What have you done today/recently to your 5?

[RS2000]

I've often thought low temp thermostats are probably a con, even on race cars.

http://www.tuneruniversity.com/blog/2012/04/low-temp-thermostats-whats-the-advantage/

[StillIC]

My understanding of thermostat ratings is along the following lines, which disagrees with at least one major point of what tuneruniversity.com states.

1) In a vehicle with a 'big' cooling system in weather/ambient temperatures/operating conditions it was designed to operate within, the temperature of the opening of the thermostat sets a ceiling (not a floor) to the operating temperature of the engine. Once the cooling system is doing its job at the temperature at which the thermostat opens, why would the engine get any hotter? (See 3)
2) Conversely to 1, any car/engine with an insufficient (small) cooling system for the operating conditions will overheat, no matter what the opening temperature of the thermostat is, as the thermostat is unlikely to be the limiting factor.
3) Many (right sized) cooling systems are designed such that the engine will run hotter than the thermostat opening temperature and control upper temperature by using fans behind the radiator or other techniques. This is where tuneruniversity.com is arguably correct in its statement about the thermostat setting a floor on engine temperature.

Renowned tuner David Vizard suggests running cool thermostats in race cars to reduce the operating temperature of the engine, to reduce air intake temperatures for slightly more power. The down side of this is that the engine will produce more pollution, it will need a cooling system capable of maintaining that temperature (see 1) and the oil used in the engine will need to be appropriate for a change in the operating temperature to ensure reasonable viscosity, I imagine. I have done this with my MX5 road/track car.

So, in line with statement 1, my MX5 never overheats on the road. I am running a low temperature thermostat and the engine arguably doesn't get hot enough. The cooling system is easily capable of maintaining the engine temp below or at the thermostat opening temperature.

In line with statement 3, on the track (SMSP) on a hot day in summer, I have to unblank the oil cooler for added cooling as the standard cooling system on its own can't control the overall engine temperature adequately.

Having said that, I think in hindsight I should run a hotter thermostat so that the car gets to a reasonable operating temperature on the road. Perhaps I will lose a touch of power on cold days at the track, but it will make no difference to hot days at the track.

As always, horses for courses.

[davekmoore]

I've set fire to the NC and put number 2 and 3 rods out the side of the NB's block. As usual, the NA just keeps going.

[KevGoat]

Well ... last weekend, as MXSE is our "main" car lately, we drove a short way to Clarendon to the pub to meet friends for a birthday dinner. On the short drive from the pub to our friends' place after dinner, the car threw up a CEL P2096 Code: Post Catalyst Fuel Trim System Too Lean (Bank 1). Pulled over and switched off the car and then restarted, CEL still there, but the engine sounded fine. Drove the short distance to friend's house and popped the bonnet, used the phone torch and checked all the hoses and as much as I could. I didn't have my OBD tool with me, so at this stage, I didn't know what the code was.
Interestingly, on the way home, the car actually felt better than it had recently - I've had some inconsistent idling issues and some low-speed roughness.
The next day, I plugged in the OBD reader and got the code, and began the online searching. My first thought when it happened was the engine running too rich as I had changed out the BEGi short ram CAI for the stock airbox, but it was the opposite, too lean. After reading more, I then thought about the MSM rear exhaust manifold bolt coming loose... it's a known issue. So today, a bit cooler weather, I jack'd the car up and started checking everything. Removed the airbox so I could move the manifold heat shield, and yup, that bolt was loose! I then went all through all the exhaust bolts front to back and found a few slightly loose (these hadn’t been checked since fitting the NitroDann exhaust). Cleared the code and took the car for a drive, and the CEL hasn't returned, so fingers crossed this was the issue.

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[Lokiel]

^
"I had changed out the BEGi short ram CAI for the stock airbox"
Why on earth would you do that?
Don't like the additional noise?
Planning to sell?

Well done with the DIY research and, it pays to periodically check all the exhaust+manifold nuts&bolts are tight (and still present )

[KevGoat]

Just the noise Lokiel. I'd tried a few things - different filters, closing off the gaps around the airbox, lining the airbox, but it was still too intrusive, especially on the longer trips we do in the car. Obviously, there's a trade-off, but tbh I haven't noticed a great deal of performance drop-off, especially as I rarely rev high anyway. On the positive side, I have noticed a slight increase in torque down low, which I actually prefer (leftover style and preference from my old 6's and V8 days). Hey, I change my mind every five minutes, I'll probably be fitting it all back in no time!!

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[RS2000]

The next day, I plugged in the OBD reader and got the code, and began the online searching. My first thought when it happened was the engine running too rich as I had changed out the BEGi short ram CAI for the stock airbox, but it was the opposite, too lean. After reading more, I then thought about the MSM rear exhaust manifold bolt coming loose... it's a known issue. So today, a bit cooler weather, I jack'd the car up and started checking everything. Removed the airbox so I could move the manifold heat shield, and yup, that bolt was loose! I then went all through all the exhaust bolts front to back and found a few slightly loose (these hadn’t been checked since fitting the NitroDann exhaust). Cleared the code and took the car for a drive, and the CEL hasn't returned, so fingers crossed this was the issue.

I thought with an exhaust manifold leak, that the oxygen sensor thinks the engine is running lean (when it's not), so extra fuel is added giving an overly rich mixture?

[KevGoat]

Yeah, the sensor/code was showing lean. Probably the way I explained what I'd done made it confusing. The code would be sent up before the ecu adds fuel, I should think. When I found the code next day and searched online, most on Miata.net said this would almost always be an exhaust leak causing the sensor to see a lean reading, which made me think of the loose manifold bolt issue, which is pre cat, so along with the slightly loose downpipe nuts which are also pre cat, these could have all been part of the cause. It's probably also why the idling has been inconsistent of late, and I've had some surging at low revs. The other loose nuts along the exhaust were post sensor, so I don't think would have added to the CEL, don't know.

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[mephisto2020]

Flushed coolant and full service. Still have to wait for the morning to bleed the coolant system more as gwr exhaust is loud. Washed and cleaned out now too.

Trying to work out what to price it for to sell now sadly. I didn't see any other 2.5 nc's go for sale so I have no idea.

[KevGoat]

Trying to work out what to price it for to sell now sadly. I didn't see any other 2.5 nc's go for sale so I have no idea.

Will mostly depend on the mileage and condition compared to any similar year cars for sale. The 2.5 upgrade may or may not add a little, depending on finding the right buyer who knows how much that upgrade adds to the car. The crazy increases in most vehicle values of the past couple of Covid years appear to be waning, so you may have missed the boat there. GLWS.


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[magenb]

So last 3 weeks is still "recent" right
Installed some foil insulation under the carpet. It didn't reduce the heat as much as I was hoping, but it doesn't feel like it's going to burn me every time I going for a long drive . It did reduce road noise a little, which was a nice bonus.

Installed the short shifter, replaced upper and lower rubbers as they were torn.

Swapped in a cheap android auto head unit, turns out the center console is a good place to store/charge the phone.

Swapped in some metal scuff plates and chrome airvents.

And put about 1000 km on it.. given I only did about 6k last year on my old daily, I think I might like it lol.

[slug_dub]

Long time no see youse Still here.

I went to Morgan park a couple of weeks ago. It was raining. Bewdy I thought a chance to practice a bit of slip.

Newp I basically drove so slow it didn't break traction. I'm still too worried about breaking it

[StillIC]

Nice concrete.

[bruce]

Slug Dub is very short!

[The American]

Nice looking Machine!