AgentSpeed

That's great news Max! Hopefully the local muffler shop can sqeeze mine in there without too much trouble. What's the measurements on your muffler?

dubulup

HA! was it considered quiet at Deal's Gap??

AgentSpeed

Well it didn't sound like the rest of the RX-7's up there. I thought it was a little more quiet at least... I take it you thought it was loud? I really wish I could get it just above stock but I don't think that will ever happen given my mods...

Hey Max, I just measured my resonated midpipe and the magnaflow muffler looks to be just like this one:
http://www.magnaflow.com/02product/s...ne=main&id=601
Which one did you get?

maxcooper

AgentSpeed, thanks for measuring. That is good to know. I couldn't find that information before, so I crawled around under my car with cardboard cut-outs of various muffler section sizes (just the end plates) and ended up selecting the same 5x8" oval, 14" long size. However, I got a Magnaflow with an offset inlet and a center outlet. I bet you could fit a center/center in there, too, but I ordered the offset/center since I figured it might help with packaging and may be a tad quieter than the center/center. The pipe through the muffler has a very gradual bend, though I am sure that the exhaust just wants to go straight and some of it runs through the perforations on the outside of the bend. That's probably good for sound abatement (forces the pulse to hit a "soft" wall) with some cost in flow restriction. The offset/center configuration worked nicely using the offset pipe as the inlet (the muffler is reversible), on the passenger side of the car.

I got the car back today, and holy crap does it make a huge difference in the sound level! I have run the car with a N-Tech high flow cat and an SR resonated midpipe (which sounded about the same, and felt about the same power-wise) so far and it is tons quieter now. I can't wait until the traffic dies down so I can go do a dB meter test to compare to my previous readings. My impression of the effect is surely exaggerated by the fact that I also had the wastegate dump tube plumbed back into the downpipe, but I really think it is substantially quieter even during times when the wastegate wouldn't have been open before. It seems to drone way less when on the highway or just cruising down the street, for instance. And although my idle was not that loud before, it is very quiet now. I am pretty amazed at the difference, and absolutely delighted in the change in sound level. It still has a deep "pulse" when listening to it idle outside the car, and it roars when you get on it, but all the tinny sound that I don't like is gone and it never gets "too" loud. Damn, it sounds great! It isn't as quiet as stock, but it is as close as my car been for a very long time and is much quieter than most modded FDs (and I've got a giant single turbo! ).

The metallic cat is doing its job and keeping the exhaust smell under control, too. However, the turbo seems to spool noticably slower now and the car also seems slower on boost. Part of my impression might be due to the reduction in sound level; the opposite of the "new loud pipe feels like +50HP" effect. I will dial in some new boost controller settings to even things out (had to go +10% between the midpipe and HF cat, so I wouldn't be surprised if it needs some tweaking now). Plumbing the wastegate back into the downpipe may be responsible for some of this effect as well. I would like to get it dyno'd again (and maybe swap the pipes in and out for a direct comparo) at some point, but no one should hold their breath for me to do that. At this point, I'm not sure how much difference in performance there really is, but I am sure there is some. The car is still fast as all hell, though, so I'm not too worried about it.

This might sound a bit silly, but I wonder if putting the muffler before the cat might be a better compromise. The muffler flows better than the cat and shouldn't hurt spool as much, plus the muffler itself has a large volume and muffler+cat might actually be better than straightpipe+cat given the same cat position. That moves the cat far away from the engine, but I suspect it would still get hot enough to work.

I was half expecting to hear some exhaust or turbo-to-frame rail clanking noises once the sound of the open wastegate was gone, but nothing hits! I must thank Matt at Performance Solutions for doing such an excellent job on the exhaust parts and for making sure all the IC pipes and turbo parts had clearance. He did an awesome job, and I can't believe all that stuff fits in there so well without hitting the body. I know it wasn't easy.

