Ram Air set-up on a 95 STS

Trickstr · #1 (**permalink**) 05-25-09, 05:22 AM

I am finishing fabrication on a custom ram air set up for my 95 STS. I was wondering every ones opinion on the location of the air temp sensor. In other cars (mostly imports) that I bought cold air kits or ram air kits for the sensor was moved farther away from the TB. Should I do the same here and rewire the sensor close to the inlet under the car at the scoop so that the car is reading colder air then what going into TB or should I just leave it near the TB? I know colder air temp will cause the car to change the mixture some. Any ideas?

Patrick
95 STS
98 Sentra SR20DET
05 Yamaha FZ-1

submariner409 · #2 (**permalink**) 05-25-09, 10:44 AM

Patrick, the whole air intake idea has been beat to death in here so many times that I'm surprised you didn't run across volumes on the subject. Search.

Since the car already has a perfectly adequate cold air intake which handles more airflow than the engine needs at WOT, you gain essentially nothing except the noise bling.

You would have been ahead of the game if you had simply changed to a WIX or NAPA Gold air filter (more surface area) and let it go at that. Install the IAT sensor BEFORE the MAF (don't fool with the MAF) not far from the original location and make sure it isn't loose in the hole.

Trickstr · #3 (**permalink**) 05-25-09, 08:26 PM

My car does not have a MAF, its a 95. I spent hours going through the threads on CAI. The biggest problem I saw was location of incoming air. The stock system draws air down in the fender well away from the hot motor. If using a short ram set-up all you would be pulling in would be warm air from the engine bay. A good cold air set up places the filter down in the fender. I am going one step further, my filter is in the fender well with a large scoop force feeding cool air from under the bumper. I run the same set up on my old Sentra and made 8hp improvement at the wheels, over 10% increase in power. I had been running a short ram intake on the car which I actually lost power with. Also I does not look COOL but if you insulate the air tube it keeps the air cool. Also if you step down the tube size from intake to TB i can cause Venturi affect helping to draw in more air, although you never will never gain much more pressure then the regular atmospheric pressure.

I guess my real question is will the car benefit from spoofing the car to think the air going in is colder then it really is?

**Ranger** · #4 (**permalink**) 05-25-09, 09:31 PM

Quote:

I guess my real question is will the car benefit from spoofing the car to think the air going in is colder then it really is?

For cars with MAF sensors, they make MAF's that do this and the answer is no.

submariner409 · #5 (**permalink**) 05-26-09, 04:50 PM

Your STS has a MAF bolted directly to the throttlebody, which is all heated by engine coolant passages to 200 degrees nominal. The IAT (Intake Air) sensor is the small clip-in thermocouple at the airbox.

In answer to your "cooler air" question - NO. Lots of us been there, done that. Take a look in my album (the little icon under my login) and find the pic of the stock and JET-modified MAF for my car. The JET MAF actually cost me power and gas mileage at all times, including two 1,700 mile round trips to Florida in which I ran one MAF down, the other back. Your venturi theory is flawed: go back to physics class. (A smaller diameter tube does not a venturi make. Don't forget that, on the immediate downstream side of the venturi restriction there is a sudden pressure drop, which is why the principle is used in small aircraft to create a vacuum source for gyro instrument power.)

Your MAF: (DON'T pull that honeycomb airflow straightener out of it - Pandora's Box. You're not fooling with a ricer now.)

Trickstr · #6 (**permalink**) 05-27-09, 10:54 PM

My car is a 95, pretty sure I do not have MAF sensor, just air temp with the OBDI., not sure if that makes a difference.
Air tube size, either exhaust or intake was explained to me once with a simple experiment. Take a piece of paper on a table and try to blow it off with a straw, then try the same thing with a paper towel tube, notice the difference. Takes a lot more effort with the paper towel tube but it is easier to breath out. Now take the paper towel tube and stick a funnel at the end and try again... easy to exhaust out the air and effective at the same time.

submariner409 · #7 (**permalink**) 05-28-09, 11:38 AM

..................hmmmmmmmmmm.....maybe the separate MAF came in 96 with the emissions change and turnover to OBD-II. In that case you have a MAP sensor, but that has no restrictions to airflow........

Google "venturi effect" to see if that applies to placing a restriction in the intake piping of an engine which is creating a vacuum as opposed to placing a restriction in a pressure line.