Designing a good NA intake manifold?

[spetz]

No really I just can not afford any more at the moment

So much so I owe money to the builder and I have an overmaxed credit card


I just want to design a really good manifold that gains power now and will be good too once cams go in

Maybe a larger single TB mounted in the middle of the plenum is the way?
I don't know if there is space. The engine is also a V6

[saxman]

with a V6, you could probably get a way with running two throttle bodies, on two intake manifolds. You do not want two throttle bodies going into the same plenum... going to cause way too much turbulence.

[BlitZ]

i read an article on hyundai excel tuning ahahahaha

they have like aftermarket performance manifolds with dual throttles on each side.. it supposidly makes power.. but its a hyundai..

[spetz]

Saxman, How would I tune this though with just a piggyback?

At this stage I think I will leave the intake manifold as is due to money constraints (just found out I need to pay for some custom rod bolts). I will run the 5mm oversize TB I already have on it, and at a later stage maybe once I get a better ECU I will upgrade the intake manifold

Assuming I have a full standalone ECU, what kind of gains will a ITB setup give me?

[saxman]

itb set up isn't going to make huge peak hp gains... what you get is huge midrange gains, amazing throttle response, etc... definetely worth it, especially if you have a well flowing head, higher compression, etc



what motor is this work occuring on?

[spetz]

It's on a 6A12 MIVEC from an FTO but in a lancer 2 door body

What will ITB effect though?
MIVEC kick in point? Top end power?
What happens with cams?
How is idle???

[TODA AU]

What are some key aspects to a good NA intake manifold?

At this stage, I am thinking slightly bigger runners, about 4-5cm shorter than factory.
Bigger plenum with two throttle bodies on each side of the plenum (48mm each)

What are ram tubes? What do they do exactly?

Anything else to look out for/ask to make?

There is no "pot of gold" in horsepower here.
Combination is everything.
There can be power to be made with different manifolds but is has to be tuned into it.
If the combination isn't right, you'll just go backwards.

Regarding ram tubes.
In quad throttle arrangements, the ram tube offers two benefits.
A) It's an ideal design that maintains laminar air flow so that the air volume entering is maximised with minimum turbulence.
b) The lengths are important. This is for shock wave tuning.
If you want to know more about this, check out "Helmholtz Resonance".
It's the wave properties of sound in closed & open pipes.
In layman’s terms, the idea is to catch the positive sound wave to stuff more into the cylinder. Further you want that to occur through the rev range. That is you want to catch the 1st, 2nd, 3rd etc harmonic.
Get it right & you get something for nothing. Get in wrong & the engine falls flat. Tuning cars with quads can be creepy. Things such as "stand off" can occur where a cloud of fuel will hover over the trumpet at full noise. Changes in injection timing will see it devoured by the engine. The cloud fuel is held stationary in the air but the sound waves.

As a general rule of thumb,
Short runners are for top end, long runners are for low end.
Plenums also resonate.
Large plenums for low end, small plenums for top end.