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RYU's "properly molested" NSX build thread
- Thread starter RYU
- Start date
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Is your friend's NA2 on this board too?
Yes, under "Kuni" but he doesn't post much.
Probably time for an update.
I was concerned about voltage drop under high load. Since i'm running a Denso Supra pump, a Water injection cooling system, and a small Odyssey PC680 battery, I would see my Voltage drop at the high RPMs. I decided to try out a high output alternator from a local shop. This is a remanufactured unit for a Prelude (opposite spin) for CTSC NSX applications. Original Prelude/CTSC alternator is 90-95 amps. This one is 130amps. My voltage is higher by 0.5-1.5volts across the power band but I noticed the voltage regulator isn't as good on this unit. It oftens spikes to 15.1 volts for a millisecond when I blip the motor or it will kick on/off at idle on occassion. It's not a huge deal and I don't mind it but I wish it was as rock solid as an OEM unit. I might consider swapping out the internal voltage regulator between the two alternators when I have some down time.
Old (top), New (bottom). You can see the old trick of using a smaller pulley isn't done here. It's a legit stator rewind job.
I have some decent seat time on the JRZ RS Pros. Love them. I'm on 11k/9k now. I want to try something softer. Maybe even 9k/6-8k.
Going to upgrade to these pillow ball top hats soon. I just don't like using the OEM top hats with my JRZs and my lift kit.
I tried the No-ABS thing. Isn't for me. I locked up at Streets of Willow and wasted a set of perfectly good NT-05s.
With my 1991 ABS unit on it's last legs anyway I finally swapped over to the 00+ updated ABS. Woooooshaaaa!
Ordered the harness from KSP. Overall the KSP is better made and allows for easier pass thru via the firewall but I do like how SOS allows you to use the OEM factory power supply connector.
You can see a bit of the SOS connector here. They glue the ends? but you can see the naked pins on the bottom which you slip into the OEM connector. The KSP requires ring terminals to run to a ground bolt and to the ABS fuse at the fuse block.
My exhaust also go louder over the years. I thought my magnaflow, ceramic 50-state legal cats were done. I then did significant research online and everything pointed me to HJS cats from Germany. They are high flow, high precious metal content cats. Each one was $500+!! I needed two. Ouch. I had mixed feelings about using these since they were 200 cell, 80-90% flow. The whole reason I have a valvetronic exhaust is to have a quiet mode and a obnoxious VTEC track mode. This would make my quiet mode more like.. sorta noisy mode. Not ideal. Here's the HJS cats. One of the best in the industry in terms of aftermarket HF cats.
When we took apart my exhaust I examined the old magnaflow cats. Much to my amazement they were perfectly fine! After further investigation we noticed all the fiberglass fill in the muffler was totally burnt off. We ordered some metallic "steel wool" type exhaust fill and rebuild the mufflers. The sound is back to drone-free and sophisticated again. Kind of like Taylor Swift. I hope this last me at least 10yrs. Sheesh.
Unfortunately, I have to cancel my eagerly anticipated June 28th No-Sound-Limit Laguna Seca track day. I was looking forward to this for months. In Monterey County's infinite wisdom they decided to change the volume restrictions of this day to 105dB from unlimited. 1 month from the day!!! I'm so bummed. We had one day (a Sunday no less) to build a makeshift testing apparatus using my cellphone. It was janky but it consistently showed 113-114dB max. I decided to cancel the trackday. Huge disappointments all around.
I should also share some test results. I've been using the A.S. Motorsports (@A.S. Motorsport) CTSC phenolic plate that Adnan and I are prototyping. The results have been incredible. On a hot socal day after an hour or more of driving my car use to have a heatsoaked IAT of 160-190F. Now, the IAT is a solid 130-138F under the same conditions. When under boost i'm easily in the 100-120F range with the water spray solution. I'm finally happy with my CTSC cooling setup. I've also been consistently street tuning my HKS F-Con VPro. Oh, did I mention I upgraded from the iS to the VPro + CAMP2? I've also learned to tune the thing a bit. My driveability has been quite good. I've even got my daily MPG back up to normal (23-27mpg).
I also found some limited edition center caps for my Volk CE28n's. Win!
Cool keychain!
Next project...
