Ae86 itbs and forged pistons

[james123]

I can pick up a set off ae86 pistons and itbs cheap and I was wondering if they fit on a mr2 ok or do the itbs need a adaptor plate or something?

[LimeyMk1]

The ol' Corolla didn't come with ITBs, are they off a 20V engine that's been put in an 86 or is it a set that's been fitted to it's stock 4AGE?

Oh and if thepistons are stock ones they'll be the same as the ones you've got in your engine.

[james123]

Yer they are off a 20v head, he just said they were forged so are they the same as standard ones or not worth getting?

[Lauren]

Standard pistons are not forged, so forged would be an improvement. You need to know what compression the pistons are designed to run.

If you want to run ITB's then you'll need an adaptor for the inlet to fit the large port head. You will need a standalone ECU too to run ITB's. Starts getting expensive at that point(!).

[LimeyMk1]

Yer they are off a 20v head, he just said they were forged so are they the same as standard ones or not worth getting?

Not worth getting James. For one the 5 valve cut outs on the piston crown won't match up with the 4 valves in your cylinder head.

[james123]

Ok thanks for your advice I'll just go for the itbs then!
What ecu would you reccomend using? Also I'll be getting someone to install and set up the itbs... Any reconmendations in the north west england as I live in the isle of man!

[PW@Woodsport]

You're also wasting your time and a lot of money on the ITB's as well unless you're doing it purely for the sound.

[james123]

Well sound , throttle response and I'm not a fan off the tvis!

[PW@Woodsport]

T-vis is one of the best things about the 4a-ge in my opinion, and i honestly wouldn't ditch the stock setup unless there was some huge performance gain for the money.

You'll struggle with ITB's, they will become tiring, you will always be tinkering with them to get it running right, just a pain really and to top it off it costs a fortune to do.

I honestly wouldn't, but each to their own.

[elbon50]

Presumably James would need large capacity injectors & mapable ECU to make proper use of the ITBs Paul ?

Peter

[PW@Woodsport]

Not necessarily larger injectors, but definately a standalone, so you're looking at throwing at least £1500-£2000 into getting it set up right, plus mapping time.... for me there's no gain for the money, and the best result you could ever hope to expect is to get close to the actual 20v power output, which is what?

It will also be a constant pain in the ass. I'm not even sure a 20v ITB manifold fits on a 16v head, pretty sure i tried it once about 10 years ago.

I'd rather spend that on a SC engine or put it towards a 2zz-ge etc

[Lauren]

You're also wasting your time and a lot of money on the ITB's as well unless you're doing it purely for the sound.

Actually it's great for power and with cams and the like good gains can be made.

This is how you make 160bhp 4AGE's.

There are various standalone ECU's from Freedom ECUs (if you can find someone to program it), to Omex or Motec etc or megasquirt if you want to make your own. Depends upon your budget.

Might be a lot cheaper just to buy a 20v and drop it in.

Best bet is to look at all the AE86 forums as tuning the 4AGE is very popular and a lot of people run ITB's.

Check:

http://www.aeu86.org/forum/ae86

&

http://www.phpbber.com/phpbb/index.php? ... ghtsixcouk

&

http://www.club4ag.com/

[PW@Woodsport]

My point exactly, with cams and all the other supporting mods you're well over £2500, you'll need a better exhaust manifold (modified 20v one perhaps).

If you're happy throwing that much money into a 4a-ge for 30-40bhp go for it, the point i was making is that it will be a pain getting there and need constant tweeking, let alone what it will do for longevity/reliability.

Fitting the complete 20v engine/ECU would be a much better option, but still ultimately disappointing.

[LimeyMk1]

Paul does have a point re the setting up but it should be a shed load easier to balance up a straight set of ITBs than my ghetto two banks of 3. That and they will stay set up once you've got them there.

Re ECU you don't need anything fancy at all, just make sure it's got a decent ignition and fueling table. I'd probably go megasquirt as the 4AGE is very well supported and you should be able to get a map to get you started, someone probably already has one for a 4AGE with 20V ITBs on their forum.

[Lauren]

Come on Paul, let's not discourage people from playing with the 4AGE(!).

A 3SGTE might be the best engine in the world but it won't sound anywhere near as good as a 4AGE on throttle bodies!

If he can get the ITB's setup I see no reason why they won't remain setup. It's not like we're talking (crappy) carbs here.

I would say a custom exhaust manifold would be the way forward.

It all costs money, sure but there are lots of parts floating around second hand if you know where to look.

[craig]

Come on Paul, let's not discourage people from playing with the 4AGE(!).

A 3SGTE might be the best engine in the world but it won't sound anywhere near as good as a 4AGE on throttle bodies!

If he can get the ITB's setup I see no reason why they won't remain setup. It's not like we're talking (crappy) carbs here.

I would say a custom exhaust manifold would be the way forward.

It all costs money, sure but there are lots of parts floating around second hand if you know where to look.

Nah, 3S-GTE FTW! Cheaper, and more performance/gains for less dollar

[PW@Woodsport]

I just don't believe in misguiding someone into thinking what they are about to do will get them a good gain or not cost a lot, neither of those statements are true when it comes to tuning a 4a-ge, as we all know.

I never mentioned the 3s-gte which isn't even the engine i'd go for anyway.

I'm actually all for tuning the 4a, i just think that people thinking of doing so should go into it with their eyes wide open, they are a bottomless pit of expenditure without much gain and questionable longevity.

Sorry but that will always be my opinion as much as i love the 4a-ge.

[Lauren]

To be fair adding ITB's seems to result in a 20-25bhp gain, so that's what I'd call a good gain on an NA. This is just going by people's dyno outputs in the AE86 world.

Personally with an NA, I think a reliable, tractable 160bhp is possible. Obviously these things cost money, but that's the nature of messing about with engines and is all part of the fun. Maximum power isn't always what people are after.

[LimeyMk1]

Lost 20 brake on my ITBs but the torque curve isn't a curve it's a flat line. Only on first tune though.

James does need to be made aware that it will be pricey to do before going for it though.

My ITBs cost £850 for the bodies and inlet manifold, the ECU was £1k (but it is a new one which should run the VVTi once I've fettled the cams).

[Lauren]

To be fair, Chris, secondhand ITB's off a 20v (often complete with adaptor plates) can be had for a few hundred quid.

Of course it's going to be pricey, that's the nature of modifying engines.

IME it's better to be sure of exactly what you want power wise and do your research into costs with all the pros and cons before you start.