Anyone tried to appy Apexi SAFC or anything similar on their YARIIIII??

[paultyler_82]

Originally Posted by cdydjded

Also VVTi does do the same as VTEC. VTEC is done with a 3rd lobe, VVTi is done with a sliding pin. Go here http://en.wikipedia.org/wiki/VVT-i if you want an exact explination.

Actually that's VVTL-i, it does vary the lift, unlike VVT-i.

and actually, all engines that use some sort of variable cam timing system like Toyota's VVT-i or Nissan's CVVT, use such a system for the performance benefit, it's there to squeeze a few extra horses out of the engine at high RPMs or hard throttle. Although it may not be as noticable in the VVT-i engine as it is in one of Nissan's CVVT engines (they can advance and retard BOTH the intake and exhaust valve cams) or in Honda's VTEC (of course the added benefit of variable lift.) but it is there for the same reason, it is a much more noticable difference on a Dual VVT-i or a VVTL-i engine, of course.

[cdydjded]

FIREFLY:

"VVTL-i, which can alter valve lift (and duration) as well as valve timing"

The above sentence is directly from the link. When you add lift and duration it adds power. It does the same thing as VTEC. If you want to learn about what a cam does please read below:

The camshaft uses lobes (called cams) that push against the valves to open them as the camshaft rotates; springs on the valves return them to their closed position. This is a critical job, and can have a great impact on an engine's performance at different speeds. On the next page of this article you can see the animation we built to really show you the difference between a performance camshaft and a standard one.


In this article, you will learn how the camshaft affects engine performance. We've got some great animations that show you how different engine layouts, like single overhead cam (SOHC) and double overhead cam (DOHC), really work. And then we'll go over a few of the neat ways that some cars adjust the camshaft so that it can handle different engine speeds more efficiently.


The key parts of any camshaft are the lobes. As the camshaft spins, the lobes open and close the intake and exhaust valves in time with the motion of the piston. It turns out that there is a direct relationship between the shape of the cam lobes and the way the engine performs in different speed ranges.

To understand why this is the case, imagine that we are running an engine extremely slowly -- at just 10 or 20 revolutions per minute (RPM) -- so that it takes the piston a couple of seconds to complete a cycle. It would be impossible to actually run a normal engine this slowly, but let's imagine that we could. At this slow speed, we would want cam lobes shaped so that:

Just as the piston starts moving downward in the intake stroke (called top dead center, or TDC), the intake valve would open. The intake valve would close right as the piston bottoms out.

The exhaust valve would open right as the piston bottoms out (called bottom dead center, or BDC) at the end of the combustion stroke, and would close as the piston completes the exhaust stroke.
This setup would work really well for the engine as long as it ran at this very slow speed. But what happens if you increase the RPM? Let's find out.
When you increase the RPM, the 10 to 20 RPM configuration for the camshaft does not work well. If the engine is running at 4,000 RPM, the valves are opening and closing 2,000 times every minute, or 33 times every second. At these speeds, the piston is moving very quickly, so the air/fuel mixture rushing into the cylinder is moving very quickly as well.

When the intake valve opens and the piston starts its intake stroke, the air/fuel mixture in the intake runner starts to accelerate into the cylinder. By the time the piston reaches the bottom of its intake stroke, the air/fuel is moving at a pretty high speed. If we were to slam the intake valve shut, all of that air/fuel would come to a stop and not enter the cylinder. By leaving the intake valve open a little longer, the momentum of the fast-moving air/fuel continues to force 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 we want the intake valve to stay open. We also want the valve to open wider at higher speeds -- this parameter, called valve lift, is governed by the cam lobe profile.

The animation below shows how a regular cam and a performance cam have different valve timing. Notice that the exhaust (red circle) and intake (blue circle) cycles overlap a lot more on the performance cam. Because of this, cars with this type of cam tend to run very roughly at idle.

[firefly1_0]

i would see no problem with using a system like an SAFC on a VVTL-i engine as it is like honda's i-VTEC.


the original question here was would it work on the yaris engine which to the best of my knowledge does not have a VVTL-i, so my answer is still no.

there is no way to even compare a VVT-i engine to an engine that has VTEC or i-VTEC.

its two completely different systems...

but i guess my line of work remanufacturing crankshafts and camshafts all day means nothing here.

[Katana]

The only thing that VVTi does is to give more power at low rpms.

Imagine that.The old Toyota Starlet had a 1.3lt engine and 83ps.The new Toyota Yaris has a 1.3lt engine and 87ps, being equipped with VVTi.So, the VVTi did not help the engine to gain some hp, but it made it more driveable, giving more power at low rpms.

[YarisPR]

We just have to wait until someone does it

I know a guy who alter the activation of the VVT-i and did some other things on his Corrolla XR-S and he sure like beating the ass of some Nissan 350Z.... I must clarufy its a engine reving at 8,000rpm

[Katana]

Μaybe he added a four throttle!

[paultyler_82]

The basic point is, Yes, the Power Enterprise CAMCON will modify VVT-i engagement, however, this isn't going to be a plug-and-play, get-more-power mod, it's really meant for fine-tuning a heavily modified intake/engine/exhaust system, and you need to know what you're doing

[ChinoCharles]

You can take your car to a dyno shop whenever you want and they will probably be able to yank more power out of it... either stock or heavily modified.

They'll kill your mileage, though.