NSX side vents

[jd cross]

I think only Kaz can answer this question.

This question has come up on th Prime Facebook page.

The side vents are made of cast aluminum.
They could have been made from some type of plastic which would have been lighter.
Given the attention to weight on the NSX why would Honda have made these vents from a heavier material than needed?

Jim

[britlude]

the same reason the b post covers can be used to stop errant boats from floating away!

[havoc]

...and why they cast the NA1 exhaust manifolds...

[Kaz-kzukNA1]

I think only Kaz can answer this question.

This question has come up on th Prime Facebook page.

The side vents are made of cast aluminum.
They could have been made from some type of plastic which would have been lighter.
Given the attention to weight on the NSX why would Honda have made these vents from a heavier material than needed?

Jim


the same reason the b post covers can be used to stop errant boats from floating away!
Have been really busy so didn’t have time responding to this thread.
[So wet and lightening delaying the FP2 (first experience for me….) in Austin so got bored and responding now.....]

I don’t know the answer so followings are just my speculation.

Considering the thickness of the fin at the side vents as well as the B-pillar outer panel, I think using cost effective, non-metal material either failed during the environment endurance test or simply not allowed based on the internal company’s know-how/criterion.

Because it’s so thin and not easy to attach the stiffener design behind at ideal direction, it may warp under heat soak testing under desert environment.
Or, the coating/painting/treatment may have resulted in hair line crack.

Each automotive companies have their own internal know-how/rule on many things when designing all sorts of parts for a car based on their long term experience/knowledge through their R&D activities.
So, it is possible that it was simply not allowed to use non-metal material such as some sort of plastic on these thin and limited space design parts.


On our NSX, these internal rules could be the reason why the rear tyre was so narrow (only 225 at the time of release) with huge gap at the wheel arch, pedal layout against the driver seat angle and the difference between RHD and LHD models, etc.

Kaz

[Kaz-kzukNA1]

...and why they cast the NA1 exhaust manifolds...
For this one, I think it’s much easier to speculate.

I think there was simply not enough time designing new manifold/header and carrying out all the emission and endurance tests from scratch after the engine spec was suddenly changed just 1 year to go before the mass production.

You can see the same reason on several area of the engine design.
The titanium connecting rod was only introduced after the engine spec was changed so not something on purposely used at the very beginning of the project.
If you have ever opened the engine, you will be surprised how simple the piston head design is on our NSX.
Because of the sudden change in performance target with 1 year to go, there was no time doing all the dyno testing all over again so the designer had to design something that won’t break and thus, there are huge extra safety margins on some area of the engine.

Looks like the limited time available affected the angle between the inlet and outlet valves, cam sprocket angle, timing belt instead of chain, etc, etc, etc.....


Although the OEM original manifold looks mono-tube structure, if you have ever cut it (I have), you will notice that it’s actually twin tube structure.
I think it was used to keep the exh flow speed and keeping the high temperature upto the CAT for torque curve and emission purpose.
Changing this would be a huge testing tasks.

Kaz

[goldnsx]

Japanese engineering at that time goes like this: it's not that they didn't know about lighter material or better ways. If they had the choice between high 'output' and low variance (or standard deviation) and very high 'output' but high variance with the risk of a higher, not tolerable failure rate they went with option 1. That the reason no. 1 why the NSX was so reliable in contrast to any other 'supercar' or 'sportscar'. Or ask the Lambo and F-guys how often they change their headers and many other things.

Don't blame them from today's point of view. The car was designed in the 80ies with technology for the next decade. One step forward was the NSX-R with carbon as a new material to introduce in a production car.

[havoc]

Thanks Kaz...always good to learn something new!

[jd cross]

Thanks Kaz
Appreciate you taking the time to reply.