Leon Cupra R25

[POPOV]

You haven't done it all until you've done a engine swap they say!
I guess it's time for me to share my Leon Cupra R25 build with others. Be warned, it won't be a fast build.

The beautiful and lovely 2.5 TFSI engine used in the TTRS/RS3/RS Q3 is my choice.
The idea of transplanting this engine into my Leon Cupra has been lurking around in my mind quite some time now and won't disappear until that valve cover and intake manifold sits nicely under my bonnet.

The intentions are not to build the greatest accelerating Leon Cupra, if so I could stick with the 2.0 TFSI engine and spend my money on upgrading it. It's all about doing something different and completing a dream of mine.

Currently my EA113 BWJ Cupra engine is powered by a lovely TTE420 turbo and all the supporting modifications needed for it. It produced healthy 434Hp and 585NM on the last Dyno I did a couple of weeks ago.

Car weights in at 1280 Kg at this stage after some weight reductions excluding the driver. I'm doing 100-200 in 8.3s with some traction loss and regular manual shifting.
I'm sure I would be able to get it down to 8.0s if I had NLS and if running on semi slicks I should get <8.0s.

I'm primarily focusing on getting all the parts needed for the swap so I can start the build. As the swap is complicated and expensive I wont convert to AWD until later in the build.

Priority plan

• Complete the engine
• Initiate wiring
• Fit & connect engine
• Complete wiring

To be continued...

 

[MJ]

Boss fox on briskoda has a 2.5tfsi engine in one of his yetis so the project is entirely possible.

 

[mike0105]

I saw that, although I was more interested in his citigogo project (1.8t AWD Citigo)!
A 2.5tfsi Cupra be awesome, although I'm not aware of any applications of this engine that uses a manual gearbox.

 

[Unit9]

Perfect engine.

 

[POPOV]

There are actually several other 2.5 TFSI engine swaps that inspired me to do this build.

MTM A1 Nardo edition, crazy FWD A1:
http://www.mtm-online.de/en/highlights/mtm?id=38

MTM T500, VW T5 Bus swap:
http://www.mtm-online.de/de/MTM/T500/2-5-TSI-348-kW-472-PS-4motion?FZID=T500q

Skoda Yeti RS, low weight track build:
http://www.briskoda.net/forums/topic/226003-the-twins-and-yeti-rs/page-49

Golf R- RS, Dutch fellow swapped in a new TTRS engine:
http://www.volksforum.com/forum/showthread.php?t=126526&page=1&pp=20

Golf RS3, UK based company initiated a swap:
http://www.vwgolf.net.au/showthread.php?19616-Golf-RS3

Golf 6 R, German swap:
http://r-golf6.de/viewtopic.php?t=3123&f=536

Dutchbuild Supercopa, Wilco's crazy Leon Supercopa build that sadly has not been completed:
http://forums.vwvortex.com/showthread.php?6892622-Seat-Leon-Streetlegal-Supercopa-with-TTRS-Engine-Sequential-Gearbox-and-4Motion

Scirocco RS Quattro build in Russia:
http://www.r32oc.com/topic/206938-vw-scirocco-rs-quattro-25-tfsi-dq500-haldex4/


I've seen several other swaps into mk2 Golf's and even a mk1 TT.
I'm sure there are other similar swaps but I'm assuming that I'll be the first one to complete the swap into a Leon mk2

 

[POPOV]

I saw that, although I was more interested in his citigogo project (1.8t AWD Citigo)!
A 2.5tfsi Cupra be awesome, although I'm not aware of any applications of this engine that uses a manual gearbox.

The TTRS has been available both in manual and DSG versions (DQ500 and MQ500 gearbox). Some regions in the world have only had the DSG as an option.
The RS3 and RS Q3 have to my knowledge only had the DSG as an option.

 

[cupra.al]

I bet it will sound awesome.
Best of luck with the project and i shall wait for more updates.

 

[swordfish103]

This is going to be one hell of a build... Can't wait to follow the process

When do you plan to actually start the build?

 

[POPOV]

Engine setup

Was browsing eBay in mid-October for no particular reason and there it was, brand new complete 2.5 TFSI head. Thus, including cams, valves, valve springs, rocker arms.
Called my local Audi dealer to confirm the price (part number 07K103063K) and realized that the seller was asking for a third of the price quoted by my Audi dealership.
The seller, Wilco from Dutchbuild, is a well known car builder from the Netherlands, with that in mind a PayPal transfer was completed and project was initiated.

Yes, I could have bought a complete used 2.5 TFSI engine but then I would miss the fun of sourcing parts and putting it all together.
You never really know the condition of used engines and it might end up costing more money to repair it then you initially planned to spend on the project in total.

