NA to TT Conversion Guide

Written by Iceman3K15 Prices listed are from 2003
Parts list – with prices below:

• Turbos from a VR4, either the TD04 9b’s or TD04 13G’s with wastegate actuators
• Both intercooler and all piping associated
• Exhuast manifolds and the manifold gaskets from a VR4
• o2 housings and precats from a VR4
• Oil housing from a VR4
• Oil feed and return lines for the turbos, and all the eyebolts and gaskets
• “Joint” on the back of the engine block for the rear oil feed line
• Modified non-turbo oil pan to accept oil return lines
• Water housing from a VR4
• Water feed and return lines for the turbos and all the eyebolts, washers, and gaskets
• VR4 downpipe
• 360cc injectors
• VR4 fuel pump (or walbro 255ltr/hr)
• Injector resistor pack
• Front motor mount bracket
• Oil cooler with lines

electronics needed:

• S-AFC or S-AFR
• Boost gauge
• Air/Fuel ratio gauge
• Exhuast Gas Temperature gauge (two is best, one for front bank and one for rear bank)
• datalogger – useful for monitoring everything, especially knock

Ok I was able to get many things used from various members on the board in the “Parts for Sale” section. So my advice is to just watch the section and when something comes available that you need, pick it up. I got the turbos, exhaust manifolds, precats and some of the piping for $210 shipped, but the turbos needed new wastegate actuators which were $145. I picked up the intercoolers and piping for $175 shipped. I picked up the oil and water housings for $60. I got the 360cc injectors for $75, the walbro fuel pump for $73, the resistor pack for $63, and the TT downpipe for $70. The front motor mount bracket was $40. The oil cooler was $110. I picked up the S-AFC (gen 2) for $260, the boost gauge, air/fuel gauge, and the double gauge pod for $235 (I got some nice gauges). I am going to eventually get two EGT gauges, and a pocketlogger; but I did not right now to help keep costs down as they are not absolutely mandatory. The long list of OEM parts that included all the oil, coolant, and water lines with the bolts, and gaskets from the dealership for $256. I also picked up various bolts, silicon gasket maker, and vacuum hose for the wastegates which all cost approximately $15.

In my search for parts I came across a Manual Boost Controller for $15 and decided to pick it up. It was not mandatory for the conversion, but I heard the MBC helps to prevent boost spiking.I hadn’t changed my spark plugs in a while either so I picked up some new denso iridium IK24’s for $63.

Now when doing the TT conversion you add a lot of power, so your transmission is going to need some beefing up to being able to handle it. When my clutch went out I got a RPS Stage 2, so I was ok in that area. But I still had the stock open differential which cannot handle the extra power. Therefore, I decided to go ahead and get a Quaife LSD. Now the LSD is not cheap and not mandatory for you TT conversion to run, but I would not chance not having it, especially if you plan any trips to the track or drive your car hard. The LSD and parts needed to install it ran me $1,050 shipped….nice chunk of change. It cost me around $350 in labor to get the LSD installed, so do it yourself if you can.
So to add it all up,

TT conversion parts.........$1,787
Non mandatory stuff.......$78
Drivetrain parts...............$1,050
LSD Install.......................$350
____________________________
TOTAL..............................$3,265


For a parts list including all OEM part numbers:
TT Conversion Parts List
For the complete step by step HOW TO I used on the install:
TT Conversion How To
To install the S-AFC I used this link:
Apexi S-AFC Install
To install the gauges I used this link:
Air/Fuel Gauge Install
To install the fuel pump I used this link:
Fuel Pump Install
To install the injectors I used this link:
Injectors Install


Much thanks goes out to Jeff Lucius, and 3SX Performance for the use of their extremely helpful websites, and the whole message board and its many members who helped me along the way (especially SLguy who was always answering questions for me). Good luck on all the TT conversions to come. I hope this will serve a good reference to help anyone out who wants to do the conversion in the future!!