My AHU Corrado VNT GT1749va Turbo Build Thread

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
I am planning to an a B5.5 VNT GT1749va turbo to my AHU. I already have the turbo, AFN manifold and now I want to get the misc parts so I can fit the turbo in the spring (yes a long build thread).

One of the best threads I have found for this upgrade is right here: http://forums.tdiclub.com/showthread.php?t=157345

First let me say that the 1749va is a small turbo upgrade. I'm looking for anywhere from 140-165whp without an IP upgrade and 170-180whp if I upgrade to an 11mm IP. I don't plan on upgrading the IP unless it begins to fail. An upgrade for this 1749va turbo is the BV43 turbo which is talked about here: http://forums.tdiclub.com/showthread.php?t=291947

Some of the reasons why I'm using this turbo is the price that I was able to get the manifold and turbo. Also this setup should clear the rear motormount & bracket.

I want to use as many factory parts as possible. I was able to get the Turbo NEW from VW for an excellent price, so good that I will have one spare on the shelf for the future (incase this one fails) and I'm rather frugal.

Here are some pictures of the 1749va compared to the GT15 (same as the kkk kO3):








The 1749va sits closer to the #2 cylinder then the KKK k03 which is almost centered between #2 & #3 cylinders so the AHU oil lines will be the wrong length but otherwise would connect to the 1749va.

My research on www.vagcat.com shows that the oil line part numbers are:

MK3 AFN Oil Return Line: 028 145 736 AB
MK3 AFN Oil Feed Line: 028 145 771 BE
Mk3 AFN Air Inlet Pipe (I think the AHU part will work) 1H0 129 965 N (1H0 129 965 P for Cold Weather Climate[PCV Heater])
Mk3 AFN Oil Line Bracket/retainer 028-145-859-J for AFN engine 1996 TDI Passat/Golf
Mk4 038-131-501-AN EGR Valve Replacement for 038-131-501-S on the AXR Engine- 2002 Golf TDI

Parts I have:
I have the 1749va
AFN Manifold
130 PD intake manifold and adapter *Installed*
PP764 *Installed*
mk4 N75 Valve
2" IC pipes *Installed*
Kerma Turbo Compressor Outlet adapter
AFN oil lines
AFN Turbo Inlet

Things I still need to get:
*downpipe, I was planning to build my own until I found a really good price on a NEW OEM downpipe and cat on the UKebay I'm just waiting for it to arrive any day now.
*ECU Modified
*adapter to the 2.25" cat back exhaust
*I might even try to get an EGR valve that works on my PD130 intake manifold so that can be fully functional. Time will tell. I know it might reduce power but I like the idea.
*Mandrel bend to adapt the IC pipe to the turbo outlet.

Finished list for others that want to put a b5.5 turbo on their Mk3/b4 1Z/AHU:

  1. AFN Oil Return Line: 028 145 736 AB
  2. AFN Oil Feed Line: 028 145 771 BE
  3. AFN Air Inlet Pipe (I think the AHU part will work) 1H0 129 965 N (1H0 129 965 P for Cold Weather Climate[PCV Heater])
  4. AFN Oil Line Bracket/retainer 028-145-859-J for AFN engine 1996 TDI Passat/Golf
  5. Exhaust/Turbo Manifold
  6. downpipe
  7. ECU Modified
  8. IC pipe to the turbo outlet modified
  9. N75 Valve
  10. Vacuum accumulator
  11. Reroute the vacuum lines


here are some pictures of my Engine bay and my AHU Corrado:




Oh and my upgrade timeline has been moved up because I made a mistake while doing my timing belt job and didn't remove my ratchet from the crank after making certain there was no interference after tightening up all the bolts during the timing belt job. So now I am going through the engine. The block will be getting new rings, the head is being rebuilt, the injectors balanced and the cam is being upgraded to a colt stage 2. I had wanted to rering the bolt at some point, I'm just frustrated that I'm forced to do it because of my mistake. At least its during the winter.

Link to a spreadsheet with part numbers, prices and sources
http://pics.tdiclub.com/data/500/Corrado_AHU_Rebuild_and_Upgrade_to_AFN_VNT_GT1749VA_Turbo_Costs_and_Parts.xls


Below are links that I'm storing here so I can begin compiling a decent AHU/1Z upgrade thread (I'm tired of searching for everything.)