It was a huge pain to source 330mm x 25.3mm (or thinner) rear rotors. I'm currently on 14" rotors and it won't allow me to run a 17" rear wheel. I've decided I want the option to run my factory 02 wheels again so with the help of friends i'll be putting together a custom BBK setup with 65% brake bias.
I was concerned about voltage drop under high load. Since i'm running a Denso Supra pump, a Water injection cooling system, and a small Odyssey PC680 battery, I would see my Voltage drop at the high RPMs. I decided to try out a high output alternator from a local shop. This is a remanufactured unit for a Prelude (opposite spin) for CTSC NSX applications. Original Prelude/CTSC alternator is 90-95 amps. This one is 130amps. My voltage is higher by 0.5-1.5volts across the power band but I noticed the voltage regulator isn't as good on this unit. It oftens spikes to 15.1 volts for a millisecond when I blip the motor or it will kick on/off at idle on occassion. It's not a huge deal and I don't mind it but I wish it was as rock solid as an OEM unit. I might consider swapping out the internal voltage regulator between the two alternators when I have some down time.
Old (top), New (bottom). You can see the old trick of using a smaller pulley isn't done here. It's a legit stator rewind job.
I have some decent seat time on the JRZ RS Pros. Love them. I'm on 11k/9k now. I want to try something softer. Maybe even 9k/6-8k.
Going to upgrade to these pillow ball top hats soon. I just don't like using the OEM top hats with my JRZs and my lift kit.
I tried the No-ABS thing. Isn't for me. I locked up at Streets of Willow and wasted a set of perfectly good NT-05s.
With my 1991 ABS unit on it's last legs anyway I finally swapped over to the 00+ updated ABS. Woooooshaaaa!
Ordered the harness from KSP. Overall the KSP is better made and allows for easier pass thru via the firewall but I do like how SOS allows you to use the OEM factory power supply connector.
You can see a bit of the SOS connector here. They glue the ends? but you can see the naked pins on the bottom which you slip into the OEM connector. The KSP requires ring terminals to run to a ground bolt and to the ABS fuse at the fuse block.
My exhaust also go louder over the years. I thought my magnaflow, ceramic 50-state legal cats were done. I then did significant research online and everything pointed me to HJS cats from Germany. They are high flow, high precious metal content cats. Each one was $500+!! I needed two. Ouch. I had mixed feelings about using these since they were 200 cell, 80-90% flow. The whole reason I have a valvetronic exhaust is to have a quiet mode and a obnoxious VTEC track mode. This would make my quiet mode more like.. sorta noisy mode. Not ideal. Here's the HJS cats. One of the best in the industry in terms of aftermarket HF cats.
When we took apart my exhaust I examined the old magnaflow cats. Much to my amazement they were perfectly fine! After further investigation we noticed all the fiberglass fill in the muffler was totally burnt off. We ordered some metallic "steel wool" type exhaust fill and rebuild the mufflers. The sound is back to drone-free and sophisticated again. Kind of like Taylor Swift. I hope this last me at least 10yrs. Sheesh.
Unfortunately, I have to cancel my eagerly anticipated June 28th No-Sound-Limit Laguna Seca track day. I was looking forward to this for months. In Monterey County's infinite wisdom they decided to change the volume restrictions of this day to 105dB from unlimited. 1 month from the day!!! I'm so bummed. We had one day (a Sunday no less) to build a makeshift testing apparatus using my cellphone. It was janky but it consistently showed 113-114dB max. I decided to cancel the trackday. Huge disappointments all around.
I should also share some test results. I've been using the A.S. Motorsports (@A.S. Motorsport) CTSC phenolic plate that Adnan and I are prototyping. The results have been incredible. On a hot socal day after an hour or more of driving my car use to have a heatsoaked IAT of 160-190F. Now, the IAT is a solid 130-138F under the same conditions. When under boost i'm easily in the 100-120F range with the water spray solution. I'm finally happy with my CTSC cooling setup. I've also been consistently street tuning my HKS F-Con VPro. Oh, did I mention I upgraded from the iS to the VPro + CAMP2? I've also learned to tune the thing a bit. My driveability has been quite good. I've even got my daily MPG back up to normal (23-27mpg).
I also found some limited edition center caps for my Volk CE28n's. Win!
Cool keychain!
Next project...
