Stupid Question - APR K04

[Highlander1010]

Hey Guys,

After the V2 map came out in Beta, I'm thinking about going KO4 if APR has a great sale. One question - APR #'s are quoted at 93 Octane with an RSC Single system. My stupid question is, "Is the RSC system required for proper performance, or just to hit those specific #'s on 93 octane?"

I want to make sure I also don't need to buy an RSC system just to make the KO4 function right, vs. hit the top possible #'s.

Thanks!

[oc cc]

You probably just need a HFC

[maga4]

Just TP or HFC. They also have a file for the K04 if you need to run a full stock exhaust.

From the APR K04 webpage:

While a full exhaust is recommended for maximum power, If you're in a situation where running a high flow exhaust is not permissable, APR has also developed software specificly to use with your OEM Exhaust system. You may switch between high flow exhaust software or OEM exhaust software free of charge any time you alter your exhaust system

(http://www.goapr.com/products/turbo_...si_vl_k04.html)

[TofuShop]

hfc or testpipe is required so that you don't choke the turbo. but any free flowing aftermarket exhaust is recommended

[TCHUN003]

Stock S3's have catalytic converters so HFC/TP are not required, but definitely recommended if you want it to get the most out of the turbo. APR has a less aggressive ECU file that would allow for you to do this.

[Highlander1010]

Thanks all. I'm APR Stage II already and have the APR downpipe installed. I used to have an APR RSC Quad Setup (V2), but it was just too damn loud and really annoyed the neighbors. I ended up selling it at a loss and buying a brand new S4 full exhaust from a local guy when he went STASIS. Then I took the setup to Dan Fast Bellevue, they took the pre-cat tubing (2) and welded it into 1 piece to join the downpipe out of the turbo. The sound is more agressive, but far less loud than the RSC.

Are you guys saying I need to bypass the current cat and either put a HFC in that location or build in a straight tube bi-pass all together? If I do that, will it get louder...and does anyone know by how much? I can go back to Dan Fast and have it done.

Is there a HFC anyone recommends?

[UmIsThisThingOn]

... Is there a HFC anyone recommends?

I like my EuroCode HFC. But really it's 6 of one, half dozen of the other...

[Highlander1010]

True...but my question was more of, isn't the APR Downpipe a replacement for the Cat and thus a HFC off the turbo? That is what their site aludes to.

[larrylam646]

If you have the APR "3" Downpipe Exhaust System with High Flow Catalytic Converter and RSC Resonator" (http://www.goapr.com/products/apr_ex...a4_20tfsi.html), then yes the APR downpipe includes an HFC and you are good to go with the V2 "Testpipes" version map.

[Highlander1010]

If you have the APR "3" Downpipe Exhaust System with High Flow Catalytic Converter and RSC Resonator" (http://www.goapr.com/products/apr_ex...a4_20tfsi.html), then yes the APR downpipe includes an HFC and you are good to go with the V2 "Testpipes" version map.

Awesome! Thanks much!

[hiwords1]

they had a great deal for waterfest. maybe they'll do it again for h20