I think I've been depressed lately...can think about stuff to do, yet can't muster the energy to get started.
Then circumstance stepped in and forced my hand.

Specifically, I've been waffling on what to do about the exhaust and finally decided on a plan.
I have to etest again this coming March and would like to hold off buying a cat (recall that my cat is gutted after causing the engine to run like poo) until just before the test.
I have new gaskets and header wrap and decided to wrap and reinstall with the open cat and hope it's not so loud after the leaks have been sealed up. Put in the new cat right before the test.
That was the plan and I dragged my lazy *** out to begin but realized my floorjack was at Sigfrid's and I couldn't get under the car easily.
Bummer, but fixable.

Besides the noise and obvious exhaust leaks, the car was running pretty well...until it didn't.
Turns out my custom throttle body adaptor had cracked and I had a nice major intake leak.
This part has always been the weakest link of my intake and frankly, I'm surprised it lasted this long but it was time to revisit my work.

The problem is that whatever plastic that elbow is made of, regular solvent based glues don't touch it. Simple surface tension makes it seem like the glue is working but there's no real melding of the parts and it doesn't take much to break them apart. A new approach was called for.
This time I used the glue (Weldon #16) to locate the two halves and then used a soldering iron to "weld" the joint, creating a physical/mechanical bond. I then JBWelded the exterior, more as a seal than anything but it might add some physical strength.
The old "glue only" version lasted over a year, I think this iteration should do much better.

To be fair, I might have hastened the failure when I installed the elbow on the throttle body. I forgot to loosen off the dynamic chamber bolts (the six that attach to the exten flange) and lift it up...if you don't do this, the bottom of the elbow does not easily clear the secondary fuel rail...it'll go, but you have to force it.
Which is what I did and probably stressed the glue joint and precipitated the demise.

My bad.)

The test ride will take me to S.'s for the jack and I'll be able to make some progress on the exhaust.
I hope.

Then I really need to get on with the gauges.

 

Yesterday my "Get Off Your Lazy ***" tour began and this happened:


I used DEI black heat wrap and it went pretty well. I thought the 2" x 50' roll would leave a lot left over but that was not the case, I used it all. The section between the flange and the O2 sensor bung got a double layer, the rest is single wrapped.
I put new gaskets on the gutted cat and bolted it all back on.

I've wrapped headers before and used the soak method to make the wrap more pliable and easy to form, so the headers were still pretty wet when I test drove her up to the grocery store.
Steam was billowing from the hood when I parked...it was quite entertaining and two concerned citizens came up to inform me my car was on fire. One guy was very insistent I move to an empty part of the lot so I didn't endanger the cars around me.
I could see his point, actually.
Didn't move though.

Absent the major leaks, the gutted cat/header combo is much more bearable but still kinda obnoxious. I hope a new cat will bring it down a few more notches and I can live with it.

Sprocket is back to running fine again, so I'm generally pleased.

 

Are there high-flow cat replacements that fit with that particular header? Might be worth looking into if you could retain some more horsepower.

 

I have learned the hard way that a n/a rotary with a header (even one that is short enough to allow the use of the main cat) is never going to be "quite", especially with a performance cat back like my Borla. If it wasn't such an issue with ground clearance, I would have a custom exhaust welded up that would uses a 1-in, 2-out resonator in place of the Y-pipe and something much quieter like super turbo mufflers vs. the straight though units that are in my Borla cat back.

 

You could go to the $ store I get some stainless steel scrubby ***** & stuff the gutted cat with those and maybe a bit of screen in the back to keep them in there... I've got rolls of stainless steel wool of several grades that are better than $ store stuff, but if you're gonna replace it soon any way... you could try it.

I like the DEI wrap & I've used it on a few different setups with good success wrapping the first resonator with the header cloth & then the silver tape to over-lap the whole thing on the Volvo P1800. The Lady-friend likes it Quiet & the Fire-Hazard is Reduced so I can drop the air ride in the grass with No Worries.

 

As I put some miles on the v.2 exhaust (header wrap and mostly not leaking), I'll get a better idea of the sound and my tolerance.
It's actually pretty quiet unless you're romping up the rev gauge...it really begins to weedwhack about 4k rpm, so neighborhood driving isn't too stressful.

 

I tried one of those infamous Grey Market Cats with that header you have there. It sounded like a Hive of Really Angry Bees & I wouldn't recommend it in any way to anyone - I didn't have any header wrap way-back then in the beginning.

My Father & I "Debated" the exhaust issue after the cats plugged. I wanted the Whole System, but Dad wanted to save some $'s & go with the Cheater/catalyzer thing & just a Header. I Lost & it Ended Up being $$$$'s down the Drain & a Do-Over after He Passed.

The RB Header is Awesome... The Cat was garbage. I still have that exact header in the Bone Yard and just bought the Full RB True Dual System & some Header Wrap & called it Finished Forever with an Awesome Look & Sound...

