive heard
i dont know for sure, cams make a big difference in evo though.
spools super quick

 

E85 doesn't change the sound of the car at idle

 

I have s2's on a stock turbo, no idle issues at all as it's tuned now. You can tune it to sound as aggressive as you like. I think the reason people perceive a loss in low end power is because of how much stronger your top end is now. My evo pushes 375whp/400wtq with just bolt ons and s2 cams on 93.

 

i have the S1 cams on my stock turbo'd IX. though i am happy with the cams now, about 2 years later and after reading through evom about the S2, i am starting to regret getting the S1 because almost everyone here says the S2 are better. before i bought the cams, i spoke with GSC and they recommended me the S1.
are there any advantages the S1 has over the S2 besides keeping stock springs/retainers and more stockish idle? does anyone have any dyno graphs comparing the 2 cams on the same car, same dyno, and stock turbo? how does the low/mid range between these 2 cams compare?
i would love to hear from the people who upgraded to the S2 from the S1

 

Its all in the tune.

 

its my opinion that the s2's will give you more power just about everywhere. The s1s give you more power where you don't need it, low rpm. Get the s2s you'll save money not having to upgrade again later.