BAD NSX

[rs182]

Dreamt about owning a 2nd gen NSX all throughout residency. Considered many other "supercars". Huracan Evo & R8 (those twin turbo kits are sweet), MC20 (yea right), Vantage V12 (another yea right). Always came back around to the NSX.

Fast forward to residency completion and the financial ability to bring this dream to life. Searched for months for the right NSX. Initially wanted Source Silver with a clear matte wrap to get that shark skin look (I'd seen a Hurcan in that color. It looked sick). Also wanted all the carbon fiber options.

Come October of last year AutoTrader delivered me an early Christmas present. Valencia Red Pearl 2021, one owner, all the CF fixins (besides rotors), great price, and an easy to work with dealership (shout out to Acura North Scottsdale). Even has full PPF.

Mileage was around 25k when I made the purchase. I didn't mind this, I bought it to drive. Drove from my home in SW Missouri to Chicago for New Years where the NSX was well taken care of.


Second and last road trip was to Kaukauna, WI for reasons that will be elucidated later. Cheese curds are fire btw.

The mod bug then began to bite. Started off innocently enough. Hood vents from Euroboutique, Girodisc rotors, LiFe battery, seat belt re-webbing.

Hood vent install wasn't too difficult. Good amount of elbow grease required. If you're going to do it yourself, practice your placement technique before exposing the adhesive. Once they're stuck, they're stuck. Finished pictures further on.



Battery requires no explanation. It's the same size, but lighter (22.5# lighter to be exact).



Seat belt re-webbing takes some doing. One of the brackets broke at the pitiful tack welds. I improved upon this design flaw with less pitiful welds.



Thus completed what I would consider entry-level modifications. Next post will further reveal the evolution of my evil plans.

 

[rs182]

Once KTuner/SoS released the E40 tune, it was game time. I previously had an IE E40 tune on my 2013 S4. It wasn't slow.

Sadly water one rainy day the laws of physics took its toll. Water is indeed less compressible than air. RIP engine block and thank you Allstate.

Back to the NSX. This is where the heavy modding begins, and this is only the tip of the iceberg.

Of course the E40 tune was first. The problem now was traction. It went away. This will require rubber reinforcements. More on that further on.



I was disappointed with the fact that Acura stopped offering the carbon fiber roof after 2019, if I am not mistaken. Everyone knows CF roofs are super fresh and the chicks dig them (they don't notice and think you're a geek if you talk about it). Found some used ones off salvages on eBay for around $5k. No thanks.
This is where Jeff Hoffman with Carbon 6 Composites takes the stage. Great guy, super talented, glad to know him. His NSX is next level, if you haven't seen it. He made all the composite parts himself. Forged CF hood, the works. Not to mention the bazooka of an exhaust. We had many stunned fans and probably scared little old ladies when we drove in that beast.
He makes, or did make, a carbon fiber roof for the NC1. Since my dealership nor the body shop they're affiliated with wanted anything to do with scalping my NSX, Jeff offered to do the install for me. So I made the nearly 800 mile drive up north where they talk ever so slightly funny (but much less funny than us Southerners do). 3 days and a lot of cheese curds ands oysters on the half shell later I had my CF roof, and damn was it a work of art.

Back in sweet home Missouri, my own modding begins with the QuickJack. Awesome device. Really a must-have for any garage greaser. I did have some trouble getting it to lift at first, which was insanely annoying. Long story short, the device needs to be able to rise load-free for a distance before it can begin to lift a vehicle. This is problematic for vehicles as low as the NSX. My solution was to cut very low profile lift blocks to set inside the lift channels and drive the tires tires of the NSX onto ~1/2" think slabs of Massanranduba. I didn't make that name up, but wish I did.



Descriptions of the installs would cause more readers to drop like flies than already have, but I will say this: downpipes and intercooler piping installation is not for the faint of heart or light of tool. If anyone has specific questions post them here or PM me, happy to help. Thanks to RedStar for the exhuast and RV6 for the more robust intercooler piping and clamps.

 

[rs182]

Glad that's over, but that won't be the last time I go after that intake.

New socks & shoes, as promised. When having wheels custom machined out of billet, measuring twice and cutting once is essential. I used WheelWise from Speedway Motors. Indispensable tool for custom wheel/tire fitments when precise backspacing and clearances are a must. Note that the picture of the tool in use below was not the final fitment.



Also changed all fluids while the NSX was airborne. Note that if you are following the available YouTube advise for changing the transmission and clutch fluid, you're doing it wrong and risking running a low (possibly dangerously) level of fluid. The factory procedure is essential to follow. Prepare for a mess either way.

