11. DIODE: ($2 NEW)
A diode is a very small electronic device with a voltage rating associated with it. What it does is regulates a voltage signal to its rating. For example, if you wire a 4.7 volt diode into a 5 volt circuit, the 5 volts enter the diode, and only 4.7 are sent out. The diode mod is a way to limit the amount of boost the ECU SEES. The ECU interprets voltage from the MAP sensor as boost. The max it is able to see on stock turbo programming is 5 volts. If it hits 5 volts, or if your boost level goes higher than what is specíd, youíll go into limp mode (5psi). By using a diode, you are regulating only the signal the MAP sensor sends to the ECU. By soldering in a 4.7v diode, the ECU will never receive higher than that voltage signal. 4.7v is equivalent to about 17psi. Therefore, if you want to run higher boost, once you hit 17psi, the ECU wonít know if youíre boosting higher than that by what the MAP sensor is telling it. If you log your boost (block 115), it will increase and then flat line at 17psi. But if you watch your boost gauge, youíll see the actual amount of boost your making. Some tend to think a diode limits boost, where itís actually limiting the boost the ECU sees so you can make more. Itís a very simple install. Jenís GLI is running a 4.3v, which corresponds to 13psi. It SHOULD be running a 4.7v, but I probably mixed the two diodes up before I installed one.
12. CRANKED WASTEGATE: (FREE)
The nice thing about this mod is that itís free power. However, there are atleast two things you SHOULD have done to not worry about anything bad happeningÖthis write-up IS to get you lots of power efficiently right? Anywho, the wastegate is a small flapper valve inside the exhaust side of the turbo that opens to allow exhaust gases to go around the turbine, and thus keeps the turbo from spooling up anymore. The way it works is you have an actuator with a vac nipple and an actuator rod. As you build boost, the charged air goes through the line into the actuator, and pushes on a piston inside, that then pushes the rod. The rod is attached to the flapper, so when the rod moves, the flapper opens. To ďcrank the wg,Ē you move the 2 nuts downward to pull the rod away from the actuator. This way, the flapper stays closed longer, thus giving you quicker spool, a higher boost spike, and more boost at redline. Youíll need a 10mm open end wrench for this. Get around to the passenger side of the engine bay, and look down behind the head. Youíll see the rod. First, turn the bottom nut down (clockwise) say 5 full turns. Next, tighten the top nut the same way. Once both are tight, youíre ready to go. Go drive the car and watch your boost levels, and if you feel safe, donít tighten anymore. If you feel like doing as much as possible, turn the bottom nut until you have about 1.5-2 full turns LEFT and stop there. If you go too far, youíll completely shut the flapper and not have any boost control.
As for the ďhelperĒ mods, itís best to run a diode on the MAP sensor wires, and an upgraded intercooler. By cranking the WG and seeing higher boost levels from a KO3(S), the air becomes much hotter. So utilizing an IC that does a better job will keep you from detonating and ruining stuff. The diode will keep you from going into limp mode because cranked boost levels far exceed what any chip is written for, even GIAC X+.
13. HIGHER BAR FPR: ($50 NEW)
This mod isnít necessary for most people as you will never need the 16% extra fueling a 4bar FPR provides over the factory 3bar. However, if you do have a cranked WG and are running insanely high boost, itíd be a good safeguard to get one of these. With all the extra air youíre pushing in, you need fueling to compensate. Iím not sure what the limit of the stock injectors are with a 3bar, but Iíve experienced no problems using the 4bar. This is an easy install, but again should only be used if you are trying to push the limit.
