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TVIS eliminator


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#1 hot richard

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Posted 19 September 2010 - 01:07 PM

Hi just wanted to ask if removing the TVIS would be a worth while expense?
What gains would i be looking at?
Any pitfalls, or is it just a pain to do


#2 Fodder

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Posted 19 September 2010 - 01:19 PM

Forget whether I ever saw hard data on this, but common theory is that it doesn't hurt at all until well past 300HP at the wheels, and does help with torque down low.

updated%20beast-at-dusk_zpshfnalfwz.jpg
- 1990 JDM ST185 - TEIN HAs / CUSTOM DMS SPRINGS - WHITELINE REAR SWAYBAR - WHITELINE REAR STRUT BRACE - CT20B TURBO - 3" AUSSIE EXHAUST / DUMP PIPE - CHINA SPEC FMIC - NPC CLUTCH / LIGHTWEIGHT FLYWHEEL - GROUP A FRONT BAR - CUSTOM PEELING CLEARCOAT - 18" OX631 RIMS - TURBOTECH MANUAL BOOST CONTROLLER (@15PSI) -


#3 ninjadaniel

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Posted 19 September 2010 - 01:22 PM

yeah ive been reading up on this also. TVIS does no harm unless your engine is built in a way which the factory switchpoint of 4200rpm is no longer best for a smooth powerband. You should be able to rig up an output from any aftermarket ecu to control the TVIS to smooth out the powerband- obviously this would require a dyno to do properly.

tests have been done which show tvis permanently on and permanently off, there are losses of some sort in each scenario which prove tvis is best retained.
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#4 hot richard

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Posted 19 September 2010 - 08:38 PM

Thanks for all the help... saves me a bit of money and effort.

#5 ken

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Posted 29 September 2010 - 10:04 AM

What your asking is like comparison of "smaller or bigger turbo?". The TVIS is better for stock, street, low end torque improvement, elimination of tvis for high boost, high flow, race, high end power. Some people try to rig up the TVIS so that the butterflies stay constantly opened. The problem with that is the rod that holds the butterflies still run across all the intake ports, which can cause turbulence at high flow and velocity. Alot of race engineers design intakes that flow smoothly without any protrusions. That is why when necessary people will port intakes for more flow and match ports for no turbulence and consistency.

2 facts. 1 the Celica GT4 st185 that ran in WRC removed the TVIS. 2 The ST205 had revisions on the design of the 3sgte and removed the TVIS altogether.

#6 Cuts

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Posted 29 September 2010 - 10:35 AM

how many people here are making enough power from a gen 2 to warrent removal of the tvis...not many.
The fact of the matter is most people here are just doing it for something to do, like fodder said unless your making 300hp or more (like the TTE rally cars for example) keep it, it might be best to move the switchover point a few hundred rpm to keep optimal performance.

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#7 Fodder

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Posted 29 September 2010 - 12:21 PM

QUOTE (ken @ Sep 29 2010, 08:04 AM) <{POST_SNAPBACK}>
the Celica GT4 st185 that ran in WRC removed the TVIS


These motors wouldn't have spent a lot of time at rpm below the switch point anyway. A lot of things that make sense for a full race car don't for a car that'll be driven on the street, or even doing 'normal' track duties.

updated%20beast-at-dusk_zpshfnalfwz.jpg
- 1990 JDM ST185 - TEIN HAs / CUSTOM DMS SPRINGS - WHITELINE REAR SWAYBAR - WHITELINE REAR STRUT BRACE - CT20B TURBO - 3" AUSSIE EXHAUST / DUMP PIPE - CHINA SPEC FMIC - NPC CLUTCH / LIGHTWEIGHT FLYWHEEL - GROUP A FRONT BAR - CUSTOM PEELING CLEARCOAT - 18" OX631 RIMS - TURBOTECH MANUAL BOOST CONTROLLER (@15PSI) -


#8 Tinman

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Posted 15 June 2017 - 09:06 PM

Evening ... thread re ignition.

I now have a Microtech LT10C ECU and the TVIS is not yet connected.  So running with the TVIS butterflies closed all the time.  Does anyone have experience with how to setup a trigger for the TVIS with the microtech?

Any assistance would be greatly appreciated :)



#9 clixx-io

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Posted 15 June 2017 - 11:14 PM

Does your Microtech have any digital output pins ?

 

My understanding of TVIS is that it's opened after 3,000 rpm.

 

Is there an online link to the capabilities of this ECU that we can look at ?



#10 Tinman

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Posted 16 June 2017 - 05:02 PM

http://microtechefi....rt/user-manual/

 

Found the AuxRPM_ON output (white wire)

 

Just need to reconnect it to the TVIS connector.

I can set the RPM_ON that the ECU sends signal (meaning butterflies closed at say 500rpm ) and the RPM_OFF (butterflies opened at probably 3500rpm)



#11 Fodder

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Posted 16 June 2017 - 05:34 PM

Best bet to find the point is to do a dyno run with them closed, and another with it open.

 

Wherever RPM the lines cross at is where you want the change to happen.


updated%20beast-at-dusk_zpshfnalfwz.jpg
- 1990 JDM ST185 - TEIN HAs / CUSTOM DMS SPRINGS - WHITELINE REAR SWAYBAR - WHITELINE REAR STRUT BRACE - CT20B TURBO - 3" AUSSIE EXHAUST / DUMP PIPE - CHINA SPEC FMIC - NPC CLUTCH / LIGHTWEIGHT FLYWHEEL - GROUP A FRONT BAR - CUSTOM PEELING CLEARCOAT - 18" OX631 RIMS - TURBOTECH MANUAL BOOST CONTROLLER (@15PSI) -


#12 Tinman

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Posted 16 June 2017 - 08:52 PM

Thanks for the tip.
Denso 800cc injectors arrive tuesday, then new springs, then tuning mid July. :)



#13 Tinman

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Posted 22 June 2017 - 11:15 PM

Reconnected the TVIS and set to 3500rpm ... that did the treat.



#14 blakeg

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Posted 24 July 2017 - 04:14 PM

i think mine open at 3700 seemed the sweet spot when we were tuning it 


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#15 Tinman

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Posted 24 July 2017 - 09:36 PM

Thanks Blake






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