If you are interested in 272/272 cams and are thinking about cam gears, you might want to save some money and hold off from buying them. There has been much talk from different cam gear settings and have tried a couple different settings. I have went back and forth on 0/0 and -4/-1. I have found no real difference in performance and at 0/0 there is no valve tick. At -4/-1 there is valve tick probably due to the extra vaccum its trying to make. I like not having the valve tick so I kept them at 0/0.

 

How have you been checking this? Don't trust butt dynos.

 

FWIW, I dynoed the difference between a -3/-3 setting and a -4/-1.5 setting with HKS 272s, and there is a difference. Don't trust your butt dyno. The real dyno tells the truth.

 

I didnt do this on a dyno but I never tested the -3/-3 setting. Have you dynoed 0/0? Like I I was saying if there is a difference of a couple HP makes no difference to me if there is no valve tick.

 

Well it would only make sense that if you retard timing that you are going to lose some top end power. Its up to you. In my mind a -4/-1 setting would be better than a -3/-3. I dont know if retarding the intake cam more is going to draw in enough air to make the same power as the -4/-1 setup. Its been read on the boards that the -4/-1 will give you the best idle with a little more low end torque, but my 2c and based on my experince with playing with the gears 7-8 times is that at 0/0 you are getting the same idle qualities and no valve tick even at start up.

 

Moving from -3/-3 to 0/0 will cause the turbo to spool slightly earlier, will slightly increase the tendency for preignition at lower rpm, and with the HKS 272 set, should not significantly affect high rpm power.

 

In the case where you are mentioning preignition at low rpms, I have experienced this with both the -4/-1 and the 0/0 settings. The solution is, of course if you have it available is to adjust the timing in those knock prone areas with a UTEC or some similiar tool. I have eliminated all knock by playing with the timing and some help from others in those low rpm areas. My suggestion is to not go WOT in a gear that doesnt make power in those low rpm areas where the car is coming into boost.