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Grahams81-Leon 4wd, Big Turbo - Back in the saddle :-)


Active Member
Oct 14, 2010
County Durham
Hello All,

I am currently rebuilding a AUQ 2001 Cupra i bought from a mate at work with a knackered engine.

edit index-

Here is a quick index for reading -

Page 1 - Introduction.
Page 2 - Original Engine Damage, AGU Head Stripped, Cleaned, Skimmed, DIY Port & Polish, TDI crank Lightened & Balanced, Supercopa Wings Fitted.
Page 3 - Start of Engine Rebuild, crank pinning, pics of 4wd rear end.
Page 4 - Engine Rebuild continued.
Page 5 - Engine Rebuild Finished & start of 4wd conversion.
Page 6 - 4wd Conversion & final engine pics.
Page 7,8,9,10,11,12 - 4wd Conversion.
Page 12 - Rear Diff assembly fitted, car back on its wheels, Mounting Rollcage.
Page 13 - Roll Cage Fully Mounted, Welding sealed up, Interior Parts Stripped out.
Page 14 - Shell, Rear Panel Finished
Page 15 - Clutch & Flywheel, Engine Mounts Arrived, Front & Back bumpers.
Page 16 - Coilovers Pics, New Turbo preview.
Page 17 - Turbo Talk...
Page 18 - Engine Bay cleaned up, BFI Engine Mounts Installed, Clutch & Flywheel Installed, Engine IN !!! EFR8374 Turbo Arrived pics.
Page 19 - More Turbo Pics, Mounting ideas for turbo.
Page 20 - Mounting position of turbo.
Page 21 - Pics of Chop Saw, Comparison Photo between EFR8374 & ko3s, Manifold Collector Fabrication.
Page 22 - Mounting of Collector on turbo pics, collector all tacked up, brace fab'd up to hold turbo flange in relation to head flange during fabrication of headers.
Page 23 - Nattering.....blah blah blah.
Page 24 - Manifold Fabrication Continued, Headers for Cylinder 1 & 4 tacked up, manifold trial fitted to engine - Turbo fitted to check alignment.
Page 25 - Manifold Fabrication Continued, Restarted again.
Page 26 - Chatting, and Manifold Design & I dropped a bollock on the pipe sizing !!!
Page 27 - New 1.25" Collector Made, Manifold Fabbing in 1.25"
Page 28 - Manifold all tacked up, Fitted to engine with Turbo. Front end build up.

Here's a pic of the car when i got it -

Car was totally standard apart from lowering springs...but not for long !!!

The plan is to build a 500bhp-700bhp car for weekend fun / track use.

Edit - Current Engine Spec & New Parts fitted to engine -

Engine -

Block -

APX Engine Block Bored to 83mm (4 thou piston - wall clearance)
ALH 1.9 TDI 95.5mm Forged Crank (part number 038105021E) - Lightened & Race Balanced by Quasar Engineer
ABA Crank Sensor Trigger Wheel (Fits TDI Crank) bolt's TIG welded.
Intergrated Engineering 06a Girdle kit
Intergrated Engineering Bring Your Own Crank Stroker Kit -
83mm JE Forged Pistons 8.5-1 Compression
20mm JE Tool Steel Wrist Pins,
144mm IE Forged Connecting Rods
Modified IE Crankshaft Pulley with Pinning kit
Calico Coated Main Bearing Set
Calico Coated Rod Bearing Set
New OEM Thrust Bearing Set
ARP Main Bearing Stud Kit
ARP Head Stud Kit
ARP Crank Damper Bolt
ARP Flywheel Bolts
ARP Camshaft Pulley Bolt
IE Ekagrip Friction Disc for Flywheel / Crank,
Gates High Performance Kevlar Cambelt,
IE Billet Manual Timing Belt Tensioner Kit & Billet Roller Back Plate
IE Billet Crankcase Breather Adaptor
IE Billet Camcover Breather Adaptor
IE Catch Can
83.5mm Overbore Full Gasket Set
New OEM Front Crank Shaft Seal
New OEM Rear Crank Shaft Seal
New OEM Water Pump with Metal Impeller
New OEM Timing Camshaft Chain
New OEM Oil Pump with Bolt TIG welded
New OEM Oil Pump Chain
New OEM Oil Pump Chain Tensioner
New OEM Windage Tray
New OEM Oil Filter Housing Bracket
Redline Assembly Lube
INA Shallow & Baffled Sump
Fluidamper Crank Pulley

Cylinder Head -

AGU Large Port Cylinder Head - New Valve Guides Fitted, Exhaust Ports DIY Ported & Polished & Head Face Skimmed by Quasar Engineering
Super Tech Black Nitirided Intake Valve Set (3 Groove)
Super Tech Inconel Valve Set (3 Groove)
Super Tech Valve Guides
Super Tech Valve Performance Springs
Super Tech Titanium Spring Retainers
Super Tech Valve Stem Seal Intake x 12
Super Tech Valve Stem Seal Exhaust x 8
Integrated Engineering IECVA1 Street / Strip Camshafts
Integrated Engineering Cam Pulley
ARP Cam bolt
EKA Grip for Cam Pulley
New OEM Valve Retainers collets
New Hydraulic Lifters
SEM Large Port Inlet Manifold with 80mm Throttle opening


Borg Warner EFR8374 Twin Scroll Internal Wastegate 0.92 A/R T4 Divided Flange, V-Band Outlet, Dual Ceramic Ball Bearings,

Home Made Tubular Manifold

12mm 304 Stainless Steel Head Flange
12mm 304 Stainless Steel T4 Divided Flange
Runners & Collector from Stainless Steel 316 & 304 1.25" Schedule 10 Steam Weld Fittings

Fueling / Tuning / Software

Standard AUQ Wideband ECU.
Eurodyne Maestro 7 Tuning Suite
1000cc Injector Dynamics ID, High Impedance Injectors
All SAI & N249 & Evap Removed.


