20V Quads on 16V Bigport > Vacuum Layout.

[GeeEss]

I've checked out the Forums but haven't really seen anything definitive regarding proper vac. layouts for this conversion so I thought I'd throw this out there to see what the Quads Gurus have to say. . . .

I would like peoples thoughts on my proposed layout and associated queries. I’ve attached a schematic I knocked up last night; top ½ is current TVIS vacuum layout and bottom ½ (rotate piucture 180) is what I think Quad vacuum layout should be. Dashed lines signify hidden detail; dotted lines mean I’m not sure if that section is correct.

if you look at OEM Toyota S/T vacuum layout, they have a lot of check valves, switch valves etc; which I figure have been put in to allow for many environmental scenarios; my point being that I have concerns about the reliability of a layout like this because of the system’s lack of checks & balances. . The cars will be more a weekend / track vehicle not a daily driver but I will be keeping P/S and A/C and want to be able to run it in cold / hot weather w/o it running like a pig..

1. What size vacuum hose should I be running? The T3 Adaptor and OEM Vacuum outlets are all 3mm Dia. but the T3 Vacuum Reservoir I also ordered was supplied with 6mm / 1/4" outlet unions. I take it I need to insert restrictors / reducers somewhere?

2. What do you I do with the vac inputs to the;
I. Idle up control
II. Airbox VSV
III. Throttle Opener
IV. Manifold VSV & Vacuum Surge Tank
V. Charcoal Canister

3. There is Gas Filter in the MAP Sensor vacuum line (and looking at my Blacktop, there is also a Gas Filter in its MAP sensor line; do I need to put one in?

4. What about the VSV’s & Vacuum Surge Tank in TVIS Vacuum Layout; are these components necessary for the proper functioning of this system?

5. My schematic shows the balance line (from the four T3 Adapter outlets) running to the end of the vacuum box; in-line with the outlet/line running to the Booster; is this OK or should I / can I also run the Balance line direct to one of the 6 in-line unions on the T3 Vacuum reservior?

6. Looking at the two water bypass pipes< see 2nd Photo >; do I just block off the outlets that run to the TVIS Plenum?

7. I will initially be using a stock S/T Plenum Cover. I noticed that It has two vacuum outlets as shown in the schematic (1) 3mm Dia & (2) 10mm Dia; do I / can I use these or do I have to block them off? (I don’t have access to a S/T but looking at my B/T the Power Steering Air Valve is driven by a runner from the 10mm Dia Plenum outlet and another from a small 3mm Dia. outlet on the Main Inlet casting).

8. Will I need to get the car re-tuned and/or re-route any vacuum lines if I want to run open intakes/trumpets on track days?

Cheers

[Animal15]

First of all i tnk u make things so complicated.
DO YOU WANT TO RUN ITBS ON 16V ? AM I RIGHT?

if yes the answer it's so easy...

4AGE 16v ITB Install - Coming Soon! - Drifting forum - Driftworks

read it, (if you already looked into that link and still having problem with set-up i think you should get professional help) then u will c how simple it is.

one more thing there are heaps of information about ITB set-up; Toymods is not the only forums you can get good information, try clu4ag, Hachiroku.com, AE86DC.

[GeeEss]

Thanks for pointing me to that thread but vacuum Layouts ARE complicated . . . IF you're trying to maintain the drive ability of the car. If you're not running either power-steering OR Air-Con and prepared to put up with crap idle then that's another matter. . .

I.e. Did you have an idle speed control in your System; and if so; did you just use the AE86 / AE92 Idle Up or did you need to replace this with an ISCV off a 20V? and if you did, how did you plumb the ISCV?

1. Teeing into 4x 3mm lines from T3 manifold to collector and running 4-to-1 lines back to ISCV inlet, with ISCV outlet line to 3mm Dia. union on S/T plenum box, OR
2. As above but running 4 lines from 4 OEM risers at top of TBs to ISCV inlet?

Responses welcome o/w I'm sure I'll figure it out myself. . .

PS: Harness is out getting mods+ECU o/w I'd just do running tests to suss this out. .

