Tvis, Turbo, 4efte... (gt starlet engine)... a cozmo post ;)

[CozmoNz]

Haha, yes, a cozmo post.

im curious....

my gfs 5efhe has what is known as Acustic (spelling) induction control system.

i checked what this is... on the american forum's - Paseopimp, (a paseo is a cynos btw), and it turns out its... *Dual runners per cylinder, with a butterfly in one of each runner per cylinder*... ok... thats what tvis is...

turns out it does the same thing, 5,000rpm it *turns on* or opens the butterfly's which IS easier heard from her car @ that rpm....

ok so it has tvis (or something very much like it), let me go back... why was tvis put in? to create low end torque in *high revving* engines... correct? since a long runner create's more torque down low and a wider shorter runner creates more high end power... (or something along those lines).. tvis was put in.. thus low end torque, PLUS high end power.

Now anyway, we are planning a 4efte swap (1.3L turbocharged engine from gt starlet)...

after searching the paseo forums, it turns out the 5efhe manifold (tvis.. if you will), bolts on... ok shell be a 4efte, 1.3L turbo with tvis...

now i figured, hey... you want low end torque BEFORE boost, and NOT at 5,000rpm... so how about a switch / solinoid?

ok, stick a solinoid in to detect anything over 0.5-1psi etc (my old subaru leone had one), and when it does, run a circut through it, to be earthed to the manifold. thus... 0.5-1psi comes on, and tvis comes on...

so, when not using boost (vac only) then you have a single runner, and when you plant it / use boost, tvis butterfly's open, causing a larger entrance for boost / flow.

sounds good... cant hurt any however (from what i see).... slightly better low end torque BEFORE boost. and if the manifold (with all extra butterfly's open) is the same size, roughly the same output up high... so how is this bad?

it may become possible to get even better mililage (spelling... its late ok?) from a 1.3 turbo! which... cant hurt also .

my questions are this.

A) while changing gear, slowly but continiously boosting. eg, getting up to 100kph on the motorway without giving it TOOO much shit, or going up hills etc. one would want the tvis to stay on, during gear change also... how is this possible if a solinoid will cut the circuit when it detects vac?

B) can anyone think of any possible down points, other than pissing around setting up switches and such to use tvis / control it from in cabin?

and in short, is this a good idea, or just a crack pot idea?

im quite seirous, so this isnt another bla bla thread, im quite interested in the outcome of this one. So constructive posts only please. if you choose not to obey these rules (much like i do not..) dont then life goes on. ^_^ so... *looks at fivebob*... what are the downfalls of a turbo tvis setup?

[thaphatty]

well on bluetops turbos they usally take the tvis out to try and get rid of the restriction dont they?

sounds like the mean time waster to me.

do it anyway and find out if it will work or not for yourself

[Ae92typeX]

I think quite a few of the turbo 4age guys put the tvis back in, without any problems. My 1ggte has tvis also. Im sure toyota wouldnt have put it in if it was a bad restriction.

[Stu-]

Give QikStarlie on this or the StarletCentral website a PM as he's know all about the ACIS induction and has some pretty awesome ideas for running it in a turbo application.

My spare EP71 has a 5efhe conversion and had up till recently just run the normal 4efte inlet manifold. Recently thou, Qikstarlie (while borrowing the car) swapped the 5efhe ACIS manifold on and found a fair gain of torque down low. We don't have quite the right solinoid setup to controll the ACIS so its more of a off/on affair rather than a smooth transition between the two but its goes a fair bit better and skins up un provoked in low gears now.

[CozmoNz]

Give QikStarlie on this or the StarletCentral website a PM as he's know all about the ACIS induction and has some pretty awesome ideas for running it in a turbo application.

My spare EP71 has a 5efhe conversion and had up till recently just run the normal 4efte inlet manifold. Recently thou, Qikstarlie (while borrowing the car) swapped the 5efhe ACIS manifold on and found a fair gain of torque down low. We don't have quite the right solinoid setup to controll the ACIS so its more of a off/on affair rather than a smooth transition between the two but its goes a fair bit better and skins up un provoked in low gears now.

id have to agree, it does have a bit of torque down low (on the account that its a 1.5 lol).

yeh, im wondering about controlling it myself also... does it simply run on a 12v current? (im told its switches via a 12v current to the controler, rather than a vacumm (spelling) setup).

in which a control from a solinoid would be a good idea. on the account of... when you hit boost, you get a jar in the seat feeling, so an extra one (acis kicking in) wont hurt any .

ill defentially give it a go now . Cheers guys

[kingcorolla]

so, when not using boost (vac only) then you have a single runner, and when you plant it / use boost, tvis butterfly's open, causing a larger entrance for boost / flow.

