Haha, thanks dudes. Yeah, super amped on the whole package right now. I honestly had no idea that tuner Hondas had that signature sound due to induction noise. Glad I'm still continuing to learn lol.

Gonna keep messing with the tune and hopefully get those magic numbers from Fab9 today or tomorrow. If this thing cracks the 190whp mark, I'll be stoked!

 

This intake makes me want to get an NC lol

Near-ITB noises without the ITB headaches

 

The fun continues! Did some troubleshooting and got more tuning done this weekend, and have started to prep the car for WSIR in two weekends.

So first off, these showed up.



Gonna be swapping my track tires to Toyo R's for the last two NASA events of the season. GRM's testing showed they're 0.1 seconds slower than the Maxxis RC1's on a 1.5 minute course, so I'm confident they'll work well once I get used to them. I was very excited to try these but I did shed a tear inside reading that they only have 3.6/32" of tread straight from the factory Went with the same 235/40/17 size I've been running for track tires since I got this car. I was thinking about going wider but I don't think more rubber will benefit me at the car's current power level. I'll be upping to 255/40/17's next season and will do some flaring of the fenders before then. Hoping I'll be able to use these to reap some contingency rewards and pay for the 255 set of RR's I'll start with next season.

So yesterday I messed with VVT and fueling a bunch more. I had no plans in the afternoon and decided I was going to hit the beach (a ~20 minute drive away) to do a little freediving. I loaded up the Miata with plans to do a couple pulls on the way and mess with a couple things in the tune. Long story short, I never made it to the beach. Got sucked into experimenting with VVT and fueling and spent over three hours street tuning the car before heading home



Long story short, the car liked 15* of VVT advance at redline more than 10*, and it liked 20* even more than that. I experimented with 25* at redline but it didn't seem to make any more power than 20* so I left it at 20*. My VVT table at WOT throttle now is basically max advance (33*) by 2,500rpm, tapering down to 25* at 5,500rpm, then 20* at 6k and above. There's a pronounced drop in engine load around 5.4k rpm so I played around with holding the VVT at max advance until both lower and higher rpm, but it didn't seem to have any correlation with the drop in load.

What I messed with for much much longer: I was getting some fluctuations in my MAF sensor readings late last week which made me think either there was turbulence in the intake at certain RPM or an issue with my MAF sensor. From 4,100-4,700rpm, MAF readings were actually oscillating up and down just a bit (less than 5%) resulting in a slight lean condition (+0.5 AFR points) through that part of the rev range. The same thing would happen super briefly at 5,200rpm, resulting in a very brief rich condition (-0.3 AFR points) as the engine passes through there.

I'm not expecting anyone to remember this but back in May, I put a MAF sensor from a Mazdaspeed 3 in the car, which is able to read 1.36 times as much air as the factory Miata sensor. This is advantageous for a turbo car as the stock Miata MAF can't read more than about 280-290whp worth of air when placed the stock 2 3/8" MAF housing. Now that I have a 3" MAF housing, though, I won't really need to run the Mazdaspeed sensor, since the housing area increase means the stock sensor can meter 1.59 times more air before maxing itself out.

So I popped in my stock sensor again, rescaled the MAF tables for it, and did some more driving around. The "noisy" MAF areas of the RPM range didn't go away, but they lessened up quite a bit and MAF readings were much more linear throughout the rev range at WOT. Unfortunately, there was still a lot of fine tuning to be done even after I rescaled the MAF tables. I think I ended up doing at least 10-15 pulls and a bunch of street cruising to get fuel trims and WOT AFR's back in check. The engine still goes just a touch lean at ~4,400rpm and a touch rich at 5,200rpm, as MAF readings fluctuate mildly, but it's much better than before. I've tuned it out mostly via the load scaling table, although said table isn't as effective due to it being based off the MAF readings to begin with. Next I'm going to try moving some of my intake tubing around, so the MAF isn't so close to the bends, or maybe I'll swap my 45* elbows with 30* elbows if I can make that work.



Current load scaling table after a little bit of messing around. I think my MAF scaling tables are more accurately matched to this sensor as the overall load scaling numbers I landed on are lower than before. You can see where I'm adding all that extra fuel around 4-4.5k at WOT to counteract the lean condition.