It all depends on what You Want... I've been there... Happiness Does Exist in RX-7 Heaven...

 

I got RB headers, and (broken glass) RB presilencer going into 2 Magnaflow mufflers, its really not that bad as long as you don't do 70 @ 3K RPM, the drone is horrendous, and deafing, and if you romp on it and bring it up to redline, it sounds like a VERY pissed off wasp. But most of the time when I drive it, I'm doing 55-60, and its not loud at all.

I really do wonder if I got some new/better mufflers how much it would help with the drone. But thats the last thing on m list of things to do. I gotta bad coolant seal, I just drive it here and there to keep it cleaned out so the internals don't rot away on me

 

I think this is the cat I used on mine: 2400230-Catalytic Converter ? Universal ? 240 Series ? 3.00 in. Inlet/Outlet ? 49 State
I had an exhaust shop weld flanges on either end, and a tube and flange for the airpump line , so it mounted just like the stock main cat - except that it breathes as well or possibly better than with the Racing Beat resonator and mid-pipe that I used to have - the engine makes power to 8700 rpm, and occasionally I'll hit 9000rpm.

 

With a background in two stroke racing, I have no aversion to the weedwhacker exhaust note (within reason) but to be obnoxious AND slow is just embarrassing.

She's actually pretty tolerable now and I'm thinking a new cat will take her down to "just right".

 

Steve
I bought my vert with nothing but strait pipes to the rear bumper welded to the OEM 'Y' pipe. Also had a gutted Bonez downpipe cat combo. It was an out of body experience to rev that thing-Blood shooting from my ears!!

I first did a cat, then mufflers, then changed the mufflers. I believe I have it right and have enjoyed the sound for over 12 years now.

The cat will help, but won't be the total solution. Pick a cat that has a 2.5-3.0 diameter pipe plus the largest GVW rating. summitracing.com has a pretty nifty selection process. Pick inlet,outlet,airtube yes, gvw.


Now for the quiet part: I use a pair of turbo mufflers-the old school type without any stuffing, rock wool, brillo pads or whatever. You remember the type-GM designed it for the Turbo Corvair!

They are cheap. buy them with an offset inlet and a center outlet (reversible of course) and they will tuck up in the oem location very nicely. I've had a pair of 2-1/4" diameter using the original 'Y' pipe on my S5 vert for nearly 10 years, over 40000 miles. I have a single 2-3/4 " on my 10th Anni.

Turbo mufflers tame the noise on a rotary. Nothing but pleasant deep low sound, pretty much drone free. And cheap. Did I mention Cheap?

 

Now THAT i gotta remember, put some corvair mufflers on rx7 lol

 

If a Picture is Worth a Thousand Words than this Clip speaks Volumes!

https://www.facebook.com/earl.sanders.50/videos/1009911385790562/

 

Speaks volumes of how much oil your burning.

 

Bug repellent

 

Mazda RX7, The anti-prius.

Should be a commercial.

 

I stomped the Pedal for Max OMP Flow after a turn-key warm start. I intentionally "Over-lubed" after start-up before holding a steady 4 & 5k rpm. You can tell when I'm intentionally stabbing it for Lube & it runs rich... I really kinda wanted to demonstrate the "Audio Qualities" as well as the Zika-Fogger Defense. If I can find some DDT to Pre-mix It'll be Awesome!

What about the Sound? I waited for lawn guys to finish across the street & Wanted the "Ambient Feeling" of the Environment to give a Better Context for the Exhaust Note under various throttle conditions... (check the settings box for the HD quality?)

I kinda thought the discussion had been about Exhausts & was Hoping this might be better than endless typed drivel or colorful metaphores. I could be wrong of course...

 

It was a joke...

The guys at work refer to my car as "inboard lawnmower".

 

My Lady Friend found out the Hard Way... Don't Forget the Lube!

I don't care to rev the motor sitting still without a stab or 2 to be sure everything has a good coating... Failure to do so seems harmful. The Billowing Clouds are an Obvious Indicator that the OMP is Functional & ready to Rev!

I've been told that Shifts under Load shoot fire about 3 feet out the back instead of smoke, most prominent at night... I'm not allowed out after dark these days... So that video will have to wait... :P

 

I appreciate all the advice- audio as well as pixelated.
I have a nice RB catback already and plan on keeping it because I'm sure the raspiness is all from the header (long, thin-wall tubes instead of the lumpen iron manifold and three cats...whadya expect?) and mufflers won't change that inherent trait.
She's really not all that bad now (although I'd love to watch her drive by and get an external impression) and the cat has to have some muffling effect over the hollow shell now installed.

I've been so fixated on how she sounds that I've kinda ignored how well she's running and how bloody lucky I am that this crapshoot, Craigslist engine turned out so well.
It's about time to dump the oil/filter (gone about 600-700 miles and I want to see what comes out) and maybe revisit the TPS, timing and plugs (again, just to see) but those are more prophylactic than necessary.

