I recently purchased a Magnaflow y-pipe, Dynomax catalytic converter, and Magnaflow cat-back system for my 89 IROC. Currently my IROC has the stock y-pipe, (which is not in the best of shape), no cat, and a Flowmaster cat-back system.

I ordered the y-pipe and cat from Jegs, and after checking Summit's website I found a magnaflow cat with shipping that was less than what Jegs wanted for just the cat. After I though about it, the Magnaflow cat will probably be a better fit with a Magnaflow system than a Dynomax part, so needless to say I removed the Dynomax cat from my order and went through Summit.

Anyways, I just received the cat today and decided I am going to document the installation of the exhaust. I'll be installing this system in my garage without the aid of a lift so I thought it might be useful/interesting to other Thirdgen members and fellow shade-tree mechanics like myself. I'm still waiting for the y-pipe and cat back to arrive!

I'm including pictures but thought I would give the specifics on the inlet/outlet sizes of the cat. The inlet which is the longer end has a 3" outer diameter, and the outlet also has a 3" flared end. I'm not sure what size the y-pipe outlet is but I'm guessing that it is somewhere between a 2.5 to 2.75" outer diameter.

 

Nice cat. . Sounds like its going to be a really great set up .

 

Good luck MI ROC-Z. I will be looking forward to reading your thread on this diy project.

 

I'm still waiting on the other parts but I thought I should share this with the Thirdgen community and anyone who is reading this thread.

I ordered the magnaflow cat back system p/n 16829 off of ebay from a seller named worldwideperformance for 375.00 with free shipping. They are classified as a power seller with 100% positive feedback.

Before making my purchase I went to a local exhaust shop near me that is an authorized magnaflow dealer/installer in an attempt to see if they could match the price from worldwideperformance, (my attempt to boost the local economy). I spoke with the owner who looked at the ebay printout and his words were, " I can't even come close to matching that".

Everywhere else I have checked this system is between 450.00 to 475.00 so at the bare minimum I saved myself 75.00.

I'm including the item number in case anyone wants to look it up on ebay. Item #170524810306

 

I tried to take a couple shots of the innards of the cat but there is a metal mesh screen on both ends which make through pictures near impossible. I'm posting one of the pics I took though even though it's not too good.

 

I beleave that's the actual honeycomb that runs the full length of the cat.There like tiny long tunnels. Its what the exhaust passes through when being converted. Its some really strange stuff to see for the first time. I was able to handle some at a muffler shop once that had been removed from the cat. Here's another picture to get a better idea of what I'm talking about. By the way I also have the Magnaflow cat and they come highly recommended.

 

I was wondering what the mesh was for on both sides but after looking at the cutaway of the cat you posted I kind of understand a little bit more about what is going on in the cat.

I was wondering though ronusmcmma, besides the magnaflow cat do you have a cat back system or y-pipe and from which company, and how does it all sound in combination?

I'm looking for a very subtle exhaust note at idle and hope that it screams at wide open.

 

From what I have read and heard you should be "really" happy with your Magnaflow Y pipe, cat ,and cat back. IMO Thats all "top of the line" stuff. I still have the stock manifolds and Y pipe with a Magnaflow cat and American Thunder 3in. 80 series cat back. It fits me just fine. Nice and deep and not raspy like some Flowmasters Ive heard. Each car seems to be a little different.

 

Beware of the dual cat magnaflow set. The part of the ypipe going over to the driver's side manifold DOES NOT FIT.

 

I'm buying a magnaflow front y-pipe with precats and a new main cat for my car next week. I am going to try a set of LT1 muffler eliminators on my car though and see how it sounds without the mufflers. This is a Y-Body though & I will try a sound clip of there stuff.

 

I purchased the single cat y-pipe for my 89 since that was the stock setup so hopefully there will not be any major fitment issues, but thanks for the heads up anyways megtom2.

I just checked my order status through Jegs since I ordered the y-pipe on the 11th. When I ordered it said this item ships in 7 days, but I still haven't been billed which makes me think its on back order or it will be shipped tomorrow.

