Map hose

[bosv]

Hi

I'm wondering about the length ot the map-sensor hose.
I have my ECU inside the car and the hose becomes pretty long.
Will this affect the readings , air is quite compressive .
I have used other fuel injection systems and they have the map-sensor placed near the intake manifold.

bosv
(from a snowy Sweden)

[DaveEFI]

My MS is situated on the bulkhead by the passenger's feet. False floor to protect it. So over 1 metre of vacuum hose.

[Dennis930]

My MAP sensor hose is probably 6 feet long. It runs from the throttle body, down under the transmission (rear engine) and into the cabin under the driver's seat. Just do not use squishy silicone hose. Use hard rubber vacuum hose. I have no issues with the MAP signal, the engine sees 17 PSI boost.

[Six_Shooter]

The signal will be slightly delayed over using an engine mounted MAP sensor, but not enough too be a huge concern.

As stated use a good gates house and you'll be fine.

I use 1/4" plastic tube on my two cars. This can be found at Home Depot in the plumbing section. On one car I used a reducer about 6" from the ECU top go to a softer vacuum hose. On the other car I realized the 1/4 tube fit right into the MAP sensor barb and use a quick coupler a few inches from the ECU to be able to remove the ECU without fear of breaking the MAP sensor.

If you're really concerned about the slight delay you can use an external (engine mounted) MAP sensor. This would allow for the possibility of using the internal MAP for real time baro updating.

[bosv]

Thanks for the answers.
I have about 3 feet hose
It is 4 mm good rubber hose
so I will not worry about this.

[billr]

I think this was discussed a while back, and the general consensus was that the pressure signal (near-zero flow) travels at the speed of sound; and is influenced only very slightly by the tubing diameter.