All that being said, though, I've got AFRs under control at WOT and the car rips. I've got it holding close to 12.5:1 regardless of temps/altitude at this point. It's gotta be making a good bit more power above 4k rpm onward, and I'm really excited to see what it makes on the dyno in two weekends. I took it up to the mountains today for some more "research" and "verification" and was pleasantly surprised to find that the engine seemed to choke up less than before as we climbed in altitude. I'm still sure that 50% of my perception here is due to all that extra induction noise, but I'm pretty sure the car is marginally faster. Again, I'd be amped to find it's making 190whp now.



So next up: CHUBs, messing with the intake/MAF housing, getting the Toyos mounted, maybe a bolt check.....

 

How are you verifying the increased performance from the VVT changes? Just feeling it out, Virtual Dyno, other parameters in the tune/log?

 

TBH, I should have downloaded Virtual Dyno by now but I'm getting pretty positive feedback via the MAF sensor readings. Don't have my laptop with me so I'm just going off a screenshot from above. The G/rev (grams of air per engine revolution I believe) readings highlighted in green are basically an expression of cylinder fill, so any changes made that result in higher or lower readings in a certain part of the rev range will be reflected there.

A lot of the guys self-tuning these recommend taking a **** ton of logs with different settings for one output (VVT/spark/etc), compiling all of the data into a histogram, then using said histogram to choose the settings that reflect the highest load readings in a given part of the rev range. I haven't gone that far yet but I've had luck doing back to back pulls on different settings in the same conditions then directly comparing readings from the logs.



Couple histogram examples, more for posterity/anyone looking for info on NC tuning. I swear I'm not trying to bore you to death





Long story short: MAF sensor and logs work pretty good to see if your changes are making more power

 

Wow, cool. I still need to harness the power of histograms. They seem super powerful for processing certain sets of data.

 

Got some work done this weekend, and then created waaaaay more for myself

I got the Toyo R's mounted on my track wheels last week, then yesterday I went out on the street and made a detuned copy of my current tune in case I go over my TT5-class power limit next weekend. Ended up having to limit max throttle angle to 43* to get MAF readings to drop ~10%. If I go over my power limit (~185WHP depending how much my car weighs in at) on the dyno, I'll take another 3 pulls with the nerfed tune and adjust it in the paddock if I have headroom. I ended up playing with the DBW tables manually but forgot there's an "Engine Load Limit" table that will dynamically limit throttle opening to keep you under a certain torque value for a given RPM range. I'll play with that next time.



I then took the car up to the mountains today and absolutely clobbered the splitter on a huge rock.



This was my fault entirely, but I feel extra dumb because I could have so easily avoided it. Came around a corner and saw the rock in the road maybe 5 seconds ahead of where I was at. I looked at it briefly and decided I had enough ground clearance to make it over, instead of going around it into the other lane. Wrong! I hit the rock and grenaded my splitter, leaving a crack all the way through it along with a gaping hole right in front of the radiator. The car then dragged the rock along under the subframe until I came to a stop. The rock (or something) actually got so hot, it singed the AC foam I'm using to duct the radiator with which resulted in me thinking I smelled a blown tire.



Honestly, I'm pretty pissed since I could've avoided it, but the damage is way less than it could've been. The rock missed my radiator and oil cooler by an inch and did no other damage aside from the splitter. Subframe is fine and honestly the splitter was still sturdy enough to stand on even after taking that Mike Tyson hook to the face. You might notice, however, that it's slathered in wood glue in the above picture. "C'mon Zak, don't do ghetto sh*t, just cut a new splitter. You've got all week."

Well I would, but I still have all of my car prep to do, plus deal with this.


So on the way home, I did a pull and got a flashing check engine light near redline (different from my standard check engine light which is permanently on ). Flashing CEL means you've got a catalyst-destroying misfire. However, I wasn't getting a misfire. Oh god, I know what this is...

