bogle's 1991 mild build thread

[RYU]

I pondered for a while what numbers i'd get with the CTSC and tuning for meth. At the end, I tuned for without meth and simply used it for cooling. I was driving the car pretty hard at the time. I didn't want to succumb to any one failure point. I also wanted the ability to simply put water in there in a pinch. With that said.. In the 5yrs or so I was on that setup it never once failed AFAIK. Also, my AFRs didn't change materially to require a retune. IIRC it added about 0.5-1 AFR of richness in the tune at WOT under prolonged sprayage (i.e. a long track day session)

Noted on the plate. Definitely sounds like the dream. I really want low air temps on demand. Having to have it sort of primed and using so much is not ideal. I’d love to be able to spray a little meth and get the octane boost but not have it hugely affect the AFR.

I emailed AS Motorsport about it and asked a bunch of questions. We’ll see if he’s down to make one for me



Man I really want a fully ecu controlled solution. The data alongside the rest of the engine data, plus the ability to precisely set it up would be amazing. When I eventually move to a haltech I’ll make an attempt to have it run the system in a nice way. Though I still haven’t seen anyone with a simple ecu-only setup. The pump requires a lot of current. So it’d probably be a PWM out to the dumb AEM box.

 

[bogle]

I took the car to an autocross at Sonoma raceway a couple weeks ago. Two years into ownership, I still hadn't really had the car at its limits. Kinda absurd, tbh. I've been wanting a lightweight way to see the limits of the car before a full track day. Does it do anything crazy? Do I? So an autox. Just the tip, just to see how it feels, you know?

I had general car questions: What is the balance of the car? What does it feel like at / near the limit? How long does the water tank last? (not very long) What do temps look like? (hot af) But also ... it's been a long time, have I totally forgotten how to drive? (no) What do I do under duress? Do I revert to my front wheel drive habits and stab the throttle when the rear steps out? (no)

I didn't take very many pics, so mostly words. The one car pic I took was way early in the morning. The fog was pretty cool and I kinda wish I would have brought the proper camera

I'm about 45 min north of Sonoma raceway so I've been keeping my eye out for events that pop up. Occasionally some HPDE org will rent out the track then set up a little autox in the paddock as a sideshow. This event was with Trackmasters. They put the autocross together super last minute and basically didn't advertise it; it was small. When I was doing SCCA autox, even in podunk eastern Washington, ~200 cars would come and you'd get 4 runs, maybe 5.

Something like 40 cars showed up to this one and everyone got at least 25 runs, probably more. I recorded 18 of them, blanked with the gopro on the first few runs, skipped some runs to adjust tire pressure & fiddle with the WMI, then the camera was in a weird state for my last 5+ or so runs. 25 runs? 30 runs? idk. It was a lot.

Bro do you even drift? (no)

How did the car behave? For some reason I had it in my head that it would be unpredictable snap-oversteer city, like the slightest hint of braking mid-corner or wheel spin on exit and it'd come around. It doesn't do this on the street, but you never know? Overall it felt awesome and I gained a lot of confidence over the course of the day. It was predictable, communicative, and I wasn't fighting it (other than the steering ratio).

The RT660s were nice, they liked pretty low pressures. They felt a lot better in the low 30s at both ends. IIRC I was 31-32psi front and 33-34psi rear by the end of the day. I had read they like to be even lower than 30psi, but I was hesitant cause they'd be cooler on the drive home.

Currently it has an Tein RAs with 10k front and 12k rear spring rates, an NSX-R front sway, and a stock rear sway. The course was pretty smooth, so the highish rates were nice. I thought the rear-stiffness would make it oversteer prone, but after a few runs I wanted _more_ rotation. I could occasionally make it oversteer if I wanted. I really only understood how to get it to rotate under braking (those FWD habits tho), or on exit if the car was already headed that direction + I had some space to stretch. There were a few sections where it would understeer mid-corner, or on exit with no throttle room and I didn't really know how to get it to rotate.

That said, the course was obscenely, unreasonably tight. Other than the very last 50-100 ft, it was all 1st gear for me, 15-25mph corners, the first corner was full lock, etc. Probably not totally representative of the capabilities. 100% I would have been faster in the civic.

Did you win tho? (no)

The course was 41-46+ seconds. The fastest times were in the mid 41s. Except for a sorta-stock-looking C8, the fastest cars were all prepped autox cars on hoosiers. I was about a second off the top time with a 42.5. Part of me was disappointed I wasn't FTD, but to be expected. If I really understood the car I could have been in the mix, which was especially apparent after watching all the vids of me blowing the first corner, weird lines, swimming through the really tight middle section, etc.

