# GCTech Motorsports 6765 2.5L Build Thread



## Serrari (Jun 29, 2008)

Hi guys, I had a 2.0T FSI engine in my car and made 653whp, here is the link to th build thread: http://forums.vwvortex.com/showthread.php?4956061-Leon-Cupra-PTE-6262-build. Just blew a valve and I decided it was time for a change. I am building a 2.5L engine and will be trying to get 850whp. Here is the parts that will be used in my setup:

*Engine*



VW 2.5 CBT Engine
Pistons JE 83mm 8.5:1CR
Rods IE 4340 Chrome Moly steel +900hp
Ferrea Valvetrain kit +1mm oversize +9000rpms
Port and polish head by GCTech
Custom aluminum intake manifold by GCTech
90mm Throttle body
BSH engine mounts
ARP head studs
ARP main studs
Calico rod bearings
Radiator Koyorad

*Drivetrain*



Transmission 02Q
Spec Mini Twin Disc Clutch
Billet flywheel
Wavetrac LSD
Custom traction bars by GCTech

*Turbo setup*



Comp Turbo triple Ballbearing 6765 T3 .82ar CT4 +900whp
Tial wastegate 44mm
Tial BOV 55mm
Garrett FMIC 24x12x4.5 950hp
Hotpipe aluminum 3" by GCTech
Chargepipe aluminum 3.5" by GCTech
Turboheader stainless steel by GCTech
Dumptube stainless steel GCTech
Downpipe stainless steel 4" GCTech

*Fuel system*



5 Injectors 1200cc
2 Bosch 040 fuel pumps
Fuel pressure regulator
Return line kit by GCTech
Direct port Coolingmist meth kit

*Electronics*



Standalone (havent decided which)
AEM wideband UEGO
Turbo Smart Eboost2 Boost controller
Autometer tachometer 10,000rpms
Autometer oil pressure gauge

*Suspension*



Bilstein shocks
Eibach Pro-kit
Tires Nitto NT05
TSW Nurburgring wheels
AWD conversion (after the engine is done)

*SPONSORS ARE WELCOME!!!

*The car is a Leon Cupra 2008, this is a pic of my last setup:










I just got the engine, but will be ordering a lot of parts and to update the thread with pics:


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## pennsydubbin (Mar 3, 2010)

Wow this is going to be awesome :thumbup: how long do you expect it to take till its completed?


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## Serrari (Jun 29, 2008)

pennsydubbin said:


> Wow this is going to be awesome :thumbup: how long do you expect it to take till its completed?


Fully tuned around 4-6 months, many custom parts are going to be designed.


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## TylerO28 (Jul 7, 2008)

I'm in!

This is going to be GREAT!
good luck man!


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## CoNGLoMeRaTeGTi (Apr 4, 2007)

looking good!


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## [email protected] (Mar 4, 2011)

Looking good! :thumbup:


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## kevin splits (Aug 23, 2010)

:heart:


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## sagerabbit (Aug 14, 2007)

SUBSCRIBED.

ALL CAPS.

opcorn:


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## GTACanuck (Feb 20, 2009)

I just got a boner

Sub'd


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## ReinertAngle (Jun 11, 2009)

This will be a sweet build. Interesting how he will sort out the fuel management and still be able to "drive" the car. Hope it doesnt end up a trailer queen.


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## [email protected] (Jan 2, 2009)

Hey, shoot me an email before you order those +1mm valves. We have made valve seats for much bigger valves, plus even the 1mm hang off the edge of the stock seat. 

This should be an interesting 6 months for the 2.5L


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## GTACanuck (Feb 20, 2009)

[email protected] said:


> This should be an interesting 6 months for the 2.5L


Indeed


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## [email protected] (Jan 2, 2009)

ReinertAngle said:


> This will be a sweet build. Interesting how he will sort out the fuel management and still be able to "drive" the car. Hope it doesnt end up a trailer queen.


There are tons of good standalones that will drive the intake cam VVT, the drive by wire, and hell- even haldex. 

Vipec v88 is one- that's what we use and sell. I'll have basemaps for the 2.5L here pretty shortly. :thumbup:


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## Serrari (Jun 29, 2008)

[email protected] said:


> There are tons of good standalones that will drive the intake cam VVT, the drive by wire, and hell- even haldex.
> 
> Vipec v88 is one- that's what we use and sell. I'll have basemaps for the 2.5L here pretty shortly. :thumbup:


Im interested, just sent you a PM and email you.


