Toyota Supra Alleged Revival: 2015.

[Matador]

Originally Posted by Dimman

The video is very interesting, the concept was kind of what I imagined, some way to change the leverage of the cam to the valve. But I see at least one problem with it. Space. Like you mentioned about how they may be able to get direct injection in it.

The big problem for me is that they move the camshaft down and to the side, which could cause problems for optimal port location and shape. It could force a tighter bend from the manifold to the valve. Or at the very least restrict the option to use straighter more vertical ports. This may be an excellent economy and emissions setup but I don't know about from a pure performance point of view.

As for the VVTL-i, think I have it. A VTEC-style profile changing system attached to a VVT-i variable pulley. Hence all they did was add (L)ift to a VVT-i system.

I wonder sometimes if they are maybe getting too gizmo-happy instead of focusing on simpler things (from a manufacturing point of view) like airflow analysis. (Except direct injection. That has awesome potential.)

Well, these technologies are really eco minded in all cases (NEO VVL from nissan stands for nissan ecology oriented VVL), more so for better combustion, economy and emissions (without having to give up performance).

I take it you are worried about them not being able to manufacture "G" heads anymore?

With the LFA, the forwent Direct injection because they could optimally place the injectors where they wanted, for what they wanted.


I see where you are coming from though, and I agree to an extent. Blame the governments and the over eager eco weenies that vote for them.
At least Toyota and other auto makers are trying.

[Dimman]

Originally Posted by MatadorRacing_F1

Well, these technologies are really eco minded in all cases (NEO VVL from nissan stands for nissan ecology oriented VVL), more so for better combustion, economy and emissions (without having to give up performance).

I take it you are worried about them not being able to manufacture "G" heads anymore?

With the LFA, the forwent Direct injection because they could optimally place the injectors where they wanted, for what they wanted.


I see where you are coming from though, and I agree to an extent. Blame the governments and the over eager eco weenies that vote for them.
At least Toyota and other auto makers are trying.

It's not even the 'G' heads that I'm worried about. What would be actually better for flow would be the narrower 'F' angle but with 'high' ports going out much straighter than the way they're horribly kinked in standard 'low' form. (If you don't quite understand I'll sketch something up...)

This straighter path allows for faster, high volume flow due to being able to use smaller diameter ports without having to worry about flow disruption and loss from direction changes. It also allows for bigger valves due to less interference during overlap.

The 'G' head will be ok still with Valvematic I think. But they won't have much room to improve with a better port design. Which is another way that combustion could be improved and thus improve emissions and economy.

But you can't patent an intake port, I guess. That may have something to do with it.

[Matador]

^ Sketch please, as I have an idea, but I don't want to misinterpret your description.

Toyota's heads flow pretty damned decent as is.

[Dimman]

Originally Posted by MatadorRacing_F1

^ Sketch please, as I have an idea, but I don't want to misinterpret your description.

Toyota's heads flow pretty damned decent as is.

Best I could do on short notice and with windows paint. Hope you get the idea, and don't die of laughter...



Even the G heads are considered a bit primitive these days. The trend is to straighter, smaller ports for higher velocity but still high CFM flow. Narrower valve angle is part of that trend too. Basically during overlap the intake and exhaust valves aren't moving towards each other as aggressively so bigger valves can be used without risking collision.

I think if you look at the LFA's in the cutaway you posted from the magazine a while back, they will look more like the narrow angle high port than the G heads.

[Siriusly.Andrew]

Fuck this is so technical. I love it lol, I'm learning so much its making me silly!

[Matador]

Originally Posted by Dimman

Best I could do on short notice and with windows paint. Hope you get the idea, and don't die of laughter...



Even the G heads are considered a bit primitive these days. The trend is to straighter, smaller ports for higher velocity but still high CFM flow. Narrower valve angle is part of that trend too. Basically during overlap the intake and exhaust valves aren't moving towards each other as aggressively so bigger valves can be used without risking collision.

