Intake location....

[TiTiKo]

Hi guys, talk about the position of your intake system in yours fsae cars.
How have been your experience about the location of the intake system (resctrictor), in the side of the car, in the high part of the main hoop or other location, many teams have theirs intake inlet in one side of the car, others near the main hoop. which advantages between one and other location? what about the inlet pressure?

[Maverik]

This topic gets into aero and fluids. Ideally any way you can increase the pressure in front of the restrictor (ie some sort of ram air effect) will result in a higher mass flow through the restrictor and into the engine up until the choking point. Look into what sort of pressures you could get having the intake inlet pointed perpendicular to the center line of the car and vertical (ideal ram style, short of further aero consideration). Taking an average of 35 mph as your air velocity and knowing your manifold vacuum you can figure out the pressures that drive the restrictor and figure out how influential any additional pressure can be.
I don't believe personally there is a big enough effect to make it a critical feature. I think packaging rates higher up on the list then a ram air effect. Now if you have the room it might not be a bad idea. We have not had any problems with our inlet mounted in almost any direction possible. The only other consideration I have heard of is if you put the inlet too close to the exhaust outlet, you might have a terrible time passing sound at comp.
Dan

[Alexandre D.]

I suppose it's more a air temp issue than ram air. The pressure gain is minimal(with Bernouilli at least).

Packaging is probably the main issue.

[TiTiKo]

thanks guys, so i know too that the pressure gain in minimal, why might i have a terrible time passing the sound test if we put the inlet near the exhaust outlet?

[Marshall Grice]

the inlet makes a lot of noise at the test rpm and when it is near the exhaust it is also near the sound meter.

Our inlet was near the exhaust this year and we had no problems at all passing noise. If you're a borderline case though the inlet placement may make a difference.