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This is a reproduction/collaboration of the RE Amemiya dolphin tail muffler in Titanium and it is also available in larger 90mm size.
Gonna be very expensive though ($3,000 in 80mm).
My dream exhaust would be regular stainless steel 90mm RE Amemiya dilphin tail.
. Just $900 for cat back plus midpipe before tax, tariff and shipping from Japan.
Dream downpipe for me is SMB 90mm downpipe whch is still available for ~800 plus tax, tariff and shipping from Australia.
Its for stock twins. If you are single turbo your kits manufacturer should offer 3.5"/90mm downpipe option.
Last edited by BLUE TII; May 18, 2025 at 10:43 AM.
Downpipes I usually go for the largest quality downpipe available like the SMB or Knightsports. High quality high flow cat to keep the smell down and Cat back really comes down to what you like for looks. Most aftermarket catback exhausts are 3" or larger and will support the typical person's HP goals so this is entirely what you want to look at on the back of your car.
But if you aren't on a standalone computer (PowerFC, Haltech etc.) you don't want to remove the main cat as you risk losing your engine from boost creep.
Downpipes I usually go for the largest quality downpipe available like the SMB or Knightsports. High quality high flow cat to keep the smell down and Cat back really comes down to what you like for looks. Most aftermarket catback exhausts are 3" or larger and will support the typical person's HP goals so this is entirely what you want to look at on the back of your car.
Agreed. I might add the HKS DP into that mix and regardless, have it heat coated or wrap it.
Originally Posted by boostin13b
But if you aren't on a standalone computer (PowerFC, Haltech etc.) you don't want to remove the main cat as you risk losing your engine from boost creep.
I don’t think a standalone will help with boost creep on the twins. It’s by definition a boost level that hasn’t been tuned for. Only wastegate porting or keeping some restriction in the system…even a high-flow cat in my experience. And as you mentioned it keeps you and the parking lot from smelling like the inside of the cat-ladies’s house.
MAZDA SPEED Trunk Tower Bar AUTO EXE Carbon Bonnet AYTO EXE Under Brace Set HKS GT-RS Turbine HKS Air Cleaner SAMCO Sport Piping KNIGHT SPORTS Muffler BBS RG-R 18 inches Aluminum Wheels Aragosta Coil Overs RECARO Full Bucket Seats momo Steering wheel KARO Floor Mats LAILE Beatrush Bar After Market Inter Cooler
Sounds like that was taken from the “For Sale” ad when you recently bought the car. I’d recommend that to keep it from being a parts donor, you keep things the way they are and not add anymore performance mods. Go read thru all the FAQs and stickys at the top of this section. Then do baseline maintenance by downloading the Factory Service Manual and changing all fluids. You’ll be alot more knowledgeable about the car and THEN you can worry about getting a new exhaust.
So intake, intercooler, cat back exhaust. Unknown if the stock cat is in place. Stock ECU since it isn't listed. No fuel system upgrades. Definitely keep an eye on the boost levels and keep them to ~10 psi so you don't run out of fuel and run lean and blow the engine.
Not trying to be alarmist but definitely learn about the car using the resources SgtBlue mentioned
As others have aluded to, the FD RX-7 is a Manifold Absolute Pressure regulated fuel and ignition mapped car- you cant add modifications that will add power without it also running lean.
At this stage of the car, any power mod must be accompanied by dyno or road Air Fuel Ratio tuning.
I would add a fire extinguisher, wideband gauge, boost gauge, a fresh set of sticky tires, and replace all the rubber coolant hoses and fuel lines before any sort of power mods.
And if the car already has an aftermarket ECU, I would add a fuel pressure sensor too. The factory fuel pump wiring prevents the factory fuel pump from getting enough power to work well, so you will probably measure that fuel pressure isn't keeping up with boost pressure. Aftermarket fuel pumps need even more power, instead of solving the fuel pressure problem an aftermarket pump can make it even worse unless the wiring is upgraded.
IMO, assuming the car has a Power FC, as a part of preventative maintenance OP should purchase a copy of FC Tweak and the DL-340XB interface and software to get a safe tune established based on the current mods. Then change the exhaust and redo the tune with the auto tune function and a decent a/f meter.
Recommendation, hmm. I'll tell you what I have and absolutely love it. I put the HKS downpipe (still running twins) and the HKS Hyper cat back. I was previously running the stock cat (without air pump) and the car had a nice throaty tone without that raspy note some get. I just this weekend put a new high flow TIC air pump less cat and wow does the car sound awesome now. It has a perfect loud deep tone, no raspy sound and does it wake up under full boost. I couldn't get enough yesterday just driving around listening to the car singing under boost. It's exactly what I was looking for out of the rotary as far as sound goes. Amazingly enough, HKS produces such good quality for crazy reasonable prices still.
