# Home made ram air



## veesix (Jul 18, 2004)

I connected a pressure gauge to the intake manifold (inside filter) and reved it up to 3,500rpm. I saw absolutely no movement of the needle (positive or negative). 

The real change in air pressure must be further along (in the throttle body). 

I am planning to cob up some sort of ram air system in the hope that it will improve performance at highway speeds. 

Anyone have some experience with this? 

88 SE-V6 PU with electric fuel injection.


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## se-r-57 (May 1, 2002)

Ya don't really want to force air into a MAF sensor. It will just mess up the voltage readings to the ECU.


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## chimmike (Oct 17, 2002)

"home made ram air" doesn't constitute "forced induction"

this is getting moved to NA.


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## Zen31ZR (Mar 24, 2004)

se-r-57 said:


> Ya don't really want to force air into a MAF sensor. It will just mess up the voltage readings to the ECU.


 Umm, how do you propose that ram air works then?  Seems to work that way on the WS6......


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## Zen31ZR (Mar 24, 2004)

veesix said:


> I connected a pressure gauge to the intake manifold (inside filter) and reved it up to 3,500rpm. I saw absolutely no movement of the needle (positive or negative).
> 
> The real change in air pressure must be further along (in the throttle body).
> 
> ...


 Ram air obviously does not work when you are sitting still revving the engine.  Ram air is only effective above around 40 mph.


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## veesix (Jul 18, 2004)

I know basically how ram air works. 

I was expecting to see a small amount of negative pressure at 3,500rpm. This measurement came from a vacuum fitting at the bottom on the air cleaner housing, between the filter and the injectors (too far from the throttle body to read a pressure change). 

Trying to get some "before" pressure numbers. If I increase pressure at the throttle body to 4psi (for example) at highway speed with the ram, I wanted to know if I started with -1, -2, or 0 psi before the project. 

If this thing has a MAF I have not seen it.


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## Zen31ZR (Mar 24, 2004)

veesix said:


> I know basically how ram air works.
> 
> I was expecting to see a small amount of negative pressure at 3,500rpm. This measurement came from a vacuum fitting at the bottom on the air cleaner housing, between the filter and the injectors (too far from the throttle body to read a pressure change).
> 
> ...


 The engine will need to be under load to see any change in airflow like what you are looking for. Kinda like how most turbos won't spool up past a couple psi if the engine is not under load. Simply revving it won't give you what you are looking for.


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## Rathi134 (Jul 11, 2003)

[email protected] said:


> Umm, how do you propose that ram air works then?  Seems to work that way on the WS6......



last time i checked we werent driving trans ams or im pretty sure there arent any v8 engines in sentras. i would heed se-r57s advice.......


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## Murph (Aug 8, 2002)

I would be very interested in the numbers you get when this works out for you. I really dont understand how you have it hooked up but it SHOULD be hooked up past your throttle body and I think it should read approx -25psi at idle and maybe -3psi at WOT depending on your intake, but I could be way wrong about everything.

May not be a forced induction theme, but _if_ you can decrease the intake vaccuum at WOT then you will be netting gains.


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