Mark P

My understanding is that the stock 1.8T has a max boost around 7psi, and is capable of around 11psi with no mods (air filter suggested) and will do so without major stress problems. HOWEVER, I am under the impression that if you upgrade to a 12+psi chip, that you should upgrade the exhaust to allow for good air flow. It is this lack of air flow that overheats the turbo and causes premature malfunction due to the overstressing. I have noticed MANY A4.orgers that seem to have 1bar chips with no exhaust mods. I am one to stay on the side of caution, but shouldn't all of these others be concerned. Please confirm/deny my thoughts. <p>P.S. Reinforcement to my thoughts come like how TAP's stage 2 (12.5psi) also includes 70mm exhaust.<p>P.P.S. Additional thought: Is cat-back sufficient, or are aftermarket (legal) cats sold that also increase air flow?

PAS

installed a Techtonics (Borla) cat-back system. APR recomended a cat-back system for their 1 bar chip. Since installing the exhaust I noticed that the turbo spools up quicker and sooner in the rev range. This is probably attributed to the decreased back pressure of the restrictive muffler and resonator that comes with the car. The TT exhaust is 2.5" mandrell bent tubing (stock is 2.25") and the muffler is a staright through design.

Dimitri

====<br>99.5 1.8TQMS w/ APR in the mail

Cris

Correct me if I am wrong, but I am pretty sure TT only tune VWs. <p>Cris<br>

PAS

but the A4 uses almost the same exhaust with shorter piping. Call Todd at Air and Water Tuning (Philly) to find out if they have na application for the A4. I paid only $489 for a cat-back stainless steel system and am very satisfied although its not as "flashy" at the Neuspeed system.