Grumpy post. But, let me get the misery out of the way first... I am fed up with constant posts and threads about tuning 1.8t's and how to do this and should I do that. I am king of the K03s on this forum, so I will share my findings and knowledge with you guys. If at this point you think I am being big headed; you probably own an S3 so click the back button now I am sure a mod will sticky this, so we can use it for future use. It is basically a one thread summary of the FAQ thread nobody ever reads... - So you have just got your 1.8t and you want to know what dump valve and decat or air filter you should put on it? Well stick with this thread and all will become clear Does my car have a K03s? You have probably read about this, if not then let me fill you in... Your turbo is a Borg Warner KKK series turbo in one form or another they come in two types, K03 and K03 "s". Specification is as follows - Ko3 - 97-2000 COMPRESSOR WHEEL Inducer: 33.6mm Exducer: 46mm Tip height: 3.7mm TURBINE WHEEL Inducer: 45mm Exducer: 38mm Tip height: 6.8mm Blades: 11 Ko3S - 01+ COMPRESSOR WHEEL Inducer: 38mm Exducer: 51mm Tip height: 4.4mm TURBINE WHEEL Inducer: 45mm Exducer: 38mm Tip height: 6.8mm Blades: 11 Generally speaking if your vehicle is a pre-facelift car with an AGU engine it will have a K03 turbo, if it is a facelift car it will have an AUM engine and a K03s turbo. For now, that is all you need to know. Your engine code can be found on a tab on the left hand side of the front of the head, just behind the throttle body. A K03 turbo is capable of making 195bhp, and a K03s in top condition and spec is capable of making 250bhp (but yours never will) A K03s upgrade is a simple remove and refit procedure for a K03 car. No modifications or additional parts are required. A brief introduction to your ECU and software. Our cars use a Bosch ME ECU; it is a beautifully clever piece of kit and is the envy of almost everybody who doesn't have a standalone ECU. Pre facelift AGU cars use a narrow band ECU and hardware package called "ME3.8", which is quite frankly dumb as **** and tough as houses. These ECUs do not have a MAP sensor, use bolt down coil packs with a three wire plug (which almost never fail) which use a separate ignition amplifier which is formed into your air box (more on that later), and a cable throttle body to name a few differences. An AGU engine with "ME3.8" software WILL NOT WORK with a Bluetooth ELM OBD2 sender and the Torque phone app. - Facelift AUM cars use an "ME7.5" Bosch ECU and are much more sophisticated than the AGU setup. AUM cars use a MAP sensor to request and deliver boost, they use an electric throttle body and fly by wire throttle pedal, they use push down coil packs with built in ignition amplifiers, have a different connector on their MAF as well as many other modern enhancements above the AGU. Most of which do not need to be discussed here and should be looked up as needed. An ME7.5 car WILL WORK with an OBD Bluetooth adapter and the Torque app. Both AGU and AUM cars can be port mapped; however be prepared that early AGU engines need to be removed and physically chip tuned. Very rare though. What dump valve for my pride and joy? STANDARD DVs ARE TOTALLY BOSS FOR 1.8t ENGINE ON THEIR STOCK TURBO. Just wanted to throw that out there right away, to save you guys some money. It is a common misconception and as somebody new to tuning you might not understand this, but in short the standard DV can safely and leak free hold more boost than our turbos can make whilst reacting quickly and efficiently, so unless yours is faulty there is no need to change it. If your car flutters and sounds like a rally car when you lift off, or does anything other than a crisp and clean "Kachooo" noise then your DV is toast. You can press up from the bottom port, and place your thumb over the top nipple and see if the valve itself drops. If it does, it is split and fit for the bin. The purpose of a dump valve is to rapidly remove pressure from the intake tract to stop the air from trying to return through the turbo and causing compressor stall. You can fit a Forge 007p dump valve, but if you do then please make sure it has the newly revised piston with the rubber o ring at the base of the piston. DO NOT EVEN THINK ABOUT FITTING A SPLIT R OR AN ATMOSPHERIC DUMP VALVE, THEY DO NOT WORK. Prepping your car for more power! "You can't polish a turd." Prep prep prep. Before making any modifications it is well worth ensuring your vehicle is at a good state of tune before stressing the components. By this I mean ensuring there are no fault codes from faulty hardware, smoke testing the inlet pipes to ensure you are boost free, spending money on servicing the vehicles with new plugs (BK7RE if you are a man), fresh oil (Quantum, straight from TPS), ensuring your brake fluid has been renewed, that your coolant has been refreshed and flushed, thermostat changed and cam belt and waterpump changed to interval. This will ensure the best result when you do come to making your beast go faster. This also includes running V Power or Tesco Momentum high octane fuels only. Basic modifications for the average Joe. So you want to go a little faster. My best advice to you is write a list, plan what you want and think about the steps you need to take. Plan your purchases and budgeting accordingly. Your list of mods should go like this.... 1.) Air Filter. 