Hot_Dog

Rehashing from my May 28, 2019 post:

"On May 28, 2019, I replaced my 15 year old Bonez Superflo system (https://www.rx7.com/store/rx7/superflo.html) with a new one. The old system was rusting and had seen better days. The old monolithic cat upon inspection was partially clogged too. During the past 20 years, this was the 3rd Bonez Superflo system that I used on my car. I was expecting an uneventful install, but on the contrary had problems with this install. The pre-silencer was hitting the transmission cross member. I was getting vibration in the cabin during start, on idle and during acceleration. The y-pipe inlet and cat were misaligned by maybe a 1/4" due to the Bonez system not fitting properly. I had to force the pipes into alignment with a pry bar in order to bolt them together. This was difficult because these pipes are both very rigid. The whole exhaust system is screwed up due to improperly fitting Bonez system."

"Obviously, this Bonez Superflo system wasn't manufactured to the same specs as my first two Bonez systems. I tried contacting rx7.com via email in an effort to resolve this issue, but I never heard back from the a$$hole. The only thing that concerns me is that I bought this Bonez system in 2014 and had it in storage until last week when I finally installed it. My backup plan might be to buy a RB down pipe and Bonez cat for an S5 NA, and just eliminate the pre-silencer completely. So, I guess we'll wait and see how this all plays out."

A few photos of the Bonez Superflo as mounted on my car:





New exhaust as of July 25, 2019:

After nearly two months with this POS system, I had to make some improvements. I bought a used very-good-condition RB NA downpipe (p/n S16206) on Ebay, a new RB Y-Pipe (p/n 16447) and a Bonez NA 20" cat (p/n EX800655). I installed a RB catback exhaust system back in Feb 2006 and the Y-Pipe had seen better days with over 100k miles. Of course, the mufflers were fine since they are made out of SS. The Bonez converter is actually an Eastern Catalytic Converter (p/n 70965) that I was considering buying directly from eastern, and having a welding shop weld an extension piece and flanges on to it. The converter has to measure 20" flange-to-flange to fit between the downpipe and y-pipe, which is the same length of a RB pre-silencer. The Eastern Catalytic Converter would have run me about $130, and with the flanges and welding probably would have run me about what I paid rx7.com. I also replaced all 10 rubber muffler/exhaust hangers, which set me back another $130. Here's some photos of my new system:






.
There's two hangers on the Y-Pipe that used the stock asbestos insulating washers. These washers were originally a series of laminated asbestos washers that had de-laminated into many individual washers. In other words, they were a big PITA to keep all the pieces together. I bought from McMaster-Carr (p/n 93785A222) High-Temperature PEEK Plastic Washer for M16 Screw Size, 17 mm ID, 30 mm OD. I used three washers on each side. PEEK is able to withstand temperatures up to 500F degrees. So, I think they should hold-up fairly well considering the mounting location. Here's a photo of the insulator washers:



At least, no more annoying vibration in the cockpit. I've recorded and attached an mp3 audio file for my new exhaust system. This exhaust sounds fairly similar to my original Bonez Superflo system, but may be even slightly more quieter. I recorded the audio with my cell phone, which was approximately three feet behind the RX7. I first run the car at idle then step it up to 2k, 3k and 4k RPMs. I then back it down to idle and then I goose it up to 5k and 6k RPMs a couple times. Please ignore the squeaky fan belt as you can hear in the background,

I'm planning on taking the car on a 300 miles road trip next weekend to Watkins Glen NY for the NASCAR races. We will see how it sounds during the roughly 5-1/2 hours trip. Hopefully, there won't be any annoying droning noise during my drive.

rudynick81

300 mile road trip with a leaking fuel line? look at your last picture

WayneBrady

iTrader: (4)

Ari at rx7 dot com was always super helpful for me

Hot_Dog

Yeah...I hear you! I wouldn't want to get stranded out in the middle of nowhere. I'll probably just use my new Mustang.

I think that's the fuel return line (i.e., low pressure line) that's leaking. Apparently, the fuel is evaporating faster then it's leaking because I never noticed any drops of gas on the ground. I occasionally smelled gas, but that's about it. I've probably been driving the car for months while in that condition and had not even noticed it.

It's getting hard keeping up with this car. For every fix that I do, there's two more things that I find broken.