MAP sensor hose length?

[mickeymarrows]

Does anyone have any thoughts on the length of the hose from engine to the MS MAP sensor?

I've tended to install with the shortest run I practically can, but what should be considered the maximum? Or should bore diameter be considered when going to an extended length?

To put this theoretical question into a pactical scenario I have an install where realistically the distance will be somewhere around 3 to 4 metres, around 3 times longer than I'm used to using. Rather than run small bore rubber hose for that distance I was considering using semi rigid nylon or PU tube with normal rubber vac hose joiners at each end. But then do I run 4mm OD nylon tube (2.5mm bore) or do I use a larger tube with 4mm bore?

Anybody got practical experience on this? maybe a longer length will help smooth spikes in MAP readings, or maybe it will 'dumb down' the response enough to risk lean conditions etc..

[Matt Cramer]

If you're using TPS AE, no enhanced acceleration enrichment, and just using it for the main fuel table, you could run an entire 50 foot spool of ordinary rubber MAP hose and not have a problem. Tuning settings that use the MAP sensor for transients do get some benefit from a shorter hose or even an intake mounted sensor. But the MAP signals travel at the speed of sound.

[jsmcortina]

i.e. 3ms per metre.

James