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Big McLargeHuge’s 1990 JDM NSX Adventure Thread

Nice work. Too bad about those expansion tank hoses, hopefully they won’t be too much of a pain to replace. Good call on the temp sanding unit while you’re in there.

How long did the hose replacement + fill and bleed take? I’ll be following in your footsteps here in the next couple months and will definitely be referencing this post!

Just replaced them actually, so everything works now (kinda).

Draining takes me about 1-1.5 hours actually, Five drain spots along the car and the engine block drains can be hard to get to. Radiator replacement maybe 30 mins. Front bay hoses maybe 2-3 hours, middle about 2 hours, engine bay the longest at about, uhhh...4-6 hours? Fill & bleed realistically 1.5 hour or so. Definitely possible in a weekend.

The first time you do drain & fill will take longer to figure out your technique. I follow the FSM for the most part, but it will leave extra air in the system, so I run the car for 15 mins with the heat on watching the temp carefully, then crack open all the bleeders again and wait for a solid coolant stream, then fill the tank a bit over max. Over the next few miles of driving the rest of the air will work its way out and the level will drop a bit, so I keep the bottle in the car just in case to top up. After that the coolant shouldn't need touching again.

Perhaps try some higher quality worm clamps. I've had some cheap ones fail on me as well. The OE BMW ones are very solid. There are no holes in the clamp. https://www.fcpeuro.com/products/bmw-hose-clamp-64218367179

See below :). No more worm clamps anymore.

Managed to replace the tank hoses without removing anything, just lost a bit of coolant. Pretty simple.
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One last thing I forgot was the tiny heater hose to the front bay heater actuator or whatever it is, so I had to lose a bit more coolant and replace it. This in all seriousness was probably the hardest hose on the whole car to replace. The clips are buried way in the back with no room to undo them, the hose is super short and hard to slip off, coolant dripping everywhere...but NOW all the hoses are done.
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Filled & bled again and everything works like it should. I can call that project done.

One last thing, my VSS replacement doesn't work at all, I think the wiring was wrong, so no speedo at all, and EPS/MIL lights. I matched the factory sensor but with the new one I probably just need to do a 1:1 wire run instead of having the blk/ylw swapped like factory. I will try to plug the engine harness right into the sensor which I read is possible, if that doesn't work then I'll just rewire it and hope it finally works. More difficult than it needs to be for sure.
 
Big McLargeHuge said:
One last thing, my VSS replacement doesn't work at all, I think the wiring was wrong, so no speedo at all, and EPS/MIL lights. I matched the factory sensor but with the new one I probably just need to do a 1:1 wire run instead of having the blk/ylw swapped like factory. I will try to plug the engine harness right into the sensor which I read is possible, if that doesn't work then I'll just rewire it and hope it finally works. More difficult than it needs to be for sure.

There is a thread on Prime describing using a replacement sensor that does not have the pigtail. Apparently, the 91 harness will reach the sensor just fine. Wish I could find it...
 
There is a thread on Prime describing using a replacement sensor that does not have the pigtail. Apparently, the 91 harness will reach the sensor just fine. Wish I could find it...

Yeah I'll try plugging the harness directly into the sensor first, the diff sensor will have to come with though so I'll have to add another zip tie to the growing roster, lol.

Nice work. Hose grip pliers are helpful when it comes to those small hoses in tight spots.

https://www.harborfreight.com/3-piece-long-reach-hose-grip-pliers-37909.html?_br_psugg_q=hose+pliers

I have a set but didn't end up using it that much. If I didn't work around the hose with a pick first, most of them would be way too tight to safely yank on with the pliers especially for the really small hoses. I tried them on the horrible heater hose but the actuator nipple is plastic and I didn't want to break it, and it just ended up ripping holes in the hose anyways.

The most used tools were a large and small mechanic pick, needle pliers, long articulating needle pliers, and silicone spray w/straw nozzle. Also useful to have a pair of large tongue & groove pliers to get the leverage you need to compress the largest clamps. With those I was able to slip off and install all the hoses by hand. With a blood sacrifice here and there.
 
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Tonight I removed my crap VSS harness and managed to plug the plug straight into the sensor. It's a bit tight with the diff sensor on the same harness branch but works fine, you don't even need to remove anything from the top of the engine as long as you don't have meaty arms. Seems to work just fine now :). Did you know that with a non-working VSS the RPM limiter lowers to 7000? For autos ECUs at least.

I'll probably work on the main & fan control relays next. Really just have brakes as the last major maintenance item and a few wrap-up things left.

Looking forward to going to the Petit Le Mans this Saturday, come find me if you're going :cool:. No fancy Acura area this year though.
 
