Double post :(

 

Sim, weird you missed it. I'm installing a ZF6 transmission in the car to futureproof it for whatever power adder I decide to go with. This is a decision I don't see myself ever regretting.




Ok no, I've had a 6 speed for this thing sitting around for a few months now lol. The last parts I needed showed up this morning so I'll be installing that over the weekend. I wasn't in a rush to bolt it up but the AIM data shows my buddies with 6 speeds and similar power pulling on me in multiple sections of different tracks. Gonna toss the trans in and hope I can shave a little more time off my laps.

Codrus and Option, great input! I'll order a set of toe plates this weekend. Never considered getting a set before since I've got access to the alignment rack at work, but you make a good point that they could be useful at the track. Using toe as a reference point if an eccentric slips is pretty brilliant haha. Not that I've ever had an eccentric slip at the track and had to guess its previous position

 

I always set my eccentrics to the max deflection, and managed the result by the usual alignment tools. Reason being the wishbone loads are fed in with little to no angularity through the alignment bolt - ie the turning moment is near enough zero. I can't remember ever having an offset bush turn under load.

 

I think we're in the same boat Gee. I was referring to the alignment bolt eccentrics slipping at the track, although I could've done a better job of clarifying haha. I set the new control arm offset bushings to max deflection. Figured that's where they were meant to be in the first place.

In other news, quite the successful weekend!



Went into the shop early yesterday morning and got the 6 speed swapped in. I haven't done a trans swap in a while and it went a lot quicker than I expected. The process in the NC is the same as an NA/NB but a tad easier and quicker. The NC's PPF is simpler to remove and there's more room in the trans tunnel to zap off the top bellhousing bolts. I went about it lazily and the trans was out in 45 minutes, though I was cheating a bit with the lift and pneumatic tools of course.


Room in the trans tunnel. It's free real estate.

Topped off the install with a SuperMiata clutch. Went organic this time as my previous 4-puck was a little gnarly to street drive and I don't have any desire for this car to make above 290 crank TQ for the foreseeable future...


Mmmmm, orange.

Only hiccup I ran into was filling the trans fluid. I thought I had read somewhere that the NC 6 speed could be filled from the turret just like the NB's. I confidently poured half a bottle into the turret only for it to overflow and dump all over the trans and down the exhaust. So yeah, if you have an NC 6 speed, don't do that...



The NC 5 and 6 speed use the same pressure plate, but the clutch disc and driveshaft differ between the two. 6 speed driveshaft on the left, 5 speed on the right.

Not pictured is the Cobalt short shifter I purchased off of FB marketplace, as my trans didn't come with a shifter. I procured a bronze shifter bushing and between the two, there is next to zero play in the shift lever. It feels incredible. Unfortunately, when first installed, it rattled pretty bad from 6k rpm up to redline. As I drove it more today, the rattling lessened, but still isn't entirely gone. We'll see if that becomes a point of contention in the next couple weeks.

With the transmission bolted in and no mishaps, I told a couple buddies I'd link up with them for a drive today. Left the house at 5:45am to beat the crowds, and met up with the group at 7 on the coast northwest of LA. Miles of canyon driving ensued. I hadn't driven this spot in a couple years and was regretful of that after as the roads are great, as well as the views. We drove for a couple hours until the rest of the world started to get out of bed, then hung out at the beach for a bit and hit a local spot for breakfast after.



Oh, I also reinstalled my RT615's yesterday too. No point in burning up the RC1's until the car's next track day on 4/19. Honestly, the car looks better with the 225/45's than the 235/40's. Wheel wells are much more filled out. Still no rub with the fender liners removed, though.





Unfortunately, I wasn't able to display my car in front of our decided breakfast location.

My ID1050's showed up but I'm still waiting on my e85 tune from Fab9. Maybe they'll send it over this week, maybe not. Luckily I'm not in a huge rush to get them in. I've been reading a ton on how the NC's ECU strategies work (the DIY tuning community is blowing up for these cars, lots of great info being spread currently), and I have the version of ECUtek necessary to create a tune for my car. That being said, my current tune is working fine, and I don't want to add another thing to my plate right now. Might play around with my own tune over Summer if I don't have any other projects, but otherwise I'm gonna leave well enough alone for now.

