is it possible to drill the exhaust on the FJ to make it louder ?
has anyone done this and if you did how many holes and size ?

This will give you the desired results!!!
 
 
Inside the FJ muffler
https://r.tapatalk.com/shareLink?share_fid=1030683&share_tid=556&url=https%3A%2F%2Ffj-09%2Eforums%2Enet%2Fthread%2F556&share_type=t

Here's a short version..
 
https://fj-09.org/post/82173/thread

It’s more complicated than just drilling holes in the exhaust, but the result is very nice considering it’s free (if you can weld)

Any drilled links that currently work?

8 hours ago, Gldean said:

Any drilled links that currently work?

Both of those links are now broken after the move to the new forum.  I dont know of any other threads.

EDIT- Proceed with caution. After drilling my exhaust (Read below) the bike sounded much better and ran great on the couple of short test rides I did. HOWEVER, when I actually got it out for a real ride today, it felt like it was missing something. I turned off the TCS and it will no longer do a wheelie in 2nd gear A mode. This MOD appears to have killed the torque. It still rips through the revs like normal but has just lost a lot of grunt. I'm going to weld up the holes and see if I can confirm this is what's going on.

 

JCG- Thanks for the idea. I didn't realize it until I'd posted a different thread tonight but your question is what got me started.

I did as much research as I could online but most examples were FZ-09. I honestly didn't care if I made a mistake and the exhaust was destroyed, It's not worth anything anyway. So why not take a stab at this before spending $600-1200 on a new exhaust?

I drilled seven 3/8" holes under the guard in the back of the muffler. Here are the results although it has a deeper, more throaty tone than my phone could capture. I'm thrilled with this ZERO $ mod and it took 20 minutes start to finish including test drives.

 

 

Edited April 26, 20196 yr by DeepSix

I put a Delkovic on mine and I felt like it was flat after. I spoke with Dave from Vcyclenut and he confirmed that it probably was losing some grunt. I sent him ECU and he flashed it and the bike came back alive.