Is the TVIS plate made of steel on a rev 1?

[moscoworbust]

Is the TVIS plate made of steel on a rev 1?

or is it made of aluminium or anything else?

I need to get a quote to get it welded before I remove it.

Thanks in advance.

[calum4492]

the body piece is alloy and the rod and flaps are steel
i have a gutted 1 if u are interested pm me

[moscoworbust]

What kind of alloy?

Any special welding required?

[bobhatton]

Why do you want to remove it?

[moscoworbust]

Because it's not opening properly, it's broken, not working.

I'm also upping the boost and as the japs removed it when they upped the boost I have no problem in doing so.

I read that when you up the boost you need to lower the opening rpm, but then I read that it opens at 1800 rpm or something but will count for 5 seconds then open in other conditions. There is a thread on it where someone went into the ECU and worked it out. I can't be bothered to do that.

This stuff : http://www.turbomr2.com/MR2/Reference/TVIS/TVIS.htm

look at the graph, the graph.

The main difference between the rev 1/2 and 3+ is more boost and more air flow and they removed the TVIS for the rev 3+, so I'm assuming that if I up the boost the same logic applies.

If you want to come and fix it, I'll leave it in. If not, I'll remove it.

[bobhatton]

So how do you know it is not working?
Is it staying shut or open?

Toyota went to a lot of expense to use this system to give low down power and if you remove it you are going to lose this power.

On the Rev 3 the whole inlet was changed together with the head, so just removing it will not make it work like a Rev3

[moscoworbust]

I understand that.

It is staying closed. It feels slow at high rpm and when i rev it up sat on the drive i can't see the flaps move.

I am currently installing a new downpipe/exhaust/intercooler/boost controller/service parts.

I decided to clean up the engine bay and paint all the bits, intake/cylinder head cover/ back plates/ throttle body and clean around the fuel rail and check the injectors so I'll have access to it. Maybe I can see the problem, a loose hose or something.

All I know is some dude did the same mods I am doing to my car, the rev1 and when he dynoed the car with the TVIS open and closed he found the point they crossed was a lot lower down the rev range than the stock setting so you are actually losing power. I.E. the power curve with the TViS open was producing more power than with it closed at that the set rpm. Now, this guy went to the trouble of dynoing the car with a sound method.

I haven't read any other study on it. Have you? I'm keen to find out but it does make sense and if we are talking about it reducing from an average of 4500 rpm to 3500 rpm and i only drive below 3500 rpm when pulling away in first what is the point of having it?

I really didn't want to get into this again, we discussed it on an old thread about the TVIS. I just wanted to know what material it is made of in case I can't fix it.

[bobhatton]

All you need to do is unplug it and take the hose off and plug it. This way it will stay open all the time.

I race one of my cars and have over 300hp, all with the TVIS working.

My son has removed his and he now has a big hole in his power curve at lower revs

As has been said above the housing is made from aluminium

[moscoworbust]

Ah OK, so you have actually experienced this.

Awesome. Fine then, I'll keep it in. Do you have the dyno graphs?

OK, can you check if it should open when not under load, i.e. at rest, 0 mph, if i rev it.

If it shouldn't anyway due to the ECU maybe it's not broken. If it should, at least I can use this to tell if it is fixed.

I'm aiming for 300hp too. You have a rev1? What set up do you have?

You can still use the TVIS but set it to come on at a lower rpm, 3600 rpm is recommended for 1 bar of boost. This is the best way i think.

You can get a switch really cheap to do it.

[bobhatton]

The ECU does all the controlling, it does not just open at a set RPM, there is much more to it than that.
I think it will be closed at idle but will not open just because you rev the engine.

A dyno graph will not show up how it helps the engine run at low RPM, its not just a matter of it being open or closed, but you can try it yourself, unplug it and it will stay open all the time

[moscoworbust]

Here it is, how the TVIS works.. a guy posted it before and posted it in my previous thread when I was asking how the TVIS worked..

http://www.imoc.co.uk/forums/viewtopic. ... highlight=

It comes on after 2200 rpm after 3-6 seconds and doesn't come off again until you go below 1800 rpm, 3 seconds if you hit 3600 rpm quickly.

I wonder if it ever opens in 1st gear then as with a quick launch i don't think I spend that much time above 2200 rpm. Plus when changing gear if you don't let it drop it won't close again, which is odd I guess.

He took the code out of the ECU.

[sidewaysmk2tubby]

The majority of people ive seen discuss this topic just gut the tvis or fit a blanking plate.

IIRC it wont open in first gear anyway because the standard rev2 engine does not fully boost in first gear, so second gear......onwards?

[moscoworbust]

It's rev1.

And i think it won't fully boost in 1st/2nd due to the ECU VSV control but as I'm fitting an aftermarket boost controller I disable the VSV so it will fully boost in 1st/2nd.

The main thing being that with a fast launch it won't have time to open in 1st as you'll be in 2nd within 3-6 seconds. Only if you let the revs drop below 1800 rpm during a shift will it close again.


I have to agree with Bob that there is a reason to have it. But when you look at the control, it basically turns on then doesn't turn off until you come to a stop again (drop below 1800 rpm). So there isn't much need to remove it, and it will provide some extra low down torque if you ever do drop below that , i.e. on motorway cruising in 5th etc.

The interesting thing is the guy checked the Rev2 ECU and found the time had been reduced to 1 second. So maybe they made a mistake first time round.

Anyway, the fact it opens at 2200 rpm or there abouts is fine. I thought it opened a lot higher.

[Driftlimits Performance]

If you think it's the tvis plates are jammed shut (which I'd doubt, and if they are, there's another problem ie blowing oil) then just fix them open and see if makes a difference!

[moscoworbust]

If you think it's the tvis plates are jammed shut (which I'd doubt, and if they are, there's another problem ie blowing oil) then just fix them open and see if makes a difference!

ok buddy.

I'll just paint it up. Install my bits, turn up the boost and try it with and without.

no harm in it I guess.