I know there are people who love the sound of their test pipe, but in my experience, it consistently makes the exhaust sound tinny and cheap. I used a test pipe and OEM cat on the following exhausts:

OEM Cat back
Ebay Cat back (Larger muffler one)
UK Exhaust Mod (38mm)

On the oem exhaust, the test pipe raised the pitch and made it sound hollow. The exhaust sounded empty and raspy.

On the Ebay exhaust it sounded the best, but it enhanced the exhaust's tendency to drone. Also raised the pitch and resonated with a metallic sound during the vtec crossover. Very annoying. With the stock cat the ebay exhaust sounded OK. A little deeper with some drone. Better than stock.

On the UK exhaust the test pipe sounded cheap and raspy. It sounded low budget, and very loud. Like I had a rotted out exhaust. With the OEM cat, the UK mod is near perfect, its sounds clean, and throaty with a good tone. No rasp, no drone, maybe slightly too quiet, but almost perfect.

The common denominator... The test pipe makes everything sound worse! I know this does not cover all exhausts, but I would love to hear the exhaust where a TP improves the sound.

I do like it for power, but it just sounds bad.

 

With a nice catback you don't have this problem. Key here is a cat acts almost like a added resonator. If you get rid of it on a NA S2k better have a nicely designed muffler. Turbo S2k's don't have this problem.

 

Of all the exhausts I have heard in person, HKS with test pipe sounds amazing. Some of the quality, subtle exhausts like Fujitsubo also sound nice with a test pipe.

 

My ap1 mugen sounds great with test pipe.

 

Something must be wrong with your stock exhaust because adding a test pipe barely makes it louder at least in the cabin.

However adding a test pipe to most exhausts does make it raspy at WOT. As 1nate7 pointed out the HKS dual is quite the opposite, it sounds amazing.

 

adding a test pipe adds rasp. change the header and test pipe. perfection

 

The tp did not make the oem exhaust louder. It just raised the pitch and gave it the empty can sound.

I would say if the mufflers were designed with a TP in mind, the sound could be appropriately tuned. The problem is those exhausts are expensive, and usually much louder than stock.

I have heard many S2000 exhausts. I have not heard anything better than oem cat with UK mod. I am talking about sound quality, not volume. This setup is not very loud. If you want loud there may be better, albeit more expensive options. I would try a HFC or larger bypass pipe for more volume before I spent 500-1500 on a aftermarket catback.

Just my thoughts, if you are on a budget, don't expect nice sound from adding a test pipe

 

Thank you for doing this.
I was highly contemplating purchasing a TP for the performance gains but I didn't want the OEM exhaust to sound like garbage.

I think I will be doing only the UK exhaust mod and calling it a day in terms of messing with the Exhaust system.

 

You will like the UK mod.

 

The raspy tinny sound maybe caused by the wrong size test pipe. If the exhaust does not move through the system smoothly it will not make a plesent sound. If you had used a 70mm tp it may be to large and created turbulence in the exhaust system. Tuning the exhaust requires a little trial and error for the end users like us. My advice is to use a 60mm ID test pipe with the UK mod or other aftermarket exhausts with tubing sizes 63.5mm or less. If you run a large tube exhaust use a like size tp for best sound.