Thanks, didn't know that.

Start at the radiator opening in the front garnish, close off EVERY opening/path that might allow incoming air to bypass the cooling stack. Remember, air will also flow forward into the nosecone and out the sides, and up out that shiny trim in front of your radiator, etc etc.

Doing it bit by bit is just prolonging the pain, air will always follow the path of least resistance, so even a smallish opening will undo prior efforts .

Look in the aero subforum, see how others have handled it, but the basics are very basic - ALL the air coming in goes through the radiator.

ETA: I think it is the cooling system thread I should have directed you to, but see also some of the quicker car build threads.

 

AFAIK there is no undertray that is pre-cut for intercooler piping.

That said, in my experience hacking up the stock one actually works pretty well, at least with FM-style intercooler plumbing. The tubes go through the sides of the undertray but otherwise sit outside of it, so you just need a hole big enough to fit the tube through and enough other material removed to be able to install it. You do need to remove the front where it bolts to the stock air guide, what I did was to rivet on another piece of piece of plastic to extend it forwards, which I then cut to fit onto the bottom of the front bumper. Flip the little clip nuts on the bumper over, drill a few holes in the new piece of plastic, and it attaches there. I'll see if I can find a picture of it.

Also, on the engine failure thing, I agree with Curly that it sounds unrelated to the tune. Lean tunes will melt holes in pistons, but they don't usually break rods, at least not without some really obvious detonation noise. The spontaneous rod failures I've seen on Miata motors seem to be more rev-related, and there's a hypothesis about how a "money shift" can weaken a rod to where it fails in seemingly-normal driving a little while afterwards. Did you ever overrev it? How many miles did you put on it between taking ownership and when it blew up? Is it possible the previous owner overrev'd it and then sold it before it could blow up on him?

Oh, one other area to hunt down on the IAT thing -- make sure that your sensor is working properly. A bad sensor (or the wrong thermistor calibration settings in the megasquirt) could potentially explain it.

--Ian

 

Hey man thanks for the response. I have never over revved the car, but the PO may have. After I got the car I came across videos he posted of him banging off the rev limiter shooting flames out of the exhaust so anything is possible lol. The rod snapped where it meets the big end and the piston appears to be undamaged.

 

Every time you mention new lore about the PO the picture of this poor car's previous life becomes more and more clear

 

Haha. There's no doubt this car had a rough life before me. Just the number of missing and loose bolts told a pretty crazy story. I'm working on it.

Let's add another leak to the list. This time coolant
A few drops, but I see it. The joint that comes off the water pump to the heater core is leaking. Probably my terrible rtv job.

 

 

I wish it was just that hose. The hose isn't leaking. Guessing just a poor rtv job.

 

Happy father's day to the dads here at MT!

I no longer have ANY leaks on my car. Hopefully for a while. Only thing really going on is tuning which seems to be a whole lot of tail chasing at this point. I was planning on swapping the Torsen in today but we finally got to take the jet skis out so my garage is currently occupied and it's raining today.

 

Picked up another project tonight. For $1500 I couldn't pass it up. 2008 Mazdaspeed 3. Needs some work, tires and motor mounts for sure but it runs well and the trans seems solid. Interior is a solid 9.5/10. No rips or cracks and nothing missing. Ill probably fix the issues and move it and make a little money on it. Really don't have room for another car but for the price I had to bring it home.

 

Drove the car 170 miles yesterday with the top off. It was close to 100 degrees and sunny. Probably won't do that again lol. Car did great though. Lots of 65-80 highway driving with zero issues. Tuning is just about done. Still working on starting but otherwise she's good. Figured out the idle dips are caused by power steering so stopped chasing that.

Tonight I noticed the car didn't want to drop back down to idle. It's going into cl pid, afr is correct, but it wants to idle at 1.1k. Checked the throttle cable. Checked all the vacuum lines. Can't find any issues. Researching it people say to check the iacv valve. I'm not sure if that would show in a data log but from the tuners end everything checks out. I did have an issue with the iacv valve when I first got the car. It would make a buzzing sound then the car would die. Took it off and cleaned it with brake clean and it didn't do it again.

 

Are people just giving away Speed 3's right now? My buddy just picked one up around here for $900, although it needed a clutch and is in need of much more TLC than yours. Cool ride, I'd love to have one as a functional daily.

Glad to hear the car is leak-free now and you've been able to take it out and enjoy it! As far as the idle issue goes, I'd remove the IACV and use output state control in TunerStudio to cycle it open and closed, then at different duty cycles to see if the plunger is getting hung up/stuck open at all.

 

I sold it Saturday lol. Brought it home and cleaned it inside and out fixed the motor mount for free and sold it for 2500. It was pretty rusty underneath. I would definitely love to have one but I'm looking for a cleaner example.

Oddly enough, when I left the house today the car was still idling high. Got to work turned the car off, did a few things then jumped back in the car to do a few things. Still idling high. When I got to the first red light it was idling high, then the sound of the engine changed and idle dropped to normal. Been normal since. Guessing it's the IAC. I think I have a couple spares.

 

Does anyone run a TR8 or TR8L?

 

Treadstone TR8 installed. It's thicker than the CX Racing IC and much heavier but fit nearly the same. Mounting was different, sides vs top so I had to modify the old brackets to work but they worked well. I do want to move it down and forward more, further away from the radiator, closer to the bumper opening before I make ducting. I went for a drive and iat's were about 25 over ambient the whole time which is a huge improvement. I know I still have work to do though.

Car has been doing well. Still working on tuning. No improvement in the starting department and idle has been weird. Swapped to a different IACV with no improvement. Not really sure what's going on.

 

Great threat, spent about 45 mins reading through it. Was a nice rollercoaster for the reader albeit at your expense. I almost bought this car when it was listed with the Milwaukee logo a while back. Glad I didnt, plus I wanted the satisfaction of boosting a car myself. Glad its getting some love.

 

IAT's were 25 over ambient with the front bumper off or with it on along with the undertray (I can't remember, you have an undertray right?)? Either way, solid improvement for sure! Amped to see what you do for ducting, major gains to be made there as well.

 

It was with the bumper off lol. I drove around town today and it isn't better, just takes longer to heat soak. It is better at speed, it'll drop temps very fast where the CX racing one wouldn't once it's hot.

 

Yea, I hated myself for trading my Civic for it initially. Especially after it blew up on me. I'm glad you didn't buy it to, for a number of reasons. You dodged a bullet.

 

The good:
Miata is doing good. New IC didn't completely fix the iat's, however, it did bring the max temps I would see down. Never goes above 140 now which was always the goal for a street car.

The bad (depending on how you want to look at it lol):
The Miata no longer belongs to me. I traded her for a more modern rwd "sport" coupe WITH AC lol. It was a deal I couldn't pass up. 2015 FRS with 59k miles. More money into the mods than the car is actually worth and other than a few poor cosmetic choices a pretty nice car. Going to drive this through the summer and fix a few things and I figure this will give me more bargaining power to get into a nicer NC eventually.

So, not goodbye for good. Ill be back with another project. I want to thank you all for the help and feedback along the way. Very much appreciated 👍

 

Wow, rollercoaster of a thread right there haha. Glad to hear the NB is still in action and hopefully you and the buyer both enjoy your new cars.

See you back here when you get a real man's car and trade that 86 for an NC