Velocity stacks = more power, now which to get?

[4000GT]

4AGE 20v, some mods...

Made 169WHP with a full plenum with velocity stacks, and with the plenum removed and velocity stacks in place, it made 175WHP. So assuming the plenum has some kind of restriction in it somewhere, either the volume or length of intake pipe etc.

So just wondering what the best (non restrictive) velocity stack and filter solution might be? Pipercross foam? K&N system? Uni foam with springs? Just wondering about peoples experiences testing these if any data is out there!

[Uzelac]

tube sucking air from good location + airbox + velocity stacks = best solution for cars.

[4000GT]

Not on my application, the size of the box, because of size restrictions, doesnt work, I think its too close to the mouth of the stack.

[4000GT]

[rooty]

Maybe you did some miscalculations? What kind of stacks you got there? Length, opening etc. I always thought a dedicated box with stacks will perform better.

Maybe try positioning the filter closer to the outside for better suction? Looking at what you have right now, there is room for improvement

[4000GT]

I always that that as well... but I am the third person I know (the other was a modded and another a stock 20v using factory intake) that removed the plenum and gained HP.

The thing is you cant just try an unlimited combination unless you have several thousand dollars for dyno time. The guts of it is, it made 5WHP more with the plenum off (retaining the backing plate and velocity stacks).

[Uzelac]

Then split the engine bay, make large "airbox" on intake side of engine.
There is enough place in AE86 for it.

You will get your regular "noairbox" HP plus some extra for colder IAT.

[mech5107]

Don't forget that on a dyno, the hood is open and the stacks suck in clean and cold air.
On the road, the stacks will suck hot and dirty (oil mist, etc). So the real power will differ.

[jondee86]

[rooty]

mech5107 Wrote:Don't forget that on a dyno, the hood is open and the stacks suck in clean and cold air.
On the road, the stacks will suck hot and dirty (oil mist, etc). So the real power will differ.

Why would you do that on a dyno? That's what the blower is for. In real life, you drive without it?