I could use some help figuring out what is causing high TTFB
Here is the latest after resizing some images and removing a couple of plugins.
Hi 
How are you getting on with discovering your bottleneck?
I recently wanted to discover my bottleneck, but it was nothing like yours. I was looking to reduce a 300ms ttfb.
I had a wordpress installation that was just taking too long. I started with a few on-page optimisations like combining requests and scripts, using wordpress plugins for cache and lazy-load.
In the end this was not enough. I decided to go futher.
Following DB optimisation and checking my server CPU/Mem loads I needed to setup and install somthing to monitor more deeply the server process.
I discovered that PHP was my bottleneck and set about some optimisations in the PHP.INI.
Still with no real results I setup ZEND OPCACHE. This along with all the previous work took my 300ms ttfb down to 30ms. I was very pleased.
What kind of server are you using and what software?