It was a huge pain to source 330mm x 25.3mm (or thinner) rear rotors. I'm currently on 14" rotors and it won't allow me to run a 17" rear wheel. I've decided I want the option to run my factory 02 wheels again so with the help of friends i'll be putting together a custom BBK setup with 65% brake bias.
Hi Roman, it's amazing what the 4x4 off road community has available in terms of reservoir mounts. SOS sells these for almost $200. I think I found a set for less than $70 a pair.I was just about to say how great those reservoir mounts look but then I scrolled down.. and oh wait there is more
//sucks you won't be here @Laguna
I'm pretty bummed about MRLS man...
And your build just keeps getting better and better. Looking forward to the next time our paths cross.
Found a free version of the video. Hope you enjoy 2 NSXs gonewild.
<iframe src="https://player.vimeo.com/video/121747866" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe> <p><a href="https://vimeo.com/121747866">NSX</a> from <a href="https://vimeo.com/user38219249">T</a> on <a href="https://vimeo.com">Vimeo</a>.</p>
<iframe src="https://player.vimeo.com/video/121747866" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe> <p><a href="https://vimeo.com/121747866">NSX</a> from <a href="https://vimeo.com/user38219249">T</a> on <a href="https://vimeo.com">Vimeo</a>.</p>
[MENTION=20915]RYU[/MENTION], did you end up using the HJS cats or did you go back with your original cats? I've had those cats before and they are awesome. I am going to build a custom exhaust down the road using either HJS cats again or try out the Gesi HO series cats.
I didn't have to modify my Magnaflow cats so I ended up keeping them in place. It wasn't without mixed feelings though. I know the HJS cats are better and even at 200 cell they probably catalyze better than the 400 cell ceramic Magnaflows. I didn't swap them over because I really did not want my "quiet mode" to be any louder. I love the way it sounds now and the 400 cell cats are all part of the exhaust design equation. I guess it's great to know that the Magnaflows held up after 3yrs. I even had my car running quite rich for most of that time too.
I poked and prodded HJS to build me a 400 cell cat but the volume just isn't there for such a niche product. Option 2 was to locate a set of 911 turbo or M3/M4 turbo OEM cats. However, they were bigger and would require me to redo a big portion of my exhaust layout. All in all, I think I ended up with the best result from this exercise. The steel wool brought back the sophisticated sound I had when it was new. Hope it lasts!
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HJS was the company that first sold me on being able to run high hp while still using cats. From my personal experience they did their job very well and removed rasp/drone from the exhaust. They lowered the volume some but I would not think they are quieter than 400 cell mags. You pay for the material used in the cats for the HJS more than anything.
Kooks "Green" cats are suppose to be good as well but I can't seem to find a comparison analysis. [MENTION=16531]stuntman[/MENTION] uses Kooks.
For FI applications, (and in general) metal substrates are more durable than ceramics, which have been known to fall apart over the years. Most 'metal' cats use mild steel or cheap substrates and a stainless steel housing. Kook's "Green Cats" use stainless in the housing and substrate, market their cats for only a few HP loss over a straight pipe, and 49-state legal.
Thanks for taking the time to take pics, document your progress and answer questions via pm's. Your build has so much useful information that I often refrence as I plan out my mods. Keep up the great work, i'm sure alot of members like myself appreciate the attention to detail that you bring to modding your nsx.
Enjoyed the video Regan!
What suspension does Kuni run?
Don't sell the Magnaflow cats short. For a given cell density and substrate length, their square cell shape has a lower pressure drop than the triangular cell shapes used in those other more expensive cats.
Also, you can replace four Magnaflows for the same cost as one German or Canadian cat!
It doesn't matter what brand catalytic convertor you have or the substrate material - if your engine burns oil (phosphorous and zinc) it will ruin your cats. When I was running my engine break-in oil, I temporarily removed my cats. The air/oil separator helps too.
You and I may still be the only ones with the variable exhaust design where our cats are bypassed anyways when absolute performance is demanded :wink: That makes them last a lot longer....
After all these years and tons of money spent on raw exhaust fabrication components, I finally settled with another active exhaust that actually gets freer-flowing AND quieter under a load at WOT. Still waiting for a patent on the other design, but it is too restrictive for my particular goals. Now I tune the sound with variable packing, straight-through perforated core designs, and muffler case volume only.
Actually, my car is out of commission again while I tweak the header primaries and collector design again. A little too much reversion as measured from the combustion cylinder pressure sensor.
