Insufficient clearance between top of valve guide and retainer at full lift?

Failure to measure properly when fitting the cams.

Yet another problem to eliminate.

 

You mean low 400 maybe?

 

From what I read, low end power difference isn't very noticeable. And the hta71 is so affordable that anyone can buy one. I'm just helping him to avoid paying again to upgrade to S2.

 

Nothing wrong with S1's. They make a little more torque, power up top on small turbo's is good to about 500whp before the S2's will start making significant gains. And for a car that is just street driven, the much smoother idle of the S1's gets the nod.

 

I thought the stock 9 would be plenty enough for me when I traded my modded wrx in. My 9 didn't last 2,000 miles before I added some power mods. Lol
If you're already getting beehive upgrades, it makes more sense to me to get S2 so that when you upgrade your turbo, you don't have to upgrade cams again. Talk to those that went through S1 and S2.

 

I think he was trying to say the S1 is good to 500whp.

 

I searched for more info on differences and these are what i found. S2 has more lift, especially the exhaust side.




Stock vs S1 vs S2

Strange that S2 looks like it makes power faster than S1 as turbo is spooling up. Could be a glitch.

 

From reading further, the MIVEC will help with the low end difference. Idle is definitely smoother with S1.
For me, I didn't add cams because I chose the hta71 upgrade over cams, so until I build up my reserves, I'll most likely get the S2 with beehive springs and retainers. On E85, 1st gear acceleration is at traction limits of my tires, so I don't see the benefits of S1. Normal freeway driving will be nicer on S1 for ease of passing, but there should be plenty of power on S2. Both are great sets if cams, so you can't go wrong either way.

 

we have super smooth, 950 RPM @ 14.7 AFR idle with S2 cams on E9...

 

everyone says they well upgrade but often don't. Then they are stuck with a setup that is less than optimal. I can count, on one hand, the number of people I know (personally) that make over 500whp.

Not on a stock turbo, they aren't.

 

Exactly...lol.

 

I think he was saying it's good for 500whp *and won't need it on stock turbo.*

 

So idle depends on how creative the tuner is. I like them even more!

 

From the chart above, it looks like S1 makes about 20 whp more power 3600-4800 rpm. S2 makes about 30-38 whp more 5500+ rpms. I wonder if this is on stock 9 turbo.

 

Not what he posted.

" I've had stock 9 turbo cars with the s1 cams do low 500 dynojet with a good power band"