cbusjay12

I am seriously considering buying a 2001 S4 with 105k and was thinking about upgrading the turbos right away. I found some k04 turbos with the inlet and up pipes for about $1400. I was wondering what else is needed to complete this upgrade? I'm not looking to cut corners, but at the same time want to keep the cost as low as possible, so I'm only looking to buy the absolute necessary components. What kind of hp increase can I expect from this upgrade? I saw that AWE tuning has a kit available with these K04 turbos and it produces about 460hp, but the kit is way out of my price range and includes a lot of stuff, which I'm not sure is totally necessary. Would it be possible to get something close to this performance without paying the $8k AWE wants for this kit? Thanks

donromani

You will need a fueling kit - inejectors, hitachi-maf, rs4 airbox, etc. Plus an reflash of the ECU to change the program to utilize the new components. Without the ECU and fueling you will get zero additional HP.

You can typically buy the fueling kit separate from the turbos. Be aware that the 460hp advertised might include their exhaust manis, down-pipes and other upgrades, but you should expect around 450 crank horses with a proper fueling kit from K04.

search the forums for RS4 fueling. Also try homebrew tune.

thejulex

Sane minimum list:
K04s
inlets
injectors
bigger maf housing
RS4 maf accordion pipe
clutch (a must, you will fry stock one guaranteed)
ECU re-program

highly recommended:
new Diverter Valves
new tranny+engine mounts (aftermarket, stock or RS4 are just too soft)
bigger rims/wider tires
brakes tune
new fuel pump
new fuel filter

recommended:
new N75
new TBB
bigger and better intercoolers

Add ons:
meth injection

Flyboy

RS4 motor mounts are too soft? Why would you want to rattle your teeth with solid motor mounts?

Bigger rims/wider tires? Why?

Brakes? Why?

I don't see why you would highly recommend items that would simply be personal preference and in no way are close to being needed with a K04 setup.

thejulex

RS4 are too soft for stage 3, been there done that. The fact is that Sterns or 034 mounts poly mounts are close to stock in feel but a major improvement in limiting drivetrain travel.

Re tires/brakes.
These are in recommended group, not "a must" so chill.

#1 Handling, safety, the car will have pretty much 2x as much horsepower as stock car so that would only make sense.

#2 I didn't tell him to get BBK, I just advised a tune up.

What's wrong with these suggestions, they make more than just a little sense?

CC Lemon

It makes perfect sense to upgrade the brakes, tires and suspension when you're talking about adding that much more power. Most people recommend it. It's not necessary as part of a K04 build, as that is mostly seeking engine performance, but it would be recommended for the overall benefit of the car.

unglaublich

From stock, about $10k to do it right.

Flyboy

RS4 motor mounts are perfectly fine on a Stg3 car. Too soft? Are you kidding, again, why do you want engine mounts that are just going to transfer engine vibrations into the frame so you can enjoy them in the cabin?

Getting larger wheels/tires does not make sense, how exactly are they improving the safety and handling? Stock size wheels and tires are just fine.

Getting the brakes checked out would be smart, but that doesn't have anything to do with a K04 setup, just a good thing to do with any car.

I don't think any of those suggestions make sense when it comes to essential upgrades with a K04 setup. A better clutch is about the only essential, aside from the components necessary to actually get a K04 setup running.

Flyboy

Upgrading to a BBK only makes sense if you plan to track the car or you want the look. It isn't going to provide any benefit in DD situations.

How exactly does engine HP relate to the suspension choice? Spring rate is one of the key attributes of a suspension, what spring rate is recommended for K04 power level? If there's a recommended upgrade, what is it? For instance, I'd advise getting a better clutch, at the TQ levels a K04 car makes there are clutches rated to handle that much TQ, so you find a clutch that can take the force. What grade of suspension component should one get with a K04'd motor?

Most people recommend these upgrades because they don't really understand how the components interact. Not that there is any harm in putting upgraded components on the car, but the logic of adding more power requiring these upgrades doesn't make sense.

P0234

I'll just toss in my brief 0.02. Find a kit/setup that you will be happy with, not based on price. Buying twice is always more expensive. If you love tuning and doing it yourself, by all means do it yourself. If you want it right the first time, buy a well sorted kit.

PS, these cars have cheap-*** detectors and spit crap parts back at the owner.