On the other hand I checked the UPS shipping tracker for the cat back system I purchased from worldwideperformance on ebay and it's supposed to be arriving on the 21st.

I'm curious though... did anyone who has read this post check out the cat back system and buy it?

 

I am in the process of doing a similar installation, however, I'm still trying to figure out which cat I need. What model number cat do you have there, the 93456 or 93441?

Thanks!

 

I purchased the 93441 cat for my system. Do you happen to know the difference between the 93441 and 93456?

I'm calling Jegs today to find out when my y-pipe is going to ship... I still haven't been billed for it!

 

The 93456 has a 2.5" flange and I don't recall the inlet size (2.75"?)
The 93441 has a 3" flange and no AIR connection.

I think the 93456 is the correct size for my car's y-pipe (I have a '91 Z28 305) but I'm not 100% certain.

 

The 93441 I received does have the air tube connection installed. I called Jegs and the y-pipe is shipping this Friday so I should get it by next Monday.

What kind of exhaust set-up are you putting together Joe?

 

It does have the AIR connection? That's interesting, I read somewhere that it doesn't. Interesting.

My intention is to keep the existing exhaust manifold and y-pipe, and then replace the cat and everything after it. I bought the the Magnaflow 16829 cat-back, and like I said, am just figuring out which cat I should put on. The 3" or 2.5" flange outlet of the cats doesn't bother me because the cat-back I got comes with connections for either, but I'm not totally sure which cat will slip over my y-pipe. I'll have to get under the car and take a quick measurement, but I'm 99% certain the 93456 cat is my answer.

And not to steal your thunder, but I had also intended to do a little step by step procedure with pictures. It will be nice, especially for people inexperienced with exhaust like I am, to see a step by step.

 

It sounds like you'll have a good exhaust set-up with what you described Joe. And by all means post pics of the install you do because they may help me. It's probably going to be a week or so before I can tackle the whole job so if your going to do yours ahead of that you might be able to share some tips and tricks you learn from your install.

I'm expecting the arrival of the catback system tomorrow, so I'll be posting pics after I tear the box open like it was Christmas morning.

 

Went to Jegs site and it did not give me all the info. I was looking for on line so went to Summit Racing and this is what it has to say about about the 93456 Magnaflow cat dimensions,etc.It says its a "direct fit"
= http://www.summitracing.com/parts/MPE-93456/
This is what I found for the 93441
= http://www.summitracing.com/parts/MPE-93441/

 

MI ROC-Z,

Question of the day: the inlet outer diameter that you measured in your first post, is the flare 3" or is the reduced pipe after the flare 3"?

Thanks!

 

Sorry for the delay in response Joe, it's been kind of a crazy week around here at the house. My wife and I are expecting our second child soon and my wife had to be put on bed rest until she delivers. There was a couple long days at the hospital and now even longer days as I am now taking care of my wife and two year old.

Anyways I guess an update is in order! To answer your question Joe the diameter of the flare is a little over 3" and the tubing itself is 3".

I also received the cat back system from worldwideperformance on Wednesday which was only a day late because I was not home to sign for it on Tuesday. I haven't had a chance to mock up the system off the car yet but did start matching up the cat to the downpipe supplied in the kit. I'm not sure but I think they put two downpipes in the kit in case you are going to install the cat back system to a stock y-pipe.

I should be receiving the y-pipe on Monday from Jegs so I will update and provide pics when I get it.

 

I wanted to add some pics I took tonight of the cat back mocked up with the catalytic converter on the garage floor.

In one of the pics you'll see that Magnaflow does include a second downpipe which is smaller in diameter. I'm guessing the second smaller downpipe is for installation of the cat back onto a stock y-pipe.

Also the included band style clamps they include with their system are way better than using u-bolts and should make installation and removal alot easier.

 

Very Nice !!!

 

I was able to remove the entire exhaust setup from my IROC today so I thought I would post some pics of the removal.

I decided to lift the front of the car first to remove the y-pipe and straight pipe which was fitted in place of the old cat. I'm guessing the previous owner removed the cat and had some muffler shop put in a piece of straight pipe.

The second pic just kind of shows you the underside of the IROC and the exhaust setup.

