Custom 5SFE Intake Manifold Project Options

[doory100]

Got this off a 97 3sfe rav4. I'm going to customize a intake manifold body for it at my work(custom sheet metal shop). this is the starting process should look close to a beams intake when in done. Ill be using 0.100" 5052 aluminum for the body with a machined 0.250" T6 aluminum flange. I will most likely make 2 when i take the intake form my 95 GT off. So I'll have one for sale then. Any thoughts??

This post has been edited by doory100: Oct 6, 2014 - 7:40 PM

[Bitter]

the second link in my post with two links. the plenum volume is tiny to keep air velocity high at low RPM for best torque due to the head's low flow. a bigger plenum volume at low rpm with a low flowing head will cause a loss in power since the air will be stagnant and have to be literally sucked into the engine (meaning you end up with less air in the cylinder) instead of the ideal situation where air is a constantly moving column and the timing of the movement of the column of air hitting the valve has the valve opening before it rebounds off and looses it's energy and becomes a stationary mass of air. If you blow down a long pipe you can feel more air being pulled into pipe after your initial 'pulse' is sent down it, the whole column of air is now moving, the intake and runners do a similar think and that's the driving force behind exhaust scavenging. Those intakes on that racerx page are for forced induction which has less of an issue with intake tuning since the air being forced into the engine, it doesn't matter if you have the wrong plenum volume or runner length once the turbo is making boost, it's more just that all the cylinders are seeing an equal amount of air.

I'm willing to bet just putting a bigger plenum on the stock manifold runners will get you a loss in low RPM torque and a very very slight gain at higher RPM, but not enough to offset the loss. I'd love to see a back to back series of dyno's to compare and confirm my theory.