I have been on the fence with cams for years. It seems for the NSX, in order for cams to make sense you need other mods to work with them: high comp pistons, adj cam gears, engine management, etc. It also seems that Honda intentionally designed the cams to not provide maximum usable power (I doubt they cared about chasing peak numbers), but instead hit a specific target, which was 280 ps per the gentleman's agreement.
If you think about it, the C30A puts out 93 hp/L in stock config (276 / 3). NSX developers have said they intentionally used the crappy NA1 manifolds to choke the engine, and adding factory NA2 headers adds about 16 hp at the crank, giving us 97 hp/L (292 / 3). So, a stock C30A using Honda's correct manifolds is a 97 hp/L engine. When you consider the F20C, designed by the same people using similar technology, is at 120 hp/L, it is evident to me there is a lot of NA power in the C30A to be tapped- about 69 hp using the above calculations.
Since the exhaust is optimized and we know the heads flow extremely well, it seems the rest of the NA power is really bottled up in the valvetrain. But valvetrain is tricky, since most of the time it results in a tempermental, unruly engine. You need good tuning and engine management to make the most of a cam upgrade, and that is very hard to find with the NSX. One thing holding me back from mods like these is all of the reported problems I see. A hallmark of the NSX is its reliability and versatility. That means it runs the same no matter if is 20 degrees outside or 100, humid or dry, 6000 ft or next to the ocean. It always starts, idles smooth and pulls hard. Almost every single person who posts starting, idling or running CEL issues here on Prime has some sort of engine management mod- AEM, HKS, CT, chips etc. This tells me that now matter how good your Honda tuning "guru" is, he still is a self-taught kid with a laptop and a wideband trying to guesstimate the fuel and timing curves of my $25,000 engine.
So, if I put cams in my NSX, that means I am going to have to have someone tune it to run correctly. I have not seen anything yet to convince me the aftermarket can do it as well as Honda. Hence, I am running stock valvetrain, though I would love a solution that would deliver the maximum reliable power potential of our C30A. Cams seem to be a big part of that, after exhaust, but like Loc said, there really is no market solution.
It would be interesting to see how the RDX mod performs with (1) stock cams; (2) SOS mild lift; and (3) CT or Toda high lift. I wonder if the two would compliment each other?
If you think about it, the C30A puts out 93 hp/L in stock config (276 / 3). NSX developers have said they intentionally used the crappy NA1 manifolds to choke the engine, and adding factory NA2 headers adds about 16 hp at the crank, giving us 97 hp/L (292 / 3). So, a stock C30A using Honda's correct manifolds is a 97 hp/L engine. When you consider the F20C, designed by the same people using similar technology, is at 120 hp/L, it is evident to me there is a lot of NA power in the C30A to be tapped- about 69 hp using the above calculations.
Since the exhaust is optimized and we know the heads flow extremely well, it seems the rest of the NA power is really bottled up in the valvetrain. But valvetrain is tricky, since most of the time it results in a tempermental, unruly engine. You need good tuning and engine management to make the most of a cam upgrade, and that is very hard to find with the NSX. One thing holding me back from mods like these is all of the reported problems I see. A hallmark of the NSX is its reliability and versatility. That means it runs the same no matter if is 20 degrees outside or 100, humid or dry, 6000 ft or next to the ocean. It always starts, idles smooth and pulls hard. Almost every single person who posts starting, idling or running CEL issues here on Prime has some sort of engine management mod- AEM, HKS, CT, chips etc. This tells me that now matter how good your Honda tuning "guru" is, he still is a self-taught kid with a laptop and a wideband trying to guesstimate the fuel and timing curves of my $25,000 engine.
So, if I put cams in my NSX, that means I am going to have to have someone tune it to run correctly. I have not seen anything yet to convince me the aftermarket can do it as well as Honda. Hence, I am running stock valvetrain, though I would love a solution that would deliver the maximum reliable power potential of our C30A. Cams seem to be a big part of that, after exhaust, but like Loc said, there really is no market solution.
It would be interesting to see how the RDX mod performs with (1) stock cams; (2) SOS mild lift; and (3) CT or Toda high lift. I wonder if the two would compliment each other?