Fluidampr just put out their balancer for the NC a couple years ago, and it's a known issue that the first batch had some units where the trigger wheel bolt holes were countersunk too deep. This led to the trigger wheel working its way loose over time despite the bolts staying loctite'd in and bottomed out. I'd already installed mine when this info came out, and had bought it quite a while after the first batch was released. I thought I was safe, but I guess this one may have just sat on the shelf for a while because I checked and found my trigger wheel has about a degree of play in it today. Fluidampr has been sending out new units to folks with the issue, but some guys have gotten away in a pinch by pulling their damper and replacing the countersunk bolts with ones that have larger heads. Other guys have reused the original bolts but used epoxies to take up the dead space.

https://www.facebook.com/reel/1197009918415421

Normally a damper swap would just be a damper swap, but on an MZR/Duratec, most folks running these engines in NC's recommend the friction washers on both sides of the crank gear be replaced since the crankshaft isn't keyed. It's basically a full timing job. Valve cover, front cover, and timing chain all have to come off which is a bit of a PITA. First real bummer I've had with the MZR engine family.

Now, the workshop manual for these engines says that you can just replace the outer washer and crank bolt if you replace the damper and be done with it. I've done this on a number of 2.0L Duratecs at work with no issue. However, in an application where the engine's getting raced and run a full 1,000rpm above the factory redline, I feel like it'd be prudent to replace both washers. I'm undecided on what to do yet. Hell, maybe I'll even put some retaining compound between the trigger wheel and damper body at equal intervals and send it this weekend. I'll make the call tomorrow. I got a lot of prep done on the car today, but still have plenty more to do this week...

 

Bummer on the splitter man. Glad it didn't do any damage to the cooling stack though. Didn't you have a spare splitter lying around somewhere? Not saying you should throw it on, I just thought I remembered you cutting one up a while back.

Bummer on that crank damper too. Nothing like doing a job properly only to be foiled by faulty parts.

 

Dude. Bummer. Also lucky, but bummer.

 

Sheesh man. I know you'll get this sorted in record time, but damn, that sucks. And I was annoyed by having to pull my fluiddampr to replace the failed fab9 36-2 tone ring, even though I didn't have to redo the timing.

 

Sim, funny you'd mention the spare splitter. I had my old one laying around at the shop, but last week we had a major cleanout and I ended up having to toss it in the dumpster. Flawless timing lol. That splitter only had 2" of protrusion with my airdam setup instead of my current 4" one, but it would've been real nice to trace that thing and make myself a new one this week. Oh well.

I ended up doing some ghetto fabulous fixes to the splitter last night and stitching it back together. Took a 1/8" piece of plywood and screwed it into the bottom of the splitter where it was cracked. I then screwed a 3/8" wedge of plywood into the 1/8" piece where the gaping hole was and used a bunch of screws and all the aluminum angle I had laying around to stitch the cracked area back together. I rounded off the leading edge of the 1/8" piece as well and used lots of wood glue everywhere to smooth out the top and bottom of the crack. I think it's actually sturdier now than before I put a hole in it Just needs a little more black spray paint because I ran out.


After our final race on 10/18-10/19, I won't have to limit my aero setup to fit the TT5 class rules anymore, and will be able to run a 3D splitter with more than 4" of protrusion. I'm gonna run this one with the ghetto fixes until then and will build a new splitter with ramps and probably 5" of protrusion after that.

As for the Fluidampr, I emailed them to start a claim and was told I need to send the damper in for inspection. I flatout don't have time for that so I'm going to band-aid fix it for the time being and revisit the issue the next time I need to swap the motor. I took the trigger wheel last night and pushed it away from the damper body to get the bolts to bottom out in the countersinks and center it up. I then dripped some (a lot) of retaining compound between the trigger wheel and damper body. Came out this morning, spun the motor over 180* and did the same thing on the other side of the wheel/damper to hopefully allow the retaining compound to spread at equal intervals and not create any balancing issues. The second round of retaining compound is still curing but as it sits, the wheel is secured in place. I'm gonna fire it up later and rip the car around to see if it stays secured. Will probably add more retaining compound to the damper at 90* and 270* after that. The trigger wheel only moved maybe 1-2mm toward the front cover so I don't think I'm going to run into an alignment issue, but if I do, I can just take a little material off of the CKP sensor bosses to get alignment back in check. It still looks about perfectly aligned just by eyeballing it.
Again, since everyone with the issue said their bolts were bottomed out tight, I'm not too worried about losing the trigger wheel.

