Cams with VVT-i

[shoryu]

I was just thinking, "What would happen if you were to put some slightly wild blower cams in a VVT-i 1UZ?" Would you still have the bottom end torque because of the valve timing along with a stupendous top end, or would you sort of flounder around town wondering why you decided on such a combination. It would be tremendous if it were the former because along with the blower you'd need (which is why this thread is in this part of the forum), you'd possibly have the widest powerband this side of the new Audi RS4 or a Merc AMG something or other.

Has anyone thought of this before? Just think, 80%+ of peak torque off idle with a power peak of who knows what? 7k? 8k? Of course the entire engine would have to be built for such strain and high rpm efficiency, but still. The idea by itself makes me feel all tingly. :bigeyes2:

 

[Nick M]

Why would it flounder? Variable valve timing is the best thing to happen to the automotive engine. The cam timing is set at one point to maximize the powerband. It is a compromise. Variable cam timing can move the point of maximum scavenging, as it moves with RPM.

If you can control it with tuning, you would have a stable idle, strong midrange torque, and a high horsepower. Something that will never happen on standard camshaft. Yes, engineers thought of this before. Ever hear of the NSX? It came out in 1989, made peak power about 7000 RPM, yet drove like an Accord or Camry.

 

[turboandrew]

You might have less low end power than the stock vvti cams, but you would probably have lots of gains elsewhere, including mid-range. Eventually I would like to do this, and personally, I would have the intake cam less agressive than the exhaust cam, since its timing can be varied.

 

[Nick M]

You are not going to lose low end, you will gain. Unless the tuning of the cam is wrong.

 

[shoryu]

Thanks guys, I had a feeling that would be the end result if I were to do something along those lines. I just have to find a 98-00 1uz to go nuts on.

 

[WDoherty]

i was thinking about this topic too and may have brought it up here before,but the biggest problem you are going to have is tuning for the vvt-i. Which i think the stock ecu would have to go and you'd have to have a bad a** who can tune a stand alone and figure out the valve timing curves along with fuel and ignition timing all together.

 

[MitchP]

I'm working on it. Take a look at my post in the FIAT section.