• Protip: Profile posts are public! Use Conversations to message other members privately. Everyone can see the content of a profile post.

Big McLargeHuge’s 1990 JDM NSX Adventure Thread

Big McLargeHuge said:
I shipped LTL freight through Freightquote which I chose Estes through as the cheapest option, Fedex was somewhat higher cost. Never again with UPS lol. No problem with Estes except I had to call the terminal 3 times to get them to finally get a guy to come pick up the pallet from the dock at my office. The total weight I put down on the BOL was ~275 lbs, I added about 50 lbs more than what the manual trans was. Having a good deadlift 1RM is a must for solo transport :biggrin:

I'm assuming the fluid pooled in the bottom of the case and in all the crevasses inside even though I also drained it from the plug beforehand, maybe doing it again would've helped. Once I tipped it over it mostly poured out of the axle shaft hole, way more than I expected. The torque converter didn't have anything in it once I juiced it last year. I shipped with the converter splined on the bottom of the input shaft.

The Diablo was definitely the star of the show, benefits of living around ATL :)

Thanks, Tyler. I have a decent deadlift, but I will enlist some neighbors to help lift the pallet into my F-150. :D

Also, sorry I scratched up your timing lower cover, dude. I felt genuinely bad when the pliers slipped LOL.
Petit Le Mans 2021

I've been slacking on the updates but there's a few posts coming this week.

I was fortunate to be invited to bring my Honda to the Acura corral at this year's Petit Le Mans at Road Atlanta. Link to last year's post (http://www.nsxprime.com/forum/showt...nture-Thread?p=2023515&viewfull=1#post2023515).

Thanks to Acura for providing tickets, meet & greets, food, and hospitality for all of us. There were way more NSX (and other Acura) owners than I expected, especially considering that I was the only NSX I saw last year and this is the most I've seen in one place so far. I didn't get a good overall pic of the corral but there must've been 20-30 NSX's and a handful of other new & old Acura models.

Part of Friday's lineup


DPi driver Q&A

Front row to pushing out of the trailer pits

Something about having the windows down and rear hatch open seems to bring the boys to the yard. To my left is Edgar's RHD ('93?) car, right is Ed's ('02?) SoS twin-turbo imola. All 3 next to the main walking path which brought in a lot of onlookers.

On the plus side, the car was popular throughout the event; on other hand having so many people pass by meant that not everyone was the most respectful. It was pretty dusty in the infield and I caught someone's kid drawing pictures in the dust on the rear quarter, and I found other marring all along the left quarter and headlight where someone ran their hand along the paint, I guess to sate their curiosity that dust really exists. All can be polished out, but there's only so many times I can do that and it still bugs me.

Is that a supercharger?

Anyways, I had a great time this year meeting lots of new people, which I spent most of my time talking with instead of watching the race. Great meeting Rafael, Steven, Richard & Liz of LOTW, Edgar, Ole, John, Ed, and plenty of others for the first time in addition to those I know already. That really was the best part of the weekend and you never seem to run out of stuff to talk about with NSX (and other Acura ;)) owners.

Thanks again to Acura for hosting the corral and hope to see everyone again next year (maybe before then too if I can make it to a NSXcapades/etc.)

Oh, and no worries on the timing cover Paul ;)
Last edited:
Misc. Mechanical Misadventures

Catch-all post from several minor projects over the past few weeks that I haven't made a full post on.

Number 1 is that I ordered an NSX-R "wiring harness" cover to replace the old grey one. I think it pops a bit more, and still says VTEC. I think it'd look a bit better with deeper black valve covers but I still have to figure out what color I want them during my next engine job. Maybe red if I go with better cams, or just a new black coat if kept mostly stock.

3rd try's the charm for fitting LED low-beam bulbs. I ordered Bosla 9006 bulbs at first, then realized that JDM NSX's use H1-style bulbs for the hi/lo beams instead. The beam pattern is surprisingly still good, and it's much brighter than the OEM halogen bulbs. I still need to adjust the beams a bit further up to get more throw down the road.

I went with Hikari H1 bulbs, I've used them in the past and they last for about 1-2 years normally, hopefully longer with how little I drive the NSX in the dark. Of course, the terminal leads on the bulb are flipped around from the car's wiring polarity, so the red of the bulb actually goes to the black/GND of the car's harness. The +/red terminal is larger in size so you can't mix them up, therefore I had to grind it down to fit in the "incorrect" negative female terminal.

The 3D-printed dust caps are made by Jasser Valerio on FB. Fits perfectly without removing the headlight covers completely and includes enough space to fit the LED drivers with a vent to help with airflow.

Next up, you might've noticed that I'm back to the OEM rubber front lip. Predictably, I managed to annihilate yet another front lip while entering a friend's parking deck where there was a slight depression in the road right before a small concrete lip where the ground was uneven, which I've taken before just fine but this time the front left corner of the lip caught fast and ripped it straight off the car. In the process, it further cracked the paint on the very bottom of the bumper and the smaller piece popped up to leave several scratches and chips along the upper bumper. You probably couldn't see it from the previous post since I touched everything up and it's close to the ground, but it's there.