14. WATER/METHANOL INJECTION: ($400 NEW)
This is probably one of, if not THE favorite mod Iíve done to a 1.8T This is the most recent thing Iíve done, and itís something that perhaps should be added to the common list of mods one should really do. Water/methanol injection is like running another intercooler, but there are even more benefits besides having lower intake temperatures. Because the air coming out of your intercooler is still around 100 degrees farenheit, the water will vaporize, and steam clean your cylinders of any and all carbon deposits. Also, when water is introduced into the combustion chamber in small amounts, it will lower your exhaust gas temperatures (EGT) as well as give you some detonation controlÖie you wonít be pulling timing. Many are unsure of this mod because youíre actually injecting a liquid into the airstream, but many have been convinced after the write-up I did for the kit I installed. I chose the Snow Performance Boost Cooler Stage II MAP-based kit. You can get it from any USRT dealer. They also offer a MAF-based kit, but I prefer the MAP kit since there is no other sensor to go bad. If your MAF fails, the water/meth wonít spray. The MAP kit gets a vac line run to it and the controller will see boost and turn on the pump accordingly. Unless you are running standalone engine management, do not buy the Stage I kit. Itís basically an ON/OFF kit, and this is not optimal for performance. The Stage II varies the spray on your boost levels or MAF sensor voltage depending on the kit you get. Youíll see your biggest performance gain from using Lemmiwinks to up your ignition timing from doing this mod. If you donít have access to Lemmiwinks, you wonít see a ďbutt dynoĒ gain.
15. LEMMIWINKS TUNING: (FREE)
Lemmiwinks is a free program from REVO that you use on a lap top. As far as I know, it only works on lap tops that have a 9-pin serial port out the back. My laptop is a Dell 600M and has this port. I mainly bought this laptop so Iím able to use LW and do data logging. Anyways, LW allows you to change certain parameters around, such as your idle rpm, startup and warmup fuel enrichment, and your ignition timing. Iím not THAT GREAT at LW tuning as I donít know what everything really does. The best adjustability it has is the ignition timing. Ignition timing is simply when your spark plug fires. Itís set to fire JUST BEFORE the piston reaches top dead center. By advancing the timing, the spark plug will fire earlier, and what happens is the air/fuel mixture explodes before the piston reaches the top. When it does, the explosion has more power to it, and thus will cause the piston/rod assembly to slam back down harder and faster, which makes more power. A side effect though is heat, and you can only go so far with ignition timing on pump gas. Using race gas or water/meth allows you to advance the timing more without the ECU pulling timing back out. Ideally, you donít want the ECU to pull more than 8 degrees of timing. You can check this by logging block 020 on VAG COM. The max the ECU can pull is 12 degrees, and you DO NOT want to test this. If your knock sensors fail, youíll blow your engine. If you log and are pulling 8 degrees of timing, lower your advance one click and you should be set.
16. MISCELLANEOUS MODS: ($125 TOTAL)
An oil catch can is a cheap efficiency mod in that it keeps oil from going through your turbo and into your intercooler. In stock form, oil fumes exit your engine through the front of the block and on the side of the valve cover, and go into a black plastic flapper valve, and get sucked into the intake. This oil goes through the turbo and gets trapped in the intercooler. A catch can will trap the oil before it goes into the intake. You can get them on eBay for pretty cheap, and it doesnít take but some fittings from Home Depot and some heater hose to properly hook it up. Youíre just bypassing the line to the flapper valve by running it to the catch can, and then from there back to the valve.
ECS sells a magnetic drain bolt that doesnít really have performance gains, but is another safe guard by chance you have metal shavings or material in your oil. As oil empties into the pan, any ferrous material will attract to the plug and not go through your motor. When you pull the plug to drain the oil, you may see small metallic shavings on the end, which means itís working.
A vacuum manifold is sort of like an electrical outlet strip. You plug it into the wall socket, and then you get 5 more. A vac mani is the same. You tap into one source, and can run 6 more off of it. Itís main benefit is cleaning up the engine bay and making it easier to sort through your vac connections. Robear Racing sells the Golden Eagle brand and is a quality piece. You tap into the brake booster line coming out of the end of your intake manifold, and then can run any other vac connections to it. On Jenís GLI, we have the boost gauge, boost controller, blue balls (under passenger fender), PCV system, and water/meth system hooked into it. The holes are 9/10thís of the way drilled out, so you just drill the ones youíll be using and leave the others closed.