The videos aren't so exciting, and I didn't end up filming the fastest run(s), unfortunately, but here's one ~1/2 sec slower where I did ok in the last section. This is one of several runs spent trying to be smoother, use less hand-over-hand, plus work out the first corner. The first corner was an awful full-lock gymkana-style loop around a cone that I never groked. There was easily 1/2 second in the dumb thing and it was there that the car understeered the most. Some people were drifting around it, but by the end of the day, times were lower with less drama.

https://youtu.be/shVJCIB2dWg

Note: check out the navpod, you can see that the air temps are super high (big number, left side, 2nd from bottom). It was a perfect storm: 95F+ afternoon after the car had been sitting in the sun, and I had to turn the WMI way down cause it was almost out of water. Maybe next time I'll have that phenolic plate, either way, I'll definitely be bringing more water

All in all, everything went well. Nothing broke, I used a lot of water, and I feel like I understand the car a bit more.

 

[bogle]

K-series coils

A little while back I had a misfire that was solved with a new-to-me used Legend coil. If one went bad, the others surely are not far behind, eh? The igniter can also supposedly occasionally go bad, again causing a misfire. I want to live in a misfire-free world. Can I replace all this junk with better stuff?

K-series coils are more modern than ours. The big selling points are that they have an integrated igniter plus overheat protection. Aint nobody want to run an external igniter, and with these you don't need to. I guess if I blow it with the dwell time and they get hot, it's fine, so that's neat too.

The lure of newer, better tech in the car is forever interesting. While there are a couple options, I upgraded the old, stanky coils with k-series coils to keep it in the family.

Parts

Parts were simple. I got a kit with wiring harness and mounting hardware from foundry3, then I had to buy my own coils.

The kit specifies coils with Honda PN 30520-RRA-007, applications being the RSX and 04-05 S2000. The cheapest I found the Honda coils was about $60 each from Amayama. But the Honda part appears to be rebranded Denso coils with part number 673-2301. The denso coils are $37 each from rock auto. I bought 8 of them just in case.

The whole kit:

And one coil top

They seem to have all the exact same markings on them that the OEM Honda coils have: 099700-115.

Mounting

The Foundry3 kit comes with these pretty cool coil spacers. They seat into the coil's grommet nicely:

Then each coil gets a little metal tab to bolt it to the valve cover

We wont be using the factory plugs or coil harness, so they will just float around in there.

Edit: I had to break this into 2 posts as it was too long to edit...

 

[bogle]

K-coils part 2: Wiring

The instructions said the install would take 30-60 minutes. FMLLOL. Nothing aftermarket is easy. I have several whole hours just routing the harness. I’m not sure where the igniter is on a stock car, but it must be in a different spot vs the CTSC setup. The foundry3 harness layout was not well suited to the supercharged setup. Most of the time was spent trying to find pathways through parts where the harness wasn’t laying on something hot, wasn’t kinked, and wasn’t rubbing anywhere.

Here’s the harness laying on the supercharger inlet snout for directional reference. The top connector plugs in where the old igniter would go, then there are looms going to the front bank, rear bank, a ground, and the VSS (probably for power?).



Seems legit, eh? Holy crap it was annoying. The main problem is that the igniter plug and front bank loom need to route between the snout and intake manifold in the same orientation—they both need to point toward the front of the car. But they come out of the harness in opposite directions.

The only reasonable path: thread the top bit of the harness with the igniter plug between the snout and intake manifold. This will make the front bank loom come out toward the back of the engine. Then wrap the front bank loom around and under part of the intake manifold back to run toward the front of the engine. This is hard to visualize and hard to take pics of, but here’s an attempt.



The igniter part of the harness is routed from the right (rear of the car) to the left (front of car) to be sort of in the same position as the OG igniter. Then the front bank loom is wrapped under and back to the left, passing by the EGR valve.

In this orientation, the challenge was to actually have enough wire to make it to the front bank coils, but also nicely plug into the original igniter plug. When there was enough wire for the front coils, the igniter plug connector would stick out several inches beyond the OE igniter, which made placing the igniter plug to new harness connection hard. I depinned and tried routing the igniter connector 10 different ways. Total pain.

A couple changes to the harness would have made this significantly easier:

* If the front bank loom and the igniter plug came out of the new harness in the same orientation
* If the wires to the igniter plug were like 1" shorter to place it exactly where the old igniter was.
* Or even if everything was the same orientation, but the wires to the igniter plug were 5-6" longer. I would have had many more plug stashing options.

