Monring all

Would anyone out there be so kind as to educate me on the differences between JUN's Stage 1,2, & 2R camshaft kits for the 4b11? Appreciate any help you gents/ladies can throw my way.

 

It's explained right on JUN's web site.

 

Sic...I checked the site before posting but do thank you for the link.

Assume for a moment that I dont know a damn things about what cams do in the car (because I don't). That I'm just a total donkey (not entirely) with 10k to throw away on my EVO.

Thanks again all

 

http://auto.howstuffworks.com/camshaft.htm

so in simple terms, "High Lift" cams, push the valve farther into the cyl. creating a larger/longer open event, allowing more air in/exhaust out.

 

Cozmo thank you for the educational link. If I understand correctly by leaving the intake valve open longer the momentum of air/fuel going in forces additional air/fuel into the cylinder as the piston starts its compression stroke. So the faster the engine goes, the faster the air/fuel moves, and the longer I want the intake valve to stay open. Yes? With that in mind what happens when I bolt on my new single scroll 35r turbo kit? Would it be better to have a camshaft with a mild duration of 64 (256) or more extreme like 70 (280). At what point does lift come into the equation?

 

well....the first part, you are essentially corrent....

think of it like this, plug your nose with your fingers...try breathing in....unplug your nose for a split second.....now unplug your nose for 2 seconds.....the "open event" the second time, was longer, so you got more air into your lungs....

an engine is like your lungs....more air (and fuel) = better.

as to the second part, re: the 35R....a pro evo tuner I am not, and in the real world, cam lobe profiles & timing, are allot more complicated then I've just explained. these cams are likely designed for a stock turbo system, to produce a very specific result in a given RPM range. changing the intended parameters (such as an upgraded turbo) that the cams were designed for, may not yeild the result you're after. Similar to an ecu flash...if you design the flash for a stock turbo steup, it may function decently with an upgraded turbo, but it might not be extracting the maximum potential of the new turbo. I don't know enough about this engine/turbo/cam setup, to know what JUN were trying to make better (compared to stock) with these cams....

also...high lift does not always = open longer.....the actual time the valve is open can be the same or less then stock....this can mean your valves, will be moving further, in the same amount of time or less = it has to move faster (then stock) = harder on that part....

I know from other system tuning experience....a longer event, cam profile usually worked better for Forced Induction applications, versus a "High Lift"