No personal experience with the linked HKS system, but as a guy in the ancient WAY OVER 50 demographic, I can highly recommend the Tanabe Medallion system. It is reasonably quiet at idle and cruising at highway speeds, with zero drone or annoying raspy/tinny sounds - but it has a nice deep baritone note when you go WOT. It's quiet & comfortable enough to drive the 600+ mile interstate road trip to Deals Gap and girlfriend approved - we could easily talk in the cabin without shouting, or listen to music at less than ear-splitting volume. I've had that Tanabe catback on my single turbo (BW SXE300 series, dual external WG's recirculated into the downpipe) for about 3~4 years now. As far as setup goes, I'm running a 3" DP from the turbo into a 3" midpipe section with a large oval Magnaflow resonator before the Tanabe cat-back.
No personal experience with the linked HKS system, but as a guy in the ancient WAY OVER 50 demographic, I can highly recommend the Tanabe Medallion system. It is reasonably quiet at idle and cruising at highway speeds, with zero drone or annoying raspy/tinny sounds - but it has a nice deep baritone note when you go WOT. It's quiet & comfortable enough to drive the 600+ mile interstate road trip to Deals Gap and girlfriend approved - we could easily talk in the cabin without shouting, or listen to music at less than ear-splitting volume. I've had that Tanabe catback on my single turbo (BW SXE300 series, dual external WG's recirculated into the downpipe) for about 3~4 years now. As far as setup goes, I'm running a 3" DP from the turbo into a 3" midpipe section with a large oval Magnaflow resonator before the Tanabe cat-back.
Pete_89T2, Thank you very much for the detailed reply, you answered every question I had.
I will also be single turbo with the HKS GT3-4R with recirc on the wastegate, rx7.com bonez high flow cat. Everything you said is what I have heard, I actually had the Medllion in my cart but backed out to do more research then I came across the new HKS exhaust. The HKS tip is huge but it has slits I think inside the tip to help with sound tuning. The only reason HKS is being considered is because I personally like HKS and have some stuff on the car. I can't find any videos of the HKS super turbo muffler, but the Medallion does sound great.
@rotaryextreme your post sent me down a rabbit hole last night looking for the old YMS Mooncraft car. Aesthetically their cat-back very similar to the Revel medallion imo. I swear I remember seeing one for sale in Jp some years back but I'm guessing they're part of the uber rare parts thread now though. Unfortunately I cleared out my magazine collection some years ago so I don't have anything specific to reference, although I did find an image that came to mind. Maybe someone with better internet skills can find more info.
ps- on my way to 50 and very much appreciate a pleasantly melodious exhaust tone
Federighi
thank you so much for the reply and the link to that cool magazine. I see the similar looking exhaust on the second picture.
long gone are the days where I can afford stuff like a titanium exhaust or would be willing to spend that much money on something like that. I'm at a transitional point since I got home and I'm getting older and realizing that my build is going to have to take a different direction due to how old I'm getting.
I was 100% sold on The Medallion.
but because I do love HKS I was just wondering if anyone had experience with that new exhaust yet. I'm thinking I might just get it and share some video about sounds on it and if I don't like it then I know I can sell it and move on to the medallion.
it's a trip how something so simple and trivial can become so complicated and sent us down rabbit holes.
I was really hoping someone had that hks super turbo muffler so I wouldn't have to buy it and check it out myself only to get rid of it for The Medallion LOL
it's a trip how something so simple and trivial can become so complicated and sent us down rabbit holes.
well its a rather deeper hole than one would think! everybody, and their brother has had an exhaust for an FD, and the bigger people like HKS have maybe had a dozen?
Blitz has at least 7 different cat-backs in the catalog depending on when you look.
In general, an oval muffler can is going to be more on the quiet side. If an exhaust has JASMA certification it will also be on the quiet side too - they do some sort of sound level test.
That HKS does look pretty sweet. Most likely it will be on the quiet side going by the design but you'll have to roll the dice since it's so new no one has really used it.
Tanabe Medallion is a great exhaust, well built, good sound, quiet. But it's what everyone else has so there's that
In general, an oval muffler can is going to be more on the quiet side. If an exhaust has JASMA certification it will also be on the quiet side too - they do some sort of sound level test.
That HKS does look pretty sweet. Most likely it will be on the quiet side going by the design but you'll have to roll the dice since it's so new no one has really used it.
Tanabe Medallion is a great exhaust, well built, good sound, quiet. But it's what everyone else has so there's that
Dale
hey Dale yes thank you for your feedback. The HKS exhaust does have the JASMA certification.
I think I will roll the dice and get the HKS. If it's not what I like at least I know 100% The Medallion is proven.
