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Back to NA after 10 years of FI

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I never thought I would go back to NA after all these years with my LoveFab turbocharged NSX.
The main use of the car was to attend Track Day meetings in France, Belgium and Germany with the Swiss NSX sport cars club.
These were really great days with a friendly atmosphere largely brought by the late President Jean Claude Zucker.
Hélas, no one took over the responsibility of running the club any longer and I found myself having to attend mixed manufacturer Track Days with a wide variety of rider skills.
On my last outing, I had a guy running a full racing M3 with an M5 engine run into my right door trying to mimic Max Verstappen's suicide pass on Lewis Hamilton.
This triggered my decision, although other factors came into account such as the inherent NSX design fault of the ventilation of the rear cam cover that will spill out a lot of oil in any hard right hand corner or the fact that the NSX is too valuable a car to take it on track.
So given that 400 whp is not really usable on the street and that in any case this modification is illegal in Europe, I decided to call it quits.
Oh and I almost forgot, it will be a real pleasure to drive a car that doesn't smell anymore!
As I stupidly had sold my original Mugen exhaust system, I decided to go with an OEM NA2 exhaust.
I was lucky to find good second hand items here and there (except the cats from SoS) and I'm now in the process of getting them on the car.
 

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HaHa life in the slow lane......you can always get a dedicated track car...they are like boats..there are always guys willing to sell at a steep discount....my old nsx is now a street/cars and coffee machine now.
 
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[MENTION=19738]CB72[/MENTION] welcome back to the fold! :D

As you know, my wife is French and it remains a dream of mine to drive my NSX on the Mas du Clos someday...NA is so much better there anyway. ;)
 
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Hey John! good news is since you are loosing some weight (turbos) now you can go faster on turns and braking :biggrin:

Hi Bruno, I'm not sure I'll gain much weight as the stock NA2 exhaust is pretty heavy but I could go faster on some tracks as I will no more have to control the steep torque rise in slow corners and in the fast curves the pure scare factor will be greatly reduced!
But I promised myself not to try!
 
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[MENTION=19738]CB72[/MENTION] welcome back to the fold! :D

As you know, my wife is French and it remains a dream of mine to drive my NSX on the Mas du Clos someday...NA is so much better there anyway. ;)
Hi [MENTION=18194]Honcho[/MENTION], the Mas du Clos is OK for an NA car but at Spa the FI is a must.
At the top of the long straight after "l'eau rouge" I would reach 240 km/h ( 150 mph) hitting the red line in fourth while only getting 215 km/h with the NA setting...
Those were the days!
 
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The turbo setup is now out of the car.
Getting the front header out was the most complicated while getting the AEM ECU out was also lengthy due to the Comptech harness bars.
The NA2 headers are in place and we noticed that the support for the NA2 cats are missing in the NA1...
Also the AFR sensor cables need to be longer.
No great issue as I was planning to change them in any case.
My surprise came when I saw the price of the OEM items around 400 USD.
Luckily one can get Denso units for a tenth of the price!
This is some margin Mr Honda!
Here's a picture of the turbo parts:

IMG_3037.JPG
 
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The installation of the NA2 exhaust is now finished.
It's not plug and play on an NA1 body as a couple of the catalytic converter supports are missing.
Another smaller issue is that there is not quite enough clearance to fit the O2 sensors.
I replaced the old sensors with Denso DOX-0113 items that are hooked up to the OEM plugs.
The car started easily but wouldn't run more than 30 seconds?
I suppose it could be due to the injectors that have not been used for over 10 years?
At least one of them could be stuck open as the fuel pressure drops down to zero a minute or so after cutting the ignition?
Does anyone know the manufacturer's P/N for the injectors?
It could save a bunch over those from Honda I suppose?
Last question: given that I was running with a turbo, could it be that the MAP pressure sensor is no longer the OEM item?
PS: I checked the shipping list and it's the AEM Map sensor!

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I believe Keihin is the OEM vendor for fuel injectors on the NSX and a lot of other Honda products. Keihin is now owned by Hitachi and neither appears to sell automotive class components direct to retail. The Honda part 06164-P0A-000 is showing as NLA at a lot of the Honda vendors so new OEM injectors may no longer be an option. Amayama still lists them; but, even their price is in the nose bleed territory. Based upon Amayama's price, I think you are going to want to pull your injectors and have them cleaned. There are aftermarket injectors from Standard Motor Products and Ultra Power which are lower cost. I would only use them as a last resort.

The service manual provides the characteristics (Vout versus manifold pressure) for the OEM MAP sensor. Check the characteristic curve for the AEM sensor. If the slope and intercepts on the output curve are the same as for the OEM sensor it should work fine.
 
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Glad to see this thread.

As much as I enjoy my NSX with SOS twin turbo system, there are days I am considering going back to stock. This is because of the exponential increase in value for our beloved NSXs. I kept all my stock parts just in case I ever changed my mind.

Not quite ready to make that change yet, but wow…
 
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Running with unorganized and scary track groups really takes a lot of the fun out of going to the track for me too.