AHU vs ALH discussion and includes a slight discussion of pistons:
http://forums.tdiclub.com/showthread.php?t=194801
http://forums.tdiclub.com/showthread.php?t=210044&highlight=pistons+ALH+AHU
http://forums.tdiclub.com/showthread.php?t=122581&highlight=pistons+ALH+AHU

Be careful when swapping injector pumps(see post 36):
http://forums.tdiclub.com/showthread.php?t=185550

Some of the AFN or VNT threads that I have found helpful for this swap:
http://forums.tdiclub.com/showthread.php?t=76707
http://forums.tdiclub.com/showthread.php?t=257753
http://forums.tdiclub.com/showthread.php?t=231874

AFN Vacuum line routing:
http://forums.tdiclub.com/showthread.php?t=291738

AFN Wiring Diagram:
AFN Wiring Diagram

Good thread explaining the flow for the various injectors:
http://forums.tdiclub.com/showthread.php?t=246968

AHU & 1Z Intake Manifold Threads:
http://forums.tdiclub.com/showthread.php?t=260729
http://forums.tdiclub.com/showthread.php?t=299857
http://forums.tdiclub.com/showthread.php?t=248172
PD manifold with an EGR for a Mk3/B4: http://forums.tdiclub.com/showthread.php?t=314011


Adjusting the EGR Opening Cycle (won't turn it off but it can decrease it):
http://www.tdiclub.com/TDIFAQ/TDiFAQ-7.html#j

Checking & Adjusting the VNT Actuator:
http://forums.tdiclub.com/showthread.php?t=312619

AHU/1Z Timing Belt Procedure:
http://www.tdiclub.com/articles/A3-TimingBelt

Adjusting Injection Quantity Technical Explanation of the Adjustment:
http://www.tdiclub.com/TDIFAQ/TDiFAQ-7.html#h
http://www.myturbodiesel.com/1000q/multi/IQ-adjust-hammer-mod-TDI.htm

Injection Pump Timing (the mechanical process of the adjustment):
Which way to advance or retard: http://www.tdiclub.com/TDIFAQ/TDiFAQ-7.html#k
Centering the pump in the mechanical adjustment range (do this before putting the belt on):http://forums.tdiclub.com/showthread.php?t=251065
When adjusting make certain you loosen all of the bolts: http://forums.tdiclub.com/showthread.php?t=256392

Injection Pump Timing Discussion of where the setting is best:
http://forums.tdiclub.com/showthread.php?t=240450

Finished Specs of my car:(September 2011)

Engine: 1.9L AHU from a 1998 Jetta with a Passat wiring harness

Transmission: Mk3 O2A "CTN" transmission

Brakes/Drivetrain: 5x100 Lug Conversion (Eurospec Sport Conversion Hubs), 11.3" Mk4 GTI rotors, 5x100 rear Rotors, SS lines, Mintex red pads

Suspension: H&R coilovers, Neuspeed 4 point rear strut bar (modified for Quick removal) R32 control arm bushings, New Strut Bearing Bushings, New rear shock bushings.

Wheels & Tires: 16" Audi TT wheels (Very Rare) that have been stripped of their paint and Polished. Yokohama Parada spec 2 Tires 205/40/16 Tires

Exterior: Stock Body work with 20+ years of minor wear and tear with the original paint. Tinted/Red taillights, clear side markers and European headlights. 90mm Front Euro Lip Lip. Passat Moonroof Conversion. The Moonroof interior panel has a grey cloth panel that matches the OEM headliner perfectly.

Interior: Stock Black Heated Leather with a TDI Passat instrument cluster with MFA 100% operational. Auber EGT, VDO boost & oil pressure gauges. European manual seatbelts. 337 Pedals

Audio/Visual: Late Mk3 Jetta Radio (matches the Rado's instrument lighting) No more amplified door speakers

Mileage
Drivetrain: Approx 175k, the engine had 115K miles when I started the swap.
The shell had 59k miles when I started :eek: now at 120k

The car has an 15 gallon fuel tank and can get 48-52 mpg all day everyday with the 16s and driving it hard. 55-60 if I pamper it and try for economy. Why I think this car is so great? This is the car that I originally intended to build on my first TDI Corrado build, its all OEM like. Everything went together like it was built this way from the Factory.

The original build Thread:
http://forums.vwvortex.com/zerothread?id=3279771

Photo Album:
http://share.shutterfly.com/action/welcome?sid=8CZtXDdy5asRc
 
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Matt-98AHU

Loose Nut Behind the Wheel Vendor
Joined
Apr 23, 2006
Location
Vallejo, CA
TDI
2014 Passat SE DSG, 2005 Passat wagon, 2004 Touareg V10.
Looks like a sweet little upgrade :D Bonus on not having to modify the engine mount!

Are you going to re-clock the intake side of the turbo to line it up better with the stock routing of intercooler lines?

I was poking through ETKA and it seems like your part numbers are correct for the oil feed and return lines.