2.) S3 brakes. 3.) Silicone turbo intake pipe. 4.) REMAP!!!! - First thing you need to do is sack off the air box and buy a cone filter. Personally I recommend you read this thread and buy a Honda S2000 air filter and the appropriate adapters which are all listed in this thread. http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/118673-benjamins-s2000-air-filter-mod-2.html Otherwise you can purchase a Jetex filter from Bill at Badger 5 by phoning +44 (0)1453 822880 and speaking with him nicely. A Jetex filter will clamp straight into your MAF and be awesome, a heat shield to hold the MAF can be purchased from either Bill or S3Dave by PM'ing Dave. Whilst the heat shield will do very little to aid performance it does tidy up the installation and offer support for the MAF. If you have an AGU try to zip tie or secure the ignition amplifier which you pull from your stock air box in a free flowing area close to the filter where it will stay as cool as it can. - The second on that list is S3 brakes. These can be purchased on eBay, they are a 312mm disc. S3 and A3 share the same calipers so your existing pads can be used, if you are mental. The caliper carriers will need to be purchased from somebody breaking a car, the adapters from any 5x100 312mm car will work, these include Skoda Octavia, Leon Cupra, Mk4 Golf GTI Anniversary, TT's and S3's. - The third part of my list is a silicone turbo intake pipe, which can be purchased all over the place. But don't skimp!!! Forge ones have the largest constant internal diameter as an off the shelf item, otherwise SFS have started making an 80mm "supersize" intake pipe. The intake pipe will offer more torque, a smoother power delivery and more power. Cool stuff. - Last up is the remap, which is what REALLY counts. Bill at Badger 5 is your best option out of our forum sponsors (that will piss some of them off, but **** it we all know its true) so give him a ring and see what you can do. Otherwise there is AMD in Essex and I believe we also have a fair few Revo stockist on here too. I also seem to recall Mark Brodster or Brodster who is in Scotland does maps as well. Whilst I don't know his work, I know the bloke is a legend. DO NOT go to somewhere which isn't endorsed or recommended by this forum, we know our ****. A mapping session should include a fault find session and vehicle health check, a pre map rolling road with dyno print out and data logging followed by a map application and a post map rolling road run and data logging. This will provide you with an accurate and accountable before and after gain, along with a highlight of any hardware issues which the software may have exploited. MAP TO THE HARDWARE, NOT TO WHAT THE SOFTWARE EXPECTS. All cars are different, and two identical cars may make different power. With the modifications listed above and a proper map you would hope to see somewhere in the region of 185bhp for a K03 equipped car and somewhere in the region of 210bhp for a K03s car. As long as it is healthy and correctly built. Bah! I want more! So you have dipped your toe in the pool and been bitten by the modification bug...more POWAH. From here you can look to go to "stage 2" figures, unless you have a K03...then you need to go home and fit a K03s and then come back to this section. Stage 2 referes to a higher standard of modifications, and takes your vehicle to the next level or performance. The map should be custom, and will offer you much more mid range punch as well as a higher peak power and a raised rev limit. Stage 2 for me is much more than the engine, it is the accompanying and supporting modifications which provide a complete package. It is also my opinion that a stage 2 A3 is as good as an 8L gets, quicker than an S3, balanced, usable and reliable. Modifications list for a "stage 2" A3 - 5.) Coilovers. 6.) Fast Road brake pads. 7.) N249 bypass and PCV delete. 8.) Front Mount Intercooler. 9.) VR6 clutch and ABF Flywheel. 10.) Rear ARB kit. 11.) Polybushed suspension arms and "dogbone" mount. 12.) S3/LCR Steering rack. 13.) Front ARB (at the same time as the rack) 14.) SAI delete (for AUM cars) 15.) Downpipe and decat or sports cat 16.) Exhaust. 