Over the past few months i have seen many posts from guys who have installed Biturbo pipes on their Silver Bullets and Golden Bullets with the A3 engine. Almost all of them have stated that they were dissapointed with the performance increase (or lack of). I have had the same exact experince with a Silver Bullet after a Biturbo was intalled! Very little difference in performance!! At first i thought this was just the nature of the A3 engine?
But, then i noticed something that has never occured to me befor! The stock exaust pipe on the Silver Bullets and Golden Bullets with the A3 engine drops straight down out of the engine and runs straight back without all the "snakey" bends and turns that the A35 stock pipe has! Also the diameter of the stock A3 pipe is much larger than the A35 pipe!
All of this, leads me to the conclusion that the A3 stock pipe is much more efficient that the stock a35 pipe! So, that is why you don`t get much of a power increase when you install a Biturbo on a Silver Bullet with the A3 engine.
And just the opposite is true if you install a stock A3 pipe on a Targa with the A35 engine, you will get nearly as much of a performance increase as you would if you had installed a Biturbo on it!! Yes, i beleive the old A3 pipe is that much better!!!
Now, what do you think?? Am i wrong? I want to hear some other opinions on this!!