K04 FAQ (long)
04-18-2003, 07:17 AM
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K04 FAQ (long)
I think it is about time we have an official K04 FAQ. Here's my attempt at it... please feel free to add and/or correct...
K04 FAQ
Ok, your K03s are toast? now what?
These are your options:
#1 ? stick a new pair of K03s. This will probably save you a lot of mod money in the long run (assuming the 2nd set of turbos doesn?t blow).
#2 ? bare bones K04 install. So you?ve decided to step up to the K04s. You need the turbos, inlet pipes, and an aftermarket turbo-back exhaust (dp?s and cat-back). K04s will run with K03 software, be it stock or stage 2+. Things to be aware of: since you arepushing a denser air charge through, you may run lean. It would be wise to monitor your EGT temps (high EGTs are usually a sign of lean conditions), and maybe run a bottle of fuel injector cleaner such as Techron to make sure you are getting maximum flow through your stock injectors.
At this time, most people choose to install a beefier clutch, since you will need a new clutch eventually, and doing it now saves a lot of money on installation costs. With the engine out, the clutch takes half an hour. With the engine in, the clutch install is much more involved. Companies that make clutches for the S4 include Spec, South Bed, and Werks of Art.
If your car has an f-hose (?00 or early ?01) you should probably get an aftermarket part (from MTM or samco), as this and the TBB are known weak points. If you are not installing RS4 intercoolers at this time, it is a good idea to seal the end caps of your stock intercoolers with JB Weld or equivalent, as they have been known to blow off under pressure.
If you want aftermarket exhaust manifolds (currently offered by AWE and Autospeed), it is best to get those done at the same time as the turbos from a labor POV. These exhaust manifolds help your turbos spool up faster, thus minimizing lag. However, as always, caveat emptor. If they crack, you are stuck with another engine pull to get them fixed/replaced. There is no data for long-term reliability of any aftermarket exhaust manifold for the S4 AFAIK. Another option is to port and polish your stock exhaust manifolds to improve flow.
NOTE: What you CANNOT do without changing your software: throw on bigger injectors, throw on random RS4 air intake parts, etc.
#3 ? full K04 fuel/air/software kit. Different tuners have different names for their kits, ranging from Stage 3 to Stage 5 or 6. Essentially they all consist of changes to the fuel system (bigger injectors, sometimes the RS4 fuel pump) and intake system (including a bigger airbox, MAF and housing, y-pipe), and software. The parts and programming allow you to get the most out of the K04s by increasing fuel and air delivery. Tuners that currently offer these kits include: APR, AMS, Sportec (via Autosport Werks in Denver), OCT (via Stratmosphere), AWE, and MTM.
A note about intake manifolds: the S4 intake manifold was changed between the H and M-boxes (build date 10/00). The newer manifold is a smaller version of the RS4 one, and may improve flow/decrease turbulence and give you a little extra top end hp. At the very least, it seems to be designed to dissipate heat better. Blitzkrieg did a really good side-by-side comparison of the 2 manifolds: https://forums.audiworld.com/s4/msgs/1091644.phtml.
#4 ? it never ends. After you get the full k04 fuel/air/programming, you can also get aftermarket exhaust headers that can help your turbos spool up better, RS4 intercoolers for less heat soak, RS4 intake manifold, RS4 TBB and pipes, etc etc etc. Not all of these are easy bolt on mods, and not all have been shown to improve performance. Just because a part came from an RS4 doesn?t mean it?s suited for an S4. For example, the RS4 intake manifold has significantly larger ports than an S4, and cannot be mated to an S4 head. The larger ports can also result in a loss of peak torque. The RS4 TBB and pipes are bigger than the corresponding S4 parts, but it is not likely (imo) that this is the most restrictive point in your intake/exhaust airflow.
To sum up: do research, ask questions, and read the answers with a grain of salt before you commit hard-earned cash to any mod.
K04 FAQ
Ok, your K03s are toast? now what?
