Taken from jabba's recently updated website, found it very useful.
Technical spec. VAG 1.8 Turbo 20 Valve engine
Engine congif. 4 cylinder Transverse
Bore 81mm
Stroke 86.4mm
Valves 5 per cylinder (3 in, 2 ex.)
Compression Ratio 9.5:1 (150,156,180 BHP eng.)
9.0:1 (210,225 BHP eng.)
Turbocharger KKK K03 (150,156,180 BHP eng.)
KKK K04 (210,225 BHP eng.)
Notes:
All engines have forged pistons, con-rods and crank as standard.
The block is externally and internally braced and is therefore very rigid.
The standard head gasket is metal laminate which eliminates problems
even at very high power outputs.
The only limitation is the high compression ratio and con-rods which
need up-rating beyond 335lb ft.
Applications:
1 Audi A3, VW Golf, Seat Ibiza & Leon, Skoda Octavia up to 2000
200-210 BHP on standard turbo, to 370 BHP and 300lb ft with
no internal mods, with mods 650 BHP can be achieved.
2 Audi A3, VW Golf, Seat Ibiza & Leon, Skoda Octavia after 2000
210-235 BHP on standard turbo, to 350 BHP and 300lb ft with
no internal mods, with mods 550 BHP can be achieved.
3 Audi TT (225 BHP), Audi S3, Seat Leon R
275-285 BHP on standard turbo, to 370 BHP and 315lb ft with
no internal mods, with mods 550 BHP can be achieved.
Gearbox:
5 speed synchromesh in standard form will take 270lb ft, with a Quaife
torque biasing differential will take 320lb ft. Can also be upgraded to
6 speed with Quaife gear set in either synchro or dog engagement, in
this form will take 400lb ft.
