No they try to enhance the performance.
The 2004 Acura NSX has a V6 engine.
The 2003 Acura NSX has 24 valves.
The 2002 Acura NSX has a V6 engine.
The 2004 Acura NSX has 24 valves.
The 2005 Acura NSX has a V6 engine.
The 2002 Acura NSX has 24 valves.
The 2001 Acura NSX has 24 valves.
The 2001 Acura NSX has a V6 engine.
The 2005 Acura NSX has 24 valves.
The 2003 Acura NSX has a V6 engine.
You need to specify what 1990 Acura are you swapping an NSX motor into.
There's no official confirmation on the NSX Concept's performance numbers, so there's no way to know what its top speed is.