 

Zak, this is some ghetto **** and I'm here for it. Duct tape that bitch up and go racing!

 

Appreciate the support as always, Nate! I had a feeling you and the guys would approve haha

 

I also approve.

Appearance is vastly over-rated, and ugly can be as fast as pretty in the right (Zak's) hands.

You do what is necessary first, and prettify later if time and inclination allows.

 

Dude, are you the last person who owned my house? I swear that's the level of craftsmanship (arguably better) that they had.

Way to make it work, it's just a sheet of plywood after all

 

Thanks for the kind words, Gee. Hopefully I can live up to that statement this weekend haha. And Sim, that's exactly what I was thinking halfway through. Not a very dynamic part. The two "design parameters" are that it stays flat and doesn't break in two at over 100mph lol.



Got 99% of the race prep finished on the car at this point. Oil change, diff fluid change, swapped in my DTC60 brake pads f/r, installed the Toyo R's, removed all of the non-legal aero bits, reinstalled the evap canister as extra insurance so I don't go below minimum weight at weigh in, touched up the alignment, gave the brakes a quick lazy gravity bleed, fixed a torn exhaust hanger (hose clamps FTW) and bolt checked everything I could think of.

My AntiGravity ATX-12-HD battery also bit the dust last week. My fault entirely, I've ran that battery dead multiple times by leaving my OBDII dongle in the car and not driving it for multiple days. It lasted 18 months but I think it would've gone much longer if I trickle charged it and didn't run it dry multiple times. I hit up @SimBa about those non-AntiGravity lithium batteries he'd mentioned in my old car's thread. Ended up grabbing a Noco battery to replace the AntiGravity one. This one specifically is rated at 600 cranking amps instead of the Antigrav's 480, weighs a pound and a half heavier, and is just over half the cost. I got it for $150 shipped. Gonna keep it trickle charged and try to remember not to leave my OBD dongle plugged into the car overnight from here on out. Time will tell if it goes the distance or not.



My only real concern regarding the car this weekend is due to this service bulletin Toyo has out about the R's. The bulletin cites that the tread splice can begin to separate unless you mount all four tires the way they specify. I figured this was due to one or two freak occurrences, but mounted my tires as they directed anyways. However, after doing a little digging on the internet, I guess it's not incredibly uncommon to run into this issue with the tread splice.








Paging @codrus & @doward - Do you guys have any experience with this firsthand? I thought I remembered both you guys saying you've run R's before. I'm not too worried about this, just gonna be a little bummed if I have to start tossing tires before they're heat cycled out haha.

 

I have been running Toyo RRs for several years and have never encountered a visible tread splice separation. I have always mounted/rotated the tires as directed in the above documentation, and then flipped the tires for maximum life.

I would consider the tire you pictured above to be unsafe, but it's probably worth contacting Toyo to see if they might replace it...

 

I'll be interested to hear how the Noco does for you. I still haven't purchased one myself but I think a couple guys (and at least 1 with an NC) is running one. I can't bring myself to spend the money when my old battery is still working fine, but that's probably what I'll be going to next.

 

Yo, thanks for the heads up! Completely forgot you had a set of RRs for your car. Good to hear. I mounted mine that way and will only cross rotate.

Luckily the tire pictured isn't one of mine, just a pic from an E36 form. Mine are all still new until this Saturday...

I feel you on that. Hate throwing away good working parts myself haha. I'll keep the thread updated with how the Noco works!

 

I have never run the single Rs (they're only a couple years old and I've mostly been running various Hoosiers in that time frame). I did get visible tread splices on both RRs and Nitto NT01s on my M3 (the two tires are supposedly the same construction, just a somewhat softer compound on the RR). I did the special mounting procedure on the RRs, but not the NT01s. The Toyo advisory basically says to toss them if it starts to actually pull apart, mine never did so I never had to toss them for that reason.

I've seen reports of it happening on other tires too, there was one tire that seemed to have a lot of delaminations happening on track after getting them. RT660? I don't remember.

I dunno if I have any really useful advice on it, but I will say I've never seen it happen to a Hoosier.

--Ian