At this point I'm opting to get the front bumper repainted, both to correct those issues and some paint texture issues that were already existing. To that end, I might also get the headlight covers and hood redone at the same time, and potentially try to fit an NSX-R style hood or scoop which I've always been interested in getting. Once that's done I'd get the front PPF'd as well. Plus raise the car another ~1/2" and probably stick to cheaper, more flexible OEM lips from now on...

Mechanically, I also replaced the RL wheel bearing, wheel speed sensor, and outer driveshaft boot from when I damaged it during the OEM strut removal. I was planning to do the RR side as well, but getting the hub/carrier out of the knuckle was such a struggle that I'm saving it for another day. It took about an hour of hammering out the hub from behind to get it free since there was a spot of corrosion on the inside keeping it in place, when normally you can just pry it off. Maybe I should invest in an air hammer, or there's an easier way to do it. I didn't see a way to pull out the hub with the tools I had, including the driveshaft press.

The wheel speed sensor also started throwing a code, so I got a new WVE one from Rockauto and had to drill out the old one just like the other side since the plastic sensor is impossible to divorce from the knuckle without snapping it in half.

New bearing pressed on, with hub battle scars from the removal. Doesn't affect anything though. There was a slight moan from the old bearing at highway speeds even though the bearing felt fine, but this new one fixed the issue.

Finally, I ended up having to replace the two main engine bay silicone hoses with OEM ones since I developed an intermittent leak from the one pictured. I first noticed coolant drips on my parking spot and spent an hour or two tracing every line, but couldn't come up with anything more than it likely coming from somewhere around the thermostat housing. I was even considering that a head gasket had started to let go.

Instead of tearing down the engine, I rented another coolant pressure tester from Advance Auto and put 15 psig on the system, whereupon the hose in the picture below started pissing coolant like crazy. It was hard to track down otherwise because it didn't leak at all when the engine was idling or when the system wasn't pressurized. So, new OEM hoses were ordered.

Being quite adept with coolant at this point, I removed the airbox and reservoir without draining any coolant from it, and slipped the hose off the pipe to a drain pan below which was marginally successful. Then I cleaned off the pipes extra well with brass brushes and a fine scotch-brite pad to clean off any goobers I might've missed the first time.

New OEM hoses fit, parts replaced, and more coolant added and air bled from the two engine-side bleed screws along with raising the rear of the car. Since I didn't drain much coolant from the system and didn't create any additional air pockets, I was able to bleed the air introduced without going over the whole system. I'll still try the front bleeders again though to make sure.

I was pretty annoyed that the new silicone hose had leaked, I think it was a combo of a bit looser of a fit and some contaminants I missed cleaning the pipe the first time. The OEM hoses seemed like a much tighter fit as well so I don't anticipate any further issues, at least with these particular hoses.
I wish :). Ed's car to the right of mine has twins but you wouldn't know since they're buried under the rear. He also drove from TX and back which inspires me to try to enjoy mine more instead of worrying about mileage. Unfortunately having a low car and stiff lower lips doesn't lend well to driving unknown roads.

I hope I can make it to an NSXPO soon but you west coast folks keep hogging it :D. I'll make it soon though.
ABS Conversion pt2

Here's more helpful ABS-related links:
-Kaz ABS table of contents http://www.nsxcb.co.uk/showthread.php?9286-ABS-Upgrade-Support
-Kaz ABS overview http://www.nsxcb.co.uk/entry.php?2531-Eng-Refresh-Health-Check-etc-18&goto=next
-Kaz ABS upgrade series http://www.nsxcb.co.uk/entry.php?875-ABS-Upgrade-02&goto=prev
-Kaz ABS wiring pics http://www.nsxcb.co.uk/entry.php?1332-Annual-Service-Health-Check-iPod-adaptor-etc-06&goto=next
-Kaz S2K/electrical overview http://www.nsxcb.co.uk/entry.php?1790-Cooling-Sys-Health-Check-etc-11&goto=next
-Speedhunters short article http://www.speedhunters.com/2020/07/project-nsx-four-lessons-learned-in-garage-iso/
-RFY harness & instructions/parts https://www.rf-yamamoto.com/NSXbrake/1.html
-Some guy named Honcho's ABS conversion http://www.nsxprime.com/forum/showthread.php/183342-ABS-Upgrade?p=1802447&viewfull=1#post1802447
-Jay's S2K conversion thread http://www.nsxprime.com/forum/showthread.php/194252-Budget-02-ABS-conversion (and http://www.nsxprime.com/forum/showt...ersion/page4?p=1893142&viewfull=1#post1893142)
-Joe's LHD conversion DIY thread w/pics http://www.nsxprime.com/forum/showt...-R-Conversion-Instructions-amp-Brake-Line-Map
-Parts are from MITA and Amayama

In case you forgot I started this in June - http://www.nsxprime.com/forum/showt...hread/page12?p=2035787&viewfull=1#post2035787

I did a bit of preliminary testing of the old ABS to see how it was working and to unscientifically test straight stopping distance. After every stop, the pump would rattle to re-pressurize the system, and the reservoir had a lot of foam. I forgot what the reasons for that are but Kaz has plenty of posts describing the system, I just hadn't bothered studying it too closely since I'm replacing it anyways. Either normal or a stuck solenoid or something.

