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Aside from probably fitting, it doesn't look like a performance upgrade of any kind. In fact the crush bends in the 2nd/3rd turns look restrictive as hell, worse than factory. It'd bug me to spend that kind of money on something that's obviously not a performance part. The Magnaflow dual cat setup at least appears to have nice clean mandrel bends and it's stainless, almost worth spending the $150 extra just for that. Having just recently moved my extra N10 setup around, I'm not sure I ever noticed before how GM pressed the sidewall of the outer pipe back in on itself so that the inner pipe could nest up tight with minimum loss of room. It really makes me wonder how much room there is for improvement, and also how a larger mandrel bent would fit...
Anyway, just based on the pictures, the Eastern and the Walker Exhaust dual cat setups just don't give me the impression they'd be a great performance choice. Would they better than a single cat system with mandrel bent Y pipe? The larger issue I have with replacing any exhaust part, I want it to at least be as good as factory, and generally I figure if I'm replacing it, it's going to be an upgraded part. I mean why not use it as an excuse to take the banana out of the tail pipe.
If the goal is improving emissions, replacing missing parts, or something like that, it'd probably be fine. For greater performance, assuming the Magnaflow would fit with regards to other possible modifications like SFCs, I think I'd rather go MF. If the goal is to upgrade from the single cat to dual cats, I don't think I'd spend the money. It'd be better spent on a mandrel bent Y-pipe and single 3" cat.
Curious what aftermarket N10 setups people have used. You don't usually hear about anyone installing a new dual cat setup, just see a lot of straight piped dual cat Y-pipes or headers/aftermarket Y, no cat or a single cat, some kind of phoney baloney dual exhaust, or 'other' exhausts. My spare GM N10 setup has a rattly catalyst, or at least it did when I pulled it. Probably has two junk cats now since it's been sitting. I'm torn between cutting the pipes ahead or behind the cats and busting out the catalyst, then welding straight pipes in the cat shells, or just getting a couple universal 2.25" cats and welding them in. I'd probably do either of those options before paying good money for a crush bent aftermarket setup.
I was going to go with the Magnaflow 23479 but I read reviews saying there were fitment issues.
"Excellent quality, but the high performance does not fit 92 Z28.the OD on the pipes is 2 1/2". and does not fit between the frame and oil pan. Or the right side of the body. 2 1/4" fits perfectly . Spent $150 to find out OD on pipes was to large and $18 .43 to return it at UPS. Not to mention time and gas costs."
"Be careful! This was listed as fitting my '91 Camaro, but I found that some of the bends were a little off, leaving one converter up against my transmission! I was able to bend the pipe so it fits, but perhaps this should be marked as not fitting automatic transmission equipped cars."
Is there anyone who has installed the Magnaflow 23479 and not had any issues?
First off this was NOT a direct-fit or an easy bolt-on part. I guess if you really didn't care about how it fit you could bend and crush it into place under the car in your driveway but this was a serious custom job to get it to fit well for me and the guy welding it. Thankfully we had a lift.
I bought this part to replace the original dual factory catalytic converters and y-pipe on a well maintained 1992 Trans Am 5.7 L98 car. The car is almost completely original. One cat on the original assembly took some damage and the catalyst inside started rattling. No idea how the damage happened since there was no scuffing/scraping on the frame or the converter next to it. I blame the road construction.
First off the good things. The actual parts are very nice looking, definitely high quality bends and welds. I've only been running it with them for a few days but so far no issues so the quality of the cats seems good initially. I can't attest to any noticeable power increases, but maybe slightly. The pipes on this magnaflow assembly are considerably larger than the factory ones at 2.25 inches. However, the larger diameter is also one of the biggest problems for installation. If I have any complaints it is that, for me, these were far from a direct, easy bolt-in replacement. However, now that they are installed I cannot complain about the quality thus far.
We had quite a few problems with the install. The first was that the pipe coming from the driver's side manifold was just too wide to tuck it between the oil pan and frame like the originals, it just simply would not fit. We had to tweak its bends and flatten the pipe a little to push it into a more oval shape to finally wedge it between the oil pan and engine support. We wrapped the length that went behind the oil pan with heat wrap to help shield the oil pan and try and avoid rattles.