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Small Lemons 2020

Early morning parking next to a friend's Chevy SS. We got a pretty good spot for 8am on Saturday.
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Race start.
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Pretty comfy view of turn 10.
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Wish I had a Motocompo to putter around the track with. Sometime in the past I measured the trunk of the NSX vs. the dimensions of a folded-up Motocompo and I think it could fit. Imagine a red NSX & Motocompo combo, like a Honda City but fun to drive.
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I didn't see any NSX (old or new) the whole day but this cool JDM FD parked nearby. I didn't get the chance to commiserate with the owner about owning & maintaining a classic import though.
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Great day and weather to get out of the house for once. Besides the race, plenty of people came by to look at the car, take pics, or ask questions. Always happy to spread the NSX gospel :biggrin:.
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Project wise, there's a list of some minor stuff I've been putting off besides the major expenditures of wheels/tires/brakes/coilovers that I'm saving for:
-Finish sealing taillights
-Install shift knob coming on Mon. and properly secure boot
-Get the lower front engine mount helicoiled
-Have test pipe flange moved & exhaust aligned
-Wheel alignment
-Window track adjust & replace door harness connectors w/WPC
-Get fog lights working
-Resolder main relay & fan control relay
-Install CRF pulley shield
-Sell old removed parts

I'd be very happy if I could get most of the above done before the end of the year. Georgia doesn't get cold enough that I need to stow the car for the winter so I'll still be driving it, but working on & washing it is much less pleasant ;^).
 
Did you know that with a non-working VSS the RPM limiter lowers to 7000? For autos ECUs at least.

That is completely normal, the car has 2 rev limits, one for non-VTEC (7200 for m/t) and one for VTEC (8200 for m/t). VTEC activation depends on meeting a minimum speed threshold, and with a faulty VSS you might not meet that so you'll be using the non-VTEC limiter.
 
Makes sense. Related, if I was to change to a MT ECU, would it be required to lower the rev limits to the AT levels, or could I just keep them at the MT ones? It might not make sense from a performance standpoint but would be more fun. I don't know if the AT harmonic balancer was designed for that RPM range though.

What would I need to use a US M/T ECU and copy over the A/T data? Demon2 and Tunerpro? Is it relatively simple to use an A/T data file and copy over what I need? What parameters should I keep and what should I copy over?
 
Ahh RA.....I will never forget my now timid wife who was my GF at xpo 99...She hurled a little in her helmet going into T10 complex:cool:
 
Ahh RA.....I will never forget my now timid wife who was my GF at xpo 99...She hurled a little in her helmet going into T10 complex:cool:

Real long straight downhill into a chicane will do that ;^). I met some good contacts there that might get me into the HPDE events at RA soon, I've been spectating a few times already but never been on track.

Today I did some more driving and took care of some easy items. One was resoldering the main relay and fan control unit. They can be removed with just the top rear panel off but need to loosen the center speaker panel to get access to the lower bolt on the fan unit.
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Main relay internals.
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It looked a little non-factory inside. Maybe someone worked on it before?
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Fan control internals, "after" pic. Lots more joints to reflow.
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Both redone and coated. I installed the new main relay and will keep this one as a spare with my trunk toolkit. I'll see how the fan control works soon, the radiator fan didn't turn on immediately with the car cold so that's a step in the right direction.
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Finished up the warped right taillight with black silicone instead of the bathroom-tile "clear" stuff, it blends in well enough that most people won't notice. Still planning on getting new lenses soon and will likely end up tearing into these for a custom LED conversion coming up soon.
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Will organize the alignment/exhaust rework/trans bolt fix this week, which will be the first time someone else but me has touched the car :cool:
 
The LatheWerks custom shift knob came in :). Stainless steel teardrop design with a gunmetal finish. Very heavy and great feeling in the hand.

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Already installed it and secured the shift boot. Fits perfectly and doesn't stick out too much while still looking good. It shifts from a blue-ish hue to silver depending on the light.
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Really like it so far. The heavy weight dulls some of the "clacking" when getting into gear that some people prefer, I find it distracting. The momentum from the heavy weight also makes it easier to get into gear and seems to reduce my mis-shifting so far. It's so heavy (haven't weighed it but likely ~600 grams) that it might get tiring to constantly move during hard driving but so far it's been great.
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Still lots of stuff left to get done interior wise, but it's just aesthetic so I've not prioritized it. Strip & repaint the center console & switch panels (likely in NSX-R matte black), reupholster the door cards/center armrest/handbrake, get the steering wheel re-wrapped (or aftermarket one), new seat leather covers (Ridies looks great), window tinting, Honda Navpod with some sort of tablet/head unit solution, etc. etc. Next few months for sure.

