So my car was running hotter than normal yesterday sitting in traffic on the way to the track. I almost pulled over when it started moving again, cooled down as soon as I was moving again. Ran perfectly normal at the track, but there's plenty of airflow at 100 MPH.

This morning I set the fans to come on at 60F and only the driver's​ side seems to be working. I'm pretty sure that both fans used to come on.

I set the family to come on at 198 instead of 203 and took it out to sit in some traffic. Seems to be managing it but I need to figure out what's wrong with the other fan. I am guessing wiring, unless there's a separate fuse for the other fan. But still, wiring, looks like someone messed with it at some point.

 

2nd fan is AC on a NA. I'd guess it's the same in a NB. There is a relay for AC, but I don't remember how it's wired. In ms3 there's separate settings for the AC fan.

 

I am not sure which MS2 you have. MSLabs or a PNP/DIY? How they control the second fan will change things. Also does the second fan come on if you turn the AC on?

 

I have a diy ms2pnp 3.3.1.
I didn't change anything and I only see 2 on off outputs. One for VICS and one for cooling fans(plural.) I had a busy week but I glanced at the wiring and it doesn't look factory. I am pretty sure this is a fuse, relay or broken wire. Leaning pretty hard towards broken wire.
I will let you guys know what I find out.

 

This little bugger seems to be the culprit.

I thought I'd be clever and swap it for the ac relay, but it doesn't work either. My ac never worked anyway.

I can change the signal to the relay with the megasquirt, by fiddling with the single cooling fans output from .6V to 11.8V. So the wiring from the MS to the relay is fine. I can also jump the hot wire to run the ac fan with the relay removed. So the wiring from the relay to the fan is fine too. I think I have some adequate relays in a box somewhere.

 

Dang, not only do they want $50 for that thing, every parts store around said 5 to 7 days. I am going to look for a used one.

Found this.

 

Check the connector on the AC fan (driver's side). I fought a similar issue for months, and finally figured it out (intermittent **** is the worst).
On two seperate NB's of mine: The connector looked fine, was physically tight, but was intermittent. If I pushed it in by hand with the fan running, AC and car on, it would kick on. It wasn't until I unplugged it and saw the state of the inside.. All the black plastic insulation had crumbled, or melted, leaving a plastic ****-show between the pins and their 'mates'.
The shitty part, the one half of the connector is apart of the fan, but you should be able to salvage.

Another thing I discovered: Ever since the first time this intermittent issue started, that connector only got worse and worse. Why? Extreme heat. 95 degree ambient, sitting in traffic, etc.. That condenser needs that fan, or the condenser itself becomes a giant heat sink mounted to the front of the car.

FWIW: My relay(s) have always been checked as good.

 

Carlos shoot me an email. I might have that relay laying around.

 

Thanks guys, I pulled the stupid rubber cover off and it is just a basic 12v 20a normally open relay. I picked up a universal dorman unit for $8 plus tax this afternoon.

I was wondering if maybe I cooked them, they are on the hot side. I am going to make a small harness to mount it outside the engine bay.

The wiring looks Ok and has good continuity, and I can't get the fan to come on by jiggling the wires. Growing up in the fog belt of SF, I am fanatical about cleaning and vasalining every connection I touch.

 

I love seeing this car at the Wednesday night drags. VERY unassuming to the point that people snub their nose up like it does not belong, that is until it makes a pass. Then the LOL's begin.

Great job Carlos!

 

Thanks Tom! I guess I don't get the same respect from the spectators that I get from the local racers.

I was just thinking about your car and how I tried to convince you to set your fan up to come on automatically. I am ironically wishing I had a switch for mine now. Hopefully I can get a few minutes to play with my car today and make this relay work.

 

Fhhhaaak!
It's not the relay, somehow I have +12v to both sides of the relay signal, one keyed and one thermostatically controlled. I ran a ground and the fan came right on, but the main fan shut off. The only thing I can think of is that I updated my tuner studio recently. I am going to look over all my project files to see if I can figure it out.

I swapped out the signal wires for the AC clutch temporarily so I can turn the 2nd fan on manually. Works well and doesn't shut the main fan off.

 

I have both fans working themostaticaly controlled, I still don't know what the problem is though, which will bug me.

I made a wire to replace the signal wires for both fans from the main cooling fan relay signal. The new wire has 3 ends. One male spade to connect to the female spade I removed from the connector for the main fan relay. Two female spades to fit in the vacant signal wire spot at both relay connectors.

Now, the main cooling fan signal wire triggers both relays. This seems like a much nicer arrangement than the parallel fan write ups I've seen, and I didn't have to butcher my wiring harness.

Anyway, I am happy I can drive my car again in 100° traffic, now that it's cooled off.

 

I didn't get to sit in any hot traffic, listen to myself. I am actually disappointed about not getting stuck in traffic. Both my fans did come on at 200° when I was opening my garage after my test drive yesterday.

I spent a little time boxing the sides and sealing the bottom of my intercooler this morning. We'll see if it makes any difference on Wednesday.

 

Ok guys, finally broke my ****. Looks like Andrew gets back on the 17th, so I can order my rods then.
Quick question, the supertech pistons weigh slightly more than my early 8.8:1 stockers. My 8.8's are 186g, 188g and 2 189g's. I also have vvt pistons which are closer to 304g's, slightly heavier than supertechs. If I run supertechs, would it be better to run an earlier crank, balanced with the lighter pistons or the newer crank balanced with the heavier pistons? Or do I need to rebalance if I run supertechs? Or should I just not worry about it?

 

Woah woah woah. Your engine blew?

Pics?

What happened? This is a day that will live in miataturbo lore. How many miles slash boosted miles did it have? Any tally of the number of drag runs and events you did in that time? The number doesn't really mean all that much. It would just be pretty cool to see it all laid out.

Honestly... I can't wait to see how mental you go with an engine build. Maybe it's time to swap out from the all seasons!

The VVT pistons are the highest compression stock miata pistons. Isn't that the opposite of what you want?

 

Dooood, I don't plan to run the VVT pistons, my question was about engine balancing. It has already been answered.

I have over 250,000 miles on my motor, over 23,000 boosted miles on my very reliable MKTURBO, and my motor broke on the 196 1/4 mile. Not sure what broke yet.

I will likely run the stock 8.8 pistons I have been working on. My motor will not be an extreme build.

Thanks to everyone here for helping me to do this for so long!

 

The car still runs and drives fine, but it's so ******* noisy that I drove in the right lane all the way home like Grandma. Trying to balance between pissing people off and making it home, at least I didn't need a tow.

 

That motor does not owe you anything! I look at this as a great opportunity to build a strong foundation for the turbo setup.

 

I think you should up the boost to 320kpa and just wear some ear plugs. If you can't hear the rattles, then they are not there.