Hello,
Thank you for your interest in our products. I will try to answer your questions as completely as possible, but feel free to contact us again if you have any further questions regarding our products.
The TWM short shifter for the 2006 Civic Si has similar stats to the Comptech, they both reduce throw by 22% and are adapters that attach to the base of the stock shifter. We felt that this design was the simplest possible while achieveing excellent results, as did Comptech.
You may have noticed that we use a different design to attach the adapter itself, where one bolt squeezes one side of the adapter to secure it to the stock shifter. We felt that using a 2 bolt design to secure the adapter was slightly redundant and that the design we came up with achieves the desired effect more elegantly. Our short shifter does have a lifetime warranty, as do all of our short shifters.
One main difference between the TWM and Comptech is that our short shifter can be purchased alone, or for only 19.95 the base bushings can be added to create a more direct shift feel. In addition, a weighted shift knob can be added at a $20 discount while purchasing the short shifter as well.
TWM's weighted shift knobs not only create smoother shifting due to a greater mass than the stock shift knob, but are also height adjustable and can be set to reduce shift knob height resulting in a sportier appearance and feel. We offer several shift knob designs in many different finishes, all of which can be added to the short shifter while ordering with no additional shipping charges. You can view our different shift knob designs at the following link:
Shift Knobs by TWM Performance Shift Knobs
The steel plate that comes with the Comptech shifter is a special tool used during the install to remove the plastic pivot cup from the bottom of the stock shifter. We include a similar tool with many of our short shifters, however in the case of the 2006 Civic the lack of space makes using this tool quite difficult. We did initially intend to send a special tool with the short shifter, however making use of this tool is difficult with the limited space. We found a much simpler and easier solution for removing the plastic cup than a special tool. The plastic cup can be pried off using a 13mm open ended wrench by placing the wrench on the main pivot section of the shifter and using this as the fulcrum to pry from. This solution requires very little effort, and does not damage the plastic cup for re-use. I've attached a picture to explain what I mean for removing the plastic pivot cup with a 13mm wrench instead of the special tool. Note that placing a plastic bag around the cup keeps it from popping off and falling in to the console.
Our base bushings do differ from the Corsport bushings. When purchased with the TWM short shifter, our bushings are less expensive than the Corsport bushings. Also, Corsport uses 2 bushings per mounting point on the assembly, and we use only one to achieve the same effect. We designed a bushing that requires only one bushing below the shift assembly with a longer "stem" than the Corsport bushings. This achieves the same, if not an improved effect than 2 separate bushings.
If you decide to go ahead with our product, the short shifter for the 2006 Civic can be found at the following link, along with a picture of one of our shift knobs installed in a 2006 Civic Si:
2006-2008 Honda Civic Short Shifters and Shift Knobs - TWM Performance
I do apologize for the long reply, but it is difficult to answer the questions you asked in a couple of sentences.
I hope this helps, please let me know if I can assist you further.
Kevin
TWM performance