Dodge Dart Forum banner

1 - 20 of 26 Posts

·
Registered
Joined
·
1,358 Posts
Discussion Starter #1
It has arrived. MPx header (powder coated) and cat back exhaust. Now to find the time to work on this project. I will provide updates as I move forward.



Sent from my Nokia 7.1 using Tapatalk
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #2
Does anyone happen to know the torque specs for the header bolts and if there is a torque spec for the exhaust clamp bolts? Also, is there a pattern to follow when tightening the header bolts?

Sent from my Nokia 7.1 using Tapatalk
 

·
Registered
Joined
·
719 Posts
Here the torque spec for header and the pattern to follow
125884
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #4

·
Registered
Joined
·
1,358 Posts
Discussion Starter #5
Is it necessary to remove negative terminal when doing header/cat/exhaust swap? Only electrical being touched is disconnecting the O2 sensors. Opinions?

Sent from my Nokia 7.1 using Tapatalk
 

·
Super Moderator
Joined
·
3,290 Posts
The FSM says that for almost any procedure. If you are careful and don't make any shorts, you could leave the battery alone.
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #7
The FSM says that for almost any procedure. If you are careful and don't make any shorts, you could leave the battery alone.
Thanks. Probably better off safe than sorry. Was looking to avoid the CEL when the negative is removed so after completing the job I would know any CEL popping up would be due to exhaust install, and not just normal battery removal. I guess either way I am going to see if it is throwing any codes anyway. Sometimes I just need to be reminded to do things the proper way and not to take shortcuts.

Sent from my Nokia 7.1 using Tapatalk
 

·
Super Moderator
Joined
·
3,290 Posts
FWIW, I almost never disconnect the battery and have never had a problem.
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #9 (Edited)
Header, Cat and exhaust in my basement waiting for installation.

I plan on doing actual removal and installation on Saturday and Sunday. I am using Wednesday, Thursday and Friday to prep and work on loosening all parts.



Sent from my Nokia 7.1 using Tapatalk
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #10
Day 1 (Wednesday) :

PB Blaster on heat shield hardware, O2 sensors and any header bolts I can get to.


Sent from my Nokia 7.1 using Tapatalk
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #11 (Edited)
Day 2 (Thursday) :

Removal of upper heat shield and upstream O2 Sensor.

PB Blaster on all engine compartment header nuts and bolts. I also gave each bolt a strike with my hammer and a brass drift punch to work on loosening them.

Afternoon Update: All header nuts and bolts are cracked loose. Unfortunately the down stream O2 sensor does not want to budge. Been using both a 7/8 wrench and a 3/8 O2 sensor socket. Will keep lubricating with PB Blaster.

Late Afternoon Update: I watched a video where they showed a breaker bar can be used to remove downstream O2 sensor. Embarrassed to say that I do not have a breaker bar. However, I used my 3/8 to 1/2 adapter and put my 1/2 socket wrench on my O2 sensor socket. I then put the closed end of my 24mm wrench on the handle of my wrench for additional leverage. Pulled like crazy. Well, it finally cracked loose and I almost got sent on my ass when it did.

I wrapped and bagged the O2 sensors to keep them debris free and out of the way from damage. I am also posting a pic of the tools I have used so far.







Sent from my Nokia 7.1 using Tapatalk
 

·
Registered
Joined
·
74 Posts
Good deal. Did you happen to remove the bubble wrap from the exhaust yet? When I got mine on the car the flange on the Z-pipe had been welded offset. Had some grief getting it to line up. Ended up contacting MPx and they made it right in quick order. Also, you might have to re-use the copper gasket that goes from catalytic pipe and the center section of the exhaust...the grafoil one supplied was a little small for the flange bolt holes. I tried to improvise by slotting the gasket, but decided to just re-use the copper one. I also asked the question about the torque and bolt tightening sequence. I found the 25 lb.-ft. in The Bible...but guessed at the typical center out pattern. Glad to see that was the right way :).
I'm also curious to see if you'll need to cut some plastic from the area around the tailpipes.


DSCN3106.JPG DSCN3105.JPG DSCN3107.JPG DSCN3158.JPG DSCN3164.JPG DSCN3086.JPG DSCN3087.JPG
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #13 (Edited)
Good deal. Did you happen to remove the bubble wrap from the exhaust yet? When I got mine on the car the flange on the Z-pipe had been welded offset. Had some grief getting it to line up. Ended up contacting MPx and they made it right in quick order. Also, you might have to re-use the copper gasket that goes from catalytic pipe and the center section of the exhaust...the grafoil one supplied was a little small for the flange bolt holes. I tried to improvise by slotting the gasket, but decided to just re-use the copper one. I also asked the question about the torque and bolt tightening sequence. I found the 25 lb.-ft. in The Bible...but guessed at the typical center out pattern. Glad to see that was the right way :).
I'm also curious to see if you'll need to cut some plastic from the area around the tailpipes.