I used to go so often, now that I live so far away from my car it just doesn’t seem like such a priority to build a “track beast” so I get your struggle.

That said, I have been NA the entire time I’ve owned and tracked my car, currently building a 3.6 litre with ITBs and VTEC Killers…for coffee runs and track days.

I hope I can track my car more soon…

Looks like you are well on your way to going back to stock, tbh even stock the NSX is a blast to drive on the track (unless you have USDM gears) more fun to drive a slow car fast, right?


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The service manual provides the characteristics (Vout versus manifold pressure) for the OEM MAP sensor. Check the characteristic curve for the AEM sensor. If the slope and intercepts on the output curve are the same as for the OEM sensor it should work fine.

The AEM Map sensor PN 30-2130-50 ( 3.5 bar) has an ascending slope from .5V at 0 KPa to 2.5V at 100 KPa while the OEM sensor has a descending slope from 2.8V at 0 KPa to 0.5 V at 100 KPa.
It definitely won't work to use the AEM sensor with the OEM ECU.
I'll check the car on monday to determine which Map sensor is installed.
The pity is that I can't find the OEM sensor in all my spares!
 
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Looks like you are well on your way to going back to stock, tbh even stock the NSX is a blast to drive on the track (unless you have USDM gears) more fun to drive a slow car fast, right?
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It will definitely be less scary specially in the wet but goodbye to any contest with the GT3's at my driver's level at least!
 
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It will definitely be less scary specially in the wet but goodbye to any contest with the GT3's at my driver's level at least!

Just gotta get on that “weight loss” program.
.
The only route that is more expensive than the “NA power” program


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Big disappointment today as the engine won't run more than 30 seconds?
It starts easily and runs nicely at around 1500 rpm until the rpm drops and then stalls.
It's as if there was no more petrol.
We checked the fuel pressure, the fuel delivery into a basin, the power supply to the pump and everything checks out OK.
The ECU shows no fault at all, the MAP sensor is the OEM unit.
I called the Honda service manager who installed the turbo and he suggested powering the fuel pump directly.
The suspicion being that the fuel pump relay is connected in parallel with a resistor that lets the current through to the pump but with reduced power if the relay doesn't close.
Worth trying for sure!
 
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The car is up and running!
I had mentioned that I suspected the Map sensor as the LoveFab kit was delivered with an AEM 3 bar sensor.
In fact the OEM sensor was well in place but the wires had been cut and the AEM sensor was tied down behind the control box!
It's Christian [MENTION=9710]austrian type-R[/MENTION] that suggested following the vacuum lines into the control box that allowed me to find the issue.
The engine now purs like a big cat.
Thanks Christian!
 
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Success!......
 
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Success!......

Thanks John!
I went for a 100 km shake down ride this afternoon and it felt like I had just bought a new car?
Quite amazing to drive an OEM NSX again!
The engine is so quiet (too much maybe), no fumes whatsoever and a smooth power delivery that compells you to rev the engine.
The OEM ECU also does marvels to keep the AFR at an indicated 14.8 on my AEM AFR display at all times.
For some reason the car felt downscaled in size with less weight and an improved steering feedback?
Could it be due to me raising the front end by 5mm or so?
Long live the NSX!

IMG_3052.JPG
 
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RYU

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Thanks John!
I went for a 100 km shake down ride this afternoon and it felt like I had just bought a new car?
Quite amazing to drive an OEM NSX again!
The engine is so quiet (too much maybe), no fumes whatsoever and a smooth power delivery that compells you to rev the engine.
The OEM ECU also does marvels to keep the AFR at an indicated 14.8 on my AEM AFR display at all times.
For some reason the car felt downscaled in size with less weight and an improved steering feedback?
Could it be due to me raising the front end by 5mm or so?
Long live the NSX!

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You sound very much like me a couple of years ago when I removed my CTSC (in trade for lighter ITBs). It felt like a new car. So light on it's feet despite the lack of grunt. It was weird but satisfying.

Enjoy! Change is good!
 
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You sound very much like me a couple of years ago when I removed my CTSC (in trade for lighter ITBs). It felt like a new car. So light on it's feet despite the lack of grunt. It was weird but satisfying.

Enjoy! Change is good!

I remember my CTSC days before installing the LoveFab turbo...
Quite a disappointment, while it worked OK in normal use it was useless on track.
At the Bugatti LeMans circuit I would loose 3 seconds per lap after the third lap.
No wonder with the compressor located between the cylinders with no aftercooling!
 

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I remember my CTSC days before installing the LoveFab turbo...
Quite a disappointment, while it worked OK in normal use it was useless on track.
At the Bugatti LeMans circuit I would loose 3 seconds per lap after the third lap.
No wonder with the compressor located between the cylinders with no aftercooling!
The turbo is just next level FI. I've only driven a turbo on street, not track but it must be a hoot. Not sure if you've seen my videos but I went through a lot to finally get a CTSC setup track worthy. At the end of my CTSC "Journey" you could track that thing in the middle of summer in death valley and be just fine without any power loss.
 
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