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We tested only changing cams many years ago on my car, we tested Stock Auto cams, Stock Stick cams, 400+ cams, and 500+ cams with the cams being the only change.
We started with a fresh engine with ported heads, new guides, .5mm oversized valves, and JWT HD springs, the engine had 8.5 to 1 compression pistons.
We started with the smallest auto cams.....
The stock stick cams made a big overall power gain over the auto cams, no where in the curve did the stick cams lose power.
The 400+ cams did not make much difference over stock stick cams with the ported heads and oversize valves in our test.
The 500+ cams increased the whole power band and added close to 50 HP over all the other cams. The testing was done before bigger pipes were being used.
We did this testing many years ago when we were renting dynos, at that time we were just testing for our own racing and personal knowledge.
We did not have a web site, we only cared about the results for are own knowledge, unfortunately we did not save the dyno data, and the old dyno shop we used is long gone.The cranking compression is lower with 500 cams if you drop them in the way the way they come, if you back out the 4 degree advance on the exhaust cams that JWT adds, the cranking compression comes up and is more normal. The vacuum is also lower if you just drop in these cams, but if you pull the 4 degree advance back out the vacuum is much higher.
When JWT developed the cams, only small pipes were being used and JWT found in testing the advance of the exhaust cams helped spool in the restricted system.
With breather mods we find pulling the 4 degrees back out of the exhaust cams always adds more overall power including spool.
When you dyno as many cars as we do, it is easy to see trends with different parts, the trends on cams have matched the testing we did many years ago. The 500 cams have always been the cam to shine in our experience.
I have seen one really good example of 400+ used on a really well ported set of heads that was ported by Don (Alias), the overall power on that set of heads was the best I have tested, the peak power was still lower than other cars with 500 cams and the same set up with porting that was less extreme.
I believe that car would have shown even greater results from 500 cams based on all the date I have seen.
I believe the BDE VTC gear is reasonably priced for the quality and time BDE puts into that product.
The factory VTC gear lasts about 100K miles before it starts to make noise, if you price new factory VTC gears from Nissan, they run over $500 each. If you compare that cost with the BDE option, and when you know the stock VTC gear will fail with larger cams and heavier springs, the BDE option is cheap IMO.
We have only used OEM timing belts since the cars were new on every build including our own cars. We have never had a OEM timing belt failure. I know of more than a hundred cars between 500 and 800 wheel HP that have gone the full 60k on OEM timing belts without any issues.
My car that has run 9.3 at 151mph in the quarter mile has a OEM timing belt.
I could sell upgraded timing belts that have much bigger margins than factory timing belts, but I do not see the need to upgrade as the factory belt is plenty strong.
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16:08:17 06/22/15
