Ok since there is a lot of confusion going on these days about side skirts I decide to post some clarification. I will start with S13's
S13's in the 180sx form came in three distinct bodywork series
Zenki= first, Chuki or Chouki (depending on who is spelling it)= middle and Kouki=last.
Now Zenki S13 180's did come with lips but as far as knowledge goes they did not have side skirts. These lips came on the Canadian (only in 90) and American(89-90) 240sx Fastbacks.
Chuki's on the other hand came with a factory optional oem side skirt(urethane) in Japan and quite possibly Europe. They flare out at the bottom at the front and rear wheels and are a very complimentary skirt for our cars. IMHO
Canadian cars also came with a seperate Chuki side skirt and rear valence that were a touch different than the Japanese Chuki skirt. These were stock on 91 Fastback Canadian cars (according to pik420 a Canadian member) and optional on 92-93 Fastbacks.
There was also a non descript rubber Chuki lip that came on most SE Chukis in the U.S. and Super Hicas cars in Canada and Japan.
On a side not a Super Hicas model Chuki 180sx was actually a Chuki Type x! Yes Chuki type X's did exist in Japan. In Canada this car with the KA came with the Chuki skirts ,rear valances and lip.
S13 Silvias came with a different side skirt flatter across the bottom. Again this was a oem factory urethane skirt and was only available in Japan. I.E. not on U.S. or Canada coupes or verts.
People often call these Zenki side skirts but technically that is wrong.
Last but not least in the s13 lineup was the Kouki 180sx skirts. These came on 180sx's in Japan and not only on the type X model though they are quite commonly called kouki type X side skirts. Though they were available on type S, G, R and X 180sx. These also came with the Kouki optional lip and the Kouki rear valences.
Honorable mention goes to Nismo for their side skirt for the 180sx that looked like a chuki but had a small vent at the rear.
On to S14's Zenki and Kouki. Now in the Aero department of S14's only Japanese Zenki s14's came with optional factory aero (urethane)skirts,lip and valence. Canadian S14's had lip only. U.S. S14's were just hosed.
Though with the Kouki S14 the factory urethane aero side skirts and lip were available in the U.S. and Canada as well.
Below is post pics I have culled from my Thai friends Seng's for sale posts and a few other places on the net to show examples of the different skirts.
All OEM factory skirts are urethane and considered desirable by a lot of people due to the durability of Urethane.
Most every other side skirt out there is usually straight fiberglass or FRP. Not as flexable as urethane and prone to cracking.
first pic is Chuki 180sx side skirts
Canadian Chuki side skirt and rear valence [
second pic is S13 Silvia side skirts
,
Kouki 180sx side skirts
S14 Zenki Japanese oem side skirts
S14 kouki pic and Nismo S13 pics to come
I hope this clarifies things so people know exactly what they are addressing side skirt wise
thanks to Matt89 and errr for showing the Canadian side skirts and differences and to Pik420 aka Bryce for giving me Canadian dates.