'Performance VVTi Solenoids' for the Hybrid

[preperationlaunch]

Has anyone seen the allegedly performance-enhancing VVTi solenoids?

Their claim is that they enhance engine response by allowing oil to flow more quickly, thus adjusting timing to demand more promptly. I'm struggling to see why the Toyota part would be particularly constrained.

I can't say I'm entirely convinced, but I am intrigued. People on the Prius forums claim driveability and MPG boosts from them. Essentially saying that the engine feels a lot more responsive. The Prius C folks (which shares a drivetrain with the Yaris) seem to report good things too.

https://www.redbullet.net/

https://www.qspwr.com/collections/toyota-motors/products/quantum-solenoid-toyota-prius-v

Are they modern day snake oil? Some reckon that the improvements people see are from replacing tired solenoids with brand new ones. There's not so much empirical evidence.

Equally, the lithium-based Battery replacements seem quite interesting, their voltage characteristics mean the car is a lot more eager to pull power from the Battery, as well as weighing half as much, it's just a shame they can't be had in Europe yet. They have about twice the capacity too, and will use about 80% of the Battery rather than the 40% that Toyota allow from the Ni-Mh.

[TonyHSD]

Oh boy, just use 99 E5 premium or whatever is the best available petrol and you will get all that improvements without any modifications. I am totally against any of those non standard parts fitted to a car built for efficiency and reliability. 👍 

[preperationlaunch]

Higher octane won't make any odds on an Atkinson cycle would it? It just stops knock from happening at higher compression ratios, about 13:1 or higher. I've got a bike that's about 12.8:1 and that starts knocking on hot days under load on 95.

Though, on the non-Toyota Atkinson cycle engines, where they swap between to an Otto cycle, I could see it making more difference, if the compression ratios are as high, and the car is sensible enough to adjust the timing to suit. But the HSD engines hold the intake valve open to reduce the compression ratio significantly.

It's more of an interesting thought experiment around whether an allegedly faster moving solenoid would in fact make a difference to how the VVTi is operating, and whether the ECU is actually smart enough to figure out that the valves are getting where it wants them quicker. When you think how quickly the valves are being opened and closed, I suppose there could be potential mechanically.

[flash22]

This is a new one, speed of the valve is controlled by the ecu the vvti phaser is oil controlled the only to make it actuate faster is to increase the oil pressure

the Hybrid is an eco car - 12-mile trip today I got 70mpg (extra urban)

[preperationlaunch]

I wish mine got that, I've never gotten more than about 60mpg on a run, but, I sit on cruise control a lot.

Equally, I've never gotten terrible fuel economy, I'm averaging 50mpg or so with lots of short urban trips recently, and that's often including forcing the engine on to provide heat, and sitting in READY for 30 mins+ at a time with the engine cycling for heat whilst waiting.

It only has 9000 miles too, so is barely run in in the scheme of things.

I think the claim behind the solenoids is they increase oil flow by having bigger holes, which combines with a solenoid moving the plunger to the desired position more quickly.

I highly doubt it would make any odds, and I don't really want to gamble £100 for the sake of finding out.

[Cyker]

70mpg is heroically good for a Mk3! Most people only get high 50's!

This solenoid sounds bunk to me; I don't see how the speed of it switching between different valve timings would affect the performance of the car in any noticeable way, given the stock one can already change within one revolution!

I want someone to send one to the Car Care Nut channel guy to test... 

Until then I'll put this one with the fuel magnets and hydrogen generators...

[flash22]

If the pathways are larger it will lower the oil pressure, tbh it looks like they have just ordered valves with a bit of plating/anodize from China

re, 70mpg it was a balmy 15 degrees

 

[Saxmaniac]

And as to the claimed higher current capability of lithium ion batteries, the current used is determined by the inverter and the switching transistors and motor windings haven't got any heavier rated by magic! Possibly there might be some efficiency gain by being able to run on electricity more, but after all, where does the Battery get it's charge from?  And there's the safety concerns relating to using a different chemistry Battery from what the system is designed for. I'd think that it's quite a risk for minimal potential gains, though my disclaimer is that I'm only being an armchair expert here!

[flash22]

The car will see the pack as a standard nimh as the lithium pack has its own BMS (required to balance the cells) and it can give the inverter the correct information it needs to see - it will not increase the power of the motor, but it will extend the run time in EV and have a better capacity

the Prius systems tend to convert the pack over to a PHEV type

[preperationlaunch]

Flash22 is spot on.

The basic premise works on the fact that the HSD system works on pulling/regerating different amounts of current, based on the state of charge. If you've ever managed to fill the Battery up on your Hybrid, you'll see it get a lot more eager to use the Battery for a while.

The BMS in the lithium makes the car think it's sitting around the range where it can provide peak current, but can still accept peak current too. I'd assume that a more stable voltage means the car will continue pulling full power for a bit longer on acceleration/the slower climb will allow it to keep charging for longer. Most of the premise of the HSD comes from running the engine more efficiently by using the Battery to manage load, and capture energy where it makes sense to lug the engine, or when slowing down. But, the limiting factor is how much current the battery can accept. The HSD inverters are designed for a lot of current, and are popular as the basis for DIY EV inverters, just with different control logic.

This is a lot more appealing in the US where the Lithium option is half the cost of the Ni-Mh factory batteries. Toyota charge several thousand dollars for new ones. https://projectlithium.com/

I'm not advocating anyone buy one, it's more a technical interest. But, Toyota ascribe some of the economy advantages of the mk4 Yaris to the lithium battery which is able to provide significantly more current whilst being significantly lighter. The lithium retrofit packs weigh 50% less.