Removal of engine board cover

[goldnsx]

however I also found a lot of (fairly high frequency) whizzing and whirring type noises also make their way through.

I had mine off for a very short period too. The high frequency noises of mainly the gearbox and the valves were enough for me to let it in place. There is an acoustic damping mat on the back of the board they've installed for some reason.

[Midnight Blue]

This isn't ideal in recent weather, so any extra heat is welcome![/quote]

Not here in KL or Brunei it isn't ! I have my air-cond running 100% 0f the timekeeping the cabin cool. I would only consider turning it off way after midnight if the Targa roof was off.

Cheers,

Andy

[markdas]

I have an NSX-R engine cover fitted and I am relieved to hear that you guys also have a load of crap sounds coming through....I was convinced the engine was starting to rattle, tap and whistle a load more than normal.....my solution however this week is to fit the GT Exteme exhaust at last and drown out any little niggles!!!

Agree that on Prime a lot of guys remove the cover all together, some concerns about window tint but I dont think its an issue, stone chips and cracks could be an expensive problem....even dearer than a stupidly priced NSX-R cover.....

Mark

[Kaz-kzukNA1]

Hi, 666NA1. My apology in advance if I wrote something you already knew but I would like to share my own experience and the information from my friends.

1. Vibration
Without looking at the state of your engine board cover (‘lid assy, engine maintenance’ as in the parts list), it is difficult to say whether the vibration is from the board cover itself or not. You can try adjusting the height of the 3 small rubber studs by rotating them. This will make good contact between the board cover and the frame of Rear Hatch Glass.
If you think the insulator or other parts attached to the board cover are rattling and causing the vibration noise, then you can just order the insulator or associated parts from Honda and refurbish the board cover. It is much cheaper than trying to replace the entire cover.
For your reference, some of the vibration like noise that was originally reported to be from the board cover area was in fact caused by the weakened insulator at the Partition Glass (or Rear Window Glass, the one just behind your headrest of the seat).

2. Heat
Without knowing any of your modification, it is difficult to tell regarding the effect of the heat but I’ll presume that you are running close to the NA1 OEM spec for the engine/gearbox/bodywork.
As the radiator is at the front and the engine at the middle of the car, the air temperature inside the engine room while driving NSX is lower than you expect.
You will have better airflow inside the engine room by keeping the board cover.
There are lots of people running the car without it (including myself until recently) and they seems to be happy with no heat related problem. I ran the car without it for more than 10 years and never experienced any issues.
I don’t have the test experience of airflow using Type R mesh cover on non-Type R car but again, there are many people running this combination so I believe the glass would be fine. The mesh cover is too expensive for me....
The heat effect on the window tint will depend on the temperature spec of the material but as it is attached to the glass and the effect of the thermal conductivity, I think the UV-ray and heat from the direct sunlight would be harsher than the heat radiation from the engine/air especially if you are running the car in KL, Malaysia.
I have been there several times and I wish I were there now after all these wet weather in UK.

3. The Rear Hatch Glass
As other members mentioned, there is a higher risk of damaging the hatch glass by removing the cover board. Addition to other posts, I know one person broke the hatch glass when he left a tool inside the engine room. It was trapped at the edge of the hatch. I heard it took more time to vacuum clean the broken glass than to replace the hatch glass. Although it was caused by a human error, the glass could be saved if the board cover was not removed.
After you removed the board cover, from time to time, you will notice a 'straight line of dirt' (in the direction of front to rear) on this glass just above the AC Generator. Yes, it was caused by the road splash picked up by the rotating belts fitted around that area.
You will also tend to get more moisture or fogginess inside this glass but you can cope with this by using some of the defogger chemical. You may not notice it because of the tinted material on your glass but knowing the way it rains in KL, it is worth a consideration.

4. UV-ray
I think this is the biggest factor.
It is difficult without knowing where/when/how you drive the car and addition to the fact that you already have tinted material on the window, may be following won’t apply to your case.
As you may know, Type-R uses a special jacket over the header tank (the one holds the coolant fluid inside the engine room). This is to protect the tank material from UV-ray and wider thermal shock range due to the use of mesh cover on this specific model. (By the way, the price of this jacket is unbelievable.)
Unfortunately, our tank tends to leak at the middle section where the upper/lower part meets each other and because of this, some people expressed concern for removing the board cover. It may trigger this issue at earlier stage due to the extra UV-ray and thermal shock. From my experience, you better replace the OEM header tank regularly whenever you started to struggle to check the coolant level under the daylight. When it is new, it will be nice clear white and eventually, it will change into creamy light yellow colour which will make it difficult to see the coolant level. I replaced my header tank regularly (about every 3 years) based on the above rule for over 10 years and never experienced a majour leak at the tank.
There are lots of rubber tubes used for the control devices and these will be affected for the same reason. However, I'm still on the original rubber tubes even after 14 years.
You can replace both the tank and the rubber tubes to different materials (metal, silicone) through aftermarket parts supplier.

Recently, I decided to put the board cover back again as quite frequently, I saw the ‘line of dirt’ on my rear hatch glass after going through so many water paddles….

5. Noise
My best advice is to try it. You can easily remove the board cover and put it back again.
By removing the board cover, it will definitely increase the sound level. I used the word ‘sound’ on purpose as it depends on each person to feel the increased sound as noise or music. For example, if you are in Type-R, you will need to shout to talk to your passenger even at just 3,000rpm because of massive increase of sound level compared to normal NSX. I loved the sound but the passenger (my wife) hated it.
Also, depending on your age/environment, you may have less sensitivity to some of the frequency band (around 4kHz) so you may only find small increase in the sound level.
Just give it a go.

Thank you for your time reading this long post.

Regards,
Kaz

[AR]

Kaz what a post!!!

I guess the reason I did not find my NSX-R that loud is the hearing bit or I am getting older!

I now have an NSX-R engine cover on my current 1993 coupe. Great advice about UV I also have the water reservoir cover too for those reasons.

Cheers,

Ary