Aq 2D pump in the trunk. Where to mount the pressure sensor?
 

The Aquamist 2D pump is going in the trunk of my MX-5. From there the water lines will be going along the passenger side of the car to the front. Which is a better location for mounting the water pressure sensor - somewhere around the pump in the trunk, or in front of the car near the hi speed valve?

Since the pressure between the pump and the HSV should be the same thorughout the line it should not matter. The manifold itself has no valves just the pressure sensor. This said I would locate the manifold near the pump to simplify your wiring.

Actually the wiring is not a problem - two instead of just one wire going from the trunk to front is not that much different.

What would be cool if I mount the manifold/pressure sensor near the pump in the trunk is that I will have a short water line there which I can disconnect easy to prime the pump.

What I am afrad is - is it possible to have a pressure drop from the manifold/pressure sensor near the pump to the HSV which will be 6-7 feet of tubing away - in the engine bay - and this way the pressure sensor not reading the real water pressure at the HSV? How do you think opening the HSV changes the water pressure in the tubing near it and 6 feet back at the water pump?

I haven't seen or heard of any pressure problems at the hsv with a trunk mount. If it is a concern you could certainly mount the manifold closer to the hsv. A pressure accumultor would also help maintain the desired pressure in the system to decrease on possible sharp pressure drops on the hsv opening.

Mounting the pump and pressure switch in the trunk poses very few problems. If you add a 806-249 check valve after the pressure switch and an good sized accumulator up front the system will be very stable. I would use on large accumulator for each 200hp for maximum protection.

I thought the accumulator bolts to the manifold with the pressure switch? Does one large acumulator in front mean that I have to get a second manifold too?
Is the check valve mandatory for a trunk mounted pump? Can the water go back trough the pump when off?

The accumulator I use is not from Aquamist, it is about the size and shape of a soft ball. It can be "T"ed into the line with and 806-360 or 806-361. The check valve after the 806-201 manifold is not required it just seems to make things work better. The check valve eliminates the effect of flex in the long line to the front. Again the check valve is not required but experiance has proven it works better. If it helps I have been involved in more than 20 setups like this and and learned from each one of them.

Where did you get that ball shaped accumulator from? Any online link?
Can't I use just the aquamist one somehow infront?

You can use an Aquamist one up front. Just modify the end so that a 806-364 can be fitted.

ok. I will buy get these exta parts.
btw, you said check valve after the pressure switch - does "after" mean between the pressure switch and the HSV, or between the pressure switch and the pump?

Brad, so the setup above will work, but from your experience if the pump and tank are in the trunk, what do you think is the best setup (extra wiring is ok)? Is the perfect setup - both pressure switch and acumulator in front right next to the HSV & jet, and then pump and tank in the trunk. and check valve right there near the pump.

Or pressure switch, acumulator, check valve - all in front and just the pump and tank in the trunk?

Or pump, pressure switch and check valve in the trunk, and acumulator in front next to the hsv and jet?

Which one of the three works best from your experience? Or if some other order is suggested? The distance between the trunk and engine will be something like 6-7 feet of 4mm tubing