300hp engine changes:
1)revised lower plenum design with shorter and fatter runners
2)more agressive cam profile
3)revised piston shape
4)stronger rod bolts (maybe stronger rods also)
5)variable cam timing on the intake and exhaust cams (287hp engine is only on intake cams)
6)higher 7000rpm redline

The 300hp engine also MIGHT have different heads. If I remeber correctly, they have a different part number then the 287hp heads. This could be for performance reason or just becuase of the added variable cam timing.

 

What is the difference between intake cam timing and variable timing to the exhaust cams. Why use one oppose to the other on the rev up motor?

 

No takers huh?

 

I would think it is easier to tune a 287 motor with an aftermarket turbo............

 

Everyone is talking HP. Nobody is talkin' bout the loss in TQ in the rev-up engine. Not to mention if these mods are bringing the TQ number back up.

Again..someone posted that the 06 weigh more..which is absolutely true

 

But still no answer.

 

You are missing the point of the thread, the original question was what takes better to mods, not what one is faster, then i somewhat hijacked the thread with my question.

 

Takes more mods is 287.
Performs better with mods is 300.
I had the same basic mods on both my old 287 and current 300. The little difference I saw came from the 300 over the 287. Now that I have fully decked out my 300, I am extremely happy with it. Of course I went the expensive route with all Nismo.

 

You seem to be knowledgeable........What is the difference between intake cam timing and variable timing to the exhaust cams. Why use one oppose to the other on the rev up motor?

 

On the 287hp engine it only has variable cam timing on the intake cams. On the new 300hp engine it has variable cam timing on the intake and exhaust cams. I think the reason for variable cam timing is to help adjust the cams for better airflow. Does this answer your question?

 

Piston engines normally use poppet valves for intake and exhaust. These are driven (directly or indirectly) by cams on a camshaft. The cams open the valves (lift) for a certain amount of time (duration) during each intake and exhaust cycle. The timing of the valve opening and closing is also important. The camshaft is driven by the crankshaft through timing belts, gears or chains.

The profile of these cams is optimized for a certain engine rpm, and this tradeoff normally limits low-end torque or high-end power. VVT allows the cam profile to change, which results in greater efficiency and power.

At high engine speeds, an engine requires large amounts of air. However, the intake valves may close before all the air has been given a chance to flow in, reducing performance.

On the other hand, if the cam keeps the valves open for longer periods of time, like with a racing cam, problems start to occur at the lower engine speeds. This will cause unburnt fuel to exit the engine since the valves are still open. This leads to lower engine performance and increased emissions.

 

Thanks for everybody’s input.

 

Yea, thats right. Valve timing controls exactly that, the time the valves stays open or closed (in the case of the 300s). Intake wise, concerning all of the 287 Zs, the CVTCS (continuous variable valve timing control system) allows for better fuel economy while also allowing for, essentially, more power at great throttle lengths. All this is done by adjusting the valves for either more air and conservation of air/fuel.
On the exhaust side (300s) the CVTCS follows in conjunction with the intake valve timing. It adjusts the valves on the exhaust side to let more exhaust out faster or slower depending on the driving style/throttle position. This, in turn, allows for more power simply because the exhaust is getting out quicker and more..."smartly".
In all, nissans CVTCS is a never-ending VTEC with all the up's of VTEC and without any of the down's of VTEC.


So which is better for mods? I'd have to say the 300's. But considering the decreased torque, heavier weight, and any other factors, I would rather mod an 05 Base with the 287. Or maybe im just biased because I have exactly that. I dunno.

 

Guys, I have a 2004 Z with NISMO Cams. I think (not sure) that the NISMO Cams do provide variable intake and exhaust timing. Anyone know if this is true, and how it compares to the 300bhp motor?

 

I think if this Motordyne mod for the Rev-Up motors pans out, it will be a no brainer.

If a simple mod can restore the lost TQ of the rev-up motor and increase hp over the range, then there is no downside for rev-up'ng

 

Cams in no way provide variable valve timing.

 

Whatever the difference is, I'm sure the one with the better driver will win.

I think the difference goes out the door once you Turbo it.

Even if you Turbo and the 300hp one makes 20 more hp, it's still a driver's race.