Keep up the good work!
What suspension does Kuni run?
Don't sell the Magnaflow cats short. For a given cell density and substrate length, their square cell shape has a lower pressure drop than the triangular cell shapes used in those other more expensive cats.
Also, you can replace four Magnaflows for the same cost as one German or Canadian cat!
It doesn't matter what brand catalytic convertor you have or the substrate material - if your engine burns oil (phosphorous and zinc) it will ruin your cats. When I was running my engine break-in oil, I temporarily removed my cats. The air/oil separator helps too.
You and I may still be the only ones with the variable exhaust design where our cats are bypassed anyways when absolute performance is demanded :wink: That makes them last a lot longer....
After all these years and tons of money spent on raw exhaust fabrication components, I finally settled with another active exhaust that actually gets freer-flowing AND quieter under a load at WOT. Still waiting for a patent on the other design, but it is too restrictive for my particular goals. Now I tune the sound with variable packing, straight-through perforated core designs, and muffler case volume only.
Actually, my car is out of commission again while I tweak the header primaries and collector design again. A little too much reversion as measured from the combustion cylinder pressure sensor.
Keep up the good work!
You are always an inspiration Dave!! I'm eagerly awaiting the day you debut all your cool designs. I have you to thank for the valvetronic thingy majigeee thing on my car.
I suspect you are correct. The magnaflow cats have probably lasted this long due to the valve bypass under load. The exhaust has worked flawlessly so far! Well, except for all the fiberglass fill burning off. Makes me wish I would have bought a Burns or equivalent muffler that was rebuildable to begin with.
FWIW.. According to HJS (so take with a grain of salt)..
perhaps it's not all about the precious metal content. for now i'm still happy with how things turned out
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Also glad other folks are enjoying these updates. I've really began a new chapter of my relationship with the car. I just want to drive it everywhere now instead of tinkering, washing, parking it
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I forgot to answer your question Dave. Kuni is running the same dampers I use to run. The DG5 coilover system. Really a great damper. In some ways I still prefer it over my JRZs.
I suspect you are correct. The magnaflow cats have probably lasted this long due to the valve bypass under load. The exhaust has worked flawlessly so far! Well, except for all the fiberglass fill burning off. Makes me wish I would have bought a Burns or equivalent muffler that was rebuildable to begin with.
FWIW.. According to HJS (so take with a grain of salt)..
perhaps it's not all about the precious metal content. for now i'm still happy with how things turned out
- - - Updated - - -
Also glad other folks are enjoying these updates. I've really began a new chapter of my relationship with the car. I just want to drive it everywhere now instead of tinkering, washing, parking it
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I forgot to answer your question Dave. Kuni is running the same dampers I use to run. The DG5 coilover system. Really a great damper. In some ways I still prefer it over my JRZs.
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You are always an inspiration Dave!! I'm eagerly awaiting the day you debut all your cool designs. I have you to thank for the valvetronic thingy majigeee thing on my car.
I suspect you are correct. The magnaflow cats have probably lasted this long due to the valve bypass under load. The exhaust has worked flawlessly so far! Well, except for all the fiberglass fill burning off. Makes me wish I would have bought a Burns or equivalent muffler that was rebuildable to begin with.
FWIW.. According to HJS (so take with a grain of salt)..
perhaps it's not all about the precious metal content. for now i'm still happy with how things turned out
- - - Updated - - -
Also glad other folks are enjoying these updates. I've really began a new chapter of my relationship with the car. I just want to drive it everywhere now instead of tinkering, washing, parking it
HJS is right - most catalytic converters (including OEM) use less than 10 grams each. If those are good enough to qualify as 50-state emissions legal, why use more? Marketing? I personally don't care to increase the oxidation or reduction process anymore than regulatory requirements if it's going to cost me 3-4 times as much! I researched all this stuff too before building my latest iteration....
Personally, I use cats because I find hydrocarbons particularly offensive and it gives me headaches. Everyone has a different tolerance to exhaust fumes however.
Thanks for the info on the dampers! Will that be your next project - continuously variable dampers? I'm patiently waiting for Tenneco to release theirs so I can retrofit it.
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Let's see some more of this brake project!
