I just had the S1's put in a week ago, no down side, more power under the curve all the way. Driveability is great for DD. Thought about the S2's, after driving in traffic and on the highway, I am glad I got the S1's. Next MOd is the HTA Green....if it ever comes out...

 

That's what I'm thinking. I might get more top end out of the S2's, but I don't want to second guess the decision when I'm driving to/from work or sitting in traffic somewhere. That and with the basic mods I have I don't think S2's would benefit me too much yet.

S1's for me. AWD Motorsports seems to have the best price at $525.

 

Get an EvoGreen. The stock IX cams are already similar to 264s; you might as well get the benefit of the turbo and then decide which cams you can live with...

 

^^He has a 05 Evo^^

 

Yeah, what he said..ha. With the '05 I think I would benefit enough from the cams to go ahead and pick a set up. Still undecided HKS 272 or GSC S1, but I'll go one way or another.

 

You said it yourself, you love how the boost hits but then feels flat. The S2's will keep the feeling you want... Your not going to lose daily driveability and the dyno might tell you that spool is delayed a 100 or 200 rpm, but nothing that you will probably notice. Do your self a favor and buy S2's and let the beast scream to redline.

 

There is a tread here by Brad Mellon, has a stock turbo with S2's, if you want to get some input on what the response is. Goint to a bigger cam will move the whole TQ-HP curve profiles up further in the RPM band. I went with the S1's because after driving cars with both and stock turbos, I liked the faster response and fatter midrange of the S1's. I do some road racing on weekends so they are better suited to higher corner exit speeds than the S2's. Have not had it out on the 1/4 yet. as soon as I do I will post some slips.

 

I feel like on the stock turbo it would shift the power band too far towards the top. I enjoy my mid range right now and don't want to sacrafice that. The S1's/HKS cams seem to keep the same bottom, increased mid range and a little up top still.

 

That's exactly why I am going with the S1s. I can't wait to get them installed and tuned.

 

don't forget studs and new gasket.

 

I was considering a belt and studs while I was in there, but I only have 26k and I don't think I'll be going any larger than stock turbo on pump gas.

 

s1's are too mild, especially if you're even considering a bolt-on stockish turbo upgrade (20g or Green). s2's seem to shift the power curve more to the topend (good for drag race, not as fun for street...)


Cosworth 272's are somewhere in the middle...


I actually swapped out my S1's (average on stock turbo; weak when I put on my Green) for Cosworths, and saw immediate improvements throughout the powerband -- yeah, even the "amazing" midrange that the S1's are supposed to provide was nothing compared to the Cosworths (better torque, faster spool, more midrange, stronger top-end = no-brainer)

 

Which Cosworths did you go with, and where did you get them from? So you think that's a better route even for the stock turbo...hmm.

 

I would imagine that S1s versus something more aggressive is about his tolerance for lope. Some folks don't like feeling the engine vibrating so much. In an 05, cams are a smart move before the turbo.
I had HKS 272s on my 03 Evo and it was a night and day difference, problem was that the idle sucked compared to stock even after a tune by turbo trix. I never got to try cam gears since I had sold it for something newer by then.

 

IIRC Brad's car saw gains across the entire power band with no loss of low rpm torque using the S2 + stock turbo...it's not until the S3's that you start losing the low rpm grunt but those cams are really for big turbo drag racing cars that don't care about low rpm anyway because they'll never be in that range when banging the gears at high rpm.