I'd also like to do a complete audio system rework in the future, but the stock head unit is growing on me and people seem to get a kick out of the cassette to aux jack adapter. I'd like a nice double-din w/Android Auto and all the audio EQ goodness but I'd probably have to get a new RHD console to avoid cutting my stock one which adds a lot of cost.
It would be nice to keep the stock radio and somehow fit the Android Auto head unit into the Navpod to have them both able to control the speakers, but I don't want to cut into the dash so options would be limited to thin tablets. I'll probably have to capitulate somewhere; I'm not sure how I feel about removing the stock radio yet.
 
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Alignment

Not much going on at the moment while I collect parts for the next project, just received another box from Amayama with a ton of brake hardware and rear pistons to help fully refresh my ugly brake system. Otherwise, I hit another roadblock when getting my first alignment done.

On the rack at Global Tire in ATL. One of the owners has his own NSX and they've done several NSX before, so they're one of the few places I'd consider going to. It took three total trips to get to the specs I'm today which wasn't that pleasant but they seem like good guys in need of a better scheduling system.
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Don't laugh too much...I knew it was going to be awful the first time around. I had replaced the two front tie rods and messed with pretty much all the camber bolts before coming in so I could tell it was way off. The first time around they were too busy to take a close look and had to get the next guy waiting on the rack so they told me to come back during a weekday. Not perfect but already a night and day difference driving now that my toe settings aren't completely off.
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Second go-around. Toe is perfect and caster is close, but there was a problem getting the front camber to match. My front right side camber bolt is maxed negative but the wheel is still just barely negative. The car still tracks straight but something on that side is out of whack. Still, happy with how the car handles at the moment.
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I'm still trying to figure out what I need to do to get everything aligned. I already knew this side was repaired in Japan and had inspected it before I bought but didn't realize the alignment was off like that. Besides some minor repairs to the underside, all the parts look to be original so I don't think they replaced any part of it for better or worse (don't mind the hideous ABS bracket, it's on the list). At this point I don't really know what to do, I'm feeling quite depressed that I made that kind of oversight. Best case I need a new compliance pivot since that's where the lower arm attaches to, worst case the mounting points for the front right subframe have shifted and then I'm really fucked. No idea how to verify that my control arms are in spec, if they're not it's at least $1k just in parts. Any sage advice for next steps to take? I'm really beating myself up over this..
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It's been a while so I'm feeling left out on the build updates.

I went about finally fixing my fog lights. They were working intermittently or not at all before. The back of the housings has surface corrosion that I'll likely end up restoring in a future project, lord knows I'm not buying new ones at $800 a set.
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One of the harnesses had a split in the insulation which allowed corrosion of the black wire, which hardened over time and was making for a bad connection.
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Minor harness surgery to repair. Most of the wire had some level of corrosion inside so I spliced in a large replacement wire. Ideally I would've gone all the way up to the connector and re-pinned it but didn't have spare WPC terminals/seals.
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Two new bulbs later and we're in business again. I like using them as DRLs at dawn/dusk to lessen the chance of a clapped-out Altima driver with no insurance pulling out in front of me.

At some indeterminate point in the future I'd like to do an LED DRL/turn signal retrofit and maybe I'll retrofit the fogs as well, but they're pricy/rare enough that I might save them and fit some new fog housings instead.
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Otherwise, I dropped off the car last week to have to exhaust alignment fixed and to move the test pipe flange away from the U-brace. They did a decent job and I removed the dumb looking spacers and replaced the OEM bolts so that's sorted. The alignment of the tips is much closer, still not 100% perfect so I'll try again with the CRF adjustable brackets. They also fixed the stripped front engine mount bolt, I suppose I'll see how robust it is the next time I drop the front beam.

Furthermore, by the recommendation of a member of the car club I'm in, I took the car to Butler Tire which is a pretty well-known wheel & tire shop in ATL to get a second opinion on my alignment issue.

Long story short, they did a much better job in much less time. They were able to get my caster in spec, and matched the front camber as intended. I paid out the ass for a very minor adjustment but everything is sorted. Third time's the charm..
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Both shops commented on the slop in my steering rack at lower speeds, I'm fairly positive I'm in need of a EPS rebuild. I know Matt @ NSX Rack Repair has glowing reviews and I'm sure they'll do a good job, but $1900 whole-ass dollars + shipping + misc parts kills a small part of me. I'm sure it's worth it though, just need to save a bit more.

Of course, I could get a manual rack and do away with the EPS altogether for about half the price and quicker turnaround. It would probably have to come overseas from JP and I'm sure shipping would be a few hundred, but it eliminates a ton of complexity and control modules from the car (i.e. the EPS computer and the A/T computer). I dunno really, I kind of like the EPS and I'm sure it'll feel great after a rebuild, and it's kind of novel to have a M/T with EPS in an early model NSX. I'm open to suggestions or anecdotes, it'll be a few months until I get around to it.

