[PSIG]

The MPX4250AP is rated to withstand 1000 kPa without damage (especially useful for intake manifold backfires), so you can certainly pressurize your MAP tube to well over your anticipated boost pressure in order to test it. That said, I have not heard of any properly-sized tubing of any acceptable fuel-resistant material blow off of the MAP sensor, including those without a spring clip or clamp. A 5mm I.D. tube has about 0.03 in² of area, and at 25 psig will exert less than 0.8 pounds of force; so a simple tug test with more than 13 ounces of force will also give you some confidence for that level of boost or less. Double it for 50 psig boost.

Using undersized tubing is possible, but you also invite shorter tubing life due to stretching and splitting with age. Every method has its pros and cons, but I think you'll be best-off overall with 5mm as recommended in the Wiki. If you test for limits, please report your findings, along with the tubing I.D. and tubing material spec's.

David

[noisymime]

As mentioned, there is a bulkhead adapter on the PNP boxes and it's fitting is slightly larger than that on the 4250. Internally I use a 4mm silicone hose that fits well on the 4250 and very snugly on the bulkhead fitting, but as I've put on the wiki page just about any 5mm or 6mm hose will be fine on the bulkhead, depending on material. 6mm you'd probably want a clamp just to make sure, but your 5mm shouldn't be a problem at all.

[lsdlsd88]

All clear, thanks!

[bond007]

Excellent news! Looking forward to getting it installed/tested/tuned!

[lsdlsd88]

What's the function of the PROG/RUN switch on the board? mine arrived in the prog position, should i put it to run before "running" it?

I've only found it referenced in 0.4.4 board wiki but without any explanation

[noisymime]

What's the function of the PROG/RUN switch on the board? mine arrived in the prog position, should i put it to run before "running" it?

I've only found it referenced in 0.4.4 board wiki but without any explanation

It's an attempt to have a switchable disable of the arduinos auto-reset feature. For most arduino boards though, this switch unfortunately isn't doing its job though, so really it doesn't make any difference which way it's set.

If you do have any difficulties uploading the firmware though, make sure it's flicked over the Prog.

[lsdlsd88]

Plugged in my board today.

Had a big headache checking the pinout because it wasn't getting cas signal.
Found out on a euro 1.6 '96 mx5 one of the cas pins is in a different position, 2F instead of 2E (apparently the same as later 1.8 models)

Bridged the 2 pins and now it's purring like a kitten

Awesome job Josh

[noisymime]

Plugged in my board today.

Had a big headache checking the pinout because it wasn't getting cas signal.
Found out on a euro 1.6 '96 mx5 one of the cas pins is in a different position, 2F instead of 2E (apparently the same as later 1.8 models)

Bridged the 2 pins and now it's purring like a kitten

Awesome job Josh

Really?? This is the first time I've heard this. I've got a mapping between the 3 main variants of the 48 pin ECUs and this particular change isn't one of those listed:

1C7D3972-7EEC-4F2D-9C21-EA13D2C65139.png (896.07 KiB) Viewed 7183 times

Either way, glad you're up and running! I'll make a note of this difference for future reference.

[lsdlsd88]

In fact it seems like they took "inspiration" from the 64 pin version on later 1.8. Your table is too generic classifying 93-98 1.8! There are more than 2 versions for what i know (maybe more if we consider special market versions like the early 1.6 in California)

https://www.miataturbo.net/attachments/ ... arness.jpg

Do you think it will be worth to add a "jumper" pin on the future release? I still have to figure out what was the white/blu pin originally in the 2E position

[noisymime]

Adding a jumper seems like it would be easy enough. I'll take a look and see if there's a decent spot that this could be added on.