TVIS or not to TVIS...

[JustCallMeOrlando]

Anyone got a pic of a TVIS plate handy?

[Lambolica]

I'll fix those links in the top post shortly as well

[mic*]

Frank i dont think there is anything you've said there that doesnt logically make sense.

In the case of a 1G - manifold is always gonna outflow the head so thinking about the flow restriction of TVIS is silly.

My opinion is that Toyota oversized the manifold so we could keep it all intact and still make big power in the aftermarket scene - the 1GGTE motor was second only to a 7MGTE in its time.

It would have been logical i think to see the TVIS shaft run right accross the whole manifold from the factory.

Turbulence is an issue but you must remember that turbulence increases exponetially with flow. If we never even get close to the flow limit of the manifold, how much turbulence will there really be??? Also, in relation to boost, increasing pressure does improve smoothness (looking for the right word) of flow. Air particles have less space between each other to vibrate and are forced in a more uniform path in the direction of flow.

What about the turbulence created by an extra runner that is blocked right at the end when the TVIS butterflies are closed? In my opinion, TVIS could have been better designed by somehow putting the setup at the START of the TVIS runner rather than at the END.

[WindeX]

Just to throw something a little different into the mix, I have a gen 2 3SGE with ACIS(or it had) and this has been disabled. The entire box/manifold attachment has been removed and plated off, this was done not for performance but for clearance issues, now if you look at my power curves it is quite peaky, much more than a normal stock 3SGE.

My tuner said that it made a little less power than normal 3SGE's he had seen, this may have also been due to the nasty stock extractors and cat. It doesnt seem to have affected the car too badly, it is a pretty stock 3SGE that dyno was done with just a 2inch exhaust and stock(modified) extractors and a wolf 3d running everything, it peaked at about 5500 rpm with 80rwkw. It is in a TA23 FYI.


http://www.myfilehut.com/userfiles/v...//IMG_2147.JPG

[JustCallMeOrlando]

Thats the first time I'd ever really looked at it...and it's as lazy as I imagined. They should have extended the rods into the last ones to even everything up! Turblence aside, it's a sound idea.

[Fattony]

mic* you have got to consider that yes the manifold will out flow the head, but what do you think is going to happen with your motor when you have more air going through 1 and 6 due to this problem with the TVIS when your reaching perofmance limits. Lean out and then detonation, and becuase the factory ecu and well aftermarket ecus bar a motec or autronic cant contoll individual injectors your going to have a big problem on your hands. I have it removed on my car and also have a car which is modied the same but still retains the TVIS and there is no difference in drivability on the road, and it feels like mine makes more power but thats yet to see.

[WindeX]

mic* you have got to consider that yes the manifold will out flow the head, but what do you think is going to happen with your motor when you have more air going through 1 and 6 due to this problem with the TVIS when your reaching perofmance limits. Lean out and then detonation, and becuase the factory ecu and well aftermarket ecus bar a motec or autronic cant contoll individual injectors your going to have a big problem on your hands. I have it removed on my car and also have a car which is modied the same but still retains the TVIS and there is no difference in drivability on the road, and it feels like mine makes more power but thats yet to see.

I think there is another thread that goes into this problem somewhere, recent, maybe yesterday, but it said about how they just put a screw accross it to even it up to prevent the leaning out of 1 and 6, not perfect, but makes it a much smaller gap than the 10cfm difference of whatever it is.

EDIT: I think the WOLF ver 4 can control each injector to account for differences, this is just from reading their manuals, but I am new to this.

[mic*]

I think there is another thread that goes into this problem somewhere, recent, maybe yesterday, but it said about how they just put a screw accross it to even it up to prevent the leaning out of 1 and 6, not perfect, but makes it a much smaller gap than the 10cfm difference of whatever it is.

EDIT: I think the WOLF ver 4 can control each injector to account for differences, this is just from reading their manuals, but I am new to this.

Tony, i just asked you a question in another thread, which is summarised by the above two posts quoted.

With toyota's laziness compensated for by some form of dummy shaft, and your bench test results taken into consideration (which seem to place some doubt over the other supposed 10CFM diff in 1 & 6) , wouldn you say that would acheive the most even flow you could hope to get?

[mic*]

And furthermore because of the two facts that;

1. Manifold always outflows head.
2. TVIS does acheive greater intake velocity at low RPM's which is a good thing.

...I would think that this would be the best base to start with, TVIS and all!

No-one has commented on the whole setup being designed for the other end of the TVIS runner. Sure it would have been more of a challenge to fit it in, but i think that would be a much better system.

[Ben Wilson]

JustCallMeFrank - That looks a lot better than a 4AG one.

The 4AG T-VIS plate just has two simple, round holes in it and a lot more blank space between them.

[Hydra]

I've heard that cylinders 1 & 6 run leaner, however I have not seen proof or it. Need to run a wideband O2 sensor on each cylinder to find out whats going on there

[JustCallMeOrlando]

How much does it cost to flowbench something?

[Hydra]

Not sure - call 0395532517 to get an idea though... I think thats for Perfectune Engineering. I know it's not in your (or mine) states but they do flowbench testing.

Got that from Race magazine

[WindeX]

I've heard that cylinders 1 & 6 run leaner, however I have not seen proof or it. Need to run a wideband O2 sensor on each cylinder to find out whats going on there

I am pretty sure some one was saying that they had melted pistons 1 and 6 in multiple 1G's due to leaning them out.

[Hydra]

They would have been running the AF ratios pretty close to the limit there, for 1 & 6 to be affected. Factory tune would be fine