The third pic shows the straight pipe that was welded in place of the cat. If you look closely you can see the air pipe tubing was never capped off. It looks like the tube leading into the cat snapped off and it was left in the air tube.

 

Here are a couple pics of the y-pipe along with the hardware that held the y-pipe in place. The passenger side of the y-pipe utilizes a large cast metal adapter piece which I'm guessing will be needed to install the magnaflow y-pipe. Also while removing the y-pipe one of the studs that should be bolted into the exhaust manifold came out with the screw.

 

Here are the pics of the straight pipe that I removed that had been put in place of the catalytic converter... hack job to say the least in my opinion.

I noticed while removing the straight pipe that the rubber portion of the hanger bracket that mounts to the passenger side of the transmission was torn on one side which you can see in the pics. This caused the exhaust pipe to hang too low.

Does anyone know if I can get another one of these hanger brackets and where do you get them from?

 

The first pic is the leftover tubing from the catalytic converter that was still in the AIR tube. This is how the u-bolt that held it in place came apart when I put a wrench on it, LOL. Luckily I had my propane torch handy and just warmed up the pipe until I could put vice grips on it and pull it out.

The other pics just show how I jacked up the rear end for removal of the Flowmaster exhaust system.

 

The first pic here shows the entire flowmaster cat back system. The pipe closest to the camera is the inlet from the long mid pipe that comes over the rear axle. It had a u-bolt on it and I thought for a minute I might be able to just separate the muffler from the pipe. Then I noticed that whoever installed it put a couple tack welds to hold it in place. I ended up having to use a mini hacksaw to cut the pipe from the muffler.

Second pic is of the entire cat back system removed from the IROC.

The third pic is of the hanger bracket that was welded onto the long pipe to keep it in place. I ended up having to hacksaw through one of the welds and then twisted the bracket off. I did this only because it seemed like if I didn't, the pipe was not going to maneuver through and over the rear axle. (I don't know how they ever got the pipe through there in the first place but I did notice that the pipe had been beaten a little to get it in place)

 

I definitely want in on this

 

All in all the entire removal took about two and a half hours and really didn't seem that bad. I am still waiting on the Magnaflow y-pipe from Jegs which should be delivered sometime this week.

I'm thinking I will be doing the install in the same order I did the removal but we'll see.

Anyways, if there is someone local here in Illinois who wants to pick up this flowmaster muffler and pipe, send me a pm and its yours.

 

.....I appreciate the pics on the how the work is coming along!

 

Nice setup u got going, i noticed how wide ur stock y-pipe is compared to the one my l03 firebird has, mine is like 2 inches and less than that in some places.

Also i dont mean to be a dick(lol) but i noticed u lifted the back of the car without blocking the front wheels with something, if u did then excuse me but u know front wheels have no way to be blocked from inside the car so u need to physically block them with something, u want all the safety u can get when u have 3500 pounds of car haging over your head, like the 2 jackstands and jack setup u got going on there .

 

Hey no worrys DSGx, I would never get upset with someone who is concerned about safety especially when working under a car. I have heard of too many guys like me being crushed under their car while they are working on them in their garage or driveway.

I did have the front passenger wheel chocked but not the driver side and when I do the install I will chock both. I like to have the jack/jackstand combo underneath the car with me even though it makes for tight working conditions.

I thought about putting jackstands at all four corners to have the car completely off the ground which would have made removal alot easier but I decided against it.

 

thought I would add a picture of my magnaflow system as well. very nice quality work and excellent welds. got it for 270.00 .... this is for california compliant cats. Nice systems for the money and I would recommend them to anyone.



I think these numbers are what the smog techs look up to verify this is a california legal system on the car. the 49 state precat pipe is 93487 mine is a 37487 not sure what the difference is in the precats though. It also calls for a different number cat as well.

I googled the the numbers and one comes up as a carb number.

http://arb.ca.gov/msprog/aftermkt/de...o/D-193-84.pdf

this is for a Y-body not a F-body though.

 

come on let's say it together pics,pics,pics,pics,pics,pics, this is awesome!!!!!!!!!!!!!!