The second, and biggest problem was that the y-pipe assembly with the cats welded in did not actually fit onto the pipes from the manifolds correctly. When the pipes from the manifolds were slipped on, the converter assembly was about an inch too far towards the rocker panels and wouldn't fit under the bolt at the bottom of the passenger side fender. If we bent the assembly to make it fit the exit from the y-pipe to the intermediate was pointing towards the driver's side rear corner instead of straight back along the driveshaft. To make it fit at all we ended having to cut and re-flare the pipes several times to get the length and angle correct. Bending it simply wasn't going to solve the problem.
We had to modify the hanger from the transmission to bring the mounting point over an inch forward. We then had to splice into the original air line to fit it to the new one which was a huge pain. The driver's side manifold does not have a donut gasket and the flare on the magnaflow assembly is almost too large for this factory seat. We had a leak and ended up having to put a custom gasket over the manifold to help seal it correctly. Finally, we had to weld the two pipes of the converter assembly together where they run parallel just like the factory assembly to keep them from rattling.
It took us a while to find all the rattles and clearance issues but after quite a lot of work they were installed with no loss of ground clearance, and no rattles or leaks. I highly doubt that if you get this part you could install it well in your driveway using just the supplied clamps. I wouldn't clamp exhaust anyway but this is a fair warning that even if you have a welder available that this will take a lot more work than just fitting it in to tack it and then weld it fully.
If anyone cares I can take some pictures. I know most go to headers but for anyone who has an original car and needs to pass smog or get these replaced I will say this part is nice but it's a lot of work to get it to fit right.
In fact the crush bends in the 2nd/3rd turns look restrictive as hell, worse than factory.
Not really. Just because it is slightly reduced in diameter, doesn't mean it is worse than factory. It isn't folded crushed, still smooth and only a reduction of diameter in the bend. On "Engine masters" they proved that crushing the primary tubes on a header made almost no difference to performance, only to the point where it was almost crushed closed. The tubes on this are unlikely to be any reduction to performance compared to stock, I would even venture that it would be a net gain, albeit so small there would be no SOTP gain. If anything, I would say the merge after the cats would be more of a problem since it is not a smooth transition in direction.
But... A header primary only flows one cylinder at a time. A pipe downstream of a collector potentially has to flow 4 cyls worth of air volume, or 1 cyls worth in rapid succession, more so than the single header tube.
Does it matter? I don't know, I'm not sponsored by Amsoil, I don't get kickbacks from Youtube, and I don't have a dream job writing for the car mags. I just don't like the implication of the restricted bends. They offend my damned elitist sensibilities.
And yes, I'm aware the Magnaflow set has a reputation for poor fit. That's why I mentioned fitting being a pro-con consideration so prominently in my reply.
I think I'd still be more inclined to put new cats in a stock downpipe/Y-pipe or run a 3" single before I'd buy a low rent stock replacement system.
Also looked around a bit last night, Walker did offer an N10 cat assembly, however it seems to have become another victim of progress.
But... A header primary only flows one cylinder at a time. A pipe downstream of a collector potentially has to flow 4 cyls worth of air volume, or 1 cyls worth in rapid succession, more so than the single header tube.
Does it matter? I don't know, I'm not sponsored by Amsoil, I don't get kickbacks from Youtube, and I don't have a dream job writing for the car mags. I just don't like the implication of the restricted bends. They offend my damned elitist sensibilities.
And yes, I'm aware the Magnaflow set has a reputation for poor fit. That's why I mentioned fitting being a pro-con consideration so prominently in my reply.
I think I'd still be more inclined to put new cats in a stock downpipe/Y-pipe or run a 3" single before I'd buy a low rent stock replacement system.
Also looked around a bit last night, Walker did offer an N10 cat assembly, however it seems to have become another victim of progress.
The last N10 cat swap I did was to a Bosal setup. Fit GREAT and had a very nice Y-pipe on the end.
Haven't been able to confirm, but just assumed that Bosal is the same as the Magnaflow, as in pretty much the exact same product in the box. Seems like if you go by the images in the ads, they use the same image. Curious.
I was looking into the Bosal set up but cant find one. Rockauto had them but are now out of stock. My car is a stock 350 supposedly putting out 245 HP. I'm not worried about a 5-10 HP loss. I just want to put in something that will fit.
Then you should be good to go with one of the stock replacement style systems.
