quad cam - Toyota Nation Forum : Toyota Car and Truck Forums

wontonjohnny · 07-10-2002, 03:36 PM

can anyone explain how it works? are all 4 cams uesd together or do they switch at higher rpms? i do notice a little pickup at 4000 rpm on my 3VZ-FE

88 LE · 07-10-2002, 10:55 PM

3VZ-FE = V6

V6 has 2 banks of cylinders.

Each bank of cylinders has 2 cams.

You figure out the rest.

wontonjohnny · 07-10-2002, 11:48 PM

can anyone back me up with the varible valve timing, at 4000rpm?.. i swear it does on my car.

midship sports · 07-10-2002, 11:56 PM

hey,

vvt-i was only on 99-2002 es300
00-02 avalon

on a 1mz-fe motor..

derek

88 LE · 07-11-2002, 01:58 AM

Quote:

On 2002-07-11 00:48, wontonjohnny wrote:
can anyone back me up with the varible valve timing, at 4000rpm?

Nobody is gonna back you up cos 3VZ-FE's don't have variable valve timing.

The boost your seeing at 4,000rpm is the powerband of the engine.

Jay · 07-11-2002, 02:38 AM

To be more specific about powerband...

It means that your engine is outputting the peak torque and horsepower around 4000 rpm. Obviously this means your car will pull hardest at this point. Unfortunately you don't have vvti. If you did, you will feel even more pull. about 25 more HP I believe.

Dark · 07-11-2002, 09:31 AM

okay, like when you read those car reviews at edmunds or wherever it will say like 135hp @4,500rpm. thats when your engine hits that peak HP...just to reiterate what jay said.

wontonjohnny · 07-12-2002, 12:34 PM

oh ic

wontonjohnny · 07-12-2002, 01:24 PM

hey i found this chart on hernys page
<img src="http://www.henrylee.ca/camry/misc/dyno.jpg" border=0>
there is a sudden change in HP and TQ at about 4000 rpm

wontonjohnny · 07-12-2002, 01:25 PM

wtf
try this
http://www.henrylee.ca/camry/misc/dyno.jpg

***Silver Streak*** · 07-12-2002, 02:05 PM

Who said you could look at my page? :grin:

The boost you feel at 4000, or more like 3800 or so is the ACIS kicking in. Notice the huge jump in HP at around 3800 RPM. It stands for Acoustic Control Induction System. Basically, at around 3800 RPM, this system kicks in...some vacuum occurs, some valves open, yada yada...it's pretty complicated...but anyway it manages the air intake according to engine rpm to ensure efficient combustion. Not a very good explanation but it's all in the Haynes manual with diagrams.

_________________
Henry

Visit my Camry Website!

<font size=-1>[ This Message was edited by: Silver Streak on 2002-07-12 15:11 ]</font>

wontonjohnny · 07-12-2002, 04:14 PM

so it sorta could be called varible valve timing right?

***Silver Streak*** · 07-12-2002, 06:29 PM

Quote:

On 2002-07-12 17:14, wontonjohnny wrote:
so it sorta could be called varible valve timing right?

You're kidding me, right?

jwa276 · 07-12-2002, 07:43 PM

actually, hes half right. instead of the timing of the valves in relation to the valvetrain, its variation of when the valves are used :grin:

wonton- in case you are wondering vvt-i means the timing of when the intake/exhaust valves open and close change with the engines RPM. its very similar to a Ferrari engine, except computer controlled i believe. believe it or not, but at specific RPM's when the intake and exhaust valves open/close make a huge performance difference. its like this- at any given RPM there is an optimal valve timing. with our engines, toyota has given us the best cam profile for a standard economy car. with vvti, it changes the profile/timing of the valves in order to get you either the most performance or efficiency of gas. this way you can get the most out of your engine at any given RPM..

with our 3vzs, we only have 1 cam profile, meaning no variable valve timing

jon

PS- if you have any questions, then go to http://www.howstuffworks.com and read up on their "What is a camshaft" section :grin:

wontonjohnny · 07-13-2002, 05:18 PM

cool... i just made a CAI yesterday and i can feel and hear the cam timing change even more and its been over 30 degrees the last coulple of days its awsome at night time