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## eatrach (May 13, 2004)

HOT TAMALES> that is going to be a nasty tune :laugh:


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## thygreyt (Jun 7, 2009)

you should talk to INA, they are the forum sponsor, and they have a lot of answers!


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## spdfrek (Feb 28, 2002)

This looks like its going to be a good build. I have a question about the trans though. I don't see those stock gears holding that kind of power. Do you have plans for a different gearset?


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## MKVJET08 (Feb 12, 2008)

opcorn:


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## [email protected] (Jan 2, 2009)

spdfrek said:


> This looks like its going to be a good build. I have a question about the trans though. I don't see those stock gears holding that kind of power. Do you have plans for a different gearset?




Powerglide! I'll make the adapter plates. :thumbup: :laugh:


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## INA (Nov 16, 2005)

Love it Serg!


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## INA (Nov 16, 2005)

[email protected] said:


> Hey, shoot me an email before you order those +1mm valves. We have made valve seats for much bigger valves, plus even the 1mm hang off the edge of the stock seat.
> 
> This should be an interesting 6 months for the 2.5L


You shouldnt be installing +1mm valve on stock seats anyway.
:thumbup:


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## 08Drabbit (Feb 3, 2011)

high horsepower number out of 2.5 :thumbup::thumbup: In for build and results. its probably hard to tell at this point but how reliable do you expect this thing to be? obviusly not DD, but do you plan on it being reliable enough to drive it to the track, beat on it, then drive it home?


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## ViRtUaLheretic (Aug 17, 2008)

08Drabbit said:


> high horsepower number out of 2.5 :thumbup::thumbup: In for build and results. its probably hard to tell at this point but how reliable do you expect this thing to be? obviusly not DD, but do you plan on it being reliable enough to drive it to the track, beat on it, then drive it home?


The 653hp motor was apparantly a DD, I bet this will be as well.


subbed!


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## Serrari (Jun 29, 2008)

Turbo is here, 6765 triple ballbearing:


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## HIBB 304 (Nov 8, 2008)

^^^^^^^

:thumbup::thumbup:


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## ReinertAngle (Jun 11, 2009)

Very exciting build. Appears that this is a "cost is no object" build... So why not hook up with Ricardo for a H/D transmission solution? Or perhaps a sequential gearbox. The built 6 speed you are planning will be short of this world when this is all together...


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## thygreyt (Jun 7, 2009)

i think so too..

you need a GOOD tranny to handle such power properly.


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## donjuan1jr (Oct 8, 2008)

thygreyt said:


> i think so too..
> 
> you need a GOOD tranny to handle such power properly.


The 02q is vws best manual trans to date. I don't think hell have a problem in that area, with that kind of power he should think about some custom axles.


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## spdfrek (Feb 28, 2002)

donjuan1jr said:


> The 02q is vws best manual trans to date. I don't think hell have a problem in that area, with that kind of power he should think about some custom axles.


The 02q might be god's balls but at the end of the day the gears were never ment to hold that kind of power and will break. The axles have a chance of holding but I wouldn't trust them if they car is going to be pushed hard.


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## [email protected] (Jun 24, 2009)

Awesome build you are putting together, I would like to see a motec ecu on that motor. Talk to Andre (Audi4u on here) he has alot of inside info that will help you in tuning this motor that might save you some time. 



thygreyt said:


> i think so too..
> 
> you need a GOOD tranny to handle such power properly.


Let us know when you want a dog box.


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## thygreyt (Jun 7, 2009)

> What types of engagement are available? This is a common source of confusion when searching for information on transmissions. There are two types of engagement: Synchro and Dog.
> 
> Synchro engagement (also known as synchromesh) is what most passenger cars use.
> 
> ...


i diddnt know what a dog box is...

oh and btw a couple of the tdi race cars are using the GTI 6spd 02q.. i was told so first hand... but they arent making the power that this is hoping to!



irish mike said:


>


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## kamahao112 (Nov 17, 2007)

very nice no more fsi bs..:laugh: 

comp turbo sound clip from the last 1.8t i finished :thumbup:


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## BETOGLI (Jul 15, 2010)

Man... You're sick! :thumbup::thumbup:


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## kamahao112 (Nov 17, 2007)

just a little tip comp turbos need oil restrictors.. well mine did my car makes 80-90 psi on cold start and 20-25 at full temp and 60psi while cruising.. just a little guideline :thumbup:


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## BETOGLI (Jul 15, 2010)

It might be an ultra-dumb question but... Did you considered as well the 3.2 or 3.6 V6 engines for your new set up?

