Yeah I am a big advocate for taking the time to learn the car as is before modifying it or jumping onto sticky tires. I still probably have more track time on Continental ECS tires than everything else I've run combined. Heck, I ran my first track days with the stock 140k mile suspension!

It seems like social media focused car communities have worshipped the build thread so much that they forgot the point of building the car was to drive it. Especially with Miatas gaining renewed interest as a first project car in recent years, the younger kids are impressionable and treat a lot of mods as a checklist to complete prior to their first track day. The upgrades that were nice to have for track regulars became necessities for everyone, because Youtube videos about stock cars don't get you likes and follows. I find it a lot easier to learn when you have to learn to work with the car and drive it the way it wants to be handled. A soft suspension and true street tires will help a newbie learn to give smooth inputs and feel the limit of traction much more than coilovers and 200tw stickies.

 

Glad to see the NeoGens aren't the worst tire in the world. That's what I'm running as daily tires right now as well, so I was pleased to see the tread pattern after hearing the positive review. I've been tempted to autocross them just to see how they do. Maybe that'll happen at one of the colder early season events next year.

That also made me wonder how old your RS4s are. I'm not familiar with them, but I'd assume they'd be a good bit quicker than the Nitto's. Are they both the same width?

 

Oh to be clear when I first started running them, I thought they were garbage. I still wish I could get Conti ECS's. The massive deep tread blocks on the NeoGens seemed to squirm a lot, but that is better now that they've worn down some. I think they were only viable due to the cold temps and because VIR is a big track with long straightaways. There's only one big long sweeper to really punish a tire - turn 1. My Hankooks are 225/45R15s on 15x9, a pretty standard setup. I bought them in the spring and forget the date code, but it's recent enough.

Honestly, I think a lot of it is down to how much I still have to learn even after a few track days there. A 20 minute session only gets me 6 laps. I've never been there under the same conditions/tires twice, and there are some spots where I know I still have a lot of time on the table. I'm still braking really early at the end of the back straight into rollercoaster for example.

 

Based on my sim racing experience you brake around the 2 board going into roller coaster IIRC. Try that and let me know how close sim racing is to real life

Fair point on the straights there, and yeah, if the tires are from this year then I doubt they're cooked. Having said that, my tires were new in March and are pretty shot after a season of autocross.

 

Hahahaha, probably not far off!

I was using 4 as my marker and both braking lighter than I could have, and coming off the brakes into the initial left kink. It's hard for me to push deeper on a high speed, high risk braking zone for an HPDE event in a car without ABS.

The top Hankook in the pile is dated 27th week of 2023. Not great, not terrible.

 

Sim racing has honestly been one of the driving factors that make me want to try the MK60 retrofit. Being able to stomp your foot down without locking and losing steering completely or smoking your tires sounds like a dream. I'm pretty decent about keeping them from locking right now, but in those panicky situations it's easier said than done.

And yeah, after that straight you certainly don't want to miss the turn unless you've recently fitted some offroad suspension I'm unaware of. The line through there is hard on the brakes, slight lift for the left turn and then hard on the brakes again to setup for the right hander, no? Again, I don't claim to actually know, this is just from messing around doing hotlaps. This does make me want to get Beavis' car out there though and see what that's like (terrible brakes on the mod of his car IMO).

 

I've been told they're shock bodies designed for a 4 wheeler. I'm still really happy with them!



The cars been looking like this for the past few days. The other day I got frustrated trying to give it a winter alignment with as little camber as possible. Plus I got a bit neurotic trying to get it bang on, not noticing that I was using the 1/32nd scale. I got back to it tonight and everything went fine. These stands are a good tool and seem to get super precise, but they're not fun to use. It's a lot of getting up and down and sticking your face in a wheelwell when you torque things. I got to within 0.1* from side to side and within 1/16" on total toe. Good enough considering my concrete floor is horribly out of level.

I couldn't get below -2.0 in the rear. Given the rubbing on the front fender liner, I'm considering raising it a bit, but an adjustable rear upper control arm would make alignments a lot easier too.

Those are lots of little lines to ignore! A little tip I have for doing toe is to clamp down your tape measure ends so they don't fall out. These old C clamps do great.



