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Just got this email today...
Website not updated but looks like ready to ramp back up |
I had the first cams from them in the states. My car just got finished 2 weeks ago from 2.5 years of down time. I cant really say how good they from stock because i completely built my motor and changed everything. I am boosted, idle is great! I dyno'd 430hp and its lots of fun! Still have more power to go too.
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Where are the NA results with cams? I am surprised no one has experimented...
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If you are referring to the valve to piston clearance at TDC, then this is a whole different story and it has to do with the actual valve timing ground into the cam lobes or what is dialed in with the cam gears... |
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And to widen the discussion, the camshaft choice for the FA20 is not an easy topic. "Hot" cams today are not what they used to be and that is the main reason we don't see many of them on the market. It is quite important for every enthusiast to understand that cams are merely valve timing tools. In the pre-variable valve timing era, cams could alter the valve timing events to suit the needs of the driver. This doesn't apply directly today since there solenoids that already alter the timing event based on input from various sensors across the car. I cannot stress this enough, changing cams on the FA20 is not the same as it was 20 years ago on a simple DOHC multi-valve performance engine. Regarding valve lift, increasing it will allow the engine to breathe better at the upper part of the rev range or perhaps beyond the stock rev limit. In most engines, lift is not a bottle neck for the 19/20's of the stock rev range and increasing it may hurt air speed at mid/low range. Careful consideration, planning and reading is required, engine tuning is not easy but its a lot of fun. Cheers :) |
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Some cam profiles run very fast opening inlet and fast closing exhaust to minimise overlap whilst having good area but those kind of profiles are found on finger followers in high end race engines, not something like an FA20. |
It is obvious that when the valve is closed (240 deg lobe example) it has more clearance than the partially open example of the 280 deg lobe.
You have to remember though that the 240 deg cam has much less time (degrees) to open a lot more the valve (2 mm) which makes it highly probable that it will have much more aggressive ramps. If we make a rough calculation, one opens 0.039 mm/deg and the other 0.054 mm/deg of average opening (and closing) rates. Its rather obvious which may have more aggressive lobes... Increase lift only if your engines needs it. Besides clearance, higher lift raises the risk of valve float as the lobe it is actually "shooting" the valve towards the combustion chamber and piston with the more aggressive ramps. To offset that, you will need stiffer springs which will robbing you power through parasitic losses at all engines speeds below the max power rpm. I am still assuming that we are discussing a street legal sports car that it will see daily driving duty as well. Pure race engines is a different story... |
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Any new feedback on these cams? I am interested from a pure race engine standpoint. Jackson Supercharger, 9 psi, built engine. Forged pistons, Carillo rods, GSC valve springs, Motec M150. I just don't know enough about camshafts in this engine to decide what will work best. The rules for my class allow 0.600" lift.
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