[Mk2] [Turbo] Removing TVIS???

[alanmr2turbo]

I just had the REV3 conversion done to lose the AFM on my REV2.

Can i removed the TVIS plate and then just put the mainifold back on or do i need one of those TVIS plates where the butterflies have been removed and welded up?

[Quigonjay]

http://www.atsracing.net/Parts/Details/E-INTAKE-SPC-2

[Al-sw20]

Is the TVIS functioning still?

Keep it if it is. You will lose low and mid range torque if you remove it.

[alanmr2turbo]

well i had boost turned up so i take it that its now not working. Plus having the rev3 ecu and sensors fitted im not sure i still need it anyways.

If i need one of those packers then i will de-gut the butterflies and get it welded as it'll be a lot cheaper than $150 + shipping plus the robbing governments taxes.

[Al-sw20]

Are you confusing TVIS with T-VSV? You disable T-VSV when you add a boost controller.

TVIS is a set of throttle butterflies that stay partially closed sub 4200rpm to keep the air velocity up to keep the car driveable at low rpm. At 4200rpm they open up.

You will lose low end for the sake of no difference up top if you take it out or if it isn't working.

[alanmr2turbo]

hmmmm, i think you're right.

So really its best to leave them in?

[Al-sw20]

If they are still working yes. Especially on the gen2 head.

The gen3 head and intake manifold solved the problems of the gen2 head.

I don't have any experience with the gen3 ecu swap, but your TVIS may now not be working simply because the gen3 ecu has no need to control TVIS, as the gen3 never had it. I could be wrong though.

[bobhatton]

hmmmm, i think you're right.

So really its best to leave them in?

The problem is the Rev3 ecu has no control of them so you will only have 4 of the manifold runners open at any time, not the eight at higher revs.

If you remove them you will be down on power at lower revs.

The best thing to do would be fit an rpm switch that will open them at say 4500 rpm

[alanmr2turbo]

Cheers for the replies

where do i get these RPM switches and how do i wire them in? I hate doing electrics so needs to have in a dumber than dumb explaination

[Al-sw20]

If you are fitting an RPM switch you will need to get the car on the dyno.

You set the runners to open for one run, then do another run with them closed for the whole run. Overlay the runs, and find where they cross. That is the point where you have the TVIS open.

MSD make a rpm switch that suits.

http://www.msdignition.com/Products/RPM ... witch.aspx

[sidewaysmk2tubby]

Don't most people just delete this and remove the butterflies?

From what I gathered once boost is raised and more power produced these become a bottleneck for the induction. I just took the plate off the mani, unscrewed the butterflies, cleaned up and replaced. Or would I of been best to have a rpm switch made? When running higher levels of boost you must want the inlet to be as free flowing as possible

[les85]

I just removed mine and replaced them with a hux racing spacer as the rev3 ecu doesn't control it so i thought there was no point in them being there.

[Al-sw20]

You will get an awesome placebo effect by removing them on a mildly modified car.

It will have such little torque down low, when the turbo finally spools you think you are actually going faster.

[jimGTS]

by default the butterflies are OPEN if not plugged in or working which they wont be on a rev3 ecu.

certainly wont have half of them closed!

they wont be harming or improving anything in your setup.

but for the sake of a tiny bit better flow, i would take the buttflies off.
i kept in the bar that holds them in, so no welding needed.
or if you wish you can remove the bar and weld the holes.


afaik, this 4200rpm switch over point is a myth.
it was proved on here by someone who read the stock ecu that the butterflies open as soon as you see boost.
they dont stay partially shut at 4200rpm, they go straight to open upon seeing boost no matter what revs.

just what i read tho.

[megamonkeyman]

by default the butterflies are OPEN if not plugged in or working which they wont be on a rev3 ecu.

certainly wont have half of them closed!

This is what I am led to believe also.

[Steve-O 2007]

i have one forsale you could gut