17. THINGS TO REMOVE: ($35 NEW)
There are two systems that Iíve always disliked in our engine bays, and thatís the N249 vac booster system and the secondary air injection (SAI). I like to make it easy to work on the car, and with these on, itís harder to do certain things. Having them removed is less clutter. The N249 is connected to your intake manifold and runs vac/boost for numerous thingsÖsuch as the DV and the combi valve for the SAI. The whole system is located right infront of your intake manifold on a black bracket. Just cut the lines running to it and unbolt it. All you do then is run all your vac lines to a boost/vac source such as the intake mani. If you have a vac mani, run what you can to that to keep things simple. The SAI is used during cold starts to heat up the cat by injecting extra air into the exhaust side of the head. The pump is located infront of the engine block near the bottom, and has two crinkled hoses connected to it. One goes to your stock airbox, and the other to the combi valve, which is what directs air into the head. When removing this system, the best thing to do is to unbolt your coolant line going into the driver side of the headÖyea, youíll lose some coolant doing this but trust me itís the only way. You can then take the combi valve off by unbolting it. There is a hole there, so you need a block off plate. Integrated Engineering offers a CNCíd block off plate with an O-ring to seal it shut. Before these came out you had to make your own, but these are cleaner and better looking than what many are capable of doing themselves.
Now that you unplugged the SAI pump and the N249, you have 3 harnesses that arenít plugged into anything. You can either leave em be and be stuck with CELs, or you can buy 330ohm resistors (theyíre cheap) and wire them in. They arenít directional, just attach one end to one wire and the other end to the other wire. This keeps the CELs from popping up. HOWEVER, when you remove the SAI system, the cat is no longer being heated up during cold start. One of the O2 sensors figures this out, and throws an ďImproper FlowĒ code. So, if you have emissions testing and/or are concerned about seeing CELs, a way to try and fix this is get into LW and adjust your startup/warmup fuel enrichment levels. If you lower them, you are leaning out the motor on startup and warmup. Leaner means hotter, and thus you can heat up the cat this way. Start by lowering both values to about 90%, and drive until a CEL for Improper Flow comes back on. Adjust in 10% increments each time. Eventually, you will either have the cat heated up enough to not throw the code, or you wonít be able to start the car easily. When the latter happens, just raise your startup enrichment by 5%, and lower your warmup. This way, you can still get the car started, but youíll also be running it hotter to get the cat warm. Remember, nothing here is irreversible, so if you think you are messing something up, just put the values back and deal with the CEL.
This is the end of what Iíve done to make all that power. Here is an official mod list:
GIAC X+ ... $500
4.3v Diode ... $2
Oil Catch Can ... $30
Cranked Wastegate ... FREE
(27psi Spikes, 15psi @ Redline)
GHL 3Ē Turboback ... $1000
Lemmiwinks Tuned ... FREE
Samco Turbo Inlet Hose ... FREE
ECS Magnetic Drain Bolt ... $10
NGK BKR7E Spark Plugs ... $12
Custom Hardline DV Return ... FREE
Golden Eagle Vacuum Manifold ... $75
Custom Front Mount Intercooler ... $400
ESE Colormatched Cold Air Intake ... $250
Relocated Forge 007 Diverter Valve ... $125
Bosch 4-bar Fuel Pressure Regulator ... $55
ECS Lightweight Underdrive Pulleys ... $120
Enginerd Coilpack Hold-down Brackets ... $35
Boostvalve Dual Stage Boost Controller ... $120
Custom 3-way switch
*Low*High*Low in 1st ONLY*
Newsouth Performance Powergasket Plus ... $70
N249 and Secondary Air Injection Deleted ... $10
Boost Cooler Water/Methanol Injection ... $370
TOTAL: $3184 I'll guess close to $3500 total.
With what Iíve done, I have no doubt that someone willing to put in the extra $$ into a KO3(S) can hit 300whp on a DynoJet. Here is a list of things I COULD do if we were staying on stock turbo:
ATP High Flow Turbo Mani
USRT Intake Mani
3Ē VR MAF
I figured that Iíd take the time to spell out what Iíve done because I owe it to the Ďtex for how far Iíve gotten and my love for dubs and making them quicker than most would think they are. To make this thread as informational as possible, if there are any questions, they will be answered below in another post. I tried being as thorough as possible but I know thereíll be case specific questions that may not be covered above.
Modified by SAVwKO at 5:35 PM 7-31-2008