And (as if I haven't said it before), there are the gauges.
Here's the problem...
I have the needles/dials to convert to black faces and I have the two VDO gauges I could graft in but I don't think I'm going to be happy and I'll have rendered the VDOs useless in the process. Although the Miata cluster has much better lighting than the absurd FC "stage lights" (which gives you needle shadows on the face) it's no comparison to new LED clusters for brightness and clarity and I think it'd be a nice touch if I could actually read the gauges.

Meanwhile, this 2006 Mazda 6 cluster sits on the desk and mocks me because I think it'd be spectacular if I could make it work.

So, I waffle.

 

I've Gauged my interest mostly on the tasks at hand... I went to extremes on the Volvo P1800 because of the Absolute Awesomeness of the Classic Look. The original clock mechanisms tended to burn out when the battery dies due to increased current at low voltage... I didn't really need a clock anyway, but what to do with it?!?

I bought an analog modern A/F gauge for a wide band & sent it & the clock with the Tach & fancy picot-tube water & oil temp gauges off to be rebuilt. I had dis-assembled the clock housing beforehand & The Restoration Gauge Dudes made it happen... The Clock has the original face & hands but will now read the AFR with Stoic at 12 o'clock.

I also spent countless hours on the freakin' dual-pressure gauge for the firestone air-ride... They just didn't sell the black-faced gauge in the silver-bezeled housing... I bought the stupid extra gauge & swapped the white for the black on silver... I had to cut both housings open...

 

Not sure it works like that...I don't believe that stabbing the throttle squirts more oil into the chamber.
My take on the system is that the OMP (which I think is too small to actually force oil into the keg) just keeps oil in the lines and the engine vacuum and the metered air bleeds suck in what they want...the engine decides what oil it needs, not your right foot.
I think you have seal/ring issues causing the excessive smoke, not "a stab or 2" on the throttle.

 

Really? Your Not Sure about how an mechanical OMP works? My take on the system is that there is a cog on the pump driven by engine RPM's & a Valve attached with a rod to the throttle.

By Stabbing the Throttle, the Valve controling OMP Output is Opened to Full Lube. If you Free-Rev the Engine by just cracking the throttle a little bit, the OMP Valve Never Fully Opens & you can burn the oil already on the seals.

This leads to pre-mature carbon-gunk build up in the rotor seals in general & un-needed wear - especially at start-up - & that this was the Actual Reason for the change to an Electric OMP controlled by the ECU instead of a direct connection to the Throttle plates.

There is no connection to the vacuum system or air-bleeds for the injectors... Engine Vacuum from the intake stroke in the housing does create vacuum for the OMP, but that's not what makes it work... OMP is a Pump.

The key to proper operation is a thin film of oil that creates a Vapor Barrier - not a direct physical metal to metal contact of the Seals to the housing. If you just Turn the Key to start, your Not Getting a Proper Lube - you need a Stab or 2 with an S4 Mechanical OMP.

God Forbid that Fast Idle routine just makes it Even Worse for Wear.

You might also rev the engine a bit then Turn off the Key with WOT while the engine stops if you have Cold-Start Sealing Issues. A Fuel Pump Cut-off Switch makes this easier if you also have nagging injector leaks that cause warm-start flooding issues & need to drop the Fuel Rail Pressure to Zero.

 

No, I'm not sure how the S4 OMP works as I only have S5 experience.
There most definitely are injector air bleeds on the S5 and although the execution is slightly different, I believe the two systems work in the same basic manner.

(Realizing it would be a bit of work) You could confirm my assertion by premixing the fuel and disconnecting the throttle rod from the OMP (which isn't something I can do).
In that scenario you no longer have the oil squirting into the chamber in response to the throttle and the billowing oil smoke should disappear.
If it doesn't, you have oil sealing issues (soft seals or maybe loose main bearings).

 

I appreciate your concern, but I don't believe any is warranted. The system appears to function as intended. Yes, the various lubricating schemes have tried to address the issue in various ways...

The Off-throttle lubrication was a part of that evolution of design that the S5 electric OMP addressed. Pre-mix has it's own off-throttle problems. It's a matter of analyzing where the Lube goes & when & where do I actually need it.

I don't need any Lube on the Rotor Face, but that's where half of the Premix lube ends up... So the amount that actually gets to the seal interfaces is not what you might think. Also... when the AF goes Rich, the Lube will be the Last Component to Burn & will hang around a bit longer because there's no oxygen left to decompose the Lube. When you come off-throttle those residuals get burned up & smoking occurs because the fuel is cut & excess oxygen attacks the Lubricant.

It's a Reliability Issue that has Dogged the Rotary Forever... I do what I do because it makes sense to Me... It might not be True or Valid or Hold Up to Scrutiny of Others & that's OK...

Throttle Stabbing Should Produce Volumes of Smoke Clouds with an S4 Mechanical OMP if it's working correctly... as Far as I can Tell... I could be wrong, but I doubt it.