I've pretty much decided I am going to stay all motor with my car. I have a few questions about camshafts because as much as I know about cars in general I know little about camshafts.

I'm considering getting aftermarket cams to increase the output of my engine.

My questions are these:

1) What is cam overlap? In the post about VQ30 vs 35 spec data Kev97 and others are talking about the overlap of the camshafts. Is this something that is controlled by the GRIND of the cam or how the timing of the cam is set? I know that the stock VQ cams are exceptionally conservative in their overlap, and if possible I'd like to address this.

2) How much would the installation of the camshafts (all 4) typically cost? It said that we have to remove the intake manifold, but at least we don't have to remove the engine. Is this something that a shadetree mechanic can accomplish on our cars?

3) Who besides Turbo95Max has custom camshafts? The VQ35 post speaks of some enigmatic person who gained 40 hp and 22ft lb from a custom set of camshafts. I could care less about my idle, as long as it doesn't stall on me at stoplights, it can be as rough as it needs to be for maximum power increase.

 

so you've decided to keep the maxima slow...eh??

 

You should do some basic research. Most of those questions are pretty basic when it comes to camshaft terminology.

As far as not caring about idle, well... if you install cams that are so lumpy that it barely idles, it will probably do a number on your emission figures also. If you cams are so aggressive as to not make very much vaccum at idle or off idle, you might run into brake booster problems too(but I doubt it)

 

Any idea where they got the cams from? I did not know that people were actually able to find a place that did them. I know some were looking before.

SuDZ

 

good info, right here -->
http://www.howstuffworks.com/camshaft.htm

 

caring about idle with a 'street legal' car is a big deal, your emissions will be garbage. I've built some big block american motors (i'm relatively new to import arena) that completely idled like crap, i run vacuum boost chambers to assist in the braking ability at idle. Thats the thing with cams, you can't have a full spectrum, but with VVT you correct for this. The other thread on this covered timing issues very well, your linky was pretty informative. Being an old school engine guy i learned a lot on the VVT issue. Thats the one downfall i've noticed of the VQ motor i have is a mild cam, SCing helped me out, makes my daily driver pretty enjoyable

 

I don't have to worry about emissions, I'm in Michigan and we don't have emissions testing, but I never though about braking being an issue. I will check out the links and then go from there.

 

thats why you get turbo cams! good idle and more power...mmmmmmm, heeh

anyways, i have heard from a company that was trying to make cams for the VQ,(another memeber can verify this) that when they set a too aggressive profile on the cam it would snap after so many hours..weird but something you might want to look into.

My first set of exhaust cam did snap, now i dont know if its because of the cam too aggressive issue or it juss happened to be a bad cam.

 

Not many people on this site have/had cams. In my limited experience I can say that if you can pull the tranny apart and rebuild it you can do a cam swap. Now you can manually adjust the overlap between the intake and exhaust cams with adjustable cam sprockets. However I don't believe anyone makes them for the VQ30DE. You could get some made but that would be expensive. As for the cams I figure go for a grind simular to the NISMO "EURO" cam specs for the VG30E. The reason being is because the VG30E and VE30DE/VG30DE have basically the same duration and minor changes in overlap. (The latter 2 are adjustable). Now a popular cam not counting the JWT grind is the ISKY/Motorsport auto 262/260 grind. Here is a link to a VG30E without cams http://z31.com/misc/view.pl?dynorun.jpg, this is a VG30E with headwork+cams http://z31.com/misc/view.pl?han-88-na-dyno.jpg. Although you can't compare the dynos completely because the 88na doesn't have headers or the UDP. You can see how the cams affect the shape of the power curve. The cammed VG is still making power to 5400rpm and it doesn't drop off as bad after 5500rpm when compared to the non cammed car. Since the VQ30DE cams are milder than the VG/VE cams then a comparable 262* duration cam should produce simular or better results. It might lose alittle low speed torque but it should extend the powerband another 250-400rpm. Now instead of the power dying out at 6000rpm the car would pull till 6250-6400rpm. You shouldn't have to remove the heads to install cams, if anything it would be simular to a cam swap on a SR20DE. Its just that you have to pull the IM and do it for both banks. You will however need to get the ECU reprogrammed. The stock timing curves will not be optimal for aftermarket cams, since you can't do a timing sweep with the cams you are pretty much out of luck. JWT was able to find a make a separate ECU program just for the cammed SR20DEs, from SE-R guys that "tuned" the car on the dyno.