My top 10 mods. Part 1. THROTTLE BODIES (ITBs)

[Papalazarou]

How do you turn an excellent car into something incredible and how much would it cost? Here’s part one. I am not an expert and I am not trying to offer any advice. I am merely starting a discussion about modding an NSX.

1. Throttle bodies - this is the most contentious. I think they sound fantastic (on youtube), but could I live with them?
I remember seeing a Ferrari 250 GTO as a child, it had a set of 38 DCN Weber carbs and looked spectacular. Recently I went to Alfaholics. They fit throttle bodies that are made to look like a set of carbs. Again aesthetically they look great.
So what are the pros and cons?

The pros; increase in power (around 30hp and a good amount of extra torque in the midrange), insane soundtrack and wonderful aesthetics.

The cons; too much when you don’t want it? I once had a gruppe M intake and it was hateful. In the end I drove off cam just to stop my ears bleeding.
A total change in the way the induction sounds. Will it take away the unique NSX induction noise? Yes it will.
So the worry is that you spend the best part of £10K and end up with a car that goes better, but has lost the delicacy of the original sound.
Most days I drive my car and I still marvel at how characterful that engine is at pretty much any part of the rev range. This will upset someone, but I had an E46 CSL for a year or so. I bought it partly based on the write-ups of the incredible induction noise etc etc. when I started to use it, I thought it sounded a bit, no a lot max power. I mean everyone was raving about it, and I just thought it sounded, well, a bit chav. Unsophisticated. It was missing something, but all I could hear was those dickhead jouros regurgitating how it was the monster **** of their not so young lives.

On the plus side, ITB’s are no longer a tuning gamble. SOS make a kit which seems pretty good value. But then by the time you add an AEM, injectors, installation and set-up, we’re probably up around £8-£10K.
AS Motorsport and Toda also do systems. The reason I would probably choose the SOS kit is because they normally bring well sorted and executed products to the market. Their manifolds and exhaust systems get great reviews and have proven results.

https://www.scienceofspeed.com/index.php/nsx/eap/intakes-induction/scienceofspeed-individual-throttle-body-system.html

https://as-motorsport.info/shop/en/engine/38-asm-billet-itb-kit.html

https://www.toda-racing.co.jp/en/product/injection.html

Anyway, if anyone’s experienced an NSX with ITBs, please post. If you haven’t post anyway. Perhaps we can get someone from Prime on here to talk about them?

Here endeth part 1.

[Senninha]

Hi James,

Here’s a link from Prime that might prove helpful if you’ve not yet seen it https://www.nsxprime.com/threads/best-way-to-tune-a-na1-na.219546/

Based on the video footage your car clearly has a good engine so what start there with your upgrades, especially TBs which are a lot of ££.

If not already refreshed, and providing tyres are good and not old, I would start with an either brake overhaul of upgrade. The upgrade can be in stages, i.e. pads then pads/discs or could be a complete system and there a re a few options. In addition, another S2k part you can use on the early NSX is the ABS unit which will provide you with better pedal feel. With many of the upgrade parts you will be saving weight as well.

With tyres and brakes sorted, turn you attention to suspension. If not yet addressed, the OEM system is now 20+yrs and quite possible no longer performing as Mr Honda intended. To maintain ride quality the advice I was given was to replace struts / hats but to retain OEM springs. This transformed the cars feel and directional stability (I have the later steering to yours). I have Bilsteins sat on the lower perch plus spacers to ensure clearance and to cosmetically improve the stance (so Im a tart, what can I say?)

Now it will stop and change direction better, there is for your car the steering rack and I note you have a separate thread on this. I owned an S2k and would echo Nicks feedback leading to the Accord as potentially the better option.

Unless you want to take the engine apart in pursuit of power, maybe consider an improved air filter, inlet pipe to the air box and an exhaust, all of which will bring further weight savings.

In the Prime link there is talk of ECU tuning which could be a final consideration on top of the above.

As for the TB’s .. I think they look fab, videos Ive seen support they sound incredible but for me they are too many ££ for the performance return. I would then consider other weight savings such as the OEM engine cover and maybe the seats in favour of some Recaros.

It’s just my thoughts and Im sure there will be others, but the ground up approach has served me well over the years, as has the Colin Chapman approach. And when combined Ive always ended up with an improved (for me) driving experience with a car capable of safely carrying more speed over a wider operating window meaning you can mix it with others who may be running considerably more power but on a less well sorted chassis …

Hope this helps and enjoy the process … rgds Paul

[Papalazarou]

Hi Paul,
Thanks for the info. I am also a firm believer in starting with a good platform. I planned to deal with brakes, suspension etc in future parts.

Cheers.