2001 Seat Leon Cupra 180
Shell stripped and converted to 4wd using body parts from a 2001 Audi S3
Audi S3 Petrol Tank - To clear the diff assembly
OMP AB/105P/226 - 10 Point Rollcage (Modified to only use back half)
Black Forrest Industries BFI MkIV Stage 2 Poly Engine / Gearbox Mounts
FK Silverline Coilovers for Audi S3
Seat Sport Alloy Wheels 17" x 9"
Sparco Evo III Bucket Seats

Drivetrain -

Audi TT Quattro Rear Axle Complete - Haldex Diff, Driveshafts, Trailing Arms, ARB.
Audi TT Quattro Front Axle Complete - Steering Rack, Driveshafts, Wishbones, Hubs, ARB.
Audi TT Quattro Propshaft - Bearing holders need welding to Tunnel of Cupra Shell
Audi TT Quattro Gearbox - 6 Speed 4x4 box with Transfer box.
USP Billet Shift Forks
ClutchMasters FX400 6 Puck Sprung Hub Clutch Kit & Flywheel.

Bodywork -

GRP Supercopa front wings.
GRP X-Sport Bonnet.
OEM LCR front bumper, modified with parts to blend the extra width of the wings.
OEM LCR Rear Bumper.
OEM Brand New LCR side skirts, with new jacking covers and fixings.
OEM Brand New front grills.
Seat Sport Supercopa Rear Spoiler
Full respray planned in Lechler Porsche GT3RS Pure Orange
New window seals.

Here's some pics of the goodies -

Engine Block Bored & Honed to accept the 83mm Pistons -

So after spending over an hour cleaning all the swarf from the block i bought on ebay (after boring) i was itching to find out if everything was going to fit.....

When i removed the main bearing caps i found that some of them were loose on the sides - 1 was tight and needed tapping out.
I found this a bit strange to have loose main caps as the caps don't use centering sleeves to align them, they rely on fitting tight on the sides into the block.
The main caps have signs of previously getting really hot - maybe somebody has ran the engine without oil and the caps have ovalled because of it.
If you push a loose cap in one direction the bore at the joint is ok - but the other side of the joint is 0.3mm stepped - push it the other way and its the same.
I put the caps against a straight edge and the outside edges of the cap are proud tapering up to the inside of the bore - the caps have definitely been pulled oval.

Tried pressing the main caps lightly over a large socket and this happened -


Should have known better (i'm an engineer and i know how brittle castings are !!!)
So i've just ordered some 034 Billet Main Caps -

Will have it line bored when they come and get this build moving.....i've also decided to convert the car to 4wd....
Been doing loads of reasearch using VAGCAT online spares catalogues - apparently all early S3's TT etc use the same rear chassis parts as a leon 4 so gonna get busy with a grinder when the weather gets better.

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Active Member
Oct 14, 2010
County Durham
Just ordered some ZeroG wide front wings and some arch extenders for the rears -

Just to get the bodywork moving in the right direction i'm going for LCR kit with the arches to accentuate those classic good looks.


Sir Bob,a geordy legend..
Oct 15, 2007
Interesting project mate, good look with it :)

Hopefully once you've got it up and running I'll see you around as I'm not far from Durham ;)


Active Member
Oct 14, 2010
County Durham
I've been doing my homework....

I'm gonna strip the car completely, remove the fuel tank. Cut the boot floor out from the joint just behind the drivers seat.
Im not 100% sure but the 4x4 trailing arms should bolt in were the existing rear beam bolts.

Theres loads of s3's being broken around so will need to find one and remove everything i need.
I'm planning a roll cage and seam welding the back end of the car, should be nice and stiff once thats done.
I might need to open up the tunnel to allow enough room for a 3" exhaust & propshaft - i'll see as i progress.
I've managed to find a s3 complete ream beam with the diff & prop for £250 + 6spd 4x4 Gearbox for £250....should get this part complete for 6-700 quid.
Control wise im thinking of a manual switch for the haldex to run it in constant 4x4 or fwd just wired direct to the haldex diff ?
Anybody done this before ?


Active Member
Aug 29, 2005
Good on you for doing this. will be keeping track of progress too!


i thought about doing this with my audi tt changing it over to one of my leons to put another big turbo on this one to and converting it to 4x4, but if i had the time and money again now i would slam a w12 beast of a of a engine in but there like 4k..!! and rare to get hold of, cant believe they were in a few vw bora''s and near the 320bhp from standard..??? my mate is just doing a 980bhp honda civic with a monster turbo.
and just put a evo 5 engine in his 205 pug ha ha he's cookoo..!!!!
this is the civic. il show you the evo pug when i see him again but thats getting ready to be nearly 500bhp ha ha. but all the best in your project mate and looking forward to seeing some pictures and vids of your beast in the making and finished :)


Active Member
Oct 14, 2010
County Durham
Wow that's a big turbo on the civic. I would love the idea of a w12 engine. I actually got passed in northern Ireland by a copper in a old shape passat w12 sounded awesome even in standard trim !


thought about making mine around the 3000bhp mark with this bolt on turbo kit from halfords ha ha ha



oh where did you get the arches from mate, got some old 19" x 10.5" wide alloys off my old porsche i thought about sticking them on but sticking out to much with the standard ones??


Wheel Connoisseur
Jan 1, 2009
Love this mate, always wondered why no one did these to SEATs, the VW do it, like rwd mk1 golfs etc

Also it wasn't a W12 in the Passat, wasn't it a W8 engine? :S

Great work, can't wait for this to be finished :)
Keep it up mate
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