New Toy

[CocoPops]

Wow!!!

For anyone that hasn't had the vtec experience at night, with the roof down and the stars twinkling........... omg!!! AWESOME!!!

I had a blat down a small lane back from Tesco's of all places! 3rd gear, between 6k and 9k (the perfect vtec zone) and she was singing!!!

Fantastic... why did I wait before trying a vtec'd car?

[dave87]

Sounds soo much fun, I am insanely jealous.

So, is she staying standard? Or have you got any mods planned?

[directhex]

so who feels like explaining vtec to me?

[CocoPops]

Zak!!!

Calling Zakkk!!!

lol

http://en.wikipedia.org/wiki/VTEC

VTEC (standing for Variable valve Timing and Electronic lift Control) is a system developed by Honda to improve the combustion efficiency of its internal combustion engines throughout the RPM range. This was the first system of its kind and eventually led to different types of variable valve timing and lift control systems that were later designed by other manufacturers

[dave87]

*Lets see how DOHC VTEC works. The figure to the right shows a simplified representation of a intake-valve VTEC mechanism (the exhaust mechanisms work similarly). So for each pair of valves, there are three cam lobes. The two on the outside are low RPM lobes and the one in the middle is the high RPM lobe. The two low RPM lobes actuate the two valve rockers, which in turn pushes the valves open. The high RPM lobe actuates a follower, which is shaped like a valve rocker, but doesn't actuate any valves. The figures show the circular section of the cam lobes touching the valve rockers, and the elliptical section pointing away. Thus the valves are closed in this stage.

During low RPM operations, the two outer cam lobes directly actuates the two valve rockers. These low PRM lobes are optimized for smooth operation and low fuel consumption. The high RPM lobe actuates the follower. But since the follower isn't connected to anything, it doesn't cause anything to happen. This process is illustrated by the figure to the right.

(missing image - original site is down and the other host didn't mirror the image)

At high RPMs, oil pressure pushes a metal pin through the valve rockers and the follower, effectively binding the three pieces into one. And since the high RPM lobe pushes out further than the low RPM lobes, the two valve rockers now follow the the profile of the high RPM lobe. The high RPM lobe's profile is designed to open the valves open wider, and for a longer duration of time, thus allowing more fuel/air mixture to enter the cylinder. The improved breathing allows the engine to sustain its torque output as RPM rises, thus resulting in higher power output


*Disclaimer - think this is the image that is meant to be here, but not entirely sure*

That is basically how VTEC works. The picture to the right is a picture of an actual DOHC VTEC engine. Note that there are two cam shafts, one for the intake valves and one for the exhaust valves. For each pair of valves, notice that there are three cam lobes: two cam lobes on the outside, and one cam lobe in the middle.

There ya go, though I'm sure zaks explaination will be a lot more interesting

*source here*

[dkmech]

I had a blat down a small lane back from Tesco's of all places! 3rd gear, between 6k and 9k (the perfect vtec zone) and she was singing!!!

Erm... Does the s2000 have a 6 speed gearbox? Coz 3rd gear in my prelude goes to 90 mph... Can't see it being much slower in the s2000 Have you been doing a naughty?

[CocoPops]

yep 6speed box.

[Shad]

http://www.s2000library.com/

Quite useful if you're thinking of an exhaust. The comparison video is good... get the J's Racing system NOW!!!

[Butuz]

Yeh you gotta get a tidy exhaust

9000rpm through stainless



Butuz

[CocoPops]

Trouble is, I want something raw for the weekends but subtle for the weekdays as I use this car for work etc.

Hence induction wil probably be first.

[Butuz]

No point trying to get more air in if the air is already struggling to get out boyo!

Butuz

[[GSV]Trig]

Agree'd, mind you my first stop is always brakes...

[Shad]

They work pretty well already, I can vouch for that!!

Stick some decent pads in for track days and leave them at that for now.