3SGTE tvis.. keep it or remove it?

[Grrrrrrr!]

Just wondering if it makes any noticable difference on a standard gen2 engine.

Just started stripping the 3s, and generally hating on the number of vacuum lines and shit, and want to remove them all so long as its not going to cost me reliability or driveability...

Opinions?

[Al]

Keep it unless you are building a monster.

[iOnic]

Half the time it doesnt work. Keep if you want, not the end of the world if you don't. Does help drivability....when it works.

[loudstealthGT-Four]

has any one ever seen any dyno plots of t-vis vs no t-vis, id be keen to see the difference as im thinking of removing it as well, while my motors out

EDIT

to answer my own question did abit of research and it seems that if you want more power from a relatively stock 3sgte then keep the T-VIS and tune it with a MSD RPM switch

http://www.mr2.com/forums/turbo-engine- ... nator.html

but if you haven't read this before, then id recommend it

http://www.mrcontrols.com/primers/power.htm#link1

[Al]

I've got my old dyno plot here, lost the image of it so I'll have to scan it again.

You can see where the TVIS butterflies opened on my old car on the plot, the boost spiked along with the HP and TQ.

[sergei]

I had to remove mine and "port match" the manifold because the diaphragm was broken inside of actuator and Toyota wanted a kidney for the replacement part (and all actuators I found on pickapart were broken).

[Heylin]

When I had mine tuned back in January they showed me the two plots with and without, the torque crossover point was the best point for opening. Yep it made a noticable difference in low end.

[Dell'Orto]

Unsurprising really, they have monstrous ports.

[LEAKER]

So how would you test if the t-vis is working correctly. Now that this has been brought up id like to have a look into getting mine set up right.

[CelicaGT8]

I got rid of mine, been fine without it

[EssDub]

So how would you test if the t-vis is working correctly. Now that this has been brought up id like to have a look into getting mine set up right.

This.

I'm sure mine isnt working right...

[Dell'Orto]

Pretty sure the BGB has a method for testing TVIS operation

[blindnz]

cant you just unplug the hose which will disable tvis, should be a physically noticeable difference with it.

Although i guess this wouldnt help if its stuck open

[sergei]

Apply vacuum to TVIS actuator, it should pull the butterflies completely closed.
Additionally it should hold butterflies closed with no additional vacuum.

[Trls250s]

Drive mr2 with TVIS, a lot more low down torque and go vs gt4. Could also be drag from 4wd driveline.

Tvis in bigport 4age is critical if you want to get off the lights without riding the clutch hard.

[Vertigo]

why would you want to cripple your engine? O_o TVIS is there for a reason..

[Malcolm]

mine's never seemed "crippled" without TVIS

[LEAKER]

Drive mr2 with TVIS, a lot more low down torque and go vs gt4. Could also be drag from 4wd driveline.

Tvis in bigport 4age is critical if you want to get off the lights without riding the clutch hard.

Huh? Same engines.

[sergei]

That is without TVIS.

TVIS might help with drop in torque below ~3200rpm, but that drop is more due to boost threshold than TVIS (at least I believe). Additionally boost curve is rising because of boost creep (it should have flattened at 10-12psi) as I was running stock CT20b wastegate pressure (un-bled), the only thing that was keeping boost in check is very restrictive el-cheapo 2.5" muffler.

[Akane]

Sorry my photoshop-fu is really shit, and I know sergei is in 3rd gear + 4WD.

But yeah, so sergei's no TVIS vs PowerFC TVIS + GT28RS.

I know it's not informative, but just for shits and giggles :/

red = Akane kW
black = Akane tQ

Blue = sergei kW
Green = sergei tQ

edit: torque is wrong and I don't know how to free transform it correctly