Also I haven't heard of anybody moding a Volkswagen's W8 engine!


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## kamahao112 (Nov 17, 2007)

BETOGLI said:


> It might be an ultra-dumb question but... Did you considered as well the 3.2 or 3.6 V6 engines for your new set up?
> 
> Also I haven't heard of anybody moding a Volkswagen's W8 engine!


i5 power 
http://www.034motorsport.com/1993-audi-urs4-jeff-gerner-bonneville-effort-a-191.html


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## AudiA4_18T (Mar 15, 2006)

kamahao112 said:


> i5 power
> http://www.034motorsport.com/1993-audi-urs4-jeff-gerner-bonneville-effort-a-191.html


you're referencing a different motor but OK


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## kamahao112 (Nov 17, 2007)

AudiA4_18T said:


> you're referencing a different motor but OK


now is de same
http://forums.vwvortex.com/showthread.php?4292438-DM-Motorsport-Unitronic-quattro-Bunny-2.5-t


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## LampyB (Apr 2, 2007)

sweet build man, very impressed and looking forward to further updates. one question though...why add 800whp onto a FWD car? what purpose does it serve considering you'll sit there spinning your tires the whole time? i can only see a project like this truly being beneficial on an AWD car like an Audi...


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## BETOGLI (Jul 15, 2010)

LampyB said:


> sweet build man, very impressed and looking forward to further updates. one question though...why add 800whp onto a FWD car? what purpose does it serve considering you'll sit there spinning your tires the whole time? i can only see a project like this truly being beneficial on an AWD car like an Audi...


Hi dude! I believe his adding a 4Motion on his setup as well!... Way to go man!


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## BETOGLI (Jul 15, 2010)

kamahao112 said:


> now is de same
> http://forums.vwvortex.com/showthread.php?4292438-DM-Motorsport-Unitronic-quattro-Bunny-2.5-t


Hi Kamahao,

Indeed a read of this awesome VW Rabbit MKV on Eurotuner a year ago! Thanks for sharing these


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## kamahao112 (Nov 17, 2007)

BETOGLI said:


> Hi Kamahao,
> 
> Indeed a read of this awesome VW Rabbit MKV on Eurotuner a year ago! Thanks for sharing these


no problem .. and a vid ..:laugh:


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## BETOGLI (Jul 15, 2010)

kamahao112 said:


> no problem .. and a vid ..:laugh:


Sweet!


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## markfif (Oct 25, 2007)

god that sounded good. Has anyone made an exhaust manifold to the mount the turbo so it doesn't interfere with the axle when going low?


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## Serrari (Jun 29, 2008)

Just received some parts:










































I will be ordering the fuel system today.


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## kevin splits (Aug 23, 2010)

markfif said:


> god that sounded good. Has anyone made an exhaust manifold to the mount the turbo so it doesn't interfere with the axle when going low?


No, not a production mani, custom maybe. They dont really affect lowness. I just dont think you'll be able to go 22"ftg static and daily it, air itll be fine imo. LOL at the sub 300hp claimed 700awhp rabbit :facepalm:


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## kevin splits (Aug 23, 2010)

IE koozie adds 50hp :thumbup::thumbup:


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## Serrari (Jun 29, 2008)

Just bought some parts for the AWD conversion:


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## thygreyt (Jun 7, 2009)

now waiting for moar.


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## kevin splits (Aug 23, 2010)

Is that a mk4 rear subframe :sly:


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## StreeterTT (Apr 22, 2010)

Sergio, your project is awesome. Is so difficult to find this type of parts?


