hi i'm about to get the Hks 272 Camshafts but it seems to me theres 1 for the exhaust and 1 for the intake So which do i buy do i buy Both???
yup yup, just like the 3037s is overrated.Jesus said:Ill say go with 272's, the idle is OVERRATED ! is nice and makes a nice broom broom broom noise ...kinda cool
In general, the valve is the single most restrictive and controlling point in the air pump known as the internal combustion engine. Small changes at this point result in massive changes in engine characteristics. However, a turbo in the system modifies that. Here is the order of restriction on the Supra engine:Does anyone on this site have enough knowledge about cams to get into the technical issues of why our motor would perform better with more duration, lift, etc.?
It seems logical that more airflow requires more duration and lift, but as the guy in the Hks post said, this has NOT been proven to be the case in domestic engines. In fact, more often than not, you tend to see turbocharged domestics running a more modest duration profile. Why?
Anyone here with some knowledge in this arena? Right now I would venture to say most Supra owners are doing one of 2 things when buying cams:
1. Assuming (possibly incorrectly) that they need more duration/lift for a bigger turbo.
2. Flat-out guessing.
Neither is really the way you should select a cam/cams.
I personally believe that around 800 rwhp 272s will start to pay off. Keep in mind that I do not have ANY empirical data to support this - only anecdotes. I have noticed that 700-800 rwhp cars equiped with 264 cams make the same power and curves to 272 cars, though the 272s seem to have a slight bit more lag. In addition, noticing the tendency of very large Japanese 3037 turbo-equiped cars running 272 cams seems to support the notion that 272 cams are just BIG TURBO cams.So my 2 direct questons to you would the be at what point would it be beneficial to select 272 cams over 264 cams? Is it merely a tradeoff of top-end power vs. low-end power(shifting the power band), or will 272 cams perform better accross the RPM range when we reach (x) power level?
Also, what are you thoughts on 264/272 split duration cams? What is the technical theory behind this and in what scenario, if any, would it be benficial? What are the possible advantages/disadvantages of this in real world MKIV applications?
Lance W. on the list suggest that one 264 exhaust cam paired with a stock intake cam could be a good option (with the exhaust cam set to center, or maybe advanced a few degrees with a cam gear). He says the intake side of the head flows so much better than the exhaust, that the extra overlap of 2 264s might not be ideal, especially for people wanting to minimize lag and maximize $/hp. Do you have any thoughts on this setup?
I suppose I could try it, and add another 264 if I don't like the results.
The stock exhaust cam is only 236 duration and has 1mm less lift than the 264.