MAP sensors

[v8ian]

Im Running a N/A Toyota 4age on Jenvey Bike bodies, dan ST manifold and Emerald ECU, I would like to run a MAP sensor, the only port I have is a single 1/8th BSP/NPT threaded port on one runner, Im assuming thats what this is for? is it ok to run a MAP sensor of a single port?, Do suitable MAP sensors with 1/8th threads exist?, or can I run one remotely via a short piece of vacuum pipe and bolted onto the bulkhead, and.... whats the best one to run?.

[Graham]

no point in running a map sensor on a n/a engine using ITB's , basically the moment you open the throttle you have bugger all vacuum. TPS is a way better way to go, because you will actually be mapping to suit real world changes in airflow

[v8ian]

OK, Good, thats the way I had originally intended, I purchaced the pre wired base loom from emerald, and the wiring was already there for the Map Sensor, Thankyou Graham,

[Tpau]

I would like to nuance the discussion on MAP sensors and ITBs.
For my NA ITB pinto with 34mm throttle blades and the RL31 cam I get a better data spread indicating load from MAP than from TPS.
The vacuum at idle is really poor but the signal improves remarkably when the revs increase.

Over the winter I installed ITB with 38 mm butterflies and went out driving without plugging in my laptop (had a crash of the laptop) and I still get a really good driveability and the AFRs are still good running with speed density (MAP) only.

I think that as the butterfly size increases the MAP spread will be even less of an indication of load, and I also believe that increased overlap will reduce MAP as a load signal.
On an aside please note that our beloved Weber’s uses MAP for load sensing and that a race distributor usually only uses engine speed.
The Weber uses TPS for acceleration enrichment which can be done for most injection systems.

AlphaN does have its uses but if you are building a road car, don’t rule out speed density for load sensing.

/T

[stevieturbo]

Don't take a reading off a single runner, it'll pulse like mad.

You'd need to link them all together with a small tube and read from that. But as others said, largely pointless. You would normally use TPS as the main load parameter ( with RPM obviously ).

But for say a single throttle type setup, MAP might be easier than trying to fit a TPS sensor to a throttle blade that never had one, but TPS would still be preferred for a n/a setup, and MAP could be an addition.

But yes, it should be easy enough to find a NPT sensor https://jti.uk.com/product/map-sensors/

KA make them but there will be others available at varying prices

https://www.kasensors.com/en/product...rs-and-sensors

https://efi-parts.co.uk/product/aem-2-1-bar-map-sensor/

https://lowdoller-motorsports.com/co...ressure-sensor