it would have to work a different way, as there is no point in shutting an intake runner during vaccum. there is no vaccuum at WOT.

one option, you could wire up a low-pressure switch, hooked to the manifold, to open curcuit the tvis curcuit when a desired pressure is reached. The one problem with this, is that the tvis will open sooner in taller gears which could be impracticle.

another option, Jaycar i think sells contollers to trigger such things as tvis, and include variable rpm control so you can adjust rpm which tvis will trigger, then you could have a wee play with that till you satisfyed. But you might have to change the rpm trigger with different gears.

is the ACIS solenoid operated?? anyone know the ecu trigger point, and if anything varys the trigger point?

[CozmoNz]

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[CozmoNz]

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[CozmoNz]

i think you misunderstood what i said, or at least in the way i ment to say it ^_^.

i mean, when you are no on boost... the acis butterfly stays shut... when you put your foot down / put load on the engine, acis butterfly's open.

now, how they open and such has nothing to do with no vac @ boost, since from what i understand, they are controled via electrmatristity... well, from what ive gathered (im looking into this).

maybe someone on here knows (or you!) is ACIS controled by Vac... or is it controled via the ecu? (like vvt sort of thing... ecu sends 12v supply). in which case. i can set it up so that a 12v suppply runs to a boost controlled solinoid... and when that boost controled solinoid comes ON boost, it earths the circut to the positive of the acis switch.

therefore, @1psi, the circut becomes live, and acis turns on... come off boost again, it turns the circut off, and acis naturally goes back to *off* position...

get it? well, thats if its controled by a 12v supply X_X.

if i can do that then i can run it through a setup of 2 switches, the first switching between *automatic* mode, and another to *manual mode*.... when switched in manual mode the second switch is used, with *on* and *off*....

ill try (TRY) draw a wiring diagram...



now... as you can see... well, that actually explains itself ^_^.

i HOPE that makes sense, my smarts with the stuff that sparks isnt excactly ace...

obviously a few fuses and stuff need to be chucked in too, but is anything else wrong with that?

[QikStarlie]

just put a turbo actuator in place of the acis one... a stock ct9 actuator should open the butterflys at about 4-5 psi, easy. 1psi will be to low


oh and do the 4efte swap now. and sell me the 5efhe flywheel

[RedMist]

I had thought that AICS was a helmholtz device. It alters the intake runner length correct? If so then the helmholtz calcs will be well off as the speed of the pressure waves under boost will be totally different.

Correct me if I'm wrong as I know FA about boost, but doesn't Helmholtz matter little in a boosted environment?

If so then your just debating a different method for reducing HP.

[vvega]

tvis helps port speed its not for runner tuning

v

[RedMist]

He's not talking about TVIS, its a 5efhe manifold with ACIS.

[CozmoNz]

its the same thing....

well DOES the same thing...

an extra butterfly in a seperate runner... long thin runner = low down torque, short stubby open runner = high end. its a way of TRYING to gain both..


how it does it is different.... this is from what ive gathered aboutt he 2 anyhow...

a turbo actuator... ok, they open at stock boost unless the spring is changed right.

remember, im doing this for low down torque around town driving, i dont want to be sitting on 0vac / 0boost all day... i like my -15vac driving styz .

it would increase torque UNTIL they opeend those runners, when the torque from the boost would take over. But say if you wanted to goto the diary, never use boost, and youll get there much quicker than say a gt starlet without the intake manifold setup...


this is NOT for high end power. If it was, id just have a custom manifold made with MASSIVE runners and port the intake something chronic... but we still want good fuel economy and low down torque . and whats this Helmholtz?

and the swap will be done as soon as i get all the parts etc.

any chance someone has a gt starlet wiring harness, the HOLE thing... not all cut up. i can get everything i need apart from the harness .

[RedMist]

TVIS and ACIS are NOT the same thing.

TVIS is an attempt to get greater velocity into the port by effectively shutting off half the port. Smaller diameter port = greater velocity, greater velocity = fuel in suspension in lower RPM, which in turn means more HP at lower RPM.

ACIS is an attempt at inlet tuning length. Open ACIS and the inlet track is much longer. Longer inlet generally equals more mid to low end power using Helmholtz theroy. ACIS closes, shorter inlet track, more up end power. NOTE HOWEVER THAT THE HELMHOLTZ CALCULATIONS ARE CYLINDER VOLUME AND PRESSURE SENSITIVE. IE place a helmholtz resonator designed for one engine on a different cc engine and it WON'T work at the designed RPM. Pressureize an engine and again the helmholtz resonance changes so it WON'T WORK.