A few months ago I exercised the system a bit and it actually overflowed without me realizing until the next day...not great for the paint next to the bracket but not really noticeable.

Step "1" is removing the glovebox to gain access to the ABS control unit.

Nice and clean stock everything, for now. You can see where I stuffed the GROM bluetooth unit on the left. Still works great though the microphone jack can't seem to stay plugged in.

ABS harness connectors test fit. The 18P TCS connector isn't at all necessary for the S2K unit but I'm keeping it installed just in case myself or someone wants to put in the NA2 unit in the future for some reason.

Here's the FSM diagram of the control unit layout in case you didn't know. My current cruise control unit is actually from Honcho's car since the JDM unit is limited to around 60 MPH.

Battery and undertray removed with just a few bolts. The lower ABS bracket has always looked like doodoo because of all the brake fluid leaking on it over the years. The silicone hoses look weird since coolant diffuses through silicone easier than stock EPDM hoses.

The blower can be removed after disconnecting the 3 connectors on the front and 4 bolts on the top/bottom corners, which can corrode pretty badly depending on the environment but mine were perfectly fine. The hardest part is freeing the two left-hand pegs from their rubber grommets to support the water valve assy. More on that later.

31 years of Japanese filth accumulation.

Next up was removing the windshield cowl, which involves snapping the upper cowl pictured away from the bigger cowl already removed to gain access to some small attachment screws. The upper one doesn't have to be completely removed.

What else do I find but a kind gift left by a previous owner? This appears to be a very JDM box with some holes in it to act as a cabin air filter, I guess just to keep larger debris out without worrying about the smaller stuff.

Just your standard Inomata household basket, for some reason I find it interesting just because it doesn't look like any basket you'd get at Marshalls/Kohls or whatever. My only souvenir besides the JP gas station receipt under the seat.

Though I appreciate the basket's performance for the last few years, I swapped over to a custom cabin filter made by Desmond Wong on FB. Great price, comes with 3 filters and a 3D-printed bracket, and a set of push clips for the cowl when the old ones break. Thoughtfully put together.

After that was getting this ugly thing out of the way. Besides the 4 obvious orange solenoid connectors up front, there was an additional one hidden below the MC that snagged me up during removal. None of them will be reused for the new ABS system unless you want to make a custom connector harness.

Otherwise, the brake lines were easy to remove with a 10mm flare wrench. Once those are removed, it's just 3 bolts to the side of the frame and the whole thing lifts away.

The old unit is bulky and heavy so it takes some creativity to remove. I ended up bringing it through the top since the lower coolant pipe reduced the space available.

The MC will also drain out with no brake lines attached, so I sucked out the fluid from its reservoir and the ABS reservoir. You should probably cap the MC to avoid it going dry, I didn't bother and "bench" bled it later on.

Taking a loop at the front of the evaporator, refrigerant expansion valve in the foreground. Not too bad, no large debris, smells, or rotten stuff but some fuzzies and dirt.

Here's another look from below for reference. Keep in mind my car is RHD so most everything's flipped around. I also don't have the water drain tube that goes from the upper cowl down next to the blower. I'm not sure if it was removed before and never reinstalled, I didn't notice any undue dirt or rust anywhere so I don't think it was an issue.

I've had a can of this stuff sitting around for over a year for this job and finally get to use it. Fairly expensive but well-reviewed off Amazon. I vacuumed out the front evap and brushed away the dirt first, then shook the can up and foamed all over the front. The foam cleans stuff off and then coalesces back into a liquid to drain out of the normal drain tube location, so it's easy to do and can be sprayed up through the drain tube instead to avoid having to remove the blower.

I didn't get a good after pic but it still looks like an old evap just with no more dirt attached, and anything living in there is now no longer with us. Should make for a nicer in-cabin experience.

However, at the moment I feel like I get a very faint, almost imperceptible smell of ND-8 Denso A/C oil from the vents when I start up the car after sitting for >1 week, which could indicate a small leak in the evap core with fumes accumulating in the HVAC unit until they're blown out the vents. It's not enough for concern at the moment but I'll have to monitor it and the refrigerant level, and potentially get a sniffer and plan for a complete dash removal in the next year or so. TBD on that but obviously taking the dash out is a huge endeavor that pretty much any NSX will probably need to do at least once.

Begone, wench.

I didn't de-pressurize the high-pressure brake fluid before removal since I don't have the bleeder T-wrench to safely do it in the car. Instead, I bought a 07HAA-SG00100 square socket off eBay to slowly crack open the bleeder outside and release the forbidden frosting inside the ABS. Now I can disassemble the rest of the unit to recover the large aluminum bracket to be re-used plus the MC brake pipes for bench bleeding.