 

and video

 

Well... I received an email from JEGS today which said the Magnaflow y-pipe I ordered is on back order and should ship out on October 12th. I wont go into a long rant about my order through JEGS, but I will say, I will never order anything through them again.

Anyways, in a previous post there were pics of the damaged catalytic converter support hanger which needs to be replaced. After searching and checking anywhere I could think of for the last several days I haven't been able to find a replacement. And the one I did find was $50.00!

I finally decided to rebuild the bracket I have by drilling out the rivets, re-finishing the bracket pieces, and seeing if a nearby muffler shop will be able to cut me a new piece of rubber hanger. I will also be putting the entire assembly back together with stainless steel nuts and bolts in place of the rivets.

Drilling out the rivets was no problem at all. I did end up having to hacksaw through two of the rivets that were expanded enough that I could not push them through one of the bracket pieces. After having to use my hacksaw again, I bought myself a new angle grinder today with plenty of replacement metal cutting discs when I went to pick up the stainless steel bolts.

As for the rubber insulator/hanger I simply laid it flat on a piece of cardboard and traced it out with a sharpie. I plan on bringing the cutout to the muffler shop to have them cut me a new one. I'm hoping this will be as easy as I think it should be!

I will be posting some pics of the disassembled hanger bracket in all of its rusted glory and pics of the reassembled/refurbished bracket when its completed.

 

I got the back order reason on my magnaflow cat. feel lucky mine won't be available till mid november.

 

How about under $15?
https://www.thirdgen.org/forums/exha...ger-fix-p.html

35245 is a Walker (Dynomax) part number. You can get them at just about any auto parts chain, or Summit.

 

I saw the Magnaflow y-pipe pic you posted and that thing looks sweet! It's a shame you have to wait until mid November and now I guess waiting a until October 14th or so isn't so bad. What kind of build are you doing?

 

Thanks Drew , I'm gonna check this out and maybe save myself some time. The only thing is, I finished grinding, sanding, priming, and painting the stock brackets today before I read your post.

I'm going to see what the exhaust shop can do for me price wise for the new rubber piece and if it's a hassle I'm getting this replacement part.

 

Ok, I thought an update was in order since its been a while so here it goes.

On October 8th, my wife gave birth to our second son, so needless to say things have been a bit busy around the house.

I went to the local custom exhaust shop the other day to see what they could offer in terms of a replacement rubber hanger strap. I was extremely disappointed with the owner who basically told me that such as part does not exist. He didn't even try to come up with any creative solutions for me except to recommend his shop do the install of the exhaust system.

I continued to check the internet with no luck and decided I would try the Walker part #35245 that Drew found. I ended up buying the part through NAPA. When I got the replacement hanger home, I tried to slip the rubber strap over the stock bracket that bolts to the transmission. It was almost impossible, and when I finally did get it around the bracket there was no way to bolt it down to keep it in place.

That was a couple days ago and when I went to return the bracket to NAPA yesterday I remembered seeing a TUFFY car repair shop just down the street, so I thought I would check to see what they thought. I ended up speaking with the manager who looked over the bracket and listened to what I was looking for. He ended up cutting a 1'x6" piece of sidewall out of an old tire for me, and wouldn't take a penny from me for it.

It turns out the sidewall of a tire appears to be an exact match to what it used in exhaust hanger rubber. So at the end of the day all it cost me was nothing to refurbish my old exhaust hanger.

I'm attaching pics of the finished and assembled exhaust hanger along with a picture of the cardboard template I made from the old rubber piece to make the new rubber piece.

As for the Magnaflow y-pipe that was supposed to ship from JEGS on the 12th... well, I got an email today saying that the back order is being bumped up to October 30th. So hopefully there won't be snow on the ground when I finally get the exhaust installed.

 

Looks good and congrats on the birth of your second child

 

Hello all, it's been a while since I have posted anything regarding this exhaust install but that was mainly due to waiting for the Magnaflow Y-pipe to arrive. I ordered the y-pipe back in mid September, and after several back order delays it arrived yesterday, but I think it was well worth the wait.

