I've searched but haven't found anything that helps me. I am planning out a custom exhaust that I want to have built in the next couple of months and need to know the dimensions on the Borla Race exhaust. Mainly just the ID of the secondary pipes, which I believe is 2.25" but I want to be sure.

The idea is to go with a 3" straight mid-pipe as opposed to the 2.5" resonated Borla. And 2.5" secondary pipes with 2.5" in/out S-Type mufflers on either side as opposed to the 2.25" Borla pipes with 2.25" in/out s-type mufflers. Then all out to quad tips, in a similar position to the Hartge four-outlet exhaust. With four 3" Borla tips.

Now, ultimately I want to try and keep that same Borla Sport sound, just obviously a heck of a lot louder. That is why I plan on using the same mufflers that the Race system uses. The reason for the larger piping is for the obvious power boost as well as sound boost. I would like input from those of you who have made custom, or bought, 3" exhausts for your MCS (not twincharge, turbo, M62) about the hp/tq.

Thanks a lot.

 

I'm also interested in what the best custom setup is to replicate the louder Borla Race or Magnaflow systems. I'm going to go Custom to save money.

Anyone run with no mufflers at all?

 

Keep in mind, my setup will end up costing just as much as the Borla Race or Magnaflow. Only it will be louder and hopefully provide more power.

 

Well, for anyone that cares. I e-mailed Borla and this is the response I got: "This system starts at 2.25” then after the Y-pipe it down sizes to 2.0”". So I'm beginning to think the 3” mid-pipe would be too big, maybe a 2.5” mid-pipe staying at the same 2.5” after the Y-pipe would suffice.

Any input? Surely someone has to have some input or theory about exhausts...