I ended up with the connection kind of under the fuel rail. I ziptied the OE harness's igniter plug to take up some of the slack. Then a piece of DEI fire sleeve went over the wires to the igniter plug to limit rubbing. It’s ugly, but it works without touching, kinking, or chafing. Without the fire sleeve, the new igniter plug part of the harness would rub on the fuel rail and the edge of the intake manifold. Pile o' connectors in there:



Once the front bank and igniter plug parts were in, the rest went easy. Here’s the VSS plug, it’s a patch harness. The orientation was also a little weird, but there is a lot of room. There is an open plug bracket down there, but the harness isn’t designed to use it and it didn’t reach, zip ties did the trick.

In! Finally! The old plugs just kind of chill there next to the coils.

Coil dwell

With the new k coils I needed to setup coil dwell time. Coil dwell time is basically the amount of time it takes to fully charge the coil at a given voltage. Set it too low and the spark will be weak, set it too high and you can overheat the coil.

The k coils charge a little faster than the OEM NSX coils so need different settings in the EMS. Various places, including the foundry3 docs, recommend 3 milliseconds at 14V for these coils. Here’s the table from the Haltech k series info page:

This should be the easy part. Just set to 3ms at 14v! There is a table in the EMS! 5 minutes of effort, max!

AEM V1 ECU: hold my beer

The series 1’s tables and settings aren’t in milliseconds, of course. There is a unitless coil dwell factor, then a battery volts vs percent (of what?) table, and a unitless rpm vs value table. The AEM pro docs do not describe how any of this works.

There is a "Honda COP" config in the AEM pro coil dwell wizard and, fortunately, a way to log the dwell milliseconds. I loaded all that up and started the car. The logged values were in the 4-5ms range though, too high. I did some experimentation to get them down, drove the car and the dwell values were kind of a mess between 2.7ms and 3.5ms.

The internet came in clutch here. I found a couple of threads with some info, then I spot checked the internet formulas against the logged millisecond values. They matched!

Now I understand. For the one person who will need this 5 years from now, here is the AEM V1 / series 1 coil dwell milliseconds formula:

2 * coil dwell factor * (dwell vs batt percent / 100) * dwell rpm raw

And the table / options configs I ultimately ended up with to match the Haltech table above:

How does it run?

Different! But generally good. I haven’t had much time to drive it with the proper dwell settings in there. The tl:dr, though:

*In boost at WOT AFRs are 0.25 - 0.5 leaner. It has always been richer than I want WOT (10s in a few places), so this is welcome. I had been meaning to pull some fuel up there...
*Tip-in overall is way crisper. I haven’t spent a lot of time with it, but maybe it’s a little leaner?
*Cruising AFRs are the same, yay
*Idle is different. I need to spend more time to get it idling a little lower but still catching the idle when pushing in the clutch. Now it idles at like 950-1k with no hunt and proper idle catch; best I could do in 30 min of experimentation

It took a couple tries to start up the first time which was a little stressful. Once it was warmed up, it ran like garbage. It wanted to idle around 1200 which is way over the target idle, then it’d hunt like crazy: 1200, burble, 800, 1200, burble, 800, etc. it even died a couple times…

I almost went back to the stock coils. Hard to start up, at the time I didn’t know how the dwell settings worked, then this hunting idle, I thought maybe the coils need to wait until I was on a Haltech. Or maybe they would be the catalyst to pull the trigger on the Haltech.

I noticed that during the idle hunt, timing was oscillating. I messed with a few tables and managed to get the timing stable and have the idle chill out. Took the car out and it felt really good. Coils stay, ok!

Fin

This was supposed to be a short post. I really really thought this was going to be an easy project. But I guess there are no quick wins with aftermarket bits

 

[bogle]

New coilovers

I got new coilovers and they are installed.

When I bought the car it had a set of Tein RAs installed. They have pretty high spring rates at 10k front and 12k rear, which make for a bumpier ride than I'd like on rough roads. It's been fine over the last two years, though, as I generally try to avoid crazy busted roads when I can. But a rally I took the car to a few months ago really was a catalyst to pick up a softer set. A big portion of the rally was over some bad roads and really highlighted the high rates.

I wanted something softer, and I figured I would stand on the shoulders of the community with a more traditional front-stiff NSX setup. Rates would be in the NSX-R range somewhere between 8k front / 6k rear (92 NSX-R) and 10k front / 8k rear (02 NSX-R).