It's not the 5-10HP you necessarily need to worry about, it's the TQ too. If you feel like you can spare a bit of thrust, go for it. If you feel like your car is already too slow, get on Ebay and look for a Bosal, or go Magnaflow and take your chances. Some times you can find stuff on Ebay at clearance prices because it's not been a great seller. For all we know, Magnaflow might have revised their dual cat setup since the negative reviews. There was a period of time that they weren't available, and they came back in, which would hint to a new production run. Maybe it's wishful thinking but they probably wouldn't keep selling something for a decade if it didn't fit at all.
There are a couple other vendors on Ebay that sell what they say is a stainless dual cat setup, complete with the MF or Bosal .jpg, sometimes it'll be flipped or edited slightly. They say things like they're not disclosing the manufacturer's name to avoid issues with minimum advertised pricing agreements. It's worth a look if you're willing to put in a bit more footwork to ensure you know what you're getting. Oh, and be sure to come back and update the thread when you've made a selection and have the part in hand or on the car. Part of what makes it so hard to know what to expect with aftermarket parts is that most people NEVER post a review.
I think I will give Magnaflow a call and ask them about the 23479 fitment issues and see if they could provide any input on any revisions they may have done. I thought about going the cat/air pump delete but that is a crapshoot too. Some say its great, some say it was a mistake.I know I know law says you cant do that but in Illinois they don't test 1995 or older cars. I am looking for a certain sound that I had back in 1991 when I ran a cat, no muffler and Ansa resonated tips. Removing a the cats going that route would be too obnoxious imo. I'm not 20 years old anymore. Whatever route I go I will definitely post a follow up review to the product.
Just a bump to mention.... Saw a listing for a Bosal converter somewhere over the weekend... Noticed in the photo it was clearly stamped Magnaflow. Has anyone verified if they're even a different company or just another branch of Magnaflow? Kinda seems like they're the same product line.
Just a bump to mention.... Saw a listing for a Bosal converter somewhere over the weekend... Noticed in the photo it was clearly stamped Magnaflow. Has anyone verified if they're even a different company or just another branch of Magnaflow? Kinda seems like they're the same product line.
I found a little information from another post back in 2018. Apparently either Bosal owns Magnaflow or Magnaflow owns Bosal now, I forget which it said. At the time I installed one of the Bosal Ys and cats, they were separate companies entierly.
I have bought two sets of these Eastern catalytic converters.
Martelius Exhaust installed converters into my car on June 3, 2019 and followed manufactures "Converter Break-In Procedure (PDF)” instructions in every step.
On July 16, after 640 miles of driving, I started to hear a rattling sound from inside the catalytic converter. Rattling sound begun when I started up a cold engine.
There has been no outside damage to converters during the installation nor while driving the car. From outside they look flawless.
The first set broke the same way after 250 miles.
I sent an email to Rock Auto and got a reply: ”It does appear at some time the manufacturer Eastern Catalytic decided to stop selling these converters for the 5.7 engine, although we do not know why. We're not sure what converter to recommend as no manufacturers are currently offering them for the 5.7 engine.”
Well I bought the set up I listed. Once I install it I will post a review of it to let you all know if its a go or blow. Wish me luck!
So, how did it work?
I just bought a 1989 N10 car that had the factory exhaust removed for Long tubes and a Borla exhaust. i am looking at going back stock, so any help would be nice!
Meh! I installed these and it was not just bolt and go. The crossover pipe hangs lower then stock. Had to do some tweaking on the pipes at the cat to get it to line up with the intermediate pipe. Does not have a AIR tube so you need to reuse yours and the left flange had a pretty good leak. I took it to an exhaust shop and they fixed 90% of this but not happy with the sound. Exhaust sounds restricted and the leak at the left exhaust flange is still there but about 75% quieter then it was. I think I'm going to put the stock front crossover pipe back on and cut the cats off. take off the rest of the emission stuff and gut the air pump to use it as a pully. Hopefully I won't go to jail for this but they don't test for 1995 and older cars in Illinois.
Meh! I installed these and it was not just bolt and go. The crossover pipe hangs lower then stock. Had to do some tweaking on the pipes at the cat to get it to line up with the intermediate pipe. Does not have a AIR tube so you need to reuse yours and the left flange had a pretty good leak. I took it to an exhaust shop and they fixed 90% of this but not happy with the sound. Exhaust sounds restricted and the leak at the left exhaust flange is still there but about 75% quieter then it was. I think I'm going to put the stock front crossover pipe back on and cut the cats off. take off the rest of the emission stuff and gut the air pump to use it as a pully. Hopefully I won't go to jail for this but they don't test for 1995 and older cars in Illinois.
