I'm looking for alternatives to fitting adapter plates to my engine-bay in order to install my aftermarket gauges' sensor set. Currently the engine-bay looks completely "stock" & I'd like to keep it that way - fitting an anodized blue Racing Beat sandwich plate & in-line water temp adapter doesn't really follow this ethos as tidy as they look.

Has anyone any suggestions on where to subtly mount (even if it means chopping/cutting/drilling etc) a...

1) Water temp sensor so that it's on the "always hot" side of the thermostat & getting the most accurate reading of the water temp - is there somewhere for example that's on the thermostat housing that's ok for tapping a hole for the sensor there?

2) Oil temp sensor so that it's reading the hottest the oil will ever be? Is this the sump or oil filter housing?

3) Oil pressure sensor so that it's going to be the most accurate? Maybe the oil filter housing?

Why?

These will take care of the oil pressure and temp part of the equation:

https://www.rx8performance.com/produ...or-banjo-bolts

1. Once the engine is up to temp, the water temp will read the same no matter where it is placed. Using a hose adapter is the best option.
2. Oil temp will read the same as well, I have read from the pan, the outlet hose, and the oil filter pedestal and it's the same unless you are sitting at idle, then it reads hotter in the pan.
3. Oil filter housing or on the lines is fine. You can drill and tap a banjo bolt yourself but using a filter pedestal plate makes the most sense.

Have to disagree; a banjo bolt is cheaper and easier to access than a pedestal plate

An oil pedestal adapter is goo for oil temp and presure sensors. Other thann that the banjo is easier like it was said above.

I'm using the RX8performance banjo bolts for both oil temperature and pressure. I have my pressure sender on the oil line coming out of the engine and the temperature sender on the other end of that same line, where it goes into the cooler.

I'm using a Raving Beat water temp sender adapter, but after receiving it I really wish I had just cobbled something together at Menard's instead. I did spend some time looking at the thermostat housing, trying to find a place to tap the temp sender directly in it. In the end, I decided there just wasn't a good spot I was comfortable using, given my limited tools for such work. Also, my temp sender is really long. I worried it would interfere with the thermostat or flow.

Firsly, massive apologies on the delay coming back ot this...

Secondly thanks very much to each of you for your input!

Because the theme of my car is "what it would look like if Mazda produced it from the factory" so I want to keep everything factory-looking. (I'm driving an MX5 NC fitted with an 6-port 13B-MSP from a Series 1 RX8)

I found a cheap oil pedestal sandwich plate that seems to be doing the job, however if the seals on it start to fail or give me trouble for any reason I'll go with this option if I can find somewhere tidy enough to put them.

1. Whilst I agree with you more or less, I want to know what the engine-side temp is as opposed to the coolant temp once the thermostat opens (& that's if it opens - my logic is it can help to diagnose thermostat degredation/malfunction if you've an accurate water temp sensor mounting point)
2. You mounted 3 sensors in each of those locations at the same time?? Wow good call - a friend remarked on his Skyline that the oil temp sensor in the pan misread as low when travelling at speed compared to the oil temp at the pedestal.
3. Aye, I follow what you're saying - I'll go with the banjo option should the sandwich plate fail for any reason. Might go with that option on my FD actually.

Is this on a Series 1 or 2 RX8?

I got a present of the Racing Beat water temp sender adapter so am pretty happy with that but like you wasn't impressed with it for what I know it cost: the fitment was massive (had to buy a separate reducer in the same colour to fit my water temp sensor in) & would've preferred it to be in black. May get it anodised in black at a later stage, it'll do in blue for now.