View attachment 125894 View attachment 125893 View attachment 125895 View attachment 125896 View attachment 125897 View attachment 125898 View attachment 125899
Thanks for all of this information. I am going to cross my fingers and take a look tonight.

Update: Checked everything and it all looks pretty true.

I will keep in mind reusing the copper gasket. I actually had replaced mine at one point when I did my motor mount and found that during my Dart's previous ownership, someone did something and stripped one of the studs connecting them. I had to use a nut cracker and a die to retread.

Sent from my Nokia 7.1 using Tapatalk
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #14
@87ShelbyZ

What torque specs did you wind up using on your O2 sensors and bracket boots?

Sent from my Nokia 7.1 using Tapatalk
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #15 (Edited)
Day 3 (Friday) - Only planned on staging and prepping items for wrench-turning to begin tomorrow. However, took less than 2 hours to get exhaust removed after work for my son and I. Feels good to be ahead of schedule. Also feels good to have someone else help under the car.... I mean to pass on knowledge to....

I want to state that I currently have two hydraulic floor jacks (I got a low profile one for Xmas from my wife and told her I would get rid of the other one. Has yet to happen) which makes this much easier along with two jack stands (and wheel chocks). Lifted the front and back of passenger side to do this work.

Full disclosure, I did break one of the studs to the cat pipe flange. It had been previously stripped. Also, to flange connecting to the other junction was so rusted out that no socket would bite it. That is why I took the entire exhaust out as a complete unit.

Oh, and finally, those rubber hangers are a bear and just want you to bust your knuckles. I used grease on them and a small flat-head worked into the bottom most opening. Pried it open a bit and pushed in the opposite direction. Once I got a feel for the first one coming off, the rest were not too bad.

Sent from my Nokia 7.1 using Tapatalk



 

·
Registered
Joined
·
74 Posts
@87ShelbyZ

What torque specs did you wind up using on your O2 sensors and bracket boots?

Sent from my Nokia 7.1 using Tapatalk
I used 30 lb. - ft. on the O2 sensors, with some anti-seize on the threads. I've got notes in my build notebook that has The Dart Bible having O2s torqued at a range of 25-33 lb.-ft. Not sure what you mean by the bracket boots?

Just another note, I have notes saying modern performance has the header torque value of 38 lb.-ft. so I went back and used that value. Let them heat cycle a couple of times and re-torqued.

Yeah, the rubber mounts are rough. I basically the same method...some lubrication and a screw driver. Funny I noticed the bolt missing from the bracket that mounts the cat to the tranny/block. Mine was offset and wouldn't even take a bolt.
DSCN2947.JPG DSCN3034.JPG

Is this the bracket you're referring to? Well was going to attach a picture, but download is angry for some reason. (edit) Well worked that time. Actually went back in and inserted some exhaust wrap to help quash some under dash vibration that had gotten worse with the exhaust install...which usually happens when you go snottier. It did help. I was under there when I put in the J-type defouler. I had to chase the threads because they got a little cross threaded coming back out. The bolt threads were gone, so had to find one from the parts bin...hence the red. I want to say I put some red Loctite and used the elbow feel torque wrench on this as I didn't want to strip out what was left of the threads. I would venture a guess around 35 to 40 lb.-ft..
DSCN3035.JPG DSCN5170.JPG DSCN5171.JPG
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #17
I believe I used 30 lb. - ft. on the O2 sensors, with some anti-seize on the threads. I've got notes in my build notebook that has The Dart Bible having O2s torqued at a range of 25-33 lb.-ft. Not sure what you mean by the bracket boots?

Yeah, the rubber mounts are rough. I basically the same method...some lubrication and a screw driver. Funny I noticed the bolt missing from the bracket that mounts the cat to the tranny/block. Mine was offset and wouldn't even take a bolt.
View attachment 125912 View attachment 125913

Is this the bracket you're referring to? Well was going to attach a picture, but download is angry for some reason.
I meant bolts, but my phone prefers I say boots everytime. I was referring to the four flange connections on the MPx exhaust. I guess I have to go look at the Dart Bible/Wiki that people have actually took the time and effort to create. I mean no disrespect to anyone and sorry for not doing so in the first place.

Sent from my Nokia 7.1 using Tapatalk
 

·
Registered
Joined
·
74 Posts
I meant bolts, but my phone prefers I say boots everytime. I was referring to the four flange connections on the MPx exhaust. I guess I have to go look at the Dart Bible/Wiki that people have actually took the time and effort to create. I mean no disrespect to anyone and sorry for not doing so in the first place.