MCS 1WNR

I ended up with a set of MCS 1WNRs + Swift springs at 9k front and 7k rear. They are 1 way adjustable (1W) and do not have remote reservoirs (NR).



They were built by AR motorsports in the Portland area. There is a bunch more info on these in this thread. The off-the-shelf 1WNR dampers have a linear damping curve, but AR has an NSX-specific custom digressive curve apparently similar to the NSX-R curves. I have not seen the damping curves, though, as AR didn't want to share the charts with me. I asked! But they didn't trust that I wouldn't share them on the internet (I wouldn't have tho...).

I went 9k/7k because I couldn't decide between 10k/8k and 8k/6k. I wanted the highest rates I could while still being reasonable on rough roads. 9k/7k would let me go up or down if I felt they were too much in either direction. AR said that the dampers can handle 10k/8k or 8k/6k no problem, so would not require a revalve if I changed springs.

Part of me wanted the 2 ways with remote reservoirs because racecar, but practicality won out here. This car is a street car and I dont need either 2 adjustments or remote reservoirs. Also if I had gone with the remotes, I would have had to figure out how and where to mount the remote reservoirs. Any problem solving like that always adds a huge amount of time to the project.

The upside of these dampers is if I end up wanting the 2 way remotes, my 1 ways can be converted to the 2 way remotes. Noice.

How are they?

They are in! I have one session on them!

They feel awesome. Even pulling out of the driveway and driving through the neighborhood they immediately felt more compliant. There is a really rough one-mile section of road I need to take to get to my favorite road. I've driven it 100 times in the car and it was a great test: it felt much more like a normal car over the bumps. I mean, it's not like prius compliant, but a ton better. I haven't adjusted the dampers yet, I am on the recommended install settings of 8 clicks (of 18) from soft. I'll try them on full soft out of curiosity.

Balance wise, I was assuming it'd understeer a lot more than it did with the rear-stiff teins. The rates are almost half the teins in the rear on the new set (7k vs 12k). But the change in feel wasn't as big as I was expecting. It does understeer a little more mid-corner, but not unusably so. Part of me wants to put the type-s rear sway on, but I'll wait until I get the car on the track for a real test. On the street I obviously wasn't near the limit.

 

[bogle]

MCS install

The install was, as usual, more difficult than expected.

AR builds the front dampers a little longer than the off-the-shelf MCS dampers. Apparently the off-the-shelf NSX set is for a race car with race car ride height. When developing the set, they couldn't get the ride height they wanted on the test car, so they made the fronts 1.5" longer.

These longer fronts caused some pain. For my setup, the front dampers could be at least 1" shorter. They came with a 7" spring, but should probably have a 6" spring instead. You'll see why in a second. The front dampers are 3/4" longer than my old teins, the teins use a 6" spring. If I were doing this again, I would ask for shorter front dampers and a shorter spring.



On the fronts, the longer springs cause the perches to interfere with the upper control arm



Then they also are longer than the natural droop of the suspension, so it's tough to get the eyelet to line up:



To install I had to raise the perches way up to clear the control arm, then droop the crap out of the suspension to get the bottom bolt in. This was a pain to do on my own. I basically was laying on the rotor to droop the suspension with my chest, then used my hands to get the bottom bolt in. But it worked out, and the 2nd side went a little easier once I had the process down.

Here they are in. Note that there are brake line brackets too. I used BC racing brackets part number A-12. There is a strip of 1/32" silicone between the brackets and the damper body to be easy on the threads.



To adjust height, I had to compress the suspension so the helper was 90% compressed, then lower the perches. I dont own a real jack, and the only thing missing from the NSX tool kit is ... the jack. So this is the weird jack out of the Audi:



I had to do this jack nonsense in several passes. A little at a time because if the helper is too compressed, I couldn’t spin the perches, and I could only go a couple turns before the perch hit the control arm. It took forever.

Long dampers make for crazy droop. Ready for dakar here. I did end up adjusting so there was less droop... less droop cause the perch interferes with the control arm



Here's the perch at roughly ride height. I ended up like 8-9 turns lower than this, which would move the perches down, but damper body up in relation to the control arm. No issues when driving!



The longer fronts made this install take at least an extra half a day between the install and the process of jacking the wheel up a little at a time to adjust.

Rears

The rears were perfect length. They went in in 30 min and I had no issue with them. Yay for easy.



And in!

 

[bogle]

Small supercharger stuff

Almost every time I take out the car, I pull the internal logs off the ECU, even if it was a drive to the grocery store. It's fun to look through stuff, and good for posterity: if something looks off, I can check out data from a couple months ago.

