I've been doing some research, lots of reading and still not totally understanding.

When someone talks about "aggressive cams", what are they actually refering to? I know it has to do with lift time .272 is a longer lift then .262. And this is how cams are usually named etc. But was dose an aggressive cam "do" more then or better then a lesser aggressive cam?

How do you choose what kind of cam to use in what cercomstances? I have "hurd"(SP?) that an aggressive cam is used for raceing. But what difference dous it actually make?

I hear that with aftermarket cams the engine idle needs to be increased. I understand this as a difference in cam lift timeing and more engine timeing being needed to compensate. Is that statement correct?

I can't seem to find any good information on a "real world" (laymens terms) definition of "aggresive cams". How do pick the right cam for the right job?

 

longer their open more air can get into cylinders for combustion.

 

That equates to needing more fuel, but dous that then equate to more HP/TQ?

 

This link is pretty interesting.

http://books.google.com/books?id=uzm...NjggkaDBwDY8-w

 

Ya know, that is a real good read on camshaft mechanics. Very useful for understanding the mechanics behind a cam and how it works together with the rest of the engine.

 

In general terms, cams vary the lift and duration to determine the depth the valve is opened (Lift) and the amount of time the valve is off the cylinder head seat (Duration).

In hot rodding, aggressive usually means "more of" or "approaching race specifications." For a cam to be more aggressive, it would have more lift and duration than stock. An aggressive cam would be better for racing than it would be for normal highway driving. Aggressive cams have so much duration that they get "lopey" at lower RPM. That's why aggressive cams usually don't idle well.

Choosing the correct cam for your car is always difficult. You might start by finding out what cams are available. If you have an earlier (non-revup) engine there are a lot of cams available. If you have a revup there are only two or three.

If you are considering putting cams in your car, I highly recommend talking to one of the established tuners here on my350z. Installing cams in a VQ is fairly difficult and very time consuming... Talk to your tuner before buying a cam. Reading these forums is also a good thing.

Hope this helps...

 

Thanks for the input __jb. So far input from posts has been on queue with information that I have gathered in research (I.E. Search FTW!). But the one question still remains that I can't seem to find a definitive answer on...

Dose a "more aggressive" cam equate to more HP/TQ? Dose a "less aggressive" cam give less power?

Lope or idle asside would the "more aggressive" cam be better for more HP, less "drivability"? Or do all the various lift and duration cams give the same end result, just a different engine sound/tune? Is one cam spec going to be better suited for FI applications over N/A applications?

Anyone reading this with aftermarket cams, please post up what type cams and what you discovered after your cams where installed (HP/TQ Increase/decrease, LOUDER/quiter etc... I think this information is the bassis for what someone looking to mod there car is really looking for. Atleast those of us that aren't real familiar moding cams.

 

http://nissanperformancemag.com/march03/nerds/

http://nissanperformancemag.com/april03/nerds/

http://nissanperformancemag.com/may03/nerds/

http://nissanperformancemag.com/june03/nerds/

http://nissanperformancemag.com/july03/nerds/

http://nissanperformancemag.com/august03/nerds/

 

a "race" cam or an "aggressive" cam won't make more power if your engine isn't suited to the rpm range for the cam. For example, if you have a cam with alot of duration and alot of lift, but you have a stock long runner intake manifold, stock heads, and stock exhaust manifolds...........this engine doesn't have the capability to breathe well at higher rpms, and the cam will be useless to you.

I am not a believer in "off the shelf" cams. I believe that you should have cams ground for your application.....but to do that, you need to know alot about your goals, and the parts going into your engine. You need to know exactly how well the heads flow at different valve lifts, how aggressive will the cam ramps be, valve spring rates, coil bind, etc.

I can go on and on..............cam science is great stuff. The cam is really the mechanical brain of your engine!!!

 

Wow, very good reads! Thanks Kwame! :-)

 

Thank you Kwame!!!
I think that was the best read on cams I have ever had. I am truley filled with a better understanding of how they work.

Now to copy past all that information for safe keeping and reference later. I will read it again, likely even 2 more times.

 

No problem!

Haha, I have hardcopies in my car at all times. If I am ever bored I read through them. I am such a nerd I know.

 

good info