17.) REMAP AGAIN!!!!! - Coilovers is a great way to make your car handle better. Read this thread, http://www.audi-sport.net/vb/a3-s3-...eap-ebay-coilover-thread-jamex-how-guide.html Do some research and make your decision. - Fast road brake pads means Ferodo DS2500, basically. Don't buy EBC, they are unsafe and known to fail. - N249 Bypass, http://www.audi-sport.net/vb/general-technical-how/84402-n249-bypass-how-2000-s3-but-same-many.html N249 is a sort of boost control system, the above thread has all the information you will need. PCV delete, DIY MKIV GTI/GLI 1.8T PCV Delete/Catch Can Install & Brake Booster Mod This will remove the crank case ventilation that dumps oil vapors into your intake, it's a spivvy system designed to save the planet. But seeing as the planet is full of clowns, you won't need it. - Front mount Intercooler, http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/107421-a3-aum-1-8t-ebay-fmic-install.html Fitting a front mount Intercooler will provide lower IATs and a chance for your ECU to make the most of the air/fuel charge you are providing the cylinders. On an AUM you will need no fit a Forge MAP sensor tube. You will need to extensively modify your front bumper as well as follow that guide posted above to the letter. - A VR6 clutch and single mass flywheel from an ABF will lighten your clutch pedal feel, offer a stronger clutch (300bhp no sweat) and a more engaging and positive bite. A hugely awesome modification for 02J 5 speed boxes. If you use google you will get part numbers for the flywheel bolts and the clutch cover bolts. Buy from eBay, get the bolts straight from VW. - Rear anti roll bar kit really livens up the feel of the car and enduces a bit of lift off over steer if you can drive. Brand names to look out for are Eibach, H&R and Whiteline. All are good. The stiffer the bar, the more you'll spin before you hit the lamp post. - Polybushed suspension goes without saying, make sure to get caster corrective rear lower arm bushes. The dogbone bush will rattle and vibrate the car, for the first 1000miles. It gives a much more positive feel on and off the throttle, and provides a much more connected feel to the car. A hugely awesome modification and takes to mins. - An S3 or LCR steering rack will provide 2.7 turns lock to lock rather than the stock 3.4, it makes for a more positive feeling drive as well as providing some much needed steering weight. Ensure that you replace the crush washers on the joins, and make sure you change the steering rack bush at the same time. DO NOT SPIN THE WHEEL WHILE THE RACK IS DISCONNECTED, YOU WILL BREAK THE CLOCK SPRING. On facelift cars fitting an LCR rack will **** up he steering angle sensor and the ABS and ESP will kick in on long sweeping bends, this can be totally disabled in VCDS, or by physically turning it off on the dash board. Pre facelift cars have no ESP so it works perfectly. - A front anti roll bar will provide less or more under steer depending on thickness, however it will allow the lows you know that you ant without rubbing the drive shaft, because the hoops are bigger. Look out for the same names as with the rear ARB, and try to buy matching brands for extra man points. You can also fit an LCR, S3 or TT bar which goes under the driveshaft, so you can go mega lows. - SAI means Secondary Air Injection, it pumps air into the exhaust to warm the cats from a cold start. If you have an AUM, buy a blanking plate and sack that **** off. It weighs a ton, look **** and does nothing for you. Removal guide here, http://www.audi-sport.net/vb/a3-s3-forum-8l-chassis/88299-sai-removal-guide.html - Downpipes on K03 cars are a HUGE restriction, like massive. So fit a DP and get more flow There is a guide for that here , 1.8T 3" GHL Downpipe Install DIY. Here is a little wri - VW Forum :: Volkswagen Forum But the downpipe and decat off eBay, £90 delivered Toyosport one. They are awesome for the money. - Exhaust is down to you, but I am a huge miltek fan. That said you could get one hand/custom made at a local specialist cheaper. You will need to cut and modify your rear bumper for this. It will be worth buying a 2.5" exhaust and modifying the downpipe and decat your bought to make it a full 2.5" system. - Have you really done all of that already? Jesus, time flys. Custom, proper mapping time. Now you really really do need to go to a specialist! All the same things I said before apply here, but are doubly important. Expect to take 4/6 hours to get this done properly, and expect to leave with around 230/235bhp and 280/290lbft torque. And a MASSSSSSSIVE smiile on your face. Tuners can map in launch control if you have ME7/AUM, which is also awesome. So does this mean the end of tuning, am I done now? Nope, there is much more to do. Leon Cupra R Brembos, K04 conversions, water meth injection, and a lot more things I will come back to tomorrow. - This little guide has taken me an hour to write up, I pray to god you newbies use and read it, I may kill you otherwise. Expect an update and the next chapter tomorrow night.