Audi TT FAQ – updated 3/9/2013
- Built in Gyor, Hungary
- Color options varied throughout the production run, paint codes are shared with other Audis (see AW Paint Code list)
- Originally shown as a concept in 1995, production based on VW a4 chassis, TT had highest-spec parts of platform
- Fit, finish, and quality got better through production, with later cars being less problematic
Wheelbase: FWD - 95.4in, quattro - 95.6in
Curb weight (coupe, roadster): FWD (2910lbs, 3054lbs), quattro (3208lbs, 3358lbs), 3.2 (3351lbs, 3500lbs)
Weight distribution: FWD, 3.2 (62/38), quattro (60/40)
Fuel capacity: FWD - 14.5gal, quattro - 16.4gal
Brakes (F/R): FWD (12.3"/9.1", solid), 180q (12.3"/9.4", vented front/solid rear), 225 (12.3"/10.1" vented), 3.2 (12.3"/10.1", 4-piston front calipers, vented)
1.8T (108.6ci), 06A block, Borg-Warner turbos
US engine codes: ATC, AWP, AMU, BEA
Bore x stroke: 81mm x 86.4mm (3.19in x 3.40in)
Comp. ratio: 9.5:1 (180hp), 8.9:1 (225hp)
Firing order: 1-3-4-2
Oil capacity: 4.5qts (4L)
Coolant capacity: 7.4qts (7L)
3.2L (194.6ci), 15° VR6
US engine code: BHE
Bore x stroke: 84.0mm x 95.9mm (3.31in x 3.78in)
Comp. ratio: 11.3:1 (250hp)
Firing order: 1-5-3-6-2-4
Oil capacity: 5.8qts (5.5L)
Coolant capacity: 11.6qts (11L)
Mk1 TT production (worldwide build numbers):
• 1999: 52,579 (Coupe 44,022, Roadster 8,557)
• 2000: 56,776 (Coupe 31,064, Roadster 25,712)
- TT initially released in USA as 180hp 5spd quattro, though one or two other types of TTs may have gotten in
- - - Three original option packs: Comfort: heated seats, Audio: Bose sound system, and Performance: 17inch alloys and xenon headlights
- Neiman Marcus Special Edition released in company's yearly holiday catalog
- - - Nimbus Grey exterior + Moccasin Red interior
- - - 180FWD with 02J 5spd manual
• 2001: 39,349 (Coupe 22,078, Roadster 17,271)
- 225bhp quattro edition w/ 02M 6spd manual released, 18" wheels optional
- Roadster released. A rare, optional hardtop was available in Europe, they pop up for sale online from time to time but are expensive
- Baseball-stitched leather option, roadster only
- FWD/quattro available on 180bhp coupe model
- 180 roadster FWD-only
- ESP becomes standard, ducktail spoiler added, new steering bushings installed, and alignment changed
- Comfort and performance packages combined into premium package, subwoofer only available on roadster
- GPS audio navigation optional
• 2002: 34,711 (Coupe 21,488, Roadster 13,223)
- Standard audio system becomes a CD player instead of cassette player
- 180 switches to wideband 02 and VVT (ATC to AWP engine code)
- 225 ALMS special edition released to commemorate Audi's victory in the ALMS series and Le Mans:
- - - 18 inch Audi 9-spoke RS wheels
- - - Misano Red exterior + Silver Nappa interior, or Avus Silver Pearl exterior + Brilliant Red Nappa interior
- - - The interior consisted of matching leather door cards, knee bolsters, seats, steering wheel rim, and shiftknob leather
• 2003: 32,337 (Coupe 20,807, Roadster 11,530)
- 225 switches to wideband 02 and VVT (AMU to BEA engine code)
- 180 becomes auto-only
• 2004: 23,605 (Coupe 14,753, Roadster 8,852)
- 3.2 VR6 released, coupe or roadster, only available with DSG and quattro
--- standard S-Line app. package: lower front bumper w/oil cooler duct, a rear ducktail extension, and an eggcrate exhaust valence
--- first production car with a dual-clutch transmission
• 2005: 12,307 (Coupe 8,368, Roadster 3,939)
- 3.2, 225, and 180 auto
- Last year of mk1 production in Europe
- - - 240hp Quattro Sport edition released in UK, ~800 sold, available in several two-tones with a black roof
- - - 16psi K04, S-Line app. pack, 1pc seats, rear seat delete, 165lbs lighter than 225
• 2006: 23,675 (Coupe 21,461, Roadster 2,214)
- 3.2, 225, and 180 auto
- 3.2TT SE (special edition) released in US, available in two-tone with a black roof
- Mk2 TT released in Europe
• Helpful TT acronyms and part names
VAG - Volkswagen Aktiengesellschaft
180q - 180hp quattro model
225 - 225hp quattro model (225TT had quattro as standard)
02J - FWD 5spd manual transmission, shared with various 1.8T a4 chassis cars (mk4 VW, etc.)