 

Great progress How are you liking the clutch?

 

Thanks Ed! Shucks, I meant to add a little bit about the clutch. Very happy with it, feels very much like OEM. Just a tiny bit grabbier bite and only a touch more pressure required to depress the pedal. Both of those are a good thing in my opinion.

 

Glad to hear it. We love our NC clutch but haven't had much feedback on it so nice to hear good news.

Not that it matters from a marketing standpoint since it's discontinued 😂

 

Ah, so that's why the 4-puck wasn't even available when I purchased it back in September. Haha, how come you guys canned it? Not enough demand? Sounds like the stock NC clutch is good up into the low/mid 200whp range which negates the need to upgrade for a lot of people, and not a ton of forced induction builds out there yet anyways...

 

Yup, nobody bought them. The NC market is by far the weakest of the 3 platforms and the clutches sold extremely slowly, even after putting them on sale. Great clutch though. If you need a replacement disc we can still get them.

 

Jeeze, putting in work man. I don't always comment but I tune in for all your updates and watch every single one of your track videos, and showed my IRL buddy with the NC your build. He's psyched on it and you got him considering aero. The car is looking dialed, and hell of an eyeballing on the toe when you were in there. That's not easy without proper tools.

 

I thought you were serious for a half second and was wondering how I'd missed the part where you crashed your mountain bike and smacked your head on something

Cool cool. I was talking to one of our local guys with a 2.5 swapped NC about E85 this weekend. Can you guys tune the stock ECU to blend maps and run flex fuel, or is it strictly a 91 or E85 tune?

 

Ed, bummer, although I'm glad I could help you guys get rid of one haha. Glad to hear I can still get replacement discs. Thanks for the continued support.

Yo, thanks Nate! That means a lot to me. Most of the reason I keep up on the thread is to document the build for myself, but I'm glad a few others are finding it entertaining! Even better if I can inspire your buddy and others to do things to their NC's haha.
The eyeballed toe job was straight up dumb luck, but thanks still! I won't be attempting that again anytime soon.

Yes, if I start talking about drivetrain swaps again anytime soon please call an ambulance

So a couple aftermarket vendors have offered FlexFuel solutions for the NC, but from what I've seen it never worked well. Actually, I have yet to see any specific success stories of people running Flex on the forums. ECUtek does offer support for Flex on their tuning software for the stock ECU, which I believe is done though the CAN. This feature popped up maybe 8-9 years ago and a bunch of the tuning vendors jumped on the Flex tuning train, but all but one have stopped offering it now. I messaged Fab9 a while back as they have a FlexFuel kit on their website that's no longer purchasable, and they flat out told me it's not worth messing with and they don't sell it anymore. That being said, the new community-driven open source tuning software "ROMDROP" is going to be adding a Flex function soon (or maybe they just recently added it). I'll keep an eye out and see if anyone has luck with that, but for now most guys are just running dedicated pump and e85 tunes. We've got more and more e85 pumps popping up here, including next to one of our local tracks, so I'm not opposed to running e85 basically full time.

 

There exists a factory Jaguar bellhousing that mounts up to a 2.5 and adapts the BMW 8HP gearbox. All factory bits from crank to tailshaft.

Do with this information as you please

 

Oh man, that's evil! Zak rn:

 

*logs out*

 

So I was going to put off messing with my front end aero for a while, if not indefinitely... However, getting bumped out of TT5 class due to my fender cuts last race got me scheming on what I could do to optimize the car's current aero package. I'm going to be grabbing a pair of uncut fenders before the next race, and figured if I'm losing the benefit from vented fenders, I should try to make up for it elsewhere. TT5 class allows for a full front air dam with a maximum 5* rake. Minimally, that's enough to almost completely cover my front tires without requiring spats, which are illegal in class.

So yeah, to the dismay of a few, the NC's getting a trash can bumper lol.

