Circuit Werks Test Pipe
 

I had the opportunity this past weekend to install my test pipes. I bought them from Circuit Werks. They are marketed as anti-reversion. They are non-resonated. I bought these for $140 shipped off Ebay. I have a tune session on August 18th and wanted to upgrade as much of the exhaust as I can. These are paired with Motordyne xyz pipe and Topspeed-like exhaust, (I bought the car with the exhaust and unsure what the brand is. Its about 2.375" inner diameter).

Having driven this setup for about a week now, the volume of the exhaust isn't too loud, even on cold start. It has a deep tone, however has a hiss during heavy acceleration, but not on decel. There is no rasp or drone. You can hear the exhaust from inside the cabin but just enough and having a conversation is very easy.


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Circuit Werks 'Anti-Reversion' Test pipes. Its came with all gaskets, O2 extension / anti-fouler fitting, and just the 6 bolts/nuts to connect to the headers. I had to reuse my hardware at the y-pipe end.

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Side by side comparison of the test pipes vs the OEM cats.

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Test pipes installed on the car. Fitment was good. I had to adjust my y-pipe connection a couple of times to keep it from hitting my transmission crossmember. I currently have it where it doesn't touch it but it is low enough that I scrap on it over speed bumps.

The O2 extensions / anti-fouler were used to keep from getting the CEL.

Circuit Werks Test Pipes vs Stock cats revving

Circuit Werks Test pipes vs Stock Cats Driving

I installed a bunch of parts right before my tune to make the most out of it, so its hard to say how much each part contributed. in totaled, I made 301 whp / 248rtq that day on Uprev. That dyno tends to read low since a 370z with full bolt-ons and cams only made 350whp.

For the money I paid for the test pipe, I like it. Its holding up fine, the flex section is still in good shape, no cracks on any welds. I have been recommending it to people due to the price point and the anti-reversion feature. Hope this helps. Let me know if you've got other questions.

Latez

Still holding up well? I jjust ordered a set for my sedan based off your review but before I install I wanted to make sure all is good! Sounds great bte

The pipes are still holding up for me. Its been through plenty of rain and some light snow in Atlanta and hasn't caused any CEL for me. I checked the welds when I was installing my Motordyne exhaust recently and it was fine. I am definitely happy with the happy, but I may be swapping it for ART pipes in the future to match the exhaust.

Amazing news!! Once I get em installed I'll post some sound clips if anyone wants to hear

looking forward to it.

a month later I finally got it installed, here’s a quick clip

Sounds good. What’s your overall opinion?

I love it. Only driven maybe 20 miles, but no CEL issues, install overall wasn't too bad. Now to go see how my neighbors like the cold start

What exhaust are you running with them? I had the Top Speed Y back paired with an aftermarket Y pipe and the rasp was unbearable for me after install. Put the stock Y back on and it cleaned it up a bit but it was still very much there over 3k RPMs. Got to the point I was barely accelerating when taking off. Installed Vibrant ultra quiet resonators and the rasp is completely gone but the sound is basically quieter than stock. I was running 4 resonators total plus the mufflers. Recently deleted the mufflers to see if that helped and the deep growl and volume is back with no rasp.

I had a Top Speed y-back also but I paired it with a Motordyne xyz y pipe with a resonated section. I had no drone or rasp, only the hiss. I am not sure what Lubin is running.

That makes sense. I had the hiss you mentioned but the rasp was so bad that I didn't even bother making a video after install. The Y-pipe I picked up wasn't resonated so that would explain why mine sounded noting like yours after install. Your set-up produced what I was aiming for; figured they were similar so it would be achieved or close. I couldn't have been more wrong.

Hey guys,

I'm running the TP'S an eBay y pipe, and topspeed y back. I do have some vibrations which I believe are just due to needed to adjust placement. It's got a VQ rasp for a few hundred RPM at times but I actually like the way it sounds. Overall I love it. I'm trying to get a bunch of footage together and make a vid of coldstart with revs, driving normally and fast, and highway !

Here's a quick clip