Oil pipe:

028 145 771 BE

Return line:

028 145 736 AB

I do know that the 1Z/AHU return line has changed from the original version. The original used a banjo bolt and the replacement requires you to buy a separate fitting to thread into the engine block to make it fit. It's a large bubble flare fitting like the Mk4s use now.

Not sure which style that part number for the AFN turbo uses.

If you do need the hydraulic fitting for the later style, this is the part number:
N 908 371 01
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
I plan on reclocking the turbo and I have the newer style oil line. Thanks for confirming the parts :)
 

VWannabe

Veteran Member
Joined
Nov 2, 1999
Location
Lawrenceville, GA USA
I have some questions concerning this. I really like what you are doing and am looking forward to updates. That being said, I am looking into a modified rear mount because then I can use most of the turbos that the A4's can use, which are more abundant over here. I can also, I believe, use an aftermarket A4 tdi downpipe for my exhaust (correct me if I am wrong). I do not have your fabrication skills so I am looking to go a route that allows me to use abundant bolt-on parts.

A big question I have is does this setup give me better performance and mpgs in a lightly modified setup over a hybrid turbo? I am not looking to swap out pumps at this time so I know that I am limited performance wise, although I think I could get enough out of the current setup to satisfy me for a while. This is in an A3 Jetta, not a Passat, so I already have a ~400 lb weight advantage. In theory, a VNT turbo gives better low rpm response and less backpressure but I don't really know actual real world examples.

BTW - what model of air cleaner setup are you running? Is that the Corrado setup or some other VW model?
 
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codeblue

Veteran Member
Joined
Aug 5, 2003
Location
Kitchener, Ontario, Canada
TDI
98 Vento GLX TDI
I have some questions concerning this. I really like what you are doing and am looking forward to updates. That being said, I am looking into a modified rear mount because then I can use most of the turbos that the A4's can use, which are more abundant over here. I can also, I believe, use an aftermarket A4 tdi downpipe for my exhaust (correct me if I am wrong). I do not have your fabrication skills so I am looking to go a route that allows me to use abundant bolt-on parts.

A big question I have is does this setup give me better performance and mpgs in a lightly modified setup over a hybrid turbo? I am not looking to swap out pumps at this time so I know that I am limited performance wise, although I think I could get enough out of the current setup to satisfy me for a while. This is in an A3 Jetta, not a Passat, so I already have a ~400 lb weight advantage. In theory, a VNT turbo gives better low rpm response and less backpressure but I don't really know actual real world examples.

BTW - what model of air cleaner setup are you running? Is that the Corrado setup or some other VW model?
While I still eagerly await the results from this project that g60 is doing, seeing the original thread quoted (hgeittmann with the 15/17 hybrid, PP520's, RC3 - the exact same setup that I have) I don't hold much hope for drastic increases in power. Hg mentions only a 4hp/4tq increase after this mod. That's pretty disappointing considering the cost of all the parts involved. But still I'd like to see what G60 can unlock from this.

I suggest running before and after dyno's if you can!
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
Before and afters are no problem. The nice thing is the price that I paid for my turbos is unbelievable so for me the upgrade's real cost is in the downpipe and chip.
 

jjordan11

Veteran Member
Joined
Jan 5, 2008
Location
Lehi, UT
TDI
1988 Audi 80 quattro PD130, 1982 Westfalia TDI
Nice, should be a good match for your Corrado. How much boost are you planning on running? Are you going to or have you upgraded the internal map sensor yet to a 3 bar map?

Jon
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
I've heard that 22psi is a safe sustained level, so thats what I'm planning on. I haven't upgraded the MAP senor yet but I plan to have that done at the same time.
 

jjordan11

Veteran Member
Joined
Jan 5, 2008
Location
Lehi, UT
TDI
1988 Audi 80 quattro PD130, 1982 Westfalia TDI
I would recommend doing the external map/temp sensor (instead of another internal sensor), I did it to the Vanagon's ecm and it wasn't difficult at all. I'm trying to remember what psi I was running on the Audi (same gt1749va turbo) before it grenaded, I think it was around 24-26, on that run I hadn't allowed it to warm up before I got on it hard and it spiked to about 30.
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
I'll plan on adding a dawes device to control boost spikes.
 
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G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
I've clocked the turbo and received the Turbo Outlet adapter





 
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G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
Thanks,


I just test fitted the turbo in the car and it fits nicely. Its close to the firewall but I managed to figure that if I too the manifold off first and then fitted the turbo to manifold after it was bolted in that I wouldn't have any issues.

The turbo doesn't come anywhere close to the stock mk3 tdi motormount bracket or mount.

The PD intake manifold fits without any issues.

The Mk3 plastic intake pipe works without issues and clears the a/c lines and my rubber hoses to my airbox still work (i turned one of my bends around for a better fit.