02Y - AWD transmission used for the 5spd 180q
02M - AWD transmission used for the 6spd 225TT
BT - big turbo kit
SMIC - side-mount intercooler, 180TT has one on passenger side, 225TT has two on both sides
TIP - turbo inlet pipe
710N - diverter valve, recirculates vented boost back into intake (TIP), OEM N revision is stronger than 710
ARB - anti-roll bar (also called a sway bar)
FPR - fuel pressure regulator
N75 - solenoid that controls boost, VAG made several versions
N249 - solenoid that regulates the DV
EVAP - evaporative emissions system (N80 solenoid, carbon canister, ribbed blue tank, hoses)
SAI - secondary-air injection (pump, hoses, kombi, N112 solenoid) - used to ignite cats at cold start-up for emissions control
• What different basic submodels were available?
- 180hp FWD model (1.8l engine with k03s turbo, 11psi; overall drivetrain shared with mk4 VW)
- 180hp quattro model (1.8l engine with k03s turbo, 5spd, and Haldex AWD)
- 225hp quattro model (1.8l engine with k04-022 turbo, 14psi, 6spd, and Haldex AWD)
- 250hp quattro model (3.2l VR6, 6spd DSG, and Haldex AWD)
The 180 and 3.2 were automatic, the 180q/225q were manual only. The 225 has a k04-02x turbo (instead of the 180’s k03/k03s); to support the bigger turbo, it has two side-mount intercoolers (rather than one), bigger fuel injectors, a dual-outlet exhaust, 20mm wrist pin connecting rods, and 8.9:1 comp instead of 9.5:1. The 3.2 had its battery in the trunk and came with no spare.
• How can I identify a TT?
Quattros will have a driveshaft and rear diff + halfshafts. The 225 was only a 6-speed manual, whereas the 180 quattro was a 5-speed. The 225 came with a dual-outlet exhaust, but it's not a good idea to use this as a distinction criterion, since it's so common for people to put aftermarket exhausts on their car. The 225's intake manifold has its throttle body on the driver's side, and also has a charge pipe on the passenger side of the engine cover (easily seen under the hood) that leads to the passenger side intercooler.
• What is special about the 3.2?
The 3.2TT, with its 24v VR6, was released in 2004, was only available with the DSG (direct-shift gearbox) and was the first production dual-clutch transmission. Visually, the 3.2 had a different front bumper cover, black ducktail and exhaust valence, paddle shifters, and a gear indicator. The 3.2 engine is about 150lbs heavier than a 1.8T, it has slightly different suspension settings, 4-piston front calipers, a unique exhaust system, and the battery takes the place of the spare tire in the trunk.
• How does the TTq AWD system compare to other VAG cars?
The TTq, like the A3 and Volkswagen R32, uses an AWD system manufactured by the Swedish company Haldex, rather than the traditional TorSen (torque-sensing) quattro system used in other Audi models. The Haldex is an electronic center diff that uses a slave shaft off the rear of the transverse gearbox to control how much power the rear differential uses. The system is mostly FWD until sensors throughout determine that power needs to be sent to the rear, which, in stock form, happens with hard acceleration or loss of traction. The Haldex system averages about 80% front / 20% rear distribution, and it can never go beyond a 50/50 split because the front half-shafts are permanently powered. Stock Haldex service interval should be 30k, with trans and rear diff fluid at 60k.
If you want a more constant 50/50 power distribution, you can purchase a Haldex Performance controller. This swap will allow more power to go to the rear in many more conditions. There are two replacement controllers in the form of either a Blue or Orange controller; with the Blue controller, more power is sent to the rear wheels earlier, but the controller unlocks once the gas is released, or if the clutch or brake pedals are pressed. The more expensive Orange controller, however, stays locked at all times. What this all means is that the Blue is good for improved street driving because of a more neutral power distribution, whereas the Orange is more track-oriented because a locked AWD system is always applying power, which allows drivetrain braking but takes away a safety net on the street. See my Haldex Blue thread.
→ If you install a new Haldex controller, lower the fluid change interval to 25,000 miles for the Blue and 20,000 miles for the Orange, depending on how hard you drive.
Buying a used mk1 TT
There are a few things one needs to look for when buying a mk1 TT. The most important thing is to check as to whether or not the timing belt has been serviced. The factory service interval is stated as being 100,000 miles, but it is well-known that the 1.8T's timing setup is THE major weak point of the engine (specifically the hydraulic tensioner), and that it should be changed by about 60,000 miles; original plastic waterpumps also were known to fail. If you are looking into buying a TT with less than 60,000 miles get the belt setup serviced, otherwise its nice to get it done if higher in mileage and service records are unknown. The reason replacing the timing setup is so important is because the 1.8T is an interference engine and if the tensioner fails you can expect to need a rebuilt head or engine. It will cost about $300 DIY or $900 at a shop for a timing belt job, but in either case that is cheaper than a new engine.
Other small problems persist in mk1 TTs, though generally 2000-2002 are more finicky than the 2003-2006 model years. The glovebox latch is problematic, as they can get stuck because the mechanism fails, or the entire latch can simply pop off. The fixes are pretty easy (such as using a nail for a latch axle). The manual transmissions can have some grinding issues but they are almost always solved with new fluid and realignment of the shifter cables. The DSG has its own reputation, but the majority of issues come from early DSGs, and they can also be flashed to improve performance.