I'm attaching a few pics I took of the y-pipe last night. Overall the finished product is what you would expect from Magnaflow. Nice welds, stainless steel pipe, and a pretty decent price. Most of all I like the fact that it will bolt directly to my stock manifolds. I'm also attaching a pic of the Magnaflow 3" cat that is a direct fit to the y-pipe. It looks like the only thing I will have to buy separately is another band clamp to mount the cat to the y-pipe.

The only thing left to do now is find some time that I can go out into the garage and get everything installed, but work keeps getting in the way, lol.

 

Well, I finally found some free time this afternoon to get out into the garage and get this exhaust installation started.

I started by putting the car up on all fours. I thought I would be able to get away with just lifting the front and putting on the y-pipe and cat, then lifting the rear to put the cat-back system on but I decided against it. It seems to me that if you have to do this in a garage or out in a driveway you have to be able to go from front to back and then back to front to get the whole exhaust fitted properly, both aesthetically and mechanically.

I started out by installing the y-pipe which was pretty straight forward. I just reused the stock spacer on the passenger side and bolted everything up loosely. The fitment of the Magnaflow y-pipe is excellent and it clears all of the body/suspension parts.

I then re-attached the cat hanger bracket that bolts to the transmission and slid the cat onto the y-pipe. The only bolts that I torqued down were the bolts holding the bracket to the trans. As for the bolts that were supposed to hold the bracket to the cat... well, they are not supplied with the cat so I had to go shopping at the local Menard's for them. After I returned home with the bolts to hold the cat onto the bracket I found out that I had only been supplied with one bolt in the cat back system to mount the front mid-pipe up to the cat... on top of that the bolt is too short! So there I went back to Menard's, where I am now on a first name basis with the hardware clerk!

When I got home, I got started on mocking up the cat-back in place and everything went really smooth. It's basically just a matter of connecting all the pipe loosely until it fits.

I have to say though... the only thing that has kind of bugged me about the install is that I had to go get new and longer bolts to mount the mid-pipe up to the cat. The other thing is that I have to get the fourth gen hanger to get the over axle pipe mounted up.

I'm not sure if they will listen but I plan on contacting Magnaflow's customer service to tell them about my experience. Hopefully it will save someone else a small hassle. Anyways here are some pics of today's work.

 

Here's a couple more pics of the driver side y-pipe connection to the stock manifold and a shot of the cat-back system mocked up.

 

It's been a while since I posted with some updates so here it goes. Basically I have the system installed and I was able to start it. It is exactly what I wanted sound wise...mellow, almost undetectable at idle and driving, but once you floor it this system screams.

I do have to unbolt the cat to y-pipe connection and install a new lap joint band clamp instead of the butt joint band clamp that is currently holding them together. I also have to tighten/adjust the driver side connection of the y-pipe to the exhaust manifold because I can hear it ticking/leaking. Last but not least I have to get some video and audio of the exhaust tones.

Before I list them on Ebay, I wanted to know if anyone would be interested in buying the exhaust tips from the Magnaflow kit. I want to put the Walker 43243/43244 stock style tail pipes on.

The exhaust tips were only installed for start-up and I'm looking to get enough money out of them to buy the Walker pipes, so I would like to get $75.00 for both. You can see what the tailpipes from the Magnaflow kit look like in the posts above. PM me if you're interested and I will get back to you as soon as possible.

 

Thanks for the info and pics, I'm thinking about the same exact set up. Subscribing. *Congrats on the new family addition*

 

No problem Oscar, I'm sure you'll be happy with a similar setup, and thanks for the congratulations, he's 3 months old now and I'm already trying to teach him how to say Camaro, LOL. My other son just turned two and when I got the whole system buttoned up for the initial startup I let him sit in the passenger seat while I revved the engine. I wish I would have videotaped it cuz he had the biggest smile on his face.

 

Looks like a nice setup. I have the same system but I went all the way getting hooker 2055's. So I used that y pipe to the magnaflow cat and cat back. Was a bit pricy in the end but I am really happy with the system

 

Hey Muskr, do you have some audio clips of your setup at idle/wide open? I looked over the 2055's after I read your post and I'm kind of interested in them now. How was installation, build quality, and how are they holding up?