I don't think the fluid is supposed to be foamy like this, but again I never bothered rebuilding or power bleeding the unit since it's so old and junky. Is there any market for these used units?

Bracket cleaned off and AP1 S2K unit attached with new rubber, bolts, brackets, and proportioning valve. I got the ABS for $36 on eBay and chose this one since the seller was thoughtful enough to cap the brake line ports to keep out debris which I figured was a good sign the unit wasn't abused. Kaz likes to test the wiring harness and modulator before installing it in the car to check for functionality, I didn't bother for efficiency's sake.

The hardest part of this for me was figuring out where all the brackets and lines go on this thing, there wasn't really a guide for that part so I relied mostly on the parts diagrams. But the prop valve, bracket, and ABS bolt up perfectly.

At this point Joe recommends loosely attaching the brake lines to the modulator before install, but for me, everything can be accessed and torqued with the modulator installed. Installing the shorter lines to the PV isn't a bad idea though, but you should go one-by-one when doing final torqueing otherwise there's no room for the socket.

I'll split off the rest of the post to Part 3 since it's pretty long. Hold please.
Last edited:
ABS Conversion pt3

Lines removed from the PV that runs to the rear of the car.

Clamps and rubber grommets for where the rear pipes and FL pipe run through. I bought new rubber, but the clamps were backordered. Either way, I didn't need them since I was expecting corrosion where there wasn't any.

Same area after some cleanup since I couldn't just leave it like that. Enter one of the harder parts which was fitting the two new lines into the two rubber grommets, which was a frustrating experience. I can't imagine how annoying it would be to try and fit new rubber grommets on the 4 pipes, so I didn't bother.

Lines installed onto the existing PV. Torqueing was performed by an lb-in wrench with a 10mm crow's foot, which is normally frowned upon since torque wrenches are calibrated to one length. To use the crow's foot socket, I calculated the modified torque value to set the wrench to since the effective length of the wrench was about 0.5" longer than normal, and came up with about 13 lb-ft instead of the normal 14 lb-ft setting. Really not a big deal in the end.

After loosely installing the ABS unit and bracket assy, I was left to ponder how to properly route the last two lines which come directly from the FL and FR brake hoses. MITA's kit doesn't include these two new lines, and Amayama didn't want to ship them since they were too big for a box, so I was stuck bending them to my will. You can see the FL one (pic left) was too long and the FR one (right) too short. None of the fittings are tight at this point.

Since this was the part I was most worried about messing up during this project, I went slowly and considered the best places to bend the lines to clear any other obstruction without rubbing and to avoid kinking, which would essentially brick the car until I could source or make a new line.

This is what I came up with at first, which I was just so proud of until I realized overnight when reviewing pictures that I had swapped the FR and FL lines to the connection points on the ABS, which are labeled...oops.

Note: how not to route the FL/FR brake lines. However, everything else looks good. I got a new brake clip and grommet (lower right) which was originally missing on my car. And yes, the MC had been leaking at some point in the past as with most cars, but it has either been rebuilt or replaced in the past and there have been no signs of further leakage or failure.

The next day for me (Saturday after Thanksgiving), I undid all my careful torqueing and re-bent the FL/FR pipes to their correct locations. I bought a pair of Eastwood brake line pliers to assist, but in the end I mostly just used some careful hand strength to make gradual bends and adjustments. The brake pliers are useful for making more acute bends without creating kinks.

After more careful massaging, the new lines were properly routed and I bled the MC to get rid of any air I might have introduced by letting the MC go dry. I stole the two old brake lines from the old ABS unit and bent them into a new brake fluid container to supply clean fluid to the MC and push out any bubbles. A bit jank but it worked. Really, the much bigger concern was all the air sitting in the two new lines to the rear of the car which I discovered later.

That's how it's supposed to look. Note that I spent about 2 hours or so massaging all the lines to ensure they didn't foul on anything else like the body or the other lines and had enough clearance to account for thermal expansion, so that I didn't create any friction points that would eventually leak.

All good in the hood. Everything in its proper place.

Note that you should torque from left-to-right (or opposite for LHD) to have enough room for a socket, and leave the MC lines until the very end. I ended up re-doing things a few times until I found the right order of operations.

Now that the hardware was in place, I routed the wiring harness in the front bay. In my case, I was able to connect the big orange-lock connector to the ABS unit in-situ without issue. The SCS-check Weatherpack connector in the foreground was zip-tied to the existing solenoid bracket and the old solenoid connectors were just plugged back together and slotted into place. Some choose to cut them off completely for a cleaner look, up to you.

Bad pic of the rear GND point that I connected the SCS ring terminal and the harness ring terminal to. There's already an unused 10mm bolt hole in the bracket that makes a very convenient and neat ground point. I think the later bracket didn't include those holes though.