In the logs from the last couple drives, I've noticed that it looks like the boost fades a lot as the RPMs rise. Check this one out, it loses 4.5psi from 5500 to 7500 RPMs:



I looked at some older logs and it still faded, but only to 5.5 or 6psi. I thought maybe this was normal: as the engine speed increases it could ingest more air in relation to what the SC is putting out. But then I looked at the boost chart from the last time it was at the dyno, and it only went down to about 8psi at redline.



I did a bunch of reading on the internet and it was unclear. Threads all did mention that a loose belt could cause boost fade, but I thought things would be a lot more abrupt with belt slip, and I didn't see any log charts from anyone showing similar boost fade. My belt also felt pretty tight on twist. I called Shad at driving ambition and asked him a million supercharger questions including: how much fade should I see? Is 4.5psi normal? No, too much. He was convinced it was belt slip.

The SC belt tightness check is twisting the belt 90 degrees on the span coming off the SC pulley toward the rear of the engine. He said basically if I can twist it beyond 90 degrees at all, it's too loose. Okay. I tightened it up until I couldn't twist it 90 degrees then took it for a drive this morning.

Shad was right, it's fixed!



Air temps were a little lower than when I usually drive it, plus with this extra boost up top, the car felt pretty rowdy! Yay for full power.

SC oil stuff

I also replaced the SC oil + oil fill plug while I was messing around in there. The fill plug was chewed up and it's annoyed me forever.



It's actually a dipstick, cool.



I bought a new dipstick from John Bond performance. They do custom dipsticks and I got it made with a notch at the same position as the original one. I also used their oil and this syringe which made the job super clean.



Then I filled it with 95ml oil. After driving it and checking the oil again, it was a little high:



Another supercharger-related nugget from Shad is that it's better to be a little low on oil rather than a little high. Apparently when the oil level is high, it can cause the oil to froth, which could cause high heat in the gear case, then the heat can cause a plastic part in the blower to melt. He said the only times he's seen one of these blowers need a rebuild are when 1) they ingest something like a rock, or 2) when this little part melts.

So I pulled 15ml out of the SC and am running 80ml, which puts it just below the fill line.

All done! The new one looks so much nicer.

 

[Big McLargeHuge]

Thanks for posting about the DEI Fire Sleeve, I was looking for something similar to insulate my injector wiring harness adapters.

Nice looking coilovers!

Sometimes I think ignorance is bliss when dealing with ECU data . Great catch in this case though

 

[bogle]

Thanks for posting about the DEI Fire Sleeve, I was looking for something similar to insulate my injector wiring harness adapters.

Nice looking coilovers!

Sometimes I think ignorance is bliss when dealing with ECU data . Great catch in this case though

I really like the fire sleeve stuff. I think I’ve used almost all of the stuff I bought. Like no way I can get through 15 feet of it, but it’s all in the car now. I shoulda used it on the abs harness when I attached it to the brake line, but it is what it is now.

Thanks! I have more experience with the coilovers now and they are . I’ll post more about the latest rally soon and they performed perfectly on some pretty bumpy roads.

Yeah the curse of data is a thing. The boost fade, the IATs, and recently when logging coil dwell for the new coils, I discovered a pretty major voltage drop in boost. I think I understand it now and I have been buying parts to solve it. Retail therapy, you know? But also more nonsense to install!

 

[bogle]

Another drive with breakfast club rally is in the books. This org does monthly 3-4 hour drives in the north bay of San Francisco: Sonoma, Marin, and sometimes Napa counties. The north bay has a huge diversity in terrain: vineyards, obviously, but also a couple little "mountain" ranges, 1500 year-old redwoods, weird desert-y patches, grassy rolling hills, flat cow pastures, and sheer cliffs on the the coast. It's all kind of jammed together; you can visit all of those things in like a 40 mile drive. I suppose that's kind of the premise of these rallys: see all the beauty in a couple hours via crazy twisty roads while chasing patina'd 2002s, pristine 993 turbos, and some clapped Miatas.

One of the best parts is the photographers wandering around the social thing beforehand plus camped out along the route. They produce a ton of photos, and lot of them are incredible. For example, a pic through the redwoods from this gallery by Zack Hubbell (I wish this dude got one of my car, but alas):



They got some good ones of the NSX too. Though the photographers do tend to gravitate toward the older, curvier stuff.

These are on real film:





Get to the choppa!



This is also actual film. I really really love this photo



There are more, but you can see a lot of, uh, me, which can stay off the internet for now. I'll have my window rolled up at the next one...