Running the vehicle at speed in drive is a part of the procedure. If you do this, make sure wheels are bolted to the rotors. The little set screws tend to bend under braking load and will likely need to be drilled out.



And when you break the drill off inside the screw, you curse yourself for being a dumbass and then use your pea-brain to figure out how to extract it.



So fresh and so clean because, why not?



This is pretty much where the standard modding ends and my business begins. Blackshear Automotive Development is born.

 

[Bricks and Bio]

This sounds like fun in the making.
What kind of doc are you (my guess is orthopedic surgeon based on your love of the wrench)?
If you are coming to Chicago again, send a heads up, coffee is on me.

 

[rs182]

Anesthesiologist, although the ortho boys almost had me convinced during med school. If you'll be at NSXPO, drinks are on me. Preferably after the HPDE.

 

[docjohn]

Dr Sleep...

 

[Bricks and Bio]

I believe that job is well described as periods of boredom or complete anxiety
I hope you use Ultane (I am an AbbVie retiree)
Sorry, I am not that committed to do NSXPO
I messed up and was too lazy to go when it was next door in WI

 

[rs182]

Old faithful sevo. Although not the anesthetic I will be exposing the NSX to.

 

[Wild Turkey]

Welcome. Also started considering ortho, but the clinic... Neuroanesthesia.

I'll be on the lookout for your NC at NSXPO.

 

[rs182]

Those crani cruises sure beat 50 MAC endoscopies. Look forward to meeting up in TX.

 

[W_Orlando]

Great post. Thanks.

 

[RyanRA]

I’ll Be Numbed.

Nice updates!

 

[rs182]

Knowledge is power, and it's something we unfortunately lack with respect to the NC1's power output capabilities. The turbine/compressor upgrade is/was exciting, but lacks real proving. What is holding the NC1 back? Factory safe guards? Maxed out volumetric efficiency? Fuel system? If so, which components? Lot's of questions need answering if we are to move this platform forward. The following is what I can divulge about my progress filling in these blanks so far.

But first, a brief description of the NC1's means of fuel delivery. The JNC1 employs dual injection (or dual-fuel) for combustion chamber fuel delivery. This is a combination of direct (DI) and port injection (PI), with DI operating all the time and PI supplementing when high power output is demanded. The idea is to utilize the benefits of both while minimizing the drawbacks.
DI achieves the most homogenous of air/fuel mixtures, delivered directly into the combustion chamber at extremely high pressures and precisely timed to occur nearly simultaneously with spark ignition. Excellent for emissions and low-load responsiveness, but for a variety of reasons lacks the ability to deliver fuel quantities sufficient for high-horsepower output without significant effort and expense. This is best left alone.
PI is capable of delivering loads of fuel into the air charge proximal to the intake valve. The delivery pressures are much lower (~58 psi in this case), resulting in less fuel droplet vaporization & air/fuel mixture homogenization. As far as fuel delivery goes, the sky is the limit with PI, as long as you have the proper components (fuel pump(s), fuel lines, regulator, injectors). This is the system on which the JNC1 relies to achieve C8-thrashing horsepower, and thus where my attention and efforts will be concentrated.



Fuel delivery begins in the fuel tank, or tanks in this case. The driver's side tank contains the fuel pump supplying the DI system, and the passenger's side tank containing the PI fuel pump. These are the beating hearts of the fuel system, and the limiting reagent when it comes to demanded flow at a certain pressure. The PI system is where the money is at as we look to coax more power out of the JNC1. There are two means by which to achieve this:

1. Replace the existing fuel pump with a higher-flowing variety. This may seem great, but it really...ain't. A larger, high-output pump demands more amps at all times, and thus more watts (HEAT). This could very well require extensive wiring alterations and would most certainly freak the PCM out. Not to mention dropping the tanks and removing the fuel pumps would be a huge pain in the ass (requires disassembly of nearly the entire rear of the vehicle).

2. Voltage boosting. This is where the money is at. Simply put, a power supply unit of sorts that is spliced into the 12V+ power supply to the factory pump. When triggered by a set input, a higher voltage will be applied to the pump, resulting in on-demand increases in fuel output. Since the fuel pump is only rarely and intermittently subjected to these loads (unless you are Ricky Bobby), the life of the fuel pump is negligibly affected. There is a good amount of literature about this modality of fuel pump flow enhancement. It's beautifully simple and effective.