Lastly, I'm working on commissioning a frame measurement report from some locally recommended body shops to see if everything is up to snuff. Not somewhere I ever wanted the car to go near, but I need to see if anything further needs to be done to the area that was previously repaired in JP. I've held off on further parts procurement until I get a clear idea of how much money (if any) I'll have to spend to get the car completely sorted. Partly for my own peace of mind, partly for a future buyer/owner that would want the info. Either way, everything suspension-wise is finally back in spec.
 
Both shops commented on the slop in my steering rack at lower speeds, I'm fairly positive I'm in need of a EPS rebuild. I know Matt @ NSX Rack Repair has glowing reviews and I'm sure they'll do a good job, but $1900 whole-ass dollars + shipping + misc parts kills a small part of me. I'm sure it's worth it though, just need to save a bit more.

Of course, I could get a manual rack and do away with the EPS altogether for about half the price and quicker turnaround. It would probably have to come overseas from JP and I'm sure shipping would be a few hundred, but it eliminates a ton of complexity and control modules from the car (i.e. the EPS computer and the A/T computer). I dunno really, I kind of like the EPS and I'm sure it'll feel great after a rebuild, and it's kind of novel to have a M/T with EPS in an early model NSX. I'm open to suggestions or anecdotes, it'll be a few months until I get around to it.

I'm with you in the steering rack department. Mine is also sloppy, but it's a manual rack.

I was looking at tie rod ends the other day on amayama and it turns out a brand new rack is only $700 (https://www.amayama.com/en/part/honda/53040sl0003). Will they ship it to you? No idea. You can also get the tie rod ends and all the related nonsense for like $250.

$700 still seems like a lot, but the manual rebuild from NSX rack rebuild is $800 alone...
 
The manual rack is at least much simpler, I know Matt offers bronze phosphor adamantium-whatever bushings that are meant to be much better & permanent. The problem with even a brand new OEM manual rack is the internal polymer sleeve will wear out again over time, and the EPS uses plastic (!) gears for the EPS signal generation and wearable internal bushings that'll disintegrate all over again.

If I was gonna take on the project and never have to touch it again I think the bronze bushings are worth the price. If I was gonna switch to the manual rack, I'd get it from Amayama or MITA. Amayama's shipping is bound to be $200+ for such a large box, MITA's price is $1050 all-inclusive. But a new rack isn't truly a permanent solution.

The EPS rebuild plus the NA2/S2K ABS upgrade are wallet killers, lol. I need a GoFundMe page.
 
Matt is a great guy. He spent years perfecting his rebuild. Great option to have in the community. With that said, I think a steering rack makes or breaks your driving experience. I'm on my second manual rack. At the time, it was hard to find a new one because they were discontinued for some time. Seems Honda has brought back many of these parts - awesome! However, I'm concerned they're now using 2nd or 3rd tier suppliers... The new OEM radiators are inferior now compared to new replacements from years ago. I mean it's been 30yrs...

The best steering rack option in my experience is upgrading to the EPS from a AP1/CR S2000. It's a quick ratio rack (sorely needed in the NSX IMO). There's a proper kit for it a member has put together.

It's nice to have options! Good luck.
 
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He's basically our US-based T3TEC or KSP Engineering for EPS :).

You say the upgrade is from the S2K to the NA1 EPS rack, or is that the other way around? I've read over a bit of nsxmugen's thread on the S2K rack and think it's great. I'd have to do more research on it esp. for a RHD NSX, and not sure how much the cost compares to an NA1 EPS rebuild. Maybe it would actually be easier for me since I'd need a USDM S2K rack instead?

The ratio of the NA1 rack doesn't bother me, maybe that would change if I were to start doing autoX. I'll have some time to think about it. Maybe an ATL-based owner can let me test out their rebuilt rack for comparison :wink:
 
>USDM NSX needs JDM rack (confirmed on my car)
>JDM NSX needs a USDM rack (in theory)

Yep, correct. I'm not paying attention...having both RHD and LHD NSX's has messed up my orientation.
 
Tyler glad you were able to get the alignment sorted and I think it's a good idea to get the frame checked anyway. I've noticed that most who have EPS like it and would not go back. I'm living out my Hot Version Touge fantasies, so I got a manual rebuilt rack from Matt with the super-duper bushings. But I have to say a properly sorted EPS on the NSX is a really nice thing. If you're not a weight reduction mental case like me, I'd definitely keep it. Since it still works, you could save up and do the rebuild later.
 
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