how does v-tec work?

[BrokenBiker]

my megane has variable valve timing, and as far as i know it is ecu controlled based on a few sensors.

i have been looking at fairly powerful rear drive cars as most of you know and a fella at work suggested taking his s2000 out and i thought it was a fun little car.

the v-tec felt like a turbo kicking in, but obviously isnt, but on the way home i decided to have some fun in the megane (which has brought up a few engine management lights...oh well) and it felt similar when going from stopped to full throttle i could feel the extra surge of power at about 2500rpm.

so, is v-tec just a mechanical version of the electronic vvt i have in my car?

 

[super noob]

V-tec doesn't work.......its a gimmick that makes you think a car has power.......really you just want a V8

 

[Kayos]

When I had my Nova turbo and the Vtec boys wanted to race, I was long gone before it kicked in

I know it uses oil pressure and different cams, but other than that I'm clueless

 

[rikrobson]

its usually a hydraulic valve that moves the cam followers or rockers onto an slightly different cam profile to give longer or higher valve lift. usually bases on engine speed due to the higher pressure generated via the faster spinning oil pump.

 

[BrokenBiker]

fair enough. think i wld prefer a 6 cylinder though :P

 

[super noob]

Buy a Godzilla!

 

[BrokenBiker]

link? or are you just talking about the giant lizzard?

 

[Norm]

you should be nursing that megane until you've nailed that new job

 

[super noob]

link? or are you just talking about the giant lizzard?

Old Skyline R32 to R34 are Godzillas

 

[BrokenBiker]

you should be nursing that megane until you've nailed that new job

im doing nothing to the megane except beating it with a stick daily to keep it inline.

Old Skyline R32 to R34 are Godzillas

ive looked down the r32 route and insurance is out of the question

 

[mike 109444]

Never having been involved with sort of engine I watched with interest an addition of "wheeler Dealers" (yes I know some of you don't care for the program!) But they had a Honda (?) with the hydraulic valve setup but as it was not working Edd C had to fix it and done his usual (good) explanation of how it should work. Much better than reading about it. The episode should be on Youtube. Maybe some one can recall the model of car ??

 

[super noob]

What about a 350 or 370? Less hair dresser, more sports car haha

 

[mike 109444]

im doing nothing to the megane except beating it with a stick daily to keep it inline.



ive looked down the r32 route and insurance is out of the question

Are you doing it correctly. Looks like you need to take a good swing
https://i.ytimg.com/vi/jeEHQzyUdC0/hqdefault.jpg

 

[atomant48]

the v-tec felt like a turbo kicking in

Nothing like a dose of 80's turbo! Those v tecs were pretty awesome when they first came out. I seem to remember they went to 9500 rpm or something?

 

[normspanners]

I know it uses oil pressure and different cams,

It is controlled by solenoid valve that opens and allows oil pressure to extend a piston and bring in a central third cam lobe into operation locking the two rockers together this creates more valve lift and overlap on the inlet cams, it does work VERY well and it makes an engine very docile and torque'y at low speed but produces more power at higher rpm allowing the engine to rev higher because standard overlap only allows a certain rev limit, because of the restrictions in the ports etc.
We used to use a different map to bring the vtec in at differnt rpms depending on throttle opening /engine load this produced an even smoother power flow. because honda do simply at a set rpm that is why it kicks in like a turbo.
toyota celicas are similar but theirs kicks in ridiculessly high rpm about 6500 when they only rev to 7500 /8000

 

[Fazerruss]

The vtecs and the like are all about having the best of both worlds, low emission economic engine when sedate driving and power when you plant your right foot. This trumps the high power only engines when you want a daily driver.
Bmw use a similar system on the n42 engine that is horrendously complicated bit it does work. It has an electronic valvetronic system to vary the amount of inlet valve lift and a hydraulic vanos system to vary the valve timing on both inlet and exhaust camshafts. It also doesn't have a throttle body or butterfly. Edit I thought it didn't cos I couldn't find it!

 

[normspanners]

V-tec doesn't work.......its a gimmick that makes you think a car has power

rubbish

 

[super noob]

 

[normspanners]

It also doesn't have a throttle body or butterfly.

dont know where you get that idea------ here is a picture of one

 

[ms08]

Get yourself a Saab then you'll know when the turbo kicks in....