My buddy picked up a Miata! It's a 2021 Grand Touring in Deep Crystal Blue with a white interior. 2024s were pretty hard to find in any color that wasn't some shade of grey. It only had 5,000 miles or so.



Man, new cars are nice. I should buy one some day.

 

Well I was going to try to find another way to share this but since you can't download youtube videos now by default, I'll just share the link.


Private video, you'll have to watch on youtube.

This was one of my big slides at the last track day. The fun bit happens around 40 seconds, but watch the whole thing to see why I was caught off guard. This guy was MOVING in a C7Z on Hoosiers, passing two far apart cars in one straightaway. Had I known what would happen I'd have let him through prior to the uphill esses. I had planned to let him by again between T10 and Oak Tree in that little bowl, but he dropped back thinking I was losing control. Pah!

You can see a bit of a wiggle in the last right turn of the esses. Into T10, I have the biggest slide of the weekend. I was a bit later on the brakes and the back end started to come around, so I took the safe route in a fast corner and kept my foot in it.

Good fun!

 

Slidey Miata is right! Haha, way to stay in it and pull out of said slide cleanly. You held that angle there real nice for a couple seconds.

 

Hell yeah that was awesome hahaha. Nice catch

 

I've been jealous of all the sideways action you've been posting, I had to share my own. My first time on track in 4 months, that's too dang long. I can't wait for the usual burst of track days this spring!

 

Well, crap.

The engine has been running a bit rough. The cold misfires have gotten worse and the exhaust is starting to smell despite the new cat. Oil consumption is also up.

A friend came over with a vacuum gauge and a borescope. He's a big believer in the vacuum gauge and the readings we got from it weren't great. Lots of bounce in the manifold vacuum, and it wasn't pulling as much of a vacuum as he'd like to see. So we pulled the plugs and peeked around inside.





Plugs looked okay.























I've got no idea what would cause these splotchy markings in the cylinders. It looks like long term corrosion, not something you'd find on an engine that has been running decent and been garaged most of the past 10 years.

The OBD Code is always for a P0304 cylinder 4 misfire, but 2 and 3 were far and a way the worst looking cylinders. I'm not sure how the misfire detection works in this engine.



I know, little engine. You've done good work. It's time for a break.

It still runs okay, but I want to address this sooner than later. I'd love to keep the original engine in it, but I also don't want the car to be down for months waiting on machine work. Maybe I'll just get a used engine or even splurge for a low mileage JDM import. A local spec Miata builder quoted me $5k for a rebuild of my engine.

I feel like the car is reliable enough just the way it is that I may not want to mess with the recipe. But I'm weighing all options.

 

Swap existing plugs and coils around, see if misfire remains in #4.

 

I've done that several times, both with swapping coils between 2/3 and 1/4, and replacing with new parts. New coils, new wires, new plugs, none of it made the misfire go away or report from a different cylinder. A compression test last summer showed around 185-190 for all 4 cylinders. I had the injectors cleaned and flow tested last spring, that was also not the root cause. I had planned to compression test the engine again this weekend, but after seeing the cylinder bores I figured I'd found the issue and didn't want to take the 30 minute round trip to the parts store that day.

The funny thing is the worst of this pitting and corrosion is on cylinders 2 and 3. It has me wondering how reliable the misfire detection is on this old of an ECU with a 4 tooth crank trigger wheel. Only once or twice has it reported a P0300 general misfire, most every time it says it's P0304 Cyl 4 misfire. Maybe this isn't the actual root cause but it seems like a silly thing to ignore when the engine has 195k and loads of track days on it.

I was going to check valve clearances as my next target of possible cause when I got around to doing the 60k mile TB/WP job. After seeing this crap, I think a full engine replacement or rebuild would be best. I'm already looking at JDM importers to get another low mileage replacement.

 

A JDM import for half the price of a rebuild and substantially less downtime sounds like the ticket to me. Although I totally understand the allure of having a fresh engine to break in instead of a 60k mile one.

Yeah that corrosion or whatever it is on the cylinder walls is strange. Nothing I've seen before, although sometimes the flashlight on the borescope distorts how things look in there.

