Mike, did you ever dunk your car? I’m curious if your power output with your setup.

 

I haven't dynoed the car yet. I just finished a near complete rebuild a few months ago and I am still road testing. WMI not on line yet. I will post it when it happens.
Mike

 

Hey man, sorry I didnt get a chance to respond to you via PM.

So the deal is, I have all the components ready to be installed. I ordered the prebent piping from Hinsen and waited.. and waited. I asked if they are going to ship and was told they would check. Then I get a refund for my $450. I asked why? I was told they sold their last one and the new price is $650. Anyways, I decided I am not going to risk buying a prebent pipe for $650 and having a regular exhaust shop try to install it with questionable results for another $300, but instead having a local speed shop do it all custom for $1,250. I have an appointment setup for the 22nd, since they are slammed, but I will report back how it sounds and performs.

 

Agreed. My EGT sensors are in the exhaust manifold and have only seen them get to 1600 usually?

 

Just dropped off the FD this morning to have the 3.5" exhaust system custom made. Vibrant GESi cat, magnaflow tiny racing muffler, and a Racing Beat 3.5" universal muffler.. He called and verified that all my parts will fit properly. Also mentioned that both my gaskets were leaking.. figures. However, he will be using v-bands instead of the factory type 2 bolt flanges. Might be ready by Friday or early next week. Ill make a video after I pick it up.

 

Picked up the car today. It's still a tad bit loud at idle (1250rpms) for my taste, but I'm becoming an old man. It has a very deep note and sounds amazing accelerating and revving. I also forgot how smelly it was before with the windows down. I don't notice any smell anymore, which I love.

Video: Video 2:

 

Sounds great! My car seems so quiet in comparison lol i'd like some more noise.

 

Sounds nice, looks nice too. I need to find a local fab shop who can do quality work here. I'm curious of what your power will be now with this exhaust and a cat.

 

Me too!

Shawn (tuner) and I think I can put down over 500rwhp on pump 91 and meth water injection with my setup.

 

I had the Vibrant 7830 GESI UHO-series Catalytic Converter 3" Inlet/Outlet (500-850HP) cat installed last week.

Made a huge difference smell wise!. Also quieted the car down slightly and cured my high way droning.

7670 efr 3" downpipe. Rx7store resonated midpipe and rb dual tip catback.

I had the middle resonater moved a few inches back and was able to fit the cat in just ahead of it.

 

Any dyno numbers of 1/4 numbers on your setup?

 

Seems like lots of folks are investing in cats recently

Must be something in the air!

Anyhoo... Just got my very own Bonez unit in, and I'm wondering for anyone else running one without an airpump, how did you plug up the air tube (or did you at all)? My first thought was to just use the included hose and shove a bolt in it as pic'd below.





Thoughts are that I can at some point take it to a welding shop and just have it welded shut, but maybe this'll do for now, but also wanted to know what other folks do.

 

I think it’s because all us old skool RX7 members are getting older and realizing AC, PS, and not smelling like **** is now important.

 

Haha, you'll find no argument here.

I've been living with this small cat (Magnaflow?) for a while now but it really does next to nothing so I am very much looking forward to not being poisoned whenever I'm stuck in traffic.

 

The hose/bolt/hose clamps aren't "sexy" but that is going to work and work long-term. You could crimp/weld it shut but that's a permanent route, I'd rather keep it an option to run an air pump or keep it like that if you ever end up selling it.

Dale

 

Yeah, my hose, bolt and screw clamp worked just fine too.

BTW DC, your P’Cola area is beautiful. First time down here. I’m typing this with morning coffee on a deck in Gulf Shores.

 

Has anyone tried one of the cheaper weld in units with positive results?

It may be you get what you pay for but I wanna check with the club before spending the money.

Vibrants 3 inch 300 cell unit is $400+ and there are a few other brands making units for less than $200.

 

Here is how this went for me, hopefully it helps. When I bought my car in 2014 it already had a new Bonez mid-pipe and had passed VA and NJ emissions at the time. Car was nice and quiet and the fumes were minimal. It was still running twins and the air pump. Pre-mixing as well, no OMP. In 2018 I bought a used single setup that could not use the stock length mid-pipe. The downpipe was recirculated and the mid-pipe was a different length. I sold the Bonez mid-pipe. I didn't want to drop $400 on the Vibrant so I ended up with a 3" from Stainless Works, $200. Their cats are primarily used on LSX cars with the cat mounted at the header collector.

My car is not as quiet as it was with the Bonez. I no longer need to be tested for emissions and no airpump. And I think the cat is holding back power for sure, which is a given. After dyno tuning etc. I learned that you can get the Bonez cat as a weld in piece, also for around $200 or so. I am going to run it this way for now, but if I had to do it all over again and wanted the cat I would get the Bonez.

3" Bönez Performance Converter (Blank)
RX7.COM | 1993-1995 Rx7 Exhaust (330)7-ROTARY

 

NJ-JDM, the increase in noise is probably from going twins to single not the high-flow cat. The twins have the flapper door (turbo control) in the exhaust manifold that really quiets things down at idle/low load driving. Also the exhaust path througha single is much less restrictive, meaning more noise.

All that said that's good to know there's a weld-in Bonez cat. So many of the aftermarket cats out there can't keep up with the heat from a turbo rotary. Bonez has been tried and tested and that's a fair price for the weld-in.

Other cats may work, but I've seen enough aftermarket cats fail (one time seeing the internals ejected on the road in front of me from another FD!) it's not worth playing roulette with other brands. What works well in a V8 may not work well in a rotary application - richer mixtures, higher temps, and oil injection doesn't help.

Dale

 

The noise, twins vs single, absolutely. I was thinking about that after I wrote it. Bigger factor for sure.

I took one for team catalytic converter. Bonez or nothing.

 

To throw another option in the mix.... 3.5" in and out, twin cat setup with 3" individual cat runners (splitting the heat and flow in 1/2), retains air pump tube (if desired) and mounts for factory OEM heat shield. https://www.rx7club.com/group-buy-pr.../#post12407148

 

whoa that's some sneaky stuff worth the OEM heat shields on there! I like it!!

 

Folks,

It looks like Vibrant cats are out of stock everywhere, so I’m assuming that they’ve gone out of business. What’s the current best option on a 200 cell with 3.5 inch inlets and outlets that will flow well and take the heat.

Thanks in advance 🤓👍🏼

 

They are still available, but Vibrant doesn't sell them anymore. Do a search for gesi catalytic converter and you'll find several resellers.

 

You want the best? Here you go

https://hjs-motorsport.de/en/product...sal-catalysts#

200 cell is a nice balance between performance and de stinking the car.