This was the first really long drive with the MCS coilovers. I've been doing a little damper adjusting on short drives here and there to see what they feel like really soft and really stiff. For the rally I decided to go like 3 clicks from full soft both front and rear. This soft, the car feels like a pretty normal car, even with the 9k/7k spring rates.

The route went basically around where I live in Sonoma county--we passed within a mile of the house, twice. I had been on all the roads before in the car and I knew there were a couple terribly bumpy patches. The soft setting was basically optimizing for these sections. I had avoided the rough patches in the past, but with the MCS coilovers they were much much more manageable.

Another rally coming up this weekend with only Japanese cars. I hear there will be a number of other NSXs, looking forward to that.

 

[Honcho]

View attachment 174694

This is really an amazing photo. It captures the dream of the NSX, I think. It should be your avatar pic lol.

 

[bogle]

This is really an amazing photo. It captures the dream of the NSX, I think. It should be your avatar pic lol.

That’s a good idea, I do need an avatar

 

[bogle]

Tokyo calling rally

I took the car to another really with the same org as last time: breakfast club rally. This time, it was only Japanese cars. It was a good time. I met a couple other internet NSX owners, and I saw a bunch of things I'd never seen in person before: pulsar GTI-R, NC1, Mugen M7s on an NSX, like 30 S2000s in one place.

Morning



There were like 8 other NA1s that showed up. A couple of us parked (poorly) together:



A couple pro shots from the social hour







The rally went through Marin county and we stopped halfway through in Point Reyes. Might take a second to see but there are like 12 S200s in this pic



And 3 NSXs. I forgot I had the japanese plate on and drove half the rally with it on there :/



Ooh carbon. Thinking about carbon on black for mine...



A few pro rollers. There were some beautiful photos taken, but the best photos were of other cars.





I only get 10 attachments I guess.... more in the next post

 

[bogle]

A couple more rollers





At the end we all double parked (@Thanhnsx in the foreground with the prodrives)

 

[bogle]

Wiring issues

On the way to the rally from the last post, the car was running a little rich. While freeway cruising, both widebands were showing around mid 13s; the car usually consistently cruises in the mid 14s.

It seemed a little weird, but I didn’t think so hard about it. It was 6:30am and this part of CA has weather like the moon: hot in the sun, cold in the shade. Ambient was probably in the 50s F, at least 30deg cooler than when I usually drive the car. The coolant temp read lower than usual: ~170F when it’s usually 176 - 180. Maybe the cooler weather had something to do with it?

I got to the rally starting point, wandered around for an hour and a half then right before 9am it was ready to go.

I started the car and the AFRs were in the 11s, much richer than usual while warming up. :/ then at 165ish coolant temp, idle was in the mid 12s. WTF?! It should be in the 14s by then. I figured maybe it would get better when it fully warmed up, and started the rally anyway.

Several miles in, the car was still way rich: both banks were cruising in the mid to high 12s. On top of that, the coolant reading was unusually stable (usually it’s super noisy) plus it was always showing 165 or 167F (never 166), even under heavy throttle. Something was wrong.

It wasn’t getting worse, though. The car was a whole lot smellier, but didn’t seem to be running rough, and wasn’t hard to start. Also, strangely, WOT was still mid 11s, so I finished the rally.

I got the car home and pulled the data. Sure enough, too rich. This is the idle and cruising part of the map on that trip home

And this is the same part of the map on a drive just a week prior, you can see it’s all 14s:

Understanding

This was tricky to track down. Was there 2 separate issues? Or something causing both the richness and coolant temp reading low?

On a lot of cars, the rich scenario would probably be a bad o2 sensor. But my car doesn’t correct based on the O2 sensors: open loop all the time. Both my widebands were reading rich. Both couldn’t have gone bad at the same time...

At first I thought something was adding fuel. Like maybe the temp reading low triggered the coolant trim, or the ECU was reading low voltage and adding fuel. But I did a bunch of logging of the trims were the same as usual. Like at idle, the ultimate pulse width was the same between the rich situation and an older log file.

I tried going back to the old OEM coils, same result: rich. Checked the plugs, they were fine. I did a bunch of tests on the coolant temp sensor, and it was fine, the pathway was fine, it showed cold.

I was frustrated, sitting in the running car, watching the stupid rich mixture, and out of ideas. I reached over and wiggled the wires on the ECUs A plug, like, “wtf, is it not plugged in?!”