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## Gctech Industries (Dec 12, 2008)

Here are some updates to the swap, 

To mate the tt awd transmission to the 2.5block was not a simple bolt on some fitting had to be performed to the gear box , the FSI Spec clutch kit is a bolt on to the block Except some clearing in the transmission bell housing is required as well in the block itself to clear the T-case. 
Still waiting for the TT awd Sway bar, after that next step is to install the rear subframe and rear diff, before I start on the Custom Intake and turbo manifold


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## thygreyt (Jun 7, 2009)

moar!


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## thygreyt (Jun 7, 2009)

what ever happened to this project?


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## madness maker (Apr 29, 2002)

Serrari said:


> Just received some parts:
> 
> 
> 
> ...


are u using stock 2.5 crankshaft ? and how do u plan on using that autronic smc on the 5cyl?


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## thygreyt (Jun 7, 2009)

the crankshaft in use is pretty much irrelevant.

there has only been 1 reported failure, and the car was making ~500 AW tq.


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## DerekH (Sep 4, 2010)

thygreyt said:


> the crankshaft in use is pretty much irrelevant.
> 
> there has only been 1 reported failure, and the car was making ~500 AW tq.


I wish i had that problem lol.

...actually, what do you do when you have that problem? Knife edge and re balance? Does the extra weight that is taken of make it less likely to explode? I would figure there is not a whole lot that can be done when you are having crank shaft failures.


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## thygreyt (Jun 7, 2009)

he just switched the crankshaft to the ttrs one.

its not a direct swap, but he made it work


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## [email protected] (Jan 2, 2009)

There are two versions of the regular 2.5L crank- a cast one, and a forged one. The cast one has failed, I have not seen a failed forged one, even at higher power levels then that. The problem is not the crank, but rather the 6 bolt flywheel interface. 

Not quite sure which motors came with cast vs. forged yet. I have a few 2.5's here and they are all forged.


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## thygreyt (Jun 7, 2009)

oh, ok. that makes sense.

when he talked about the forged on, i thought he meant the ttrs crank.


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## tchilds (Nov 21, 2008)

wow vw really cheaped out on our bottom end, i've never had a VW with such a "honda strong" bottom end before. oh well i guess that's the price we pay for a cylinder head that actually flows.


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## [email protected] (Jan 2, 2009)

No. All modern cars have "light duty" reciprocating components- this is because of the fuel crunch. Modern FEA software & analysis tools are allowing safety factors to be trimmed down more and more all the time, and powdered metal processing allows more complex shapes- all of this is done for a) reducing reciprocating weight b) *slight cost savings... Steel is very very cheap... 

Cast cranks are not really cheaper then forged. They can be, but they require very high strength, special iron. They damp vibration better then a forged crank (good) and come out closer to net shape (good). In VW land though, getting a forged versus cast crank mostly seems to depend on what plant your engine was made in / corporate inner workings we will likely never understand. The 1.8t's it was totally random with no strong correlation to power output designations. 

Most new cars are the same, whittled down to what really needs to be there to get the job done. They do *not* care that it won't hold 400+ bhp, why should they. The bottom line is a bottom end that holds 400+ bhp is NOT AS GOOD for 170 bhp as the one that the factory designed, in any measurable way. It's heavier, slower, and more expensive. :thumbup:


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## DerekH (Sep 4, 2010)

Cool, thanks for the info guys.


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## tchilds (Nov 21, 2008)

Thanks for the inside scoop pete. Now I know how the guys felt when detroit stopped building v8's with all forged internals. 

I had no idea the efficiency of these motors was the reason they're built so minimal. I always thought VW went above and beyond when it comes to quality of steel/iron in their bottom ends. This motor just doesn't give me that impression but you would know best. You have to admit though, the piston design is just junk and cheap :laugh:

I'm just accustomed to the whole vr6/16v scene which, even for their time, were overbuilt bottom ends that put the honda motors to shame.


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## CoNGLoMeRaTeGTi (Apr 4, 2007)

Serrari said:


> Fully tuned around 4-6 months, many custom parts are going to be designed.


Any updates?


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## 2DR16VT (Mar 16, 2006)

So is it running or any updates ???


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## BETOGLI (Jul 15, 2010)

Any update?


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## kevin splits (Aug 23, 2010)

2DR16VT said:


> So is it running or any updates ???


Probably cut his loses, bought a ttrs, slapped on a bigger turbo and tuned it for the same money.


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