remove the tvis plate, problem solved
The time as has almost come where I must choose if I wish to retain TVIS on my 1ggte. from This link it states the ECU triggers the grounding to the TVIS actuator at 4150 rpm. Since I am soon not going to have a stock ECU I am assuming that since no power will be applied to the acuator/VSV that the TVIS will remain open at all RPMs.
The question is should I work out a way to continue using TVIS
Now consider this also before making a suggestion;
1ggtes come on boost at 3500-3700 and make full boost roughly around the 4200 mark right where the TVIS is fully open. I am going to be running a GT28RS which is a BB turbo along also with a 6boost manifold, and im hoping for boost to start at 2700 ish RPM and be fully on song by 3500. TVIS at this time would be a restriction.
Note I am also running a ported and balance tube fitted manifold, same as kyles 9second 1g intake.
I am thinking that in this certain situation I should leave the TVIS disconnected thus in a state of "open" all the time, Am I correct in my assumptions?
Thoughts, suggestions, etc etc
Originally Posted by Jordan 76
even easier. This wont create any problems with thread lengths on the studs used to secure the inlet mani to the head?
so practical you are
A more fruitful search I have conducted and came up with lots of speculation and not many facts. http://www.toymods.net/forums/showth...ght=1ggte+tvis suggests people have run without it and noticed a difference between the low down torque levels.
A better question may be perhaps how to trigger the TVIS to close/open at a new RPM range and can an aux output on a microleb be programed to do this?
And any suggestions on how to trigger it are more than welcome.
If you have a spare auxiliary output on the microleb, then for sure you can set an RPM switch to pull to ground at whichever point you want.
Consider this for discussion from another point of view: Horsepower is a result of airflow right? So in theory, if the single port (second port is closed by the TVIS butterfly) can still flow enough air for what your turbo can supply at the switching point for the butterflies to open (4000rpm in factory case), then there should be no restriction, and hence no disadvantage, right?
Measuring port flow & horsepower potential in advance so that you can make a decision is a bit difficult obviously, but if you decide to leave the TVIS plate in place, then a back to back dyno test at 4000rpm first with the butterflies closed, then open, will show a HP difference IF they are indeed a restriction.
Food for thought, or perhaps only to confuse the situation further
AE71 Corolla 2 door window van - retired / JZA70 Supra - VVTi converted - sold
just get rid of them, you've got that really nice flowing inlet manifold, why would you wanna restrict something that was made to flow better???
I just got rid of it on mine didnt even give it a second thought
I shortened the studs and re tapped the threads
1977 RA28 Celica 1JZGTEClick Me
1980 Chrysler Sigma
never done this - we did remove the plate on steves 1g (hypo23).
i would leave it there....
set it up ..
run it on the dyno. first run leave it closed the whole run.
over lap the next graph, but this time leave it open the whole run.
this will show any benefits and disadvantages, as well as showing the perfect spot to open it - the point where the graphs crossover...
Aerodynamics are for people who canít build engines. Ė Enzo Ferrari
Blake when did you nuke it from your setup? before or after the autronic was setup and tuned?
Screamin Rolla, when does your turbo start to boost and is it less torquey since removing the tvis?
EDIT - does a 1ggeu use TVIS? Remember also that I will be using these cams now also.
the above shows there is very little to gain lower down in the rev range in which I will be spooling 2700 to full boost at 3500, im not sure i really see the point to retain the TVIS system.
Another thing I read states that if you force them closed all the time, when you have sufficent inlet pressure they will open anyway.
Last edited by Kedderz; 24-01-2009 at 06:43 PM.
I still have mine. Although we did configure the Microtech to switch the TVIS Jake Edwards found that when there was sufficient flow that they opened anyway - so you are correct. He did recommend me retaining them for my application.
Craig, would I be able to come over and have a chat today and look at your oil lines and central locking etc?
Drop me a PM with your number and ill give you a buzz.