The wire wiggle fixed both issues . The AFRs immediately went back to 14s, the coolant temp went back to normal. L O L

Wiring fix

Okay, some bad connection at the ECU. When I got the car, there were a whole bunch of taps on the wires for gauges and other garbage. It looked like this:

You can see main power, sensor ground, VSS, and tach are all tapped. Also the no 1 coil wire is wrapped in electrical tape, not a good sign. I took all the taps off long ago and told myself I’d fix the wire damage someday. Now is someday, eh?

To fix them, I wanted to crimp something over the damage and not have to cut the wires. I started this thread asking for help, and I ultimately ended up with a handful of butt connectors and open barrel splice terminals:

The no 1 coil wire was the worst, and probably the issue, at least for the rich scenario. It was hanging on by 2 strands:

It broke when I was trying to strip back the insulation, so I used a butt connector:

The sensor ground was less damaged, but still 50% cut. I was able to use a splice crimp from cycle terminal. I had to add the extra green wire in there to get a proper crimp, and it’ll act as a splint for the main wire. I cut the green wire after taking the pic, and wrapped it in shrink tube.

Fixed!

All back to normal now! There were a couple other tapped wires: ECU power, which I fixed a year ago, and the VSS + tach, which weren't all that bad, so I just shrink-tubed over the mostly-insulation slice.

 

[bogle]

Headliner reupholstery

My car was originally an ivory interior car. When I got it, the bottom half of the interior had been converted to black; the pillars, visors, and headliner were still ivory. I got all the NSX-R mesh black bits I could from Amayama a while back, the one missing piece being the headliner. For the last 6 months I've been running black pillars and visors with the white, extremely dirty headliner, uglyyy:



NSX-R headliners are super back ordered. The couple times I've seen one come up (ebay, mita for a second), they have been like $2000 all in. Seems kinda crazy, and I'd have to do something with my old one. Reupholstering it seemed like the move. I called around and all the local places quoted $200 - $300 to reupholster depending on material. Cheap, cool.

Material

Next step was matching the mesh material. I picked a place and took them the headliner and a brought one of the R B-pillars with me.

I figured they'd need to keep it all for a while and special order a couple samples in an attempt to match. On the phone they told me it could take a bit to get a good match. It's ok, I had the time.

They compared the B-pillar to a few sample boards they had, and, surprisingly, there were 3 close matches. The best match material was Keyston KFH2423 Black (KFH242318). The mesh shape and size was a perfect match. The color was a little lighter, but still super close:



The charcoal black was also an option, but a little lighter still. Both of them in the sun:



Another option was Lindsey Hall Black Ink MH2300. The color was a good match, but the mesh was bit of a different shape. You can see the mesh shape on the beige one next to the black:



One note on headliner material: the shop told me they would only put headliner-specific material on the headliner. Seems like you could put anything on there, no? What is different about headliner material? Apparently headliner boards are never straight / smooth, so headliner material is padded to cover the imperfections. They said anything without padding would look like crap. Noted!

In the end I went with the Keyston KFH2423 Black material.

They had a couple crazy cars at the shop, the coolest being a super clean 2JZ E30 with box flares and a large-pizza-sized turbo. In an ideal world I would have take a pic for y'all, but I spaced.

Uninstall

A couple quick uninstall notes. Once I got the screws out of the corners, it wasn't clear to me where the headliner had clips, especially at the rear of the liner. For that one other person searching for this on the internet, there are 3 clips across the back:



Then one on each side and one in the middle:



Matchy matchy?

Okay, so, how does the material match? Pretty well. The size and shape is the same which is awesome. Color wise, it's really lighting dependent. It is definitely a shade lighter, especially under the garage fluorescent lights. It looks pretty grey here, but really the lighting:



A closeup:



Installed

Pacific coast custom interiors in Santa Rosa did the work and did a great job.



And a pillar under normal lighting circumstances:



Super happy to have this done. The interior is now 100% black.

 

[jasserv]

Interior came out great!

 

[bogle]

New battery

I got a new battery! A group buy for GREYMRKT antigravity battery mounts came up in the vendors section on prime. I figured I’d give it a shot.

I went with the ATX-30-HD.



It’s a little bigger capacity than the non HD, and doesn’t have the re-start which apparently can be a problem in some cars. Antigravity recommends the HD units for cars. Sounds good!

Here’s the mount. It’s a nice piece. Very similar to the KC machine Shorai unit:



The bracket has a little window for the capacity indicator:



Installed. Lots of zip ties, sorry not sorry. Someday I’ll improve all this, but it’s a project.



