Difference between stock Big/Little port intake manifold. 4AGE FWD.

[justin_es]

Good day fella's

Firstly i would just like to confirm how do i know what sized port intake manifold i have.

Im assuming small port.

My car is a stock 1990 SX Corolla with the 4AGE in it from factory.

Apart from the obvious more intake air flow what sort of benefits am i looking at fitting a big port over the stock small port.

Is it as simple as bolt and drive and a tune is not necessarily needed (obviously a tune to get maximum potential)

Or is it more complicated than that and a whole bunch of other things are needed for this to work and run properly.

Reason i ask is i found a tidy looking big port manifold cheap (advertised as off a front wheel drive 4AGE) and if this is just a simple cheap (small) upgrade i thought i may as well snatch it up and chuck it on

Cheers for any info in advanced guys.

[Hiro]

1990 = AE92 = smallport.

A bigport intake would not necessarily be an improvement for a smallport engine either. Just because it has the word "big" in it, doesn't mean that it is better. The bigport intake manifold had large ports for breathing up high and individual intake runners for each port, but that caused slow port air speed down low which impacted on torque. Toyota fixed this by fitting TVIS, a variable intake system which shut off air-flow to half the port runners which increased the air speed through the other ports, increasing torque. When they designed the smallport to replace the bigport, they got rid of TVIS and made all the intake runners smaller, which improved port air speed. Drive a stock bigport and smallport back-to-back and you'll agree that the smallport is by far the better motor. Besides, the port shapes are that different that even if you did bolt the manifold on, you'd most likely have sealing issues along with a massive step-change in the runners (in a place where you want things to be as smooth as possible).

Smallports breath better all through the rpm range, have higher compression, make more power and torque. The only thing you should consider installing from a bigport into a smallport are the longer-duration cams from an early 3-rib bigport.

[justin_es]

Excelent.

Thanks heaps mate.

Answered everything i need to know haha.

I think my goal for now is just a good intake and good exhaust. Thats it for power really.

Im going to focus on a slight brake upgrade, better tread, shocks and springs.

And looks wise im going to focus on getting all the little bits and bobs that look a little worse for wear replaced and or swapped for a better condition one.

any suggestions on where i can get an intake for these things.

Been looking everywhere?

[Hiro]

If you're only after mild gains then leave the intake manifold alone, focus on exhaust (even just a cat-back, the factory manifold isn't that bad, or get some 20V headers), CAI (not a pod just whacked on the end of a short pipe in the engine bay, a proper cold air feed). When you start chasing more power then another option is to go for quad-throttles off a 20V with an adaptor plate, but you'll have to run aftermarket engine management for that)

Brakes themselves are reasonably decent from factory too, just give it fresh pads and fluid and you should be fine. Decent set of lowering springs and short stroke shocks will do wonders for handling, as would good tyres (stay with the factory 14s or go up a size to 15s - 16s and up are mainly for looks).

Take a look at what some of the guys on Twincam.org.au have done to their SXs if you want some ideas

[justin_es]

Sorry by intake i meant CAI :-) my mistake.

Yeah i actually really like the factory look of this car even with the factory rims it has that mild sleeper effect but still looks nice and sporty without being boring.

Its been lowered not sure what by yet as i havent taken the rims off to look. Handles nice. Smooth ride no body roll so im sure its been done properly already but whether or not its good quality product is a different matter.

As for the CAI's i guess ill have to ask around twincam.org for where to start looking for those.

Cheers mate you have been a big help.

[Hiro]

Make sure you go to .org.au, not .org (that's the evil American-owned one :P), and have a good search through the forums and the members rides before asking a question, they can be a little intolerant of n00bs who post before searching (to be fair, the same couple of questions get asked A LOT)

[justin_es]

Im in and signed up.

Treading carefully to get off to a good start with the other members.

Searched through the first 5 pages here and on there i cannot find anything about CAI's for my car so just gonna have to ask the question i think.

[JROLLA.]

Hi mate, just wanted to share my past experience when it come to CAI.

I too own a 4AGE Smallport and found that the best CAI for it is the stock airbox with ducting going through the

bottom hole, into the guard.. Although before this is achieved, there is a big 'anti-drone' box in that near side guard that has to be removed.

I've tried using a pod filter instead of the airbox (still with a cold air feed) and i feel as if it doesn't compare to stock, the only gains

would have to be the 'Sound of Intake' lol. :) I hope this this helps, Good luck with you car