4AGE throttle body conversion

[Bunky Twincam]

Hello all,

I am wanting to do a throttle body conversion on my 4AGE, it is fitted into a Westfield and runs fine.

I am after some advice on pros and cons of using the black top throttle bodies and what else I need to make it work, or do I used after market throttle bodies and what is needed to make it work.

Cheers

[Matt]

For a stock engine the biggest pro is the sound the quad throttles make , pure induction noise is sex. For a modified engine it'll get more air in as the quads can flow better. Blacktop throttles are usually big enough for most applications and are easy to get + the velocity stacks are also readily available.

The 20v TPS spins in the opposite direction to the 16v so you will need to swap the wiring around for the signal so it gives the correct reading.

Adapter plates are also readily available for the blacktop throttles, and you'll need a form of vacume canister. It's a fair amount of effort to get the quads on there and you'll need to retune the ECU as well.

[rallysprinter]

I've recently finished replacing the factory inlet manifold with quad throttle bodies on my 4AGE powered AE86. My 4AGE already has 288 degree cams so the inlet manifold may have been a restriction in my case.

I had some efi hardware throttle bodies that I wanted to use rather that 20v.

Advantages:
1. The noise.
2. Increased torque all the way through the rev range and therefore "power" comes on earlier. Still same max HP as with factory manifold.

Changes implemented:
1. Had trouble clearing the front water inlet so had to use 20mm spacer between the weber manifold and the head.
2. Replaced the ECU and rewired (was Microtech running MAP and replaced with Haltech with TPS/MAP combo).
3. Every 4AGE weber manifold I tried didn't perfectly match up the throttle shafts of the EFI Hardware throttle bodies and initially had trouble with balancing the throttles.
4. Setup additional return springs.
5. Hooked up to a vacuum canister to get a MAP signal for the fuel rail and ECU.
5. Running long trumpets (weber) to match the required power rev range.

Hope that helps.