I think if you look at the LFA's in the cutaway you posted from the magazine a while back, they will look more like the narrow angle high port than the G heads.

lol.. Nah, I get you. I know the difference between F and G heads, and a little bit about valve angle and intake ports and what not. I just didn't get what you were trying to get across. The sketch is adequate though, and i understand what you are trying to say.

G heads are pretty primitive now, I think Lexus described the IS-F heads as such more for marketing reasons than any real performance gain.

I don't think having valvematic would restrict those type of designs though. It all comes down to packaging, and the setup looks pretty compact, I'm sure they could adjust it for the application that they want.

[Dimman]

Originally Posted by Siriusly.Andrew

Fuck this is so technical. I love it lol, I'm learning so much its making me silly!

So what have you learned so far, Grasshopper? That MS Paint makes a lousy drafting program? Heh.

[Siriusly.Andrew]

I paint shopped an unpainted body kit on a car once. Turned out pretty good...



besides that, I never knew what the differences in the F heads and G heads were. (Because of the Matrix I know of at least 2 engines with a G and F head lol. 1ZZ-FE vs 2ZZ-GE). I had a good idea of the differences between i-VTEC and VVTL-i, and the non - i versions of both, but now they are confirmed.

Though I'm still confused a little by how exactly Valvematic works. I've been watching the video and I can SEE how it works, but why / how does it work like that.

[JoshatToyoTH]

Originally Posted by MatadorRacing_F1

I realized that it was. Was just helping you to realize that your design requirements aren't far off from what Toyota actually has... (Yes, Toyota does have a ZR engine I think , small 4 cyl).

2ZR-FE 1.8L engine used in 09+ Corolla models excluding XR-S.

[Siriusly.Andrew]

Originally Posted by JoshatToyoTH

2ZR-FE 1.8L engine used in 09+ Corolla models excluding XR-S.

Would that then be used in the 09+ Matrix, excluding XR-S as well? They've shared engines in the past so I'd imagine they are continuing that trend.

[Dimman]

Originally Posted by Siriusly.Andrew

I never knew what the differences in the F heads and G heads were. (Because of the Matrix I know of at least 2 engines with a G and F head lol. 1ZZ-FE vs 2ZZ-GE). I had a good idea of the differences between i-VTEC and VVTL-i, and the non - i versions of both, but now they are confirmed.

Though I'm still confused a little by how exactly Valvematic works. I've been watching the video and I can SEE how it works, but why / how does it work like that.

Looking at that vid again it appears I put the cams in the wrong spot in my sketch. I blame the 'transparency' for my error. The cams are actually closer to the center of the engine.

Basically the central bit with the roller element on it is what the cam is in contact with.

The slider that the controller pushes into the followers (the two fingers on each side of the part with the roller) adjusts how much they move relative to the camshafts. Think of the followers as growing longer so it pushes further for the same amount of camshaft lift.

Now if they can adjust lift to the point where it is so low the valves don't open, you no longer need a throttle to control air into the engine. Valvetrain is now precise enough to do that itself.

[Matador]

Originally Posted by Dimman

Looking at that vid again it appears I put the cams in the wrong spot in my sketch. I blame the 'transparency' for my error. The cams are actually closer to the center of the engine.

Basically the central bit with the roller element on it is what the cam is in contact with.

The slider that the controller pushes into the followers (the two fingers on each side of the part with the roller) adjusts how much they move relative to the camshafts. Think of the followers as growing longer so it pushes further for the same amount of camshaft lift.

Now if they can adjust lift to the point where it is so low the valves don't open, you no longer need a throttle to control air into the engine. Valvetrain is now precise enough to do that itself.

Erm... that's how the technology works... well not totally closed anyway, otherwise how would the engine run?

[Dimman]

Originally Posted by MatadorRacing_F1

Erm... that's how the technology works... well not totally closed anyway, otherwise how would the engine run?

Oh yeah, idle air control. Whoops...

[djohnson]

I was thinking the V160 for the Supra, not the 86. I don't think any 6's would fit in this car along with the V160 that would actually be able to make use of the capabilities of the V160, much less any 8's.