Meh! I installed these and it was not just bolt and go. The crossover pipe hangs lower then stock. Had to do some tweaking on the pipes at the cat to get it to line up with the intermediate pipe. Does not have a AIR tube so you need to reuse yours and the left flange had a pretty good leak. I took it to an exhaust shop and they fixed 90% of this but not happy with the sound. Exhaust sounds restricted and the leak at the left exhaust flange is still there but about 75% quieter then it was. I think I'm going to put the stock front crossover pipe back on and cut the cats off. take off the rest of the emission stuff and gut the air pump to use it as a pully. Hopefully I won't go to jail for this but they don't test for 1995 and older cars in Illinois.
Thank you for the follow up. Not the best news, but doesn't sound horrible as per aftermarket OEM style replacements. I am pulling the headers and full exhaust soon, so I hope to be able to put this and a dual cat OE style exhaust on it. I know it will be quiter than a wide open Borla and LTs, but the goal is to turn the car as close to stock as possible without going overboard.
Did you use the spacer on the passenger side that comes on the TPI cars? I have seen not having that will cause problems. Also did you use new donut gaskets on the manifolds? Manifolds (and exhaust to me) are always a big PITA.
Any pictures installed?
FWIW, I did talk to someone at Eastern who was very nice, informative, and said they would help with any issues if I bought it from them through Ebay. May be worth a call if you're not happy!
Just wanted to do a quick update on the Eastern Manufacturing dual cat N10 replacement.
It requires pretty extensive work to get it on correctly. The passenger side pipe coming from the manifold was made incorrectly and the exhaust shop remade it completely to fix the issue(Eastern makes it connect before the cats via a slip fit). Also the flanges on the Y-pipes were too large to seal on the factory manifolds and yes I had the factory donut on the passenger side. This required him to weld on different flanges that luckily he found around the shop. He is fixing a slight exhaust leak at the driver's side manifold to Y-pipe and besides that I am happy with it after the work.
The rest bolted up OK to my Walker, rebranded by Mac catback and I was lucky to find a factory exhaust clamp for the connection between the two. It looks a little different than the factory systems, but honestly can't remember too much.
Note, these pictures are before we finished raising the Y-pipe and adjusted the Tips. I'll also include a youtube video I made showing it off a little and talking about the issues of the install.
Well I've had it with this system. It doesn't fit right has an exhaust leak on the driver side upon acceleration and just hangs to low when I put the car on my drive up 4 post lift. I will be putting the factory Y pipe back on with the duel cats replaced with pipes. The air pump and related plumbing and hardware are coming off as well. I feel this system is a waste of money and I'm glad I didn't spend the 575 plus on the Magnaflow even though this was a waste of 275.00. Oh well its only money right. For it to work a professional shop has to go through it and try to make it work but I'm sure they would do a better job doing it custom and I would still be out the same cost out of pocket. Anyone in the market for this set up let me know you can get mine with only like 300 miles on it for cheap!
It looks eerily similar to the MAC auto parts exhaust and I was wondering if Davico was the manufacturer of the MAC piece? Anyone have any experience with this setup?
Well I've had it with this system. It doesn't fit right has an exhaust leak on the driver side upon acceleration and just hangs to low when I put the car on my drive up 4 post lift. I will be putting the factory Y pipe back on with the duel cats replaced with pipes. The air pump and related plumbing and hardware are coming off as well. I feel this system is a waste of money and I'm glad I didn't spend the 575 plus on the Magnaflow even though this was a waste of 275.00. Oh well its only money right. For it to work a professional shop has to go through it and try to make it work but I'm sure they would do a better job doing it custom and I would still be out the same cost out of pocket. Anyone in the market for this set up let me know you can get mine with only like 300 miles on it for cheap!
if you've still got it, drop me a message. I could use the setup on my car. My n10s are gutted and it makes our eyes water.
Well I didn't get around to taking it off yet but now I will have to because one of the converters is rattling around. This system is a piece of crap! Do not buy! Original y pipe will be installed with the convertors deleted. Oh and that air pump is going too!
I got the magnaflow setup. It's already on my car. We had to modify the front pipes to mate to my edelbrock headers. it looks and sounds good with the magnaflow catback that goes with it.
04-17-2019, 11:16 PM