In the lower-right, you can also see the rubber clamp I used to route the rest of the harness back across the rear bulkhead. Important not to hit the subframe, battery bracket, etc.

Harness routed along the factory front harness location with some leftover split-loom for extra protection, though the KSP harness was already sheathed.

Then along the front bulkhead to the pass-through grommet which I made an incision into to pass the interior wires through, and sealed with RTV for good measure. I ran out of black loom but it's hidden away anyways..

Small branch to the front bay fuse box to attach the harness' 40A ring terminal to the existing 40A ABS motor fuse, where I also removed the ABS motor relay directly below and jumpered the two load-side terminals with a short spade terminal loop since the relay control signal from the ABS control unit has been removed.

Here's the relevant ETM page for reference.

Now's a good time to test your ABS unit and clear any codes, but instead I decided to refresh the blower unit by cleaning out the crap inside and replacing the mummified foam gasketing with some I had lying around. The top duct is from the upper cowl, the larger one presses against the bulkhead to the interior HVAC unit/evap assy.

Cleaned, gasketed, and detailed.

Nasty and crumbly. I can guarantee the HVAC unit foam also looks like this, but at least I won't be leaking air into the car now.

I also gave this thing a "quick" cleaning with metal brushes and degreaser. I'm sure there's a before pic somewhere, I'd give this a 90% improvement.

Now's a good time to electronically test the S2K ABS, which follows the special procedure from the S2K. Thanks again to Kaz for the walkthrough posts on the process which I linked above.

In short, I connected the SCS jumper (that I made) to the SCS harness connector in the front bay, which shorts the SCS pin on the ABS unit to the ground on the bracket. Then follow from step 3 on the page, and if done correctly (you can't wait too long between steps or start over) the ABS light should blink twice and then go away. If it doesn't then there might be a problem with the unit itself. This is also why I needed the expensive solid-state relay shown earlier since I'm using a digital S2K cluster, the standard mechanical relay that came with the harness only works with the stock gauge cluster and bulbs and won't display properly on the S2K cluster. Benefits of doing your research ahead of time.

Can't forget to put this junky battery bracket into the blaster to give it a quick refinish as well.

And now it's all magically back together! At this stage it's reverse of disassembly, but putting the blower back in was a MASSIVE pain for me. For one, the new foam I put on is thicker than the old crusty stuff and you have to use some force to compress the foam to line the bolt holes back up, but also getting the pegs back in the water valve grommets proved nearly impossible. Barring some method I'm unaware of, I just removed the rear grommet and fit the front peg in properly, leaving the rear grommet out since I don't see how a human is meant to accomplish that without removing the water valve completely. Anyways, it should be fine.

Also, fitting the upper cowl back on was also a major pain in the ass. There's a bunch of yellow wing-looking clips that hold the cowl on that are nearly impossible to remove without breaking them unless you know the secret kung-fu procedure, so now I'm running with about 60% of the clips installed until I can get new ones the next time I remove the cowl to refinish it. That part and the blower reinstall were honestly the worst parts of the project so far if you measure by swears uttered.

Now you're essentially done except for brake bleeding, which I rushed through with my normal Motive bottle w/check valve and just me to pump the pedal and get all the rest of the air out after laboriously removing all the wheels and bleeding each caliper. Then I reinstalled everything, started the car, and was about to roll off the lift when I noticed the pedal just sank to the floor. Nice, what a waste of time.

Obviously I hadn't gotten all the air out of the lines with my normal manual bleeding procedure, so I attempted to set up my pressure bleeder that I had lying around for months since I didn't think it would work. Once I managed to apply pressure to the MC, this is how far the fluid level dropped (i.e. how much air was still left in the system and was being compressed by the incompressible brake fluid).

Here's my godforsaken pressure bleeder setup. Starting from the pump, I JB-welded a larger threaded barb fitting into the tank since the old one didn't fit any hoses I had, to a male-male barb fitting, to another barb to male thread, to a female quick-disconnect, to a male quick disconnect, to another barb/female threaded fitting, to a hose that I fit over the bleeder adapter's cap and zip-tied to help seal. This unholy combo all came to be because the stupid adapter's QD or internal threads were non-standard sizes, all the stores were closed, and none of the threaded fitting sizes matched any of the other sizes. Somehow, this still held 15 psig just fine, and actually it was the adapter's black knob O-ring seal that failed first, nothing that I had made.

The adapter is the Power Probe BA09 which has an expanding O-ring seal which juuuuuust barely fits inside the MC reservoir cup, and the chain helps hold it in place. The KTC ABX70-H1 (https://buyee.jp/item/yahoo/shopping/ehimemachine_ABX70-H1) is the standard for our master cylinders but that plus the ABX70-E1 chain was like $90 from Japan which I thought was too expensive. I ended up spending that much anyways for this dumb setup, but once I got it working it did a great job.

With 10-15 psig on the MC, I re-bled the brakes all over again and found a ton of air in the RL line, and a bit in the RR line. I'm not sure if I just stopped short with the manual bleed process or if I really needed a pressure bleeder to force the air out, but I ended up going through a bit over a reservoir's worth of fluid to make sure there were no bubbles left.