I am in the process of building a fuel pump test rig. I received no small amount of YouTube inspiration for constructing this device. From this we will be able to determine the flow capacity of the factory pumps and their response to voltage boosting. I'll be testing the DI pump simply to contribute to a comprehensive understanding of the fuel system.

These eBay beauties are on their way to me, they know not what is in store for them:



Next post will detail my progress on flow testing the injectors. Don't worry, we've got options.

 

[sca037]

FUN thread, IN for more updates!

 

[jt983]

Have you taken your car to the dragstrip? I'm curious in the numbers I plan to upgrade to ktuner stage 2 E40

 

[rs182]

Have you taken your car to the dragstrip? I'm curious in the numbers I plan to upgrade to ktuner stage 2 E40

My NSX will visit both the quarter mile and a hub dyno once I have all my data logging equipment wired up and running. I will detail this in a future post.

 

[rs182]

Let's talk injectors. The end of the line as far as fueling potential is concerned. Many different kinds with different electromechanical characteristics. To limit post length and save my fingers this won't be a review of injector design & operation. That riveting information can be found via a quick Google or YouTube search.

We will concentrate our time and effort on the injectors found on the JNC1. As discussed previously, the JNC1 features a "dual injection" model utilizing both direct and port fuel injectors. The port injectors are relatively easy to access, the direct injectors being beneath the intake manifold, not so much. Fortunately, with a caveat, upgrading the port injectors is our best means of increasing the JNC1's power potential once stock injector limits have been reached. The caveat? Per my discussions with Derek from InnovativeMotorWorks, a means to separate electronic control of the direct and port fuel injectors has yet to be discovered. Fueling capability seems to be bottle-necking at the high pressure fuel pump at this time. A plight which eventually plagues all direct injected vehicles as they quest for more power. Thus at this time we are at the mercy of the DI fuel system. Bummer.

Less of a bummer is the availability of HPFP internal component upgrades to increase flow. Unfortunately no such upgrade exists for the JNC1, yet. I performed this upgrade on my 2013 S4 HPFP and it was relatively simple as long as you keep everything squeaky clean. The result was the ability to flow 700+ HP worth of fueling from a 6 cylinder direct injection platform.

Now for some meaty information. I have had the stock JNC1 port and direct fuel injectors flow tested, as well as a Type S fuel injector. The data provided by the port injector flow testing is straightforward to interpret with any of myriad online calculators. The DI data is a bit more elusive in its interpretation. Here are the power potential numbers I have calculated for the port injectors (fuel pressure listed is differential as it relates to manifold pressure, HP figures at the crank):

@55 psi, 80% duty cycle, gasoline:
Stock: 325 HP
Type S: 415 HP

@55 psi, 80% DC, E85:
Stock: 250 HP
Type S: 315 HP

Increasing the duty cycle to 90% results in the following:

@55 psi, 90% DC, gasoline:
Stock: 360 HP
Type S: 470 HP

@55 psi, 90% DC, E85:
Stock: 280 HP
Type S: 360 HP

I encourage you to use the data in the attached pdf to perform your own calculations. Presently E40 is the highest E content tune available for the NC1, so crank HP potential will be somewhere between pure gasoline and E85 as it relates to the port injectors.

I am not going to yet attempt to interpret the data provided by the DI test plan. What was revealed is that at high load on the test plan utilized, the JNC1 DIs deliver fuel at a volume of ~96-99 cubic millimeters per injection stroke. High load test is iVM.01 on attached pdf.

What we can say with relative certainly is that the DI fuel system seems to be supplying a large amount of the fueling, which is unfortunate given its limitations and the easy scalability of the port injection fuel system. If we take the claimed all-wheel HP of the Stage 4, 98 octane tune of 739 HP, subtract 73 HP to remove the EV components from the equation (666 HP), then add back ~9% to account for drivetrain loss, we arrive at 726 crank HP from the ICE. That means the DI fuel system is supplying over half of the fueling needs (if we assume 90% DC)!

It is obvious and encouraging that this platform has potential that has not yet been realized. I look forward to sharing my progress as I push the limits of this platform and hopefully inspire others to collaborate.

Stock vs Type S port injectors, visually indistinguishable:


Direct fuel injector:


Spaghetti:


Under investigation:

 

[iconoblast]

Anesthesiologist, although the ortho boys almost had me convinced during med school. If you'll be at NSXPO, drinks are on me. Preferably after the HPDE.

Ortho focus on their own biceps, not the wrench