removing the manifold butterflies 1ggte

[1jzracing]

has anybody tried removing the little block with the manifold butterflies on a 1ggte

it looks as though the manifold could be bolted straight to the head and leave out those butterflies all together that close off half the ports at light load

is there really much less torque or drivibility or economy down low without them

i would hardly emagine it to be much worth noting and it would be great to get rid of the restriction in the ports

im sure this would have been covered b4, didnt find it though

[BeRad]

you can buy plates that have the tvis removed, dont know about the 1ggte but the threads on the studs are not long enough to be able to remove the tvis and bolt the intake to the head directly, i woudlnt bother removing it unless i had a fair amount of power which may make opening the butterflies hard to open.

the butterflies can be removed from the stock plate with a little tinkering.

.

[TA-022]

as mentioned you can volt the manifold straight on but the studs go blank
(no thread) at that point.

So if you replaced the studs with shorter items then yes its a bolt on job.

But then there is a little container under the intake the fouls on the block, i think
its part of the tvis and can probably be removed???

[1jzracing]

manifold can be bolted on with out it no problem, a little bit of a mod here and there, studs etc

I want to know if anyone has removed it or jammed it open then driven it before and/or after?

.... how much difference does it really make????

im into getting rid of everything that isnt essential

[TA-022]

rumour is at big HP or hi boost levels it does more harm than good.

Ive heard of it being wired open before...

[Forcefed6]

I have never run the TVIS on mine, and it all bots up ok with the shorter studs fitted.

Some say it's not worth it, and just sacrifices low down power/torque by removing them, as it reduces the airspeed in the manifold.

[Karma Supra]

I have wonderd this too.... but lets face it, the last thing a 1G needs is LESS bottom end torque

[IN 05 NT]

I have never run the TVIS on mine, and it all bots up ok with the shorter studs fitted.

Some say it's not worth it, and just sacrifices low down power/torque by removing them, as it reduces the airspeed in the manifold.

did you run with it on before?...ie do you have a comparison to give us?

isit as simple as just removing? replacing with shorter studs? or is it needed for the factory ecu?

i'll be keeping an eye on this thread!

cheers, blake

[Forcefed6]

No I never ran it before as it was a supercharged engine, which do not have them at all. Most people that fit a custom lpenum remove these too.

[MarkIIGT]

i removed the butterflies, i noticed very little if any performance difference. They do look pretty restrictive though

[JustCallMeOrlando]

I can't see them being that restrictive at all. That's the reason I didn't remove them. I've driven my car with the TVIS locked closed, more bottom end, strangled top end. I've driven them open, bottom end not so good, takes longer to boost. The difference made by removing them I hazard a guess, could be equalled by less than 1psi of boost.

[Ben Wilson]

If it's like the 4AG, the butterflies aren't the big restriction. It's the sudden change in area when the T-VIS setup ends which will hurt you.

If yuo want to to it properly, you should remove the butterflies and shaft, then attach the T-VIS plate to the manifold and smooth out the transition into the port.

[ddeane]

Gidday

At the risk of opening a can of worms I would strongly recommend leaving the system intact.

This matter has been debated at length in the past and general opinion based on actual experience with the system both in place and removed that there was a measurable difference in performance. Do a search.

Unless you are chasing huge power and can reach the limit of the flow of the system as it stands it would appear as though benefits of lower down power are worth while keeping.

Have a look here http://www.toymods.net/forums/showth...highlight=tvis
and here http://www.toymods.net/forums/showth...highlight=tvis
and here http://forums.toymods.org.au/index.p...t=0#msg_747882
and here http://forums.toymods.org.au/index.p...t=0#msg_519732

Just make a note - my tuner informed me that the butterflies are forced open by the flow at above 4000 rpm.

Craig