Prior to this thing, I had a Shorai battery, which was great overall. My one nit with it was the special charging plug / socket at the battery. One Amazon review described the Shorai plugs as roughly “well suited to a lab, not a garage environment”. Legit. They were pretty finicky. I made a charging cable for the Shorai that would hang out the bumper. But the plug at the battery would always sort of disconnect while driving. So even though I had a cable going from the bumper to the batter, I had to pop the hood to plug in the charger after most drives, defeating the purpose of that installed charging cable.

One of the things I hoped to do was setup a robust charging cable for this new battery.

The new battery has 4 posts. The front posts are used for all the same bits as before. Then I used the rear posts for the new bumper charging cable and an antigravity battery tracker (which is awesome fwiw).

The installed charging cable. I bought the CTEK extension, cut it, then crimped some eyelets on it:



At the bumper. When I drive it, it tucks up into the bumper support

 

[mtung]

Just came in to say you're my hero for putting LMGT4s on your NSX!

 

[bogle]

Just came in to say you're my hero for putting LMGT4s on your NSX!

Thanks! I really do love them. Super lucky they made them in a perfect stock body spec. I have another set I still need to powdercoat…

 

[bogle]

Small stuff

I've been accumulating parts and getting some small stuff done. I gotta spread this out over a few posts cause each post only allows 10 pics.

ABS connectors

Since upgrading the ABS, the dirty, bright unused connectors have annoyed me.



The top two are technically unused and I could do some surgery to remove the wires. But the easier thing is just to replace the connectors with new ones.

Alsooo, the bracket that holds the ABS power connector was rusty.



I got a new one (PN 57374-SL0-J02). It's possible there is a new version of this for the later ABS without the loop for some ABS line, but I couldnt find one. This one works!



And all replaced



Radio noise condenser

I didn't know what this thing next to the VTEC solenoid was (blk/yel wire to the connector):



Turns out it's a "radio noise condenser" (C105). It's a capacitor to clean up 12v power, I guess for radio noise, eh? Mine had a broken connector, was dirty, and the wire was exposed a bit. Amayama to the rescue. It's PN 30505-PR7-A01



Installed, much better, I can even use the connector mount now:



Throttle cable stay

For whatever reason, it is pretty soothing going through the Amayama catalog and finding little parts to replace that are dirty or sorta rusty. Here is one of those situations. New parts:



Installed

 

[bogle]

Windshield molding

I'm all about replacing anything on the car that looks worn. Since I've had the car, the lower windshield molding has had some shiny metal showing. It's one of those things that you might not notice directly, but it contributes to a feeling of "something about this looks old, but I cant put my finger on what."





This thing is part number 74202-SL0-000. Getting a new piece was kinda hard. Because of the shipping cost, I ordered one for a couple different US Acura dealerships. But each time it was canceled from the order. They said it was backordered / out of production. I decided to eat the extreme shipping cost from Amayama.

Replacing it was pretty easy. I roughly followed this thread. Basically, pull from the center, then work your way out. When popping it out, the clips actually would come out of the trim piece. This was ideal as those tabs seem less prone to breaking. Then I could use a screwdriver to get the clips out of the car.

The trim piece had definitely been off before and most of the clips were already broken, but I managed to not break the ones that were in tact. Once off, things were really dirty under there:



Cleaned up and the new one upside down for reference



The hardest part was fitting the metal corners under the side windshield trim. It's hard to describe. If you replace this thing, just pay attention to the old one when it comes off. Take pics of orientation before it comes out....

Installed! Feels good!

 

[GUNDAN323]

The headliner looks great. What did you do with grey colored plastic hardware to make it match with the black interior?

 

[bogle]

The headliner looks great. What did you do with grey colored plastic hardware to make it match with the black interior?

Thanks! Do you mean like the dome light? Or the sun visors? They are factory 02+ NSX-R pieces. My car didn’t have any grey plastic bits, it was all either ivory or had some parts converted to black by the previous owner

 

[Matt'sNSX]

I'm a little late to the part here, but I'm really enjoying this thread. I've only gone through the first page or two but am looking forward to reading the remainder. Having said that, I simultaneously love and hate threads like this. I love them for the obvious reasons, it's cool to see and can be very useful if you're planning on doing the same or similar modifications. I hate it because I get sucked into that rabbit hole where I start to worry/wonder if MY car has some of the same issues and do I need to address some of the issues and concerns your has. Lord knows I'm burning through enough cash on my own build!!

Regardless, it's great stuff and I for one appreciate all of the time and effort you have put into documenting your build!