My exhaust fumes even when the car is warm is still a bit offensive, though i'm pretty sure i'm quite sensitive to these fumes anyway. It's not nearly as terrible as having test pipes though but it's not quite like my OEM cars. My AFR is 14.7-15.1 at idle (depending on ECT) but I should probably still tweak the idle tune a bit. Anyway, it doesn't bother me too much. Just wish it was as smelly-free as OEM. I would really like to put it up to a SMOG sniffer one day. I'm curious what my readings are 3yrs later since these cats are 50-state legal.
After I finish my list above I'd like to try softer springs. I'm currently running 11k/9k and it's just a bit bouncy especially 25mph or slower. Now that i'm learning to tune 2 way dampers I'm wishing I got 3 ways. In talking with folks I respect who have had experience with JRZs (including Jon Martin) they said to try a lower spring rate. They said the JRZs tend to like a lower spring rate. Jon recommended I preserve the same rate bias but just be slightly under the Type R rates. Jon and Billy also recommended I drop the cannister pressure to ~250psi. I believe i'm at 300+psi right now. In terms of springs, might try 9-8K in front and 8-7k in the rear. I just don't want to waste money on test springs so i'm asking around with friends who have a few lying around I can borrow. Good news also.. the lift kit has been working great so far too. Hope yours is setup and trouble free.
The car has never felt this great at the track. I finally fell totally comfortable and the "oh-shit" moments are fewer and far between but since i've enjoyed driving it so much in many conditions i'd like to make it softer for the street. This means smaller brakes so I can fit the OEM 17/17 2002+ wheels again and softer springs.
If I ever find a spare trunk i'd like to screw around with a retractable OEM style wing.
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From what I understand ceramic cats aren't really recommended for Forced Induction, since they tend to fall apart.
You really do need to try 200-250psi ASAP. report back!
You really do need to try 200-250psi ASAP. report back!
Both Dave and I have automatic valves in our exhaust (like corvettes, BMWs, Ferrari, etc) so when the engine is under a lot of load the exhaust flow is bypassed away from the cats and is a true free flow. I'm not sure how Dave set his up now but mine are up to open when the VViS valves open (4800 rpm). At the track, I have it open anytime under boost. It really works quite well. This way the cats are under very little stress. I agree with you... Under boost conditions I'm not sure if these cats would have held up. Didn't want to find out!
EDIT: What's pretty cool about the valve setup is that i'm using 100% oem parts. The valves are OEM and i'm using the OEM NSX VViS vacuum valve control box near the rear driver's shock tower to control the opening of the valves. Now that i'm on the HKS F-Con Vpro I will be able to control when I open those valves. Once I get time, i'll jump on the dyno and figure out which rpm/vtec crossover point produces the best outcome for when the valves should open. At the track, i'll probably have the VPro setup to either keep the valves always open or open under boost. I get excited about improving even the smallest bit of driveability with the car but I just wish I had more free time...
I would have tried 200-250psi already, but I don't have a pressure gauge that goes up that high! Haha! I need to visit Frank or Mario in Torrance when I get some free time.
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Man... Continuously variable dampers is like the holy grail. I'd love to hear about how you plan to implement this. I can think of a few different ways.
I've got a much more digestible goal for my dampers. I'm hoping to retrofit a Tein EDFC style solution but it will require a lot machine work and I'd have to get a 3D printer I reckon.
Its just a bit annoying when every time I adjust the dampers I have to get out of the car, open the hood and/or engine bonnet, then make adjustments. Multiply this by 8 for rebound and compression = annoyance
I'd love to have a remote adjustment system for this.
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A lot fast guys love the OEM brakes. I don't. I hate going thru pads and rotors so quickly. The modulation of a 4 wheel fixed calipers just feels so much more sophisticated IMO. I dont know... I'm spoiled. I know I don't need them to go fast.
I hope with the new kit I preserve all of what I love about my current kit. I know I could use a lot less brake. My current brakes never fade with the RC4 pads. They don't even fade with street equivalent pads either. I'm also still running the rear OEM dust shields and Maxxis RC1 DOT "slicks". I just don't understand the guys who are going 6pot/4pot systems unless you're Billy Johnson!
More to come on this once I get some more free time to work on them. I'll be using 330mm rotors all around (Brembo front rotor, AP racing rear), Brembo ebrake, 4 pot/4pot Brembo calipers (65% bias), and should clear OEM 17/17 wheels. I hope... Haha
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