[Animal15]

ok man this what you have to do...

actually this is from Derek, when i asked same question form him this is his reply. ( if you search it on HR you will find this)

Run 4 vac lines into the eagle box, then one out to your fuel pressure regulator and one to your map sensor. Then of course the large fitting goes to your brake booster.

If you plan to run a ISCV (Idle Speed Control Valve) like the 20v engine does it gets tricky.

I set one up and plumbed it into the fitting on the opposite side of the eagle box. But due to the size of the pipe and opening it created to maintain the idle it removed too much vacuum from the system and the brake booster would no longer function.

No brakes is not fun.

You wouldn't think that it'd effect it, but the problem is the ISCV never shuts completely, it always stays open at the required amount to maintain idle even when you're not idling. That way it can 'catch' the revs when they begin to drop so you never stall.

If you want to use a ISCV then you'll have to make a setup similar to the standard 20v manifold where it takes the vac for the brake booster from a larger port behind throttle 1 & 4 so it gets a nice strong signal by tapping some holes into the T3 adapter yourself.

Then you can plumb the ISCV into the eagle box along with the FPR and MAP and it won't effect your brakes.

You can set the idle by opening up the idle screws or putting some tension on the throttle cable so the butterflies are always cracked open a tiny bit.

But its sooooo much nicer having a working ISCV.
If you've got aftermarket management its easy to setup, but even without being plugged into the ECU and setup it sits at 50% open and lets enough air in for a stable idle.



in my setup i didn't use ISCV, i haven't put it on dyno yet (fuel pump problem, still waiting replace one from sard) cause of that can't say anything abt how it gonna idle; but i know lot of ppl running ITBs without ISCV ; so don't worry about it that much.

one more thing you might find out ur throttle cable won't long enough (think it's jdm AE86), for that either you can use KE70 cable or you can send you cable to these guys http://www.speedscreen.com.au/
and make it longer.(cost me $55).

i saw ur other posts,
for CAS : there are few ppl selling it for nearly $250 in AUS but try club4ag i found one for $160 including postage.( if you buy a small-port Dizzy and fabricate it it might cost you same amount)
other thing y running 264 cams? y not go bit bigger 272 or 288? ur spending money on ECU + ITBs y not get max out of them. (with 272,288 still you can have fun on daily drive if you don't go on crazy lift.)
anyway it's my opinion, it's you car it's up to you man.

Hope this will help you.

[GeeEss]

Thanks; it did.

I was looking at my AE111 today and that's exactly what I was thinking of doing; tapping 2 Dia 6 holes in each side (vertical edge adjacent to TBs 1 & 4), attaching OEM S/T unions & running lines back to Booster @ S/T.

If you're thinking of ICSV; check out this link >>> Quad throttles + idle speed control - Toyota MR2 Message Board

Re. Cams; I agree with you. I was a bit conservative because in the beginning as I wasn't sure I was even going to run Quads, let alone an aftermarket EMS. Oh well; I'll set it up and see how it goes. There's a VG chance there'll be a set of 264 Tomei cams in the classifieds in 2-3 months. . .

PS: Regarding the Throttle Opener; I know people say you don't need it - and you obviously can't fit Fuel rail with it in there, but is that legit w.r.t. NC and CO emissions? I know that there are quite a few of these installations in road registered cars and can't imagine the owners are knowingly running at illegal set up.

Ed. Maybe I've just answered my own question; looked again at Bill Sherwood's section relevant to my Mods and he quotes; "You can pretty much forget about passing any emissions laws you may have in your country ... " Hmmm.

PS: Regarding Brake Booster vacuum; below excerpt was from this link in AE86 Forums;

4AGE 20v ITB vacuum instructions on Intecracing.com

Originally Posted by "Stain"

All you need is to feed the map sensor/fuel pressure regulator & brake booster from a vac source (behind the butterfly)
If ur going to use the ISCV (which is recommended) then its pretty clear where that connects.

things you don't need is the front facing brake booster line (on throttle 1) running it off the rear line on throttle 4 is enough

You don't need the throttle opener that sits in the middle. removing those two cleans it up a little.

Any ports that are 'before the butterfly' can be blocked or looped together.

lastly you'll need a charcoal canister installed to pass rwc, it can also be connected to any port behind a butterfly.