hey guys. I have a question. But first I would like to tell you about a conversation I had with a Skunk2 tech on their live tech forum. I asked about cam upgrades on my motor with boost and he told me that the stage 1 turbo cams were awesome. But then I asked him about the lack of cam control due to no K-pro or something equivalent. And he told me to get an exhaust cam gear and retard the cam timing on it a few degrees or to where I get the most power.
The basis of my thread is when I'm in full boost I'm running about 8-9 psi right now. But as soon as Vtec engages I loose about 1-2 psi. My guess is cam overlap is causing this problem. Doesn't the Vtec cam lobe have alot more overlap where both the intake and exhaust valves are open together longer than out of Vtec? I was told that honda does this for scavenging purposes where the exhaust pulse will help draw in the intake air better at higher RPM's. But with boost wouldn't that cause the boost pressure to escape through the overlap causing a slight drop in boost pressure and a slight drop in power? I remember reading somewhere that you wouldn't really want alot if any overlap in boosted cars. Is that true?
And finally would using the exhaust cam gear and retarding the exhaust cam keep the overlap less and would I be able to hold boost better?
Thanks alot guys for any help.
The basis of my thread is when I'm in full boost I'm running about 8-9 psi right now. But as soon as Vtec engages I loose about 1-2 psi. My guess is cam overlap is causing this problem. Doesn't the Vtec cam lobe have alot more overlap where both the intake and exhaust valves are open together longer than out of Vtec? I was told that honda does this for scavenging purposes where the exhaust pulse will help draw in the intake air better at higher RPM's. But with boost wouldn't that cause the boost pressure to escape through the overlap causing a slight drop in boost pressure and a slight drop in power? I remember reading somewhere that you wouldn't really want alot if any overlap in boosted cars. Is that true?
And finally would using the exhaust cam gear and retarding the exhaust cam keep the overlap less and would I be able to hold boost better?
Thanks alot guys for any help.