I'll need to modify one IC pipe but I expected this. The downpipe will have to be custom. (also expected)
 

borachris

Veteran Member
Joined
Dec 23, 2005
Location
UK-Billingham
TDI
Bora ASZ 130PD, Corrado 150PD in production
Sounds like good progress, I've had issues with the exhaust manifold whilst trying to fit a 2260 in my mk2 golf, just waiting for another manifold to arrive to test fit again.

Are you using a standard gearbox mount bracket(the one that bolts up to the trans), I'm a bit concerned about it not being strong enough.
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
The transmission bracket is plenty strong enough. All of the VRT Corrados use the same exact bracket. They have more HP & TQ and weight to deal with too.
 

borachris

Veteran Member
Joined
Dec 23, 2005
Location
UK-Billingham
TDI
Bora ASZ 130PD, Corrado 150PD in production
The transmission bracket is plenty strong enough. All of the VRT Corrados use the same exact bracket. They have more HP & TQ and weight to deal with too.
Thanks for the reassurance, one less thing to worry about.

You guys have so much more room than us RHD guys, though having a nice compact turbo helps too I suppose!

When do you expect to have it back on the road, not too far away by the look of it?
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
It will be back on the road after the road salt is gone.
 

Nitrox

Well-known member
Joined
Sep 5, 2009
Location
Algarve
TDI
Golf II TDI
Your car looks beautifull!

if I'm not mistaken i think I've seen it in PVW mag while ago, in a meeting pictures! Maybe h20, i don't remember...

It looks like the AHU looks identical to an AFN.

Why did you choose the route of the gt1749vb? Same install easyness with a little more safety at high pressures. Here in Portugal it's safe to say that the only cars that run the Va, are the factory ones...
 
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Stealth TDI

Pre-Forum Veteran Member
Joined
Feb 13, 1998
Location
Newport News, VA
TDI
2017 GTI w/PP, LP, & APR Stage 2 (336 hp/404 lb-ft)
Hmmm...

Why did you choose the route of the gt1749vb? Same install easyness with a little more safety at high pressures. Here in Portugal it's safe to say that the only cars that run the Va, are the factory ones...
Answer is in top post:

Some of the reasons why I'm using this turbo is the price that I was able to get the manifold and turbo. Also this setup should clear the rear motormount & bracket... I want to use as many factory parts as possible. I was able to get the Turbo NEW from VW for an excellant price, so good that I will have at least one spare on the shelf for the future and I'm rather frugal.
RIF,

Scott
 

Nitrox

Well-known member
Joined
Sep 5, 2009
Location
Algarve
TDI
Golf II TDI
I have just realised something!!

Altough I live 6000 away from you in the other side of the atlantic and in another continent, i have been side by side with both your Corrados :D

Here we go:









It was in 2008, h20 event! :)

I took hundreds of pics that day
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
so thats where that turbo went too.... Nice buy!

I bought my turbos from VW when they had a clearance sale on 2L FSI and Passat 130hp TDI turbos last June:



If you know anybody that needs a 2L FSI Turbo send them my way and I'll make them feel like they just found the best deal in the world because it will be. I'm not a business just an enthusiast that is passing on a good deal to other enthusiasts.
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
My AFN oil lines and turbo inlet just arrived from Germany today. A good friend of mine in the military arrived a few days after I decided I was going to get cracking on this upgrade's time line so it was fairly easy to get the necessary parts new from the dealer.

:):) Thanks Jason:):)






Now I just need my AFN downpipe and Cat to arrive from the UK:
 

G60ING

Top Post Dawg
Joined
Aug 5, 2001
Location
Alexandria, VA
TDI
No TDIs Currently, I have an R36 Corrado. I've had an ALH Corrado swap, AHU Corrado swap and 2003 TDI Jetta
The specs when its all said and done should be outlined below:

here are the engine specs:

  • AHU Engine reringed
  • AHU stock head rebuilt
  • AFN Exhaust Manifold
  • Gt1749va turbo stock from a b5.5 passat tdi
  • Stock B4 AFN TDI downpipe approx 2.25" od with cat
  • Stage 2 Colt Cam
  • Exhaust is currently a Techtonics 2.25" cat back with borla muffler (I would like to upgrade to a 2.5" cat back exhaust but its fading from the plans as the costs add up because a TT SS borla setup is $640 and then I want it converted to v-band)
  • 130hp PD Intake manifold
  • 2" IC plumbing
  • stock restrictive Corrado Intercooler
  • no lift pump
  • stock 10mm AHU IP
  • pp764 injectors balanced by franko6 when the head was rebuilt (bought a couple years ago)
  • Chip (malone)
 
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