I actually had only been able to find one example of an NC with a full front airdam, which had me questioning its effectiveness on the NC platform. Both the NC1 and NC2 bumpers are "flatter" than the NA/NB, so I thought maybe the airdam nets less of a gain on these cars? I made a thread here https://www.miataturbo.net/aerodynam...ess-nc-110264/ and Emilio and others were kind enough to offer some insight. Long story short, it still sounds like making an airdam is worth it, and there are plenty of other NC's in the wild running them.


A couple of Rapscallion Motorsports' NC's. Bitchin'.



So I ordered a 10ft roll of HDPE plastic off of Summit Racing on Monday. By some stroke of magic, it shipped from Nevada and arrived at my place the next day. Before I could stop and reconsider, I had already chopped the bottom half off of my factory bumper.



Continued the next evening and began cutting and shaping the HDPE sheet.



It's perfect. We're done.

Ok, a little more shaping maybe.



Cut out a very small mouth to start with and added some aluminum angle to the splitter to brace the bottom of the dam.





One big thing Emilio touched on was getting the radiator inlet as small as possible for drag reduction. My current cooling system is doing a great job of keeping temps in check, but I figured I should optimize it to run the smallest inlet possible. I'm also going to be running a screen over the inlet so my new radiator doesn't get killed by a spat-up rock like my other one did.

The airdam now sits a few inches forward of where the previous radiator inlet was situated. As such, the factory ducting no longer fully reached far enough to seal up the gaps. I took a couple pieces of ABS plastic and extended the side ducting all the way to the airdam. I'll go back in once I have everything else sorted and cut some new side ducts out of a single piece of ABS. While I was in there, I also plugged up 90% of the remaining gaps with A/C ducting foam and trimmed the splitter rods shorter so they could be run behind the air dam. Rods aren't mounted to the splitter yet in the photo below, I took this before lining them up and drilling holes.



Drove the car to work yesterday and today and coolant/oil temps are definitely a touch higher than before. I'm definitely going to end up opening the inlet up more (especially after installing the wire mesh), but I still got a couple tricks I can pull. I'm running a 60/40 water/coolant mix and can "lean" that out and add some Water Wetter, which I have on hand. Will probably do that before ripping the car around this weekend. Ducting can be slightly improved too once I cut single-piece side ducts. Maybe I'll add even more hood vents after if I'm feeling really gung-ho.


I did a little more shaping to smooth out the top of the airdam, and started filing my "mistake" holes with epoxy to make them less noticeable. This is about where the airdam's currently at, though.

Finally, I've got some M6 rivnuts and button head hex bolts on order for a final mounting solution. I was going to rivet the dam on, but decided on rivnuts for easy access to the radiator and oil cooler if need be. I'll get those in this weekend or next and am ordering some weatherstripping to completely seal off the bottom of the dam as well. Still got more work to do but stoked on how it's turning out!

 

Yes, yes. This is the way.

I honestly don't get the hate of the trashcan bumpers. That red NC looks tough. They work, it's inexpensive, and they look simple and purposeful.

 

Looking good!

Rivnuts are a good way to go... you definitely want the air dam easily removeable. In addition to the line across the top, I added a bracket at the rear lower corners. I don't think it's strictly necessary, but it adds a bit of rigidity to the whole assembly.

 

You might not like it, but this is what peak performance looks like
TRASHCAN GANG REPRESENT

 

I'm with you entirely, Ed. I get it, they're objectively ugly, but I like the way they look. Maybe it's just knowing the performance benefits behind it haha.
All in, I think the project cost me about 80 bucks. $42 for the HDPE roll and another $30-something for the hardware I'm gonna use. It kept me occupied for a week and I'll have an extra 30ish rivnuts, button head bolts, and large OD washers laying around when I'm done. What's not to love?

You mean like this, yeah? Or are you saying you added brackets to the "wings" of the splitter? I should've added a photo of the bracing I added to keep the bottom of the dam in place. Excuse the hammered splitter, it's made lot of contact with the ground and numerous other objects since I've built it lol.