No from the downpipe to the muffler is 3.5".

 

search is your friend. I know of at least 2 additional threads with these cams-- I think Ivey tune ran a dyno with this cams with fantastic results, they are posted.. I also have them and they are great in my view--

 

GCS S2 made much more power over the HKS , I had them both.

 

Yes i search and found those threads, but none was up to date, i wanted to see if more persons had tried them out and have any results with them.

 

How much more, where and what was the setup?

 

Go s2r if you are upgrading springs great drivability

Even the tomei 270 pro


Stay away from regular s2 if you are spending on springs...they are nice but better solutions out there

 

They had a s2r? Or are you just talking the last set of s2s on the market? Didnt they revised it around 2010
, 2011?

 

The previously dubbed S2R is now the R2, and it's more similar to the S3 than it is to the S2.

 

Werent the r2 designed for stroker motors?

 

They are, yes.

 

So why would it suit my setup well?

 

They're 12mm lift and you're on a stock block? It's not really recommended, not that it isn't doable, depending on your rev range, springs and retainers and all that. I would do milder cams since the R2s only shine at 4500+ RPM on larger displacement engines. Imagine how responsive they would be on a stock block...

 

Thinking you need to ask better questions to get better answers... What do you want from a set of cams, what are your plans for the car. What have you heard about the GS2 that you like. Do you want midrange or all out HP/big numers?
The HKS are a bit milder and build excellent lowend and midrange the GS2 come in a bit higher in rpm and build to top end depending on what you get gs2/3/r2 etc. Also what turbo do you have today and what do you plan on getting-- you ought to match the cam to the turbos power band or you just get a mix of performance with no tipping point. A well matched combo comes on turbo/cam together--and topend HP big numbers don't do anything for drivability.

 

I've tuned a few cars with all of the above setups.

- S1's will give the best all round performance for a daily, street car that spends 95% of its time below 6000rpm.
- S2's / Kelford TX272 / Tomei Pro270's give up a little below 5500rpm on a stock or small frame turbo'd car, will give perhaps ~10-12whp up top on a small setup. Once the turbo is larger, they really start to show their worth above 6k.
- R2's on a 2L small turbo drop a fair bit of torque prior to 4500, you can really feel the 'hole' in the torque curve and then suddenly it ramps up vertical around 4500 and you're away.
I think they would work fine on a road race style setup or highway monster, but for a daily/street car there are better options.
- HKS 274/278's are a pretty awesome street cam for small, quick spooling setups. They do exactly what all other HKS products generally do, and compliment under the curve power beautifully without upsetting the drive at all. They idle close to stock and make great power everywhere.

S1's are still my favourite small turbo street cam though.
Very well behaved, work perfect on stock cam gears on nearly all applications, make strong gains everywhere.

I may be a *****, but i'm sick of my S2's loping their head off.

 

I have ran both the hks and S2 in the same motor. The hks idle mush better, but they always had a slight lifter tick ( with gsc zero tick installed ) . I replaced them with S2 and the tick was gone and it gain about 10-20whp. I really liked the hks, they didnt require a bunch of base timing/1000+rpm idle to wotk well with the ac on.
Now im running the R2 cams.