thanks. How much hp is typically gained from just the HKS 264 exhaust cam? I dont have cam gears, would i need them? i heard that with the 264 most people leave them on 0. I however do have a S-AFC that i plan to get tuned soon.
I have no idea, only comparison I can validate is the one someone posted in the dyno section I believe. They have a T71 or T74, and with the addition of 264 cams, they gained 100rwhp....not sure how much power would be gained on a bpu+++ car
i also would like to change the exhaust cam....i have been wanting to do this for a while ..i read somewhere on here that it gives some more top end pull...i am just bpu right now....also i am redoing my valve stem seals soon so maybe if i can purchase an exhaust cam i can put it in since i will be in there...also does this change the sounds of the exhauts also and how much worse will the idle be??
Changing out the stock exh cam for a 264 will only give you a little difference in idle quality. Not much. It is a great time to also change the valve stem seals as well since they will be right there underneath the buckets. I recommend the use of the spring tool (tyco) and pliers that are mentioned in may threads. It will save to a ton of time and of hunting down lost lifter keepers.
I just installed both 264's on my bpu+++ car and idle is slightly lumpier nothing to worry about and in simple terms the car has slightly less torque around idle till 3000rpm but after that you can feel the extra power at 16psi it feels like i'm running 19-20psi and my gtech pro which people might laugh at but it's the best thing other than a dyno says I make more power at low boost than I did at high before cams, it also holds power band all the way to redline which you can feel when you drive it in fact it doesn't drop off at all unlike my stock cams which got the curve dropping at 5800rpm, keep in mind I had the J spec cams which had a shorter duration than your us spec so my gains will probably be slightly more noticeable, all in all I was very impressed I estimate you would gain roughly 10-15rwhp from 4000 till redline with exhaust only I've heard of gains as much as 35 rwhp with both 264's on a bpu I got adjustable AEM gears but won't change them off zero till it's dynoed