TVIS and ACIS may have the same outcome, that of generating more low end torque. However they use different principal. TVIS will probably work in a compressed situation, however ACIS will NOT unless you change the lengths involved.

Saying TVIS and ACIS is the same thing is like saying VVT and VTEC are the same.

In regards to Helmholtz, its used to pack the cylinder closer to full or over full by using the spring effect inherant in air. Obviously by changing the amount of air your packing into a cylinder you'll change the helmholtz length and likewise if you change the pressure the spring rate of the air will also change.

http://www.users.bigpond.com/pgscott/re ... oustic.htm

[QikStarlie]

hmm acis..
the long narrow runner by themselfs are only good till around 5k and it will hit a brick wall, and starting to feel flat over 4.5k. the 2ndry short runners come into effect at around 5.5k.. the best switching point if you were doing it by a rpm switch would probably be around 4K, maybe slightly higher, to get the smoothest switching point. you would need to play around with the switch rpm to get best results. you could setup a shiftlight and use it as the trigger.

using the acis on a 4efte switch via a turbo actuator, this would probably come in too soon while using the standard ct9 since it makes full boost just over 3k. altho it may not matter so much when you are on boost.


acis manifold also have a bigger plenum volume. and a nice radius on the runner enteries. along with the shorter 2ndry runners you should gain a bit of top end power,, as well as low end

yet to try it on a turbo car myself. (some one buy me a turbo and i will try it on ep71-4agte's car ) but has been done a few times, havent seen any dyno results yet..

[CozmoNz]

TVIS and ACIS are NOT the same thing.

TVIS is an attempt to get greater velocity into the port by effectively shutting off half the port. Smaller diameter port = greater velocity, greater velocity = fuel in suspension in lower RPM, which in turn means more HP at lower RPM.

ACIS is an attempt at inlet tuning length. Open ACIS and the inlet track is much longer. Longer inlet generally equals more mid to low end power using Helmholtz theroy. ACIS closes, shorter inlet track, more up end power. NOTE HOWEVER THAT THE HELMHOLTZ CALCULATIONS ARE CYLINDER VOLUME AND PRESSURE SENSITIVE. IE place a helmholtz resonator designed for one engine on a different cc engine and it WON'T work at the designed RPM. Pressureize an engine and again the helmholtz resonance changes so it WON'T WORK.

TVIS and ACIS may have the same outcome, that of generating more low end torque. However they use different principal. TVIS will probably work in a compressed situation, however ACIS will NOT unless you change the lengths involved.

Saying TVIS and ACIS is the same thing is like saying VVT and VTEC are the same.

In regards to Helmholtz, its used to pack the cylinder closer to full or over full by using the spring effect inherant in air. Obviously by changing the amount of air your packing into a cylinder you'll change the helmholtz length and likewise if you change the pressure the spring rate of the air will also change.

http://www.users.bigpond.com/pgscott/re ... oustic.htm

hmmm... you seem to know your biscuits... quite a bit really . so ill take what your saying into account.

i still want to give it a go though.

um, had a look at the gfs manifold today... looks like this:



i like drawing pictures ^_^, i know thats very rough, but it shows that there are 2 different runners... one behind the other... unlike tvis which is one large runner, with a splitter down the middle. the result is acis with 2x the amount of flow possibilitys....

think about it, what happens when boost is put into a sealed enviroment? it will try to escape / head to any direction it can... bar the fact that the valves are opening / closing, alowing it to move where we want it to.. but when boost comes on, if that butterfly opens, 2x the flow can be obtained...

this MUST lead to more power... even if it does NOT work at low rpm... and its completely standard, 2x the flow @ the high end is still worth this. i cannot, well, DO NOT, understand why this wil not flow MORE than a standard 4efte manifold...

call me dense... but a bigger runner = more flow... so 2 runners, with one being virable, will lead to the possibility of having higher flow in the high end, if the virable one is completely open. right?

[pc]

Sounds good to me. Wouldn't you want your switching method to take into account RPM and boost?
i.e if RPM above 4000 OR boost above 5psi then open butterflies. With controllers in the cabin you could play with settings till it feels right, or use dyno if feeling rich.

[CozmoNz]

Sounds good to me. Wouldn't you want your switching method to take into account RPM and boost?
i.e if RPM above 4000 OR boost above 5psi then open butterflies. With controllers in the cabin you could play with settings till it feels right, or use dyno if feeling rich.

Well, since when do you ever pass 4k rpm WITHOUT using full throttle? or at least enough for 5psi boost to come on.

that may mean id need a more expensive controller rather than boost .

but yeh, ill think about it.....

[QikStarlie]