BY ENGINE/4age/20vquads

From AE86 Driving Club FAQ

Silver top 20v quad throttle bodies

Required items

• Silvertop 20v quads, complete if you can..
• Silvertop 20v TPS (hopefully you get it with the quads)
• Manifold adaptor eg – tecnotoytuning
• 3mm vac hose (2m max)
• 5mm vac hose (2m max)
• 3mm t pieces/elbows
• 5mm t pieces/elbows
• 5-6mm barb fittings
• inlet manifold gasket
• JDM AE86 throttle cable?
• Acess to a drill press
• Tap/die set
• Small bit of sheet ally (to make a throttle cable bracket)
• Hacksaw/file (to cut/shape the ally)
• Steel cable, cable clamp from a bike shop (for accel cable)

1. remove fuel rail/manifold/tvis (if fitted) etc from the head

2. the manifold adaptor you have.. I’m going to use the T3 one for an example, the billet CNC machined adaptor, is a stunning manifold, I almost didn’t want to put it on it looks soo good! use a drill press tap 4 holes in the bottom of the manifold, 1 in each runner, infront/behind the 3mm ones.. NOT beside.. you might not be able to get to the studs if you put them beside them.. then tap thread into the ally for the barbs you have chosen, nice and easy in ally.. this is to link together with the 5mm vac hose to act as a balance tube (much smoother idle) and as a very strong vac for the brake booster.

3. The T3 one comes with 4 3mm fittings in each runner, as they are all separate I ran 3mm vac hose with elbows/t pieces linking them all up, and facing the firewall.. I used this to run the Map sensor as pic above.

4. make a small right angle bracket with 2 holes that bolt into 2 of the throttle bodies.. I just cut a U shape and used the throttle cablenuts to tighten either side of it.. you’ll see the 2 holes I’m talking about.. there only small!

5. bolt the throttles to the manifold.. make sure all the vac hose is hooked up.. use zip ties as hose clamps

6. bolt the complete manifold on the head with the new gasket.

7. I used my JDM throttle cable, having a 4AGE in there you should have a similar length cable.. I just pulled it through under the pedal to the correct length as it was about 6 inches too long and used a grubscrew cable clamp from a bike shop as the new end on the pedal.. just leave the bit of cable hanging around there.. I did.. ha ha

8. that’s about it.. fine tune the length of the cable on the car..

9. bolt on your injectors and rail to the head.. connect up the fuel lines..

10. plug in your booster line and map line

11. i had to rewire my TPS in reverse so it would read properly like so

tps side > loom side brown > yellow Blue > red Red > Blue Yellow > brown

12. start her up.. see how she idles.. the individual idle screws I didn’t really touch.. nor the butterfly adjusment ones.. I just use throttle cable tension for idle speed..as long as you checked that they opened evenly on the bench.. adjust so they all move at the same time etc..

T3 manifold

Image:Quads.jpg 20v quds on 16v head

Notes

• The stock 4AGE ecu will run them ok, although it will run on the rich side, i didn't test an SAFC, but this would be a viable option inorder to lean the fuel out an bit, A aftermarket ecu will be ideal for the setup.

• The gasket between the quads and the manifold are stock 20v ones, the little metal ones and the inlet manifold gasket is a small port AE92 inlet manifold gasket.

• The water outlets in the trottle body have been blocked off , no need for them to be used.

• The cold start injector has been blocked it off with some white thread tape and a bolt in the fuel rail. Even in stock form these are not needed as it only kicks in when the motor is very very cold, so snowy areas would need them but thats about it.

thanks to mattyshop for the article.

black top 20v quad throttle bodies

Notes

• Black to quad throttle bodies are 45mm as apposed to the silver top ones which are 42mm.

• Adapters that have the quad's the right way up, not fun. So much interference with the fuel rail and tps on the water inlet so I had to use the Tvis plate, gutted and sealed to space it from the fuel rail, then used a FWD water inlet, lopped the sensor bit off and now it clears just. It has been tried to run TVIS with the conversion although because there the issue of interference and it could also cause turbulence in the manifold itself as it would make it alot smaller internal diameter.

• First set it up to run on the Standard ECU, does this fine. Runs a little rich on some cruising parameters, idles well and the idle isn't rich, at WOT its fuel mixture is spot on. Used an aftermarket ECU and its not as good as it needs tuning and this ecu supplies little features. Sometimes likes to idle, other times doesn't.

ECU

• The standard ecu was used at first. This runs good at cruising at 1500-3000rpm although once it starts climbing in the Rev range it can run a bit rich. Idle is abit rough but varies although I think this has more to do with tuning each quad to having the same air intake. Note: BT throttles and I think possibly ST ones, have an Idle adjustment. probably best to turn these all back till they are tight and turn them up in equal lengths.

MAP

• At the moment I have the map sensor reading of Cyl. 2 & 3. I've done a bit of research into this and found a guy in japan that was playing around with it alot, have all cyls coming into 1 vacumm pot then off to sensor, then grouped, then 2 lines into pot than into sensor, then some all 4 grouped then straight to the sensor and some gave rough idle and he found a nice setup but still changed it around to meet conditions I think. Also run your Air intake sensor. Unbolt this from your manifold, plug it in, and have it close near the throttles. Temps vary from 25-35degC. Run the rear water temp sensor aswell. Make sure your O2 sensor is connected etc.

TPS

• You will need to have a 100kw TPS plug as the 20v one only has 3 wires and 16v uses all 4. You then need to reverse the wiring as the 20v throttles run backwards. This plays a big role I found as well and keeping the engine running smooth and detects the throttle, assists the MAP sensor some what.

thanks to Matt-AE86 for most of the information.