These are your options:
#1 ? stick a new pair of K03s. This will probably save you a lot of mod money in the long run (assuming the 2nd set of turbos doesn?t blow).
#2 ? bare bones K04 install. So you?ve decided to step up to the K04s. You need the turbos, inlet pipes, and an aftermarket turbo-back exhaust (dp?s and cat-back). K04s will run with K03 software, be it stock or stage 2+. Things to be aware of: since you arepushing a denser air charge through, you may run lean. It would be wise to monitor your EGT temps (high EGTs are usually a sign of lean conditions), and maybe run a bottle of fuel injector cleaner such as Techron to make sure you are getting maximum flow through your stock injectors.
At this time, most people choose to install a beefier clutch, since you will need a new clutch eventually, and doing it now saves a lot of money on installation costs. With the engine out, the clutch takes half an hour. With the engine in, the clutch install is much more involved. Companies that make clutches for the S4 include Spec, South Bed, and Werks of Art.
If your car has an f-hose (?00 or early ?01) you should probably get an aftermarket part (from MTM or samco), as this and the TBB are known weak points. If you are not installing RS4 intercoolers at this time, it is a good idea to seal the end caps of your stock intercoolers with JB Weld or equivalent, as they have been known to blow off under pressure.
If you want aftermarket exhaust manifolds (currently offered by AWE and Autospeed), it is best to get those done at the same time as the turbos from a labor POV. These exhaust manifolds help your turbos spool up faster, thus minimizing lag. However, as always, caveat emptor. If they crack, you are stuck with another engine pull to get them fixed/replaced. There is no data for long-term reliability of any aftermarket exhaust manifold for the S4 AFAIK. Another option is to port and polish your stock exhaust manifolds to improve flow.
NOTE: What you CANNOT do without changing your software: throw on bigger injectors, throw on random RS4 air intake parts, etc.
#3 ? full K04 fuel/air/software kit. Different tuners have different names for their kits, ranging from Stage 3 to Stage 5 or 6. Essentially they all consist of changes to the fuel system (bigger injectors, sometimes the RS4 fuel pump) and intake system (including a bigger airbox, MAF and housing, y-pipe), and software. The parts and programming allow you to get the most out of the K04s by increasing fuel and air delivery. Tuners that currently offer these kits include: APR, AMS, Sportec (via Autosport Werks in Denver), OCT (via Stratmosphere), AWE, and MTM.
A note about intake manifolds: the S4 intake manifold was changed between the H and M-boxes (build date 10/00). The newer manifold is a smaller version of the RS4 one, and may improve flow/decrease turbulence and give you a little extra top end hp. At the very least, it seems to be designed to dissipate heat better. Blitzkrieg did a really good side-by-side comparison of the 2 manifolds: https://forums.audiworld.com/s4/msgs/1091644.phtml.
#4 ? it never ends. After you get the full k04 fuel/air/programming, you can also get aftermarket exhaust headers that can help your turbos spool up better, RS4 intercoolers for less heat soak, RS4 intake manifold, RS4 TBB and pipes, etc etc etc. Not all of these are easy bolt on mods, and not all have been shown to improve performance. Just because a part came from an RS4 doesn?t mean it?s suited for an S4. For example, the RS4 intake manifold has significantly larger ports than an S4, and cannot be mated to an S4 head. The larger ports can also result in a loss of peak torque. The RS4 TBB and pipes are bigger than the corresponding S4 parts, but it is not likely (imo) that this is the most restrictive point in your intake/exhaust airflow.
To sum up: do research, ask questions, and read the answers with a grain of salt before you commit hard-earned cash to any mod.
04-18-2003, 07:24 AM
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Nice. :) Also might want to mention about porting / polishing your Stock Exh Manifolds...
But ask Piggie about that. 
If you have the manifolds on the ground in front of you, it's pretty darned easy to go to work on them with a dremmel/die grinder.
If you have the manifolds on the ground in front of you, it's pretty darned easy to go to work on them with a dremmel/die grinder.