Sent from my Nokia 7.1 using Tapatalk
Ahhh...got you. I went back and did some editing on my last post, but still got it wrong :) !! I basically lined them up as best I could and creeped up until they were tight and everything looked lined up and cleared things...then tightened them as much as I could with a 3/8" driver and box wrench from front to back. I was up on 4 jack stands so getting any kind of torque wrench in there was tough, and I don't think I came across a specific torque value. I should probably pull the trigger on the factory service manual. I usually end up using values from older factory service manuals, which was around 50 lb.-ft. Sorry, wish I could give you a more definitive answer on that one. I will say it was a little easier - I think - to put the complete exhaust together semi-loosely and drag it under as one piece...putting in the tailpipes first then putting the center section up in the rubber hangers, and then put in the catalytic and flex joint in. I would recommend putting some anti-seize in the connection b/w the header and the cat/flex joint pipe...so much easier to slide and twist. You can see how the offset in the flange shifted the exhaust to the left. Cardboard was used to keep the scuffs off the exhaust and always nicer to sit on the cardboard.

DartGT with Exhaust.jpg DSCN3099.JPG DSCN3100.JPG
 

·
Registered
Joined
·
1,358 Posts
Discussion Starter #19 (Edited)
Day 4 (Saturday) :

Install completed. Took our time and spent about 4 hours at a leisurely pace, thinking things through and enjoying the summer-like weather.

My son and I installed the two rear "dual exhaust" pieces prior to install. We then installed that piece on the rubber hangers. We then installed the "Z" pipe, cat/flex pipe & intermediate pipe in that order. We installed the two new rubber hangers and left the connection between the intermediate pipe and "Z" pipe completely off.

We then removed the header. As previously mentioned, had already loosened the bolts and removed the O2 sensors. Quick tip, remember to unbolt the upper bracket on the bottom of the header/cat.

Gave the entire face area of the header interface with very light pressure scotch-Brite and then wiped both faces with alcohol. Put on new gasket. Installed the header with one person up top and one person below. Used @87ShelbyZ suggestion and put antiseize in the compression area where header and cat pipes meet. Remember to put compression clamp on first and in a position you can tighten it.

Once that was positioned correctly, we installed the new header bolts and nuts at 25 ft lbs. We then tighten header/cat pipe clamp to 35 ft lbs. Tighten cat/flex pipe to existing bracket on the chassis. We then worked out way back tightening all connections to 35 ft lbs.

By the way, I also had to re-use my copper cat pipe flange gasket. I may have used the intended gasket on one of the back connections, or they just did not provide the right one. I also way have used the wrong size bolts at that connection as it was a real fight to get them to go through the re-used OEM gasket. During clean-up, I noticed two smaller bolts which may have been intended for that.

Lastly, we installed both O2 sensors to 30 ft lbs with some antiseize. The O2 sensor which reads post cat requires an extension which is provided. I made sure to keep as far from exhaust piping as possible.

Moment of truth. Started it up and it sounded great right away. A nice, aggressive growl and burble, but not too loud or obnoxious. Also, no smoke, leaks or CELs. Gave it a short Rev and it also sounded wonderful.

To the test drive. Did notice more cabin vibration, however only on startup when idling can I say I really "noticed" it. Could feel it a bit in my ear. Did not have that feeling at any other point in king test drive, even at slow speeds, stopped at lights/stop signs. I think I will take @87ShelbyZ advice and put something to damper between cat/flex pipe and chassis.

I am so happy with my total setup now. Mechanically/performance, this is what I also hoped my Dart would be. It is my daily driver that I wanted to be fun, usable and makes me smile. I understand it is not a Charger, a WRX, a Focus ST (or even a Fiesta St), whatever, but my head, heart and butt-dyno love it. It is mine and it speaks to me, makes me look back at it and smile.




Sent from my Nokia 7.1 using Tapatalk
 

·
Registered
Joined
·
74 Posts
Very nice, glad it came together for you. Did you ask for a secondary muffler in the center section? My kit only came with one. Kind of curious on the change in sound. Did you have to do any trimming of the plastic pieces? Also looks like your pipes are a larger diameter...are they 2-1/2-inch diameter? Ok I'm sold...I'm going to go back and invest in MPx's header bolts...mine are of the rusty kind, and yours are sharp!! Did you happen to see how much carbon was in the exhaust...was thinking it was a bit much...the car had about 3300 miles at this point. Sorry for the barrage of questions. Just 1/4 more tank and the 93 goes in and the Syked tune in after!!
DSCN3050.JPG DSCN3175.JPG DSCN3185.JPG DSCN5109.JPG DSCN3073.JPG
 
1 - 20 of 26 Posts
Top