Last and certainly least, while finishing up the interior wiring the day after, I decided to go ahead and remove the ABS control unit to make room for the new wiring/relay. Man, that SUCKED. The FSM lies about what all needs to be removed, plus the sub cover needs to come out, the bolts are all buried under huge harness trunks, and there's a bunch of factory clips and zip ties to remove. All that because the entire control unit bracket needs to be removed to get the ABS unit out. RIP my hands.

Fuck this thing. Lol. That was way harder than I expected.

WWith my newfound real estate, I tucked away the new connectors and relay into the open slot. With some zip ties and foam tape to make sure they don't rattle around or anything. Doesn't look great but anyone else could take off the glovebox and completely remove the new harness in about 30 seconds if they wanted to, plus it's labeled. You're welcome, person in 2080 who pulls this car out of my estate sale barn to restore again.

With that, the project was completed successfully. Took the car on short roads tests and the difference between the old unit and this one is night-and-day. Everything seems to work perfectly, the kickback from the pump is much more subtle and engages far faster and more precisely than the old system, and can go over and over again without a noisy pump having to re-pressurize the system. With my EBC yellows and Indy 500 tires I can easily activate the ABS with moderately high pedal pressure.

Speaking of, the pedal feel is noticeably different than before. It's hard to describe but there's not as much immediate tip-in response, somewhat of a more gradual, softer feeling until the wheels eventually lock up. I take that as a subjectively more "linear" feeling since there feels to be more room between light brake and wheel lockup, not good or bad so far just different. If I was a better driver maybe I'd be able to give a more accurate opinion. All set for autoX days now though :D.

I forgot until tonight, but the TCS light will stay on unless you unplug the TCS unit. According to Kaz, there will be a stored code for TCS fault but there's 2 checks to illuminate the CEL so it won't show up. It's so big that I initially mistook it for the A/T control unit, but no, it's just that (mc)large. The relay up front is the TCS failsafe relay. Honestly, I don't know if every connector needs to be unplugged or just a certain one, but it seems to be working just fine as shown without affecting anything else.

Now that that major project is done, of course I'm still adding things to my to-do list that never ends.

-Collecting parts for major engine refresh (new LMAs, cams, etc.) and future services (evap core, crank pulley, bunch of random shit). Still very torn on whether to save my time and money and slap in the stock M/T cams, or copycat other smarter Primers and get ATR Spec S cams or similar and chip a USDM ECU w/ Demon and have to do some tuning. The LMA noise is getting very annoying at times with the engine cover off, and I'm still stuck with the 7500 RPM redline/AT cams/125 MPH limiter at the moment.

-Taking off my front bumper to be repainted. Local paint shop which is very well recommended has offered their services for a decent (predictable..) price to strip down and paint-match the bumper. I need to decide whether or not I'll try and source an NSX-R style hood w/scoop and have that plus the headlight covers painted all at the same time. $1200 paint for just the bumper, or $3000 paint and ~$1200+ for a well-fitting NSX-R style hood and still have to get PPF applied, plus any contingency fees? Hard to decide.

In order to at least act like I have some financial sense, I'd like to do both the ATR cam route and the NSX-R hood/front end repaint but I'm trying to choose just one. At the moment, I'm leaning towards getting the front bumper redone and trying the spicy cam route as a middle ground, but I'm open to any opinions or advice out there.

Thanks for reading.
Last edited:
Very nice work! You are motivating me to get out there and finish wiring already!

One thing- your 12V power is connected to the wrong side of the fuse. It should be screwed to the other terminal, which will give you fused protection of the circuit. The way you have it now, your ABS is doing this every time you turn it on:


My vote is get your bumper painted and wait on the hood. The Procar Specials is the only one worth buying as the rest fit like hot garbage. It's $$$$$$ though. I'd put that coin toward the cams instead, especially if you plan on an engine refresh in the near future. Just my 2 cents.
Great write up. I definitely enjoyed reading it. I feel your pain, I recently swapped out the ABS unit and lines with an S2K ABS unit. I still have to install the new harness.
I found the best deal on updated LMA’s is through amayama, I just ordered a set for my car.
Going with stock cams will be the best value unless you are going for a N/A build longterm with a ITB setup.


You're right, I just went into the garage and changed the terminal side, should've thought of that. Thanks for pointing it out.

Also agree on the hood thing, Procar seems like the only sure thing but I'm definitely not looking at that price range. I might end up chipping a USDM ECU in the meantime anyways to copy over the A/T tables so that I unlock the RPMs and a higher top speed since I'm not planning on breaking into the engine until maybe late next fall. Wish my LMAs were updated already.

Great write up. I definitely enjoyed reading it. I feel your pain, I recently swapped out the ABS unit and lines with an S2K ABS unit. I still have to install the new harness.
I found the best deal on updated LMA’s is through amayama, I just ordered a set for my car.
Going with stock cams will be the best value unless you are going for a N/A build longterm with a ITB setup.

