VVTi system performance mods?

[m1tch]

Hi all,

Still taking my spare engine apart to be rebuilt to a fully forged engine, whilst its apart, are there any mods I can do with the VVTi system? I know there is a solinoid as well as the actual VVTi system on the end of the camshaft - are there any mods to oil ways or any internal changes I can make whilst its apart? I know that the actual timing can be altered via the ECU which is fine but wasn't sure if there was any mods I can do physically to the system to improve performance?

[shnazzle]

I know this is a huge assumption but I would think Toyota is already using the optimum valve overlaps to get the best volumetric efficiency. To my understanding, you want the best VE regardless of whether you're aiming for efficiency/environmentally friendly or max power.

In any case you'd be better off getting different cams instead of tinkering with the vvti.
The only things you could change physically is the amount of degrees overlap it allows for, which would take some serious machining skillzzzz.
Would also need a standalone ecu.

I guess that's why the next step was vvti on both intake and a exhaust cams and adding lift; they maxed out the capabilities of vvti on one cam

[m1tch]

I know this is a huge assumption but I would think Toyota is already using the optimum valve overlaps to get the best volumetric efficiency. To my understanding, you want the best VE regardless of whether you're aiming for efficiency/environmentally friendly or max power.

In any case you'd be better off getting different cams instead of tinkering with the vvti.
The only things you could change physically is the amount of degrees overlap it allows for, which would take some serious machining skillzzzz.
Would also need a standalone ecu.

I guess that's why the next step was vvti on both intake and a exhaust cams and adding lift; they maxed out the capabilities of vvti on one cam

I kinda figured that was the case, will be going with a forced induction cam for my build so the profile will be suited to that, I know that you can get quite a large change already with the OEM setup.

Think I will just run it as standard but ensure that everything is clean, shame you can't fit the VVTi-L cams/lift setup into the 1zz head - then again there is probably going to be a bit of a step up in power once the turbo spools up.

[jvanzyl]

I believe there is a small filter that needs to be cleaned in the vvti controller... You should do that whilst it's apart..

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[m1tch]

I believe there is a small filter that needs to be cleaned in the vvti controller... You should do that whilst it's apart..

Sent from my Moto G (5) using Tapatalk

Will check that out, think I remember seeing a video on it when I was looking at the 1zz engine but it was a Corolla so it was easy to get to due to the different engine layout - should be even easier now that there isn't a car attached to the engine!

[Micha]

I you have some engine modifications as MafMod, PPE intake, exhaust ect you can use CamCon which is low price in order to re-optimize the VVT and thus to get or recover some volumetric efficiency.

[ChrisGB]

I've been down the road of VVTI tuning on the the 1zz, no gains to be had there. The VVTI is really about optimising the midrange and Toyota did a good job of it. The gains in mapping come from two sources, running more advance, together with higher octane fuel, nets a little gain. Leaning the mixture out to as low 12.5:1 running super unleaded makes the most noticeable gains. With the PPE manifold, stock air box and filter and piggyback ECU, we got it up to 161bhp with noticeable mid range and driveability gains too. The PPE manifold didn't work well with stage 1 Crower cams, but others have had excellent results from the Crower cams and Zero manifold.

Beyond these steps, the cost gets really big, sleeved block,  increased capacity, uprated valve springs, higher compression pistons, standalone ECU etc adds up a lot of money. The results will be excellent, but at a price. You would be well past what would be spent on a good 2zz rebuild and fit.

[m1tch]

Thanks guys, was just wondering if there were any tweaks I could do now that the cams are out on the spare engine, going built 1zz turbo and will be running stage 2 cams so I guess just running them to optimise the midrange via mapping is the way to go.