Another issue is rust on the two roof strips, but not the actual roof, which is part of the double-galvanized unibody; taking care of the rust only requires removal of the roof strips and a respray. Finally, other common problems are squeaky suspension bits or interior panels; if you hear a strange creak when you hit a bump, you probably need new bushings, and squeaky panels can be quieted with sound deadener.
► Various things to check when looking at a used TT coupe or roadster
- Driver seat left bolster for excessive wear
- Under the front and rear bumper for damage from curb stops
- Door sills for damage from people climbing in and out of car
- Speaker grills and bottom of door card for same damage
- Correct function of windows, lights, blinkers, hatch/gas release, locks
- Missing lines on gauge info display, correct gauge function, etc
- Correct function of the radio, all speakers and 6 disc changer
- Working glove box latch, functional softtop
- Complete toolkit and spare tire parts
- Solid hoses/connections in engine bay
- Condition of the battery in the spare well on a 3.2
• How do I maximize my TT’s powertrain?
Performance chips will significantly increase your horsepower and torque. They do this primarily by advancing engine timing, adjusting air/fuel ratios, and, in turbocharged vehicles, increasing boost beyond factory limits. The major tuners are APR, REVO, GIAC, Unitronic, and Eurodyne; with all of these companies you can expect to pay around $500 for a flashtune. If you plan on chipping your car and sticking to bolt-ons, the best mods to consider include a turbo-back exhaust, a TIP, a FMIC, and a nice boost controller. You will need 1-step colder plugs gapped to .028, and should at least have a boost gauge. Some other things to consider are a new diverter valve, a catch can, vacuum hose cleanup, and improved bushings and mounts.
• Should I get an aftermarket suspension and brakes?
Good basic mods are the Haldex upgrade, a rear swaybar, and a different alignment. Beyond that, you get into the springs/struts or coilover debate. Coilovers will make a world of difference, but usually cost more and tend to ride lower. Springs and struts can work well, especially when they are made to work together (example: Eibach Pro System), but they don’t ride as low, and offer no adjustability. A good quattro suspension discussion is Let's talk TT suspension or just search for others. Along with suspension, many people also use spacers; use the AudiWorld offset/spacer calculator to figure out what you need.
Upgraded brakes will never hurt, especially if you are going to add power and drive your TT hard. You can buy a simple brake upgrade from one of many companies, use the better 3.2 front brakes, or even piece together a Porsche Boxster Brembo front caliper upgrade. I recommend SS lines, but the OEM brake fluid is DOT4 so it is good unless you plan to track the car. Pad selection (along with fluid) depends on how and where you drive your car.
• What should I consider if I want a bigger turbo in my 1.8T?
If you have a 180, you could get a K04-001, which will bolt right up but not really increase performance; it is only about +20hp over a K03, and +5hp over a K03s. The K04-02x from the 225TT can make decently more hp than the 001, but IS NOT A BOLT ON, as it requires a new manifold, injectors, MAF housing and software. Either TT can use an Eliminator kit, where something like a GT28RS has an 02x turbine flange, but in reality a little more money can buy a proper BT manifold. With a BT you will NEED new rods because the stockers cannot handle the increased torque.
The bottom line is that if you want the engine to make a significant amount of hp over stock, you need to rebuild it; during the rebuild you can also look into things like bigport heads, better manifolds, and other more trick parts. Something else that has become popular recently is increasing displacement, the stock 81mm bore/86.4mm stroke leaves quite a bit on the table, as it is very easy and relatively cheap to build a stroker (83mm/92.8mm, or 83mm/95.5mm). The bigger engine gives you better off-boost driveabilty and power, and also spools a turbo faster than a 1.8 would.
You should also only expect the maximum performance from the set-up with a dyno tune, although companies make BT tunes you will be giving up power and driveability because of the "generic" program - they are a baseline to dial in. Expect to spend a few hundred dollars on dyno sessions. See also the VWVortex 1.8T FAQ, and the AudiFreaks Big Turbo and High Performance sticky. Another common procedure with a BT is a wideband o2 conversion, which allows for better and safer tuning. Basically, do a lot of research and be patient before spending money, it really is the better option and you will skip the half-ass "learn along the way" problems you'd encounter otherwise.
If you're putting a bigger turbo in a quattro, you'll need a specific downpipe to get around the Haldex system (the ones for the 180/Golf/Jetta WILL NOT work). If you're putting a bigger turbo in a 225, you'll need to consider that you have a different intake manifold/intercooler setup than the 180FWD/Golf/Jetta, so their parts won’t fit. That said, most stuff for the mk4 VW will work for a 180FWD TT, and the TT's 1.8T engine can use essentially any parts other 1.8Ts would.
This FAQ was inspired by the posts "Its about time for a TT FAQ..." and "TT BUYERS GUIDE," though those threads are dead. Any suggestions or additions will be noted and edited into this FAQ; thank you to all who helped and to those that will continue helping. If you have links you would like to share with the forum, please post any link to parts vendors, tech sites, or general/misc. TT info as a reply to this FAQ. Thanks