Thank you! Surprisingly it was mostly the blower and control unit removal that really got me during the job.

I've got a big Amayama cart in the works right now and it includes the LMAs, thanks. I think the updated P/N is 14820-PCB-305 for the redesign without additional spacers.

I also agree that the M/T cams would be the best value for my money and time especially. Just depends on how much extra work I want to make for myself after the engine job, tuning especially. I'm also not sure if I'd need uprated valve springs yet and if I want to try and replace HG's, valve seals, etc. at the same time during head removal. It'd probably be for the best but breaking the factory seals makes me nervous.
That relay you unplugged is the high pressure fuel pump relay, make sure to plug that back in or you'll likely lean out the fuel mix at high rpm/load, the TCS failsafe relay is on the far end of the TCS computer that you can't see until you remove that last interior panel.

But yes, chip the ECU, I need more test dummies for my code. :biggrin:
That relay you unplugged is the high pressure fuel pump relay, make sure to plug that back in or you'll likely lean out the fuel mix at high rpm/load, the TCS failsafe relay is on the far end of the TCS computer that you can't see until you remove that last interior panel.

But yes, chip the ECU, I need more test dummies for my code. :biggrin:

Damn, I misread the diagram...thanks, it's back on.

Sure I'll be another guinea pig, but I'm curious, do you think the speed limiter can be removed through the Demon II and TunerPro or is it not a modifiable parameter? If so I probably won't have to buy another ECU.
But yes, chip the ECU, I need more test dummies for my code. :biggrin:

We're all John's "dummies" lol.

Damn, I misread the diagram...thanks, it's back on.

Sure I'll be another guinea pig, but I'm curious, do you think the speed limiter can be removed through the Demon II and TunerPro or is it not a modifiable parameter? If so I probably won't have to buy another ECU.

I believe the speed limiter is a modifiable parameter. However, if you have a JDM ECU, the Demon might not be compatible- I think there was something on Moates about this. You might need to grab a USDM ECU. John would know more.
I think the JDM ECU bit was partly because the physical case for other Honda ECUs is smaller. On the other hand, "JDM ECUs use different parts for chipping and modification than US ECUs. Most JDM ECUs use primarily surface mount components while USDM and European ECUs use primarily through-hole components.", but I'm not sure if that only really applies to the natively supported Civics, Integras, etc. I should probably open mine up to compare beforehand.
From what I've seen, the JDM and US market ECUs are identical except for the programming on the chip, the NSX was so low production that I can't imagine it making sense to produce multiple different ECUs for different parts of the world - I suspect thats why they used a combination of internal ROM and external ROM chips rather than only internal ROM like the 4 banger ECUs - so programming could easily be changed for different markets. @Big McLargeHuge is correct, the 4 banger OBD1 ECUs have a smaller case in Japan for whatever reason so the larger chips don't usually fit in them. Speed limit is a configurable parameter and could be removed.

It might be good to take out the 5 cover screws on the ECU to confirm though.
Last edited:
Very nice work! You are motivating me to get out there and finish wiring already!

One thing- your 12V power is connected to the wrong side of the fuse. It should be screwed to the other terminal, which will give you fused protection of the circuit. The way you have it now, your ABS is doing this every time you turn it on:


My vote is get your bumper painted and wait on the hood. The Procar Specials is the only one worth buying as the rest fit like hot garbage. It's $$$$$$ though. I'd put that coin toward the cams instead, especially if you plan on an engine refresh in the near future. Just my 2 cents.

Is the Procar specials really the only one that fits well? I am wanting to change a few body parts on my car and thought the DF stuff fit really well? Any others?
SpeedAddict said:
Is the Procar specials really the only one that fits well? I am wanting to change a few body parts on my car and thought the DF stuff fit really well? Any others?

The DF is hit or miss- some fit well, others need a lot of work. The Procar fits perfect every time, just like OEM.
Downforce Intake Scoop & Newport Museum

SoS shipment arrived 2 months earlier than anticipated, the NSX-R lower bar lead time was out to Feb. Wew!

Should be an easy 30 min job, right? Factory resonator shown in the picture.

Intake grommet shown with fuel filler neck.

Easy money, right? Nope. Despite about 3 hours of trying to fit this thing in properly, it doesn't go in without pushing the fender liner out a bit. The instructions say in that case that you need to push the scoop further into the grommet, which was impossible since the scoop hits the body bracket in the pic middle, and it can't be pushed further forward without hitting the fuel cap release mechanism. The aluminum brackets provided were more of just suggestions, I had to grind and hammer them several rounds to get close to an acceptable fit. Not impressed.

To fit the upper part into the grommet, I greased it up and tried to slide it in from below, but the scoop is just slightly too large to fit without additional leverage. After fighting with that for too long, I removed the airbox instead and was able to much more easily fit the rubber around the scoop and seat it as far in as it would go.