Here's a (lousy, from the side of the car on the ground) pic of my new midpipe:


-Max

maxcooper

Just did a drive with some highway runs and noise test. Dropped ~5 dB when cruising at 80MPH, and it is a world of difference. A HUGE difference. The exhaust drone is now gone. You can certainly still hear the exhaust, but it isn't a punishing resonance now. I love it.

I think my impression that the turbo spools slower may have been due to being stuck in traffic on my way home when I picked it up. It seems about the same now that I've had a chance to boost it up a little in the thinner traffic. I also setup the boost controller (starting duty cycle) on the highway in 4th gear and it really is about the same as before. I bumped it up at first but then bumped it back down again after overshooting the target. It still freaking flies up to 110 MPH in third gear (~8400 RPM) and keeps pulling like mad after the shift to 4th (after which I quickly let off when my better judgement kicks in). Damn that's fun.

The cat was glowing faintly (but unmistakably) red under the car when I parked it. And no I didn't boost my way into my parking spot. I hope it lasts. That might be another good reason to put it after the muffler if anyone else makes one of these.

-Max

AgentSpeed

Putting the cat second is what I was considering on mine. It looks like there would be more room with the muffler up front. I'll see what the local muffler shop says when I get time to take it in. I'm just wondering if there are any negative effects in moving the cat further away... I've got to pass emissions with mine. Hopefully that will not be a problem but we will see. Thanks for all the info Max, I really appreciate it!
~Heath

NewbernD

iTrader: (1)

Max.. I currently have the rx7 store muffled midpipe installed (with RB Duals, single turbo, 3.5" DP). When I first installed it the car was absolutely quiet. Totally odd silence. Since then the batting in the muffler has slowly deteriorated and it's increased in volume & drone. I'm interested to hear how quiet your setup is after a few weeks.

That said, the 3" cat from rpm outlet showed up yesterday, as did my VEIP inspection notification. Coincidence? I'm trying with no air pump first.

FYI, the piping on the RPM unit leaves a bit to be desired. It looks like the davesport unit with slip-on adapters welded on.. sloppilly. I'll get some pics as I grind it away.

alberto_mg

Heath - the closer you put the cat to the motor the quicker it's going to heat up and get up to optimum temps for exhaust gas cleansing.

fwiw, I actually placed mine further back in the midpipe, but I think if I had to do it again I would use both the cat and a muffler. the sound levels are OK for the amount of times I actually drive the car (weekend), but the woman complains about noisyness.

J_J

I just got a few updates on people that have asked me to ship out a cat to them. It seems like this metallic cat flows much better than their previous high-flow cat. As for weight, many have reported that this design is within a few lbs of their non-resonated midpipe. Fitment seems to be excellent, as there have been no reported installation problems.

When I get another FD I will definately be installing this cat. I went from the stock cat to a midpipe, only to revert back to the stock unit because of the exhaust smell. It was very annoying showing up for work or school smelling like someone poured gas over me.

For the FD owner seeking to reduce emissions and the gaseous smell without compromising too much performance, I believe a metal cat is one of the better options. It is true you will lose some hp compared to a midpipe, but the emissions reduction a true catalytic convertor offers makes the car much more daily driver friendly, IMO. The tradeoff - a car that won't make you and your passenger's eyes water in exchange for a few less ponies - is worth the nominal hp deficit to me.

maxcooper

Make some with mufflers in them, too. I am sure you can tell from my posts how overjoyed I am with how mine turned out. I had high hopes, and the end result actually exceeded my expectations.

-Max

neit_jnf

iTrader: (17)

i want one with resonator (or muffler) and airpump fitting

billyrohm

Just like I asked before, if you make one like Max's I'll want it and I'm sure other's will too.

J_J

I just picked up a brideported FC today. The cats have been gutted by the previous owner; that dreadful exhaust stench returns once again, and it seems to be especially nasty considering that I've been driving a squeaky clean stock Civic (ULEV) for the past few months. I just took the FC for a quick spin around the block and already I feel lightheaded.