Unfortunately any part used in a vehicle with RS initials becomes stupidly expensive.
Fortunately the 2.5 TFSI engine development requirement from Audi was to utilize as many synergies as possible from the base 2.5 induction engine found in the US sold Rabbit/Jetta/Beetle/Passat.
The major difference is in the head (that I already have in my presence) of the 2.5 TFSI engine, direct injected, turbo cams, casting and so on.
The 2.5 induction engine has following larger differences besides the head:

• Missing Oil feed and return on block
• Missing Coolant feed on block
• Casting block material might be different but not confirmed so far
• Cast crank with 6 bolt flywheel pattern in engines produced after ~2005
• Upgraded Timing chain in engines produced after ~2008
• Piston compression
• Rods

After some searching I found a complete used (42000km) 2012 Passat CBTA engine in the US with all accessories. Engine was ordered by sea transportation in beginning of November, will take some time to reach me in Europe.
I opted for the later version with upgraded timing chain and cast crank instead of forged as I wanted a block with minimal wear. Engines from before year 2005 would contain a forged crank but then the wear might require me to bore and that I want to avoid.
So the idea as you might have figured out is to mount the head from the 2.5 TFSI engine on this one.

The 2.5 induction engines are being turbo converted and pushed beyond 800hp on stock internals. First point of failure are the rod bolts and rods, in fact they are also the weak point in 2.5 TFSI engines.
Cast crank will withstand 600hp, that will be sufficient for my primary target of power output.

To ensure the longevity of the engine I'll be upgrading with following:

• Forged Rods
• Arp stud bolts
• Rod Bearings

To be continued

 

[Bignod00]

This is going to be epic.......cannot wait to follow it through to completion!!!

 

[richicupra]

How will the 4WD gearbox be converted initially to front wheel drive?

 

[lsg60]

Looks like its going to be epic

 

[MJ]

How will the 4WD gearbox be converted initially to front wheel drive?

they have a bolt on transfer box.

 

[POPOV]

Gearbox

As Mentioned in earlier post I will initially run this set up on FWD, AWD will come at a later stage when I've figured out potential hiccups and have the budget to proceed.

The standard Cupra 02Q gearbox will be reused, it fits the 2.5 TFSI block with no modifications.
This also enables me to use my current FWD CV driveshafts as there will be no transfer box for the AWD.

The crank has a 6 bolt pattern, meaning I'll be able to reuse my Sachs SMF flywheel and clutch.

Issue is that gear ratios will not be inline with the 2.5 TFSI engine but hopefully the impact on drive-ability will be acceptable.

The manual MQ500 TTRS gearbox is also used in other VAG vehicles such as the Tiguan, slightly deviating gear ratios but within close margins.
I will source a Tiguan gearbox at a third of a TTRS gearbox price.

 

[POPOV]

Pistons

The US 2.5 induction engine uses 9.5:1 compression ratio pistons, not within close margin of the 2.5TFSI 10.0:1 compression ratio.
One of my predefined project limitations is to avoid changes to the internal design of the engine if not needed due to weak OEM design.
Changing the internal design requires more of the compatibility between components and sooner or later I will run into problems, this is why I will stick to OEM parts and only change if needed.
The OEM 2.5TFSI pistons are litle bit on the heavy side but great for making power and strong, will withstand large amount of power if the car is mapped correctly.

I was looking into aftermarket pistons but nobody could deliver 10.0:1 pistons with 82,5mm bore without producing custom according to my spec.
There are available options if I could accept to bore the block but then we end up changing engine internal design and relying on the know how of the map tuner.

So, a friend of mine got me a good deal on new OEM 2.5TFSI 10.0:1 82,5mm bore pistons from Audi.
Sometimes OEM is simply good enough

 

[POPOV]

Sourcing parts

Engine from the US should be arriving this week after a long trip by sea.
I guess it should be with me next week as it needs to clear customs and be delivered to engine shop that will doing the work for me.

I've sourced components worldwide for this project bild and made acquaintance with some really knowledgeable and nice people.
I enjoy this phase of project builds as it generates new interfaces and know how!

Countries that I sourced parts from so far are:

• US
• Canada
• Poland
• Sweden
• Denmark
• Germany
• Netherlands
• Romania

My attic is full of parts for the build that I'm preparing for assembly.

 

[Beltran]

Nice project!!
I'll be looking your updates!

 

[robin cur]

WOW I wish I could do a oil change.

 

[POPOV]

TTE500 turbo

The OEM 2.5TFSI (TTRS/RS3) K16 Borg Warnet turbo can be pushed to 430hp with a matching map and hardware.
With some magic from The Turbo Engineers (TTE) power output can be pushed to 530hp.

The turbo unit is hybrid converted with the following improvements:

• Larger compressor TTE 3371X wheel
• Larger exhaust K24 turbine and shaft, curved clip
• 360 deg high performance motorsport journal bearing
• Uprated & reinforced actuator
• CNC Optimized Intake pipe
• CNC Port matched exhaust runners

Attached video should give a indication of what to expect. https://www.youtube.com/watch?v=TvJX8t4PGEI
My WMI, FWD and lower vehicle weight setup should do some improvement on those times.

An 7s 100-200Km/h car is impressive when you put it into perspective:

6.4 - Carrera GT
6.5 – Pagani Zonda R
6.5 – Kawasaki ZX6-R
6.7 - Enzo
6.8 - GTB 599
6.8 – CBR 1100XX
7.2 - SLR
7.8 - Murci LP640
7.9 - C6 Z06
8.0 - Ford GT
8.4 - 997TT
8.4 - F430
8.4 - 996 GT2
8.6 - M6
8.7 - SL65 AMG


TTE 3371X compressor wheel difference:

 

[zamzia]

This is going to be epic