After fighting with that and the brackets, I fit the fender liner back on without modifying it, but it still pushes out slightly. Not enough to rub the tire so far, but the scoop kit could've been designed to fit much better from the get-go. I'd give it a 4/10 for fitment.

Once that "easy" mod was done, I was still pleased with the great intake sound produced at WOT, it's like adding a cold-air intake while still retaining the factory airbox reliability. I can see why Honda would design a resonator to eliminate that sound for a production car, but unlocking it adds that extra bit of excitement to a weekend drive. I was concerned I wouldn't get as much effect sitting on the opposite side of the car from the intake side, but now it seems just as loud as the exhaust from within the cabin. I'm happy with the product, just wish it fit better.

Also, I raised the car by another ~0.5" on the coilovers to get a bit more clearance since I'm getting sick of the low-car life. I'm at the height limit on the fronts for the Fortune Auto 500's since I'm running out of threads; I might go down another 0.1-0.2" for safety and since I'm monster-trucking it again. I suppose that's one weakness with Fortune Auto's offering, the threaded dimensions of the coil body is heavily weighted towards slamming the car with only a 10-50% useable distance for reasonable ride heights. I'd still buy them again though.

Totally unrelated, I visited the Audrain Auto Museum in Newport, RI the other week. 300SL gullwing? Yes please.

Bonus Miura.

Porsche 904? You bet. Reference material (https://www.audrainautomuseum.org/e...ovich-collection/1964-porsche-carrera-gts-904). Interestingly, it's about the same specs as the NSX from 0-60, just in 1964.
Bummer about the intake scoop fitment, I was thinking about getting one of those.

Does the scoop change the intake sound?

Yes, and like Tyler said, for the better. Also, the fitment is terrible as described. The original scoop was designed by Mugen for the C30A GT2 engine on the LeMans race cars. Those cars did not run wheel liners, so fitment wasn't an issue. All scoops subsequently sold in Japan and elsewhere (including the DF) are knockoffs of this original shape. Why none of the aftermarket vendors bothered to adjust the shape (or even just flatten the liner-facing side) is beyond me. Most owners just live with the wheel liner bulge.
Yep, as long as you can live with the wheel liner bulge it's just fine. For me, the big increase in intake sound was worth it, way more dramatic. Maybe with an ITB airbox it's even better ;). The thing that gets me is the smarmy way the install instructions say if it hits the liner then you didn't install it right as opposed to designing it properly in the first place. That wasted a lot of my time thinking it was my issue rather than just lazy design.
Thinking Out Loud

Rambling ahead since I've been doing some thinking on future projects.

One, I keep having to re-make my Amayama order to try and bring the shipping down since they quoted me $540 by Fedex for a 7kg package. I deleted the evaporator and windshield trim since I thought it was size related, but it's still $540 and the biggest thing in the box would be the crankshaft pulley, otherwise it's all gaskets and bolts. Sent them a message to see what gives so hopefully that can get sorted out. Megazip is also another option but their prices are in the middle of Amayama and Acura. MITA can get a steering rack overseas for $150 and I can't get a simple box for that?

Otherwise, I still can't decide what cams to go with. I learned yesterday from another Prime thread that the A/T engines don't have the intake inner valve springs, so I probably shouldn't go over 7500 RPM even if I could change it through the Demon II which arrived yesterday (still needed to order the 4P header cable which wasn't included). That means I'll have to have new valve springs installed whether or not I choose the M/T or ATR cams, which means they need to be balanced and the heads "should" come off, which means I'm doing head gaskets regardless and sending my heads to a machine shop for a valve job. I have no cost basis or contacts for that either, maybe you guys would know? I'd think the labor isn't cheap. At minimum I want the M/T cams though, and I need the valvetrain to support them long-term.

If I'm doing that, what's the incremental cost for copying Paul and putting in larger intake valves and porting the intake? I don't have any unique ideas, just relying on other people's R&D and experience. I have no plans of going FI at any point, but the NA builds interest me.

Assuming I'm at that point and choose stock M/T cams, I'd put the engine back together, snip the ECU resistor to change to M/T maps, and be good to go. There are probably some gains to be made with some minor tuning through the Demon which I'm not really comfortable doing, so then I'd need to put in widebands too and take it to EBTEC or somewhere near-ish to have the car tuned. But that's a way simpler option overall.

If I go with the ATR cams, where does it end? I'd probably have to get bigger injectors to support the duty cycle requirements, I haven't done enough reading to see what the most efficient solution for that is yet. I'd definitely have to get the car tuned, install widebands and whatever other sensors, maybe fuel pump, maybe EGR delete, and entrust my engine to someone else which I'm wary of. That's at least another $3500+ above the M/T cam route, is that worth all the extra money and effort? Part of me thinks so, since if I do my job right I wouldn't have to open the engine again until 2032 after Honda stops making parts for these things anyways. Why not go the extra mile now? The "while you're in there" curse is strong with this one. I guess the cost and tuning process are my biggest holdups right now, but the cost would really be amortized over 10+ years.
Last edited: