Glossary of S-Chassis Terms (zenki, chuki, kouki, sileighty)

Glossary of S-Chassis Terms (zenki, chuki, kouki, sileighty)


When talking S-chassis there are so many terms that you need to know, whether you are talking about a RPS13 or a Onevia - these terms can sound quite obscure at first glance. We put together a glossary to shed some light on the what and the why.


S Chassis s13 s14 s15 silvia RPS13

Illustration by @drawingcoolcars


First lets start with some common terms:

Each of the below simply describes a generation; early, mid, later. These terms are interchangeable and not specific to the S-Chassis, despite the term Zenki becoming synonymous with the Early S14 Chassis. 

  • Zenki (前期 - Early Period)
  • Chuki (中期 - Middle Period)
  • Kouki (後期 - Later Period)

Next we can break down some basic Chassis Designation:

  • S13

Art Force Silvia PS13 Scan 1989

The Silvia S13 is designated as PS13 in Japan (coupe)

180sx Brochure Scan 240sx Chuki

The 180sx is designated as RPS13 in Japan (hatchback)


  • S14

 Silvia S14 240sx Zenki 1995

Zenki S14

Silvia S14a 1996 K's Aero 240sx Kouki

Kouki S14 - often referred to as the S14a


  • S15

Silvia S15 1998 Brochure SR20DET

S15 only has one generation


Below is a comparison of JDM vs USDM Models

Japan (JDM):

  • RPS13 - Production from 1989 - 1999
  • PS13 - Production from 1989 - 1993
  • S14 - Production from 1993 - 1996
  • S14a - Production from 1996 - 1997
  • S15 - Production from 1998 to 2000


  • S13 Production from 1989 - 1994
  • S14 - Production from 1995 to 1998
    • Zenki (1995-1996)
    • Kouki (1997-1998)


 Font End Swaps:

Often debated and not officially sanctioned by Nissan, these designations were created by enthusiasts and the tinkerers of the world. The most common of all conversions is the USDM S13 Coupe - Silvia Front End Swap. As you read below, we uncover some of the more esoteric and eccentric front end swaps along with their names.

Here we can use the basics of Generation and Chassis Code and start to have some fun, think of Chassis Code, Model Name, and Generation as the building block for a naming nomenclature.

Sileighty = S13 180sx body with an S13 Silvia front end. 

Sileighty Silvia 180sx Front End Conversion Initial D

Onevia = S13 Silvia body with an S13 180sx front end.

Onevia 180sx Silvia Atsushi Kuroi

PS13.4 = S13 Silvia with S14 front.
-S13.4 Zenki

S13.4 Zenki Front End Silvia S13 Swap

-S13.4 Kouki

S13.4 Kouki Front End on RPS13

RPS13.4 = S13 180sx with S14 front.
-RPS13.4 Zenki

RPS13.4 Silvia on 180sx S14 Zenki
-RPS13.4 Kouki

PS13.5 = S13 Silvia with S15 Silvia front.

S13.5 Silvia with S15 Front End Strawberry Face

RPS13.5 = S13 180sx with S15 Silvia front.

RPS13.5 180sx S15 Silvia


While analyzing the S14 Front End Swaps, there tends to be some overlap; for example a RPS13 front end on a S14 would technically be a S14.3 - the same sor a S14 with a PS13 front - so I have devised a 

S14.3 = S14 Silvia with S13 Silvia front.

S14.3 Silvia PS13 front end conversion S14

That is pretty straightforward, but we can't call the S14 with a 180sx front the same thing so - this is my rendition:

RPS14 = S14 Silvia with S13 180sx front.

S14.3 RPS13 Front on a S14 Silvia Drift

S14.5 = S14 Silvia with S15 Silvia front.

S14.5 Silvia S14 and S15 Conversion

Standard conversion everyone knows well.

Since the S15 only had one type of front end, the conversion names are pretty straight forward - can be acheived by adding a .5 to any chassis. HOWEVER, most of this is theoretical since most are not inclined to swap any other front end onto a S15.

S15.3 = S15 Silvia with S13 Silvia front.

RPS15 = S15 Silvia with S13 180sx front.

Same deal as the S14. S15 with pop-ups becomes the S15.3r.

S15.4 = S15 Silvia with S14 front.
-S15.4 Zenki
-S15.4 Kouki

Now this is strictly using the Japanese S-chassis vehicles. Not referring to USDM 240sx or European 200sx, but a lot of the terms still apply EXCEPT for the Sileighty and Onevia references at the very top.

All image scans from the Lucky Labo Personal Vault. Front End Swap scans from @start.up.go on instagram.

Thank you for reading 


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