Someone told me that the stock turbos on GTIs are watercooled and not oil cooled. Is that true? Sounds kinda iffy.

 

Well to say that it is "watercooled" OR oil cooled would both be incorrect. The turbo is cooled by both oil (which also lubricates) AND coolant. This is not in most turbos, but it is true in the 2.0T FSI. This is a rather large step in technology as it keeps the turbo much cooler than with oil cooling alone. However to say that it is "water cooled and not oil cooled" is just plain wrong on many levels afterall coolant has little to no lubricating properties and it would be pointless to use it as such. Running your turbo with no oil would be the same as running your engine with no oil, if not worse since turbine wheel speeds can exceed 105,000RPM generating enormous amounts of heat.

It works like this: During normal engine operations oil passages lubricate and cool the turbo, some turbos also have separate coolant passage built in which also assists in cooling. The thing to note about this is that the 2.0T FSI also has an auxiliary coolant pump which is only turned on once the car is shut off and the turbo is excessively hot. This pump forces coolant against the normal flow for a short period of time, hopefully saving the turbo from "Oil Lag" which occurs when the engine is shut off while the turbo is still hot, causing it to boil the oil trapped inside and "coking up" in the turbo eventually leading to failure.

Cool technology yes, and it has sparked many debates about whether there is any longer a need for turbo timers or a "cooldown period". My belief is that this system is purely to assist the turbo in fully cooling down after shutoff, it does not in any way replace the recommended "cooldown period" due to the fact that the oil has still stopped flowing and is trapped in the turbo, which is still very hot. It may reduce the amount of buildup since it cools down faster but certainly not eliminate it. For anyone who does not understand this "cooldown" procedure:

On ANY vehicle equipped with a turbocharger, it is strongly recommended that you leave the car running AT LEAST 45seconds, preferably 2 minutes after parking before shutdown to prevent the condition detailed above. Failure to do so WILL result in reduced turbo life and slow decrease in performance due to buildup.

 

thanks for the info Tech, i've picked up a lot of that before but not all so thanks for taking the time to input.

 

okay then, at what point or psi will the turbo handle before it starts to overheat, burn, melt, or whatever. i'm only asking because there are individual on this website that says it can handle up to 15psi stock. By the way this is my research, duh! i never said i've done anything, but could be, will be, possible done in the future. I'm just trying to find out my limitations with some stock internals and other aftermarket equipment (CAI, forge DV, N75J valve, exhaust maybe), before i started doing heavyduty work and modifications.

 

I've heard that the KO3S can hold that much stock, I know of people that have done this too,
and that can be attained with a chip or boost controller im sure, but safely? without damage to the turbo?
I surely dont know

 

are there any specs on the ko3s turbo. ie, temp rating, boost rating, etc. if you know anything it would be helpful. i'll try to google it. if i find anything i'll let you know.

 

Of course it can hold that much boost, whether its safe over long periods of time is debateable, it is not a large turbo. Obviously every turbo has a thresh-hold between where it makes max power, anything after which it is just generating heat because the method of cooling can no longer support the heat generated and every psi above stock generates extra heat even if it makes power, whether the cooling can compensate or not.

My professional opinions on the issue of raising boost on the Ko3S stated above, in my personal opinion though from the dynos I have done with it the max pressure is about 16psi with everything else stock. After which gains become less noticeable if any and it begins losing large amounts of power and overheating around 18psi. You can run with 15 but I recommend chipping it to make the nessessary engine adjustments to support this additional boost. You do not want to simply raise the boost ever if it can be avoided, kind of like ghetto-rigging or changing engine components without adjusting timing/fuel. Some would probably say well why are boost controllers readily available, this is purely for cars that race under different conditions/altitudes and are usually heavily modified, this massive misconception amongst enthusiasts that you can nearly double your boost and make power on stock to lightly modified probably destroys more turbo engines than I could count.

Anyway if your gonna raise boost chip it, if they allow you to choose parameters I would not go over 13psi if it was me. VW dumbs down their engines a very considerable amount which is where you get their impressive refinement from, trading raw power for quality (ex: 2.0T making max power from 5100-redline), simply changing the programming can drastically alter output while keeping in mind youll lose some of that VW tuning magic.

 

Lots of great info in this thread. Anyway i just got my intake in and as anticipated my DV is loud as hell and believe it or not ive actually gained 10 crank horsepower. About 4whp. Ill get pics up soon. It was pretty easy to install.

 

Thanks alot man, that was great, excellent, etc information. that's is what exactly i needed to know. Now i can make the adjustments that i need to do what i want with my car. I'll probably ask the dealer to flash it, if they can (when i go to get some service) to accomodate the boost controller and higher boost until i can afford an actual chip from GAIC. Or do you think that i should just get my boost controller then my chip from GAIC. What would be your reccomadation?

 

Hey man i know your question wasnt aimed at me but in my personal opinion i think you should chip your car first and then get a boost controller. I myself am going to get an APR chip and then set my boost at 12psi w/out a controller. When you tamper with boost settings alot when using an electronic boost controller your ECU doesnt get used to any regular setting and it becomes less fine tuned due to different air-fuel ratios constantly beign set because of different boost loads.