I guess I'll be testing out the metal cat on my newly acquired FC soon. I don't expect to pass stringent CA smog because of the bridgeport, but it will be interesting to see how close I can come in doing so.

And as for the FD cat...the positive comments keep rolling in. I have been told that quite a bit more CA FD owners have passed smog - both with airpumps on and off. Everything fits without any problems whatsoever and it seems like it's a good product for the price I have been letting them go for. I also got word from the manufacturer that they will warranty these cats for a total of 5 yrs, which is especially good news.

PureMdMa

iTrader: (1)

Well I put mine on today and it sounds great with the RB Dual Cat Back. I am running it without airpump but will have to wait till march to see if it passes smog here in GA.

L8r
Jeremy

MichaelFregoe

iTrader: (1)

I'll take one with a muffler.

Just Bring It

Am I the only one that noticed that the cat J_J sells is actually not a real substrate cat? This is the cat i got today




you can see it's a ceramic one not a metal mesh inside.

This is a real Metalic Substrate Cat.







My point is that this cat is pretty much like the Catco one that i have, which clogs pretty much every year without an air pump.

GUITARJUNKIE28

actually, the porting should be able to pass just fine--the aux ports are closed at low speeds.

but you gotta get that vacuum leak fixed if you wanna pass!

Kento

I'd have to agree, the photos of the first cat look like a standard ceramic brick type to me. Metallic substrate cats have the "woven" appearance of the second cat in the photos because the metal substrate has to be coated with the proper materials first, then folded and bonded to form the catalyzer unit itself.

dubulup

J_J - if this is true, how are you going to resolve this? I'd hate to have this cat clog in a year.

but if it clogs...you have a 5year warranty, probably doesn't included none stock applications or some bullsh!t that relieves them in all cases.

J_J

When I bought these cats I was told they were from the manufacturer that makes Dyntech Powercats. I started looking into this product line after a link was posted on this forum about metal cats to have welded into a midpipe. These look exactly like them and perform like a metal substrate cat should (can pass smog w/o airpump, high flowing design, etc).

I'm checking around to be double sure that these are what I was told I was purchasing. If it does turn out in fact to not be metal substrate cats then I will refund the money of anyone who has purchased anything from me.

I guess I was in a rush to start making these cats and foolishly trusted the seller's word about the origin of the cats. He claimed that these were the exact same thing as the Dynatech Powercats, only they were not labelled as such so that the manufacturer could sell them as "nameless" units at a discount without diminishing the prestige of their product line. The seller was an established business, stocking thousands of cats they purchase in bulk from the manufacturer, which was the main reason I purchased from this company.

I want to assure everyone that has purchased from me that I have an excellent selling history and will resolve any problems that may arise. If you search on these forums you will only find positive comments about transactions with me. And, for anyone that has purchased the cat from me, there should be a warranty card included. This card can be mailed to the manufacturer for warranty purposes. If such service is not granted (for whatever reason involving normal operation), then I will refund your money myself.

BoOsTin FD

Yeah, that first picture shows the ceramic cat not the metal substrate one. The metal one should have a metal filter inside not ceramic... I mean that's why it's called metal substrate cat.

Sonny

This is an "authentic" Dynatech Powercore cat. It's the one I used to make mine. Nice, but $$$.



Sonny

Just Bring It

See the difference. That is the Metal one.

d0 Luck

J_J,

i have no response from a PM i've sent you close to a week ago regarding this cat. what happened?

and regarding the ceramic and metallic substrate cats, from what i've read in the above posts, a metallic one stands superior against a ceramic catalytic converter?

J_J

Unfortunately it appears that these cats are not metal substrate versions but some other type of high flowing design. I am contacting everyone that has purchased these cats from me and have already refunded the money of a several buyers. I rushed to get these cats out and failed to do adequate research on everything and I took another person's word as the cats being sold to me to be metal substrate versions. I am working things out with my supplier but I will not those who have purchased from me wait for a refund in the meantime. Anyone who has purchased from me can get a full refund on this cat. I sincerely apologize for any inconvenience this may have caused.