Obviously the engine's tired, but are you gonna do a compression and leakdown test on it? Seems like that'd put everything to bed real quick.

Waiting for the confirmation that this car is getting the J swap

 

As tempting as it is to make this NB my J swap victim, I'm struggling to mess with a good recipe and a car that just works. A replacement engine would get me back out on track this summer, easy. On the other hand, I have a spare NB hood to cut up to clear the massive intake manifold the J series has, and I don't have that for the NA.

I looked on car part dot com and saw one supplier with a lot of VVT engine/6speed trans combos from Japan within a few hours driving distance. Flat top intake, 10.5:1 compression JDM long block, and a 6 speed, all with 60kish miles for $3,000. Seems like a decent way to get a good engine for this car, and a stronger transmission for the J swap in the NA. The only major decision for the NB engine swap would be to go standalone with the flat top, or stick with the VTCS manifold for now and standard ECU. The half point bump in compression the JDM motor brings means I'll no longer have the option of running 87 octane, but it seems worthwhile.

I'll do some more diagnostic tests on this engine, but again, I'm struggling to justify continuing to look for issues when I think I've already found a major problem. This damage looks old, and yet it's been pounding around tracks for years. Maybe it just took that long to wear out the rings?

 

IMO grab one of those JDM engines and slap a Link ECU or MS3 to it. You'll be happier in the long run and be out to the track quicker. You'll be getting > 30 mpg. Give that engine some premium gas

 

I've gotta say, I second the leakdown test. Personally reading vacuum is not a reliable method of engine health. And to be honest, even a compression test is borderline. Get a leakdown on it, then you'll know what you are working with. Maybe just needs a head refresh.

The vertical scoring is the same on any BP i've ever pulled apart. You'll find the same on the skirts too. Doesn't mean its toast. IDK about the water mark/staining, that does seem weird, but again doesn't mean she's buggered.

 

I'll try to find time to do a compression test, but the pictures of an LCD screen really don't do what we saw justice compared to what you see with your eye when the camera moves around. It definitely looks textured, like it is pitting and not just stains on the cylinder walls.

In the meantime, I'm still planning on the JDM engine swap. I went ahead and called the importer as Car-Part dot com shows way more stock than their website. On the phone they said they were making a new website to explain the lack of stock shown, and confirmed they had several 1.8VVT/6sp drivelines to choose from. Given that they're all around 60k miles, I plan to get the latest year I can in the hopes it has the best shifting 6 speed. Obviously I'll prioritize what I find when I peer into the valve cover (and maybe even borescoping the cylinders) over a year or mileage.

Any advice on what I should do with the engine out? It'll get a basic timing belt, water pump, and reseal just like the usual 60k mile service. I'd also like to do some reasonable track durability upgrades while it's out of the car. If you can't tell, I like overkill on this front. Some things I'm strongly considering

• Oil sump baffle - I like the DCBE unit best, but it is out of stock. Circuit Sports makes a similar one
• Relocate Oil temp sensor from sandwich plate to oil pan
• Fluidampr

I'm sure someone will say "coolant reroute!", but I'm still not entirely convinced I need the complication with a VVT head gasket and a big radiator. I won't rule it out, but I'm not replacing the head gasket if I can avoid it.

For a real horsepower upgrade, I'm uncertain of if I want to go down the standalone ECU path when I first install this engine. That said, the Beer Money Motorsports ECU is really tempting. Helping me avoid temptation, it is currently out of stock for 01-05. It's <$900, has a built in wideband controller, and I actually met the owner years ago when I bought the white shell shown in the first post from him!



This would let me run the flat top intake manifold and delete EGR as well, finally giving me the ne plus ultra N/A BP engine.

 

I was under the impression that the oil filter sandwich plate was the best location for an oil temp sensor, since it's further along in the oil path before the oil reaches the bearings? I could be totally wrong, just thought I'd read that a few times before.

Throwing a Fluidampr on my unopened BP engine smoothed out vibrations noticeably. I'm sure the engine was happy about that.

As someone currently having fun d*cking with tuning their own car, I back the standalone choice as well. My NA picked up noticeable power switching to a standalone. Barely noticeable, but noticeable. And that was with zero other hardware changes.