ITBs on to 16 valve head

[Brendon]

Hey guys,

I have a bigport and I have a set of ST quads. I would really like to make these work together. I have done some searching and looked extensively through this section but haven't found much info. I know it has obviously been done before, but has anyone got/seen a how to guide? What do I need, how do I do it etc? I know I need an adapter, and I believe the T3 one is the only real option, what else? I have a Motec M4 and MAP sensor, and my car doesn't run power assisted brakes, so should have no problem getting a decent vacuum signal to the MAP. I do not wish to run an airbox.

Can anyone help?

Regards,
Bren

[oldeskewltoy]

ITBs have a different character then a manifold equipped engine, the vacuum tends to be peaky and tough to use for a MAP managed engine. ITBs often run best on a TPS signal, or some form of mixed operation.

[jondee86]

Fundamentally, the difficulty with running MAP on quads is that the MAP signal hits atmospheric after the throttles are around 30+/-% open. This means that while the MAP signal is very good for tuning the bottom end, it is more or less useless for tuning the top end of a fuel map. TPS is ideal for tuning the top end of the map, but is not so good at small throttle openings.

So a TPS/MAP blended tune will use MAP for small throttle openings and TPS for large throttle openings. Your ECU should be able to handle that If not, then a TPS only tune would be the next best option.

And a good MAP signal can be obtained by sampling all four inlet runners and averaging the signal with a small vacuum collector manifold.

Cheers... jondee86

[Brendon]

Yeah, that's all good. My tuner can sort that out, and the Motec can do that stuff. Thanks for the input, though.

I just need a bit of a how to on how to assemble it, and what stuff is needed.

Cheers!

[trdee]

there is definitely a write up on here. the toymods search function is fucked though so instead i suggest going to google and searching 4age ITB dnegative

edit - I went and did it for you: http://www.toymods.org.au/forums/thr...-AW11-4AGE-16v

[Brendon]

Thanks mate. I am guessing there won't be too many differences between FWD and RWD?

[trdee]

a few differences with water outlets n stuff but nothing terribly difficult

[jondee86]

There are basically two types of inlet manifolds. The short T3 type that sometimes needs a little "massaging" to get it fitting properly, and the better flowing and longer "custom built" tube manifolds. Here is a pic of a T3 manifold on a RWD engine (right click > view image for bigger)...



Note that the T3 manifold mounts the ITB's upsidedown compared to the OEM mounting. This gets around the TPS hitting the water neck problem. It also means you can use your AE86 throttle cable.



The tube manifold usually mounts the ITB's right way up, as the runners can be made long enough to have the TPS clear the water neck. However the throttle cable needs to go forward and then come back to the linkage, so you will need a longer throttle cable from and earlier K-series Corolla. This type of manifold will clear the water pipes along the side of the block, so no modifications required there.

The other thing to consider is using a 20V ISCV to get a nice temperature and load compensated idle. Your ECU should be able to drive this OK.

Cheers... jondee86

[Brendon]

Cheers. As yet I don't have a manifold for it, but, unless something comes up for sale soon, I'll probably end up with a T3 one. And so it just uses the standard bigport fuel rail, 20v FPR or modified bigport one, and a few other little mods? Doesn't seem toooo difficult.

I don't have an AE86, and have no idea what throttle cable I have. Judging by your pic though, I'll have plenty of available length with the one that is there. Does it need to be shortened?

In regards to the ISCV, the tuner and I have already discussed him fitting an idle control valve to it when he rewires the car, which will (hopefully) coincide with putting the quads on. I'll have a look for a 20v one, but he'll just use whatever he can get if I don't supply one.

The car in question is a Westfield Lotus 7 replica.

[Brendon]

Oh yeah, and if anyone knows of a manifold for sale, please let me know! I'll get a new one if need be, but happy to buy second hand and save a bit of money.

[M.J.H]

The t3 is the go
Can't remember what TPS I used but had to mod one
Don't use a ISCV on mine just turned all the adjusting screws around and balanced all the throttles with a carb balancer. Idles fine but can't touch the throttle for the first minute on cold start till it gets a bit of heat into it
STD big port fuel rail and bigger injectors
Runs great with a set of cams

This is on a Farrell Clubman

[trdee]

The car in question is a Westfield Lotus 7 replica.

Is this Bren off PF by any chance?

[Brendon]

Thanks for the info M.J.H.

trdee, it is

[Brendon]

And just as a bit of info, I contacted MRP last night to see if they do an adapter manifold. They don't have anything ont he shelf or listed on the website, but they can make them for $350. These are welded ones, not billet. With dollar how it is now, the US$295 T3 billet one is $400 plus postage, where as the NZ$350 MRP welded one is $310 plus postage. So if one that is already in Aust doesn't show up soon, I'll give my money to MRP and get one of theirs.

[trdee]

baz does good stuff. i reckon i've put his kids through school with all the shit i've bought off him lol