How to: Flyin Miata Downpipe

[MSMzer04]

It's late so I'll get to the point....


The following are the tools I used:


1/2" Ratchet --------------- Used 2 because one broke!

10mm Ratcheting wrench   

10mm Socket   

12mm Ratcheting wrench   

14mm Deep Socket   

14mm Ratcheting wrench   

17mm Socket   

3/4" socket   

3/8" Ratchet   

3/8" Universal joint --------------- Used 2 because one broke

Cheater Bar   

Extensions   

Heat Shrink --------------- For o2 Sensor wires

Impact Driver   

Microfiber towels   

o2 Sensor --------------- Bosch 13275

o2 Sensor Socket   

Wire Stripper --------------- For o2 Sensor

Penetrating Oil --------------- Soak DP bolts in advance

Simple Green --------------- To lubricate exhaust hangers

Socket Adapter --------------- 1/2" to 3/4"

OEM Exhaust Manifold Nuts --------------- Part# JE1040355 - Ebay

Safety Glasses   

Oil proof Respirator --------------- I care about my lungs!


I covered how to remove the undercarriage bracing on the Frame Rails thread located here

Pic of undercarriage thanks to FM:


Once you have removed the stuff that's in the way, head over to the coolest part of this job 

I removed the brace at the bottom of the pic (behind the oil pan) to give me more room, I didn't realize the job is easier this way until after I took the picture:


My advice would be to spray the bolts from under the car, as you can see in this picture, the penetrating oil did not reach the 3rd bolt.


Notice there's still rust on the far corner because I sprayed the stuff through the wheel well.





Stay tuned..... I will continue this tomorrow.

[MSMzer04]

Before you advance, remember to put all the bolts back in their original place so you won't lose anything. I took a half hour to spray the undercarriage with degreaser and rinse with water/let it dry.


This is what I used to get the infamous 3rd bolt out:


The angle I used to break that bolt loose


This is why you need more than one universal extension, I had to run to pick up another and wasted a good hour. My 1/2" ratchet broke as well (Pittsburg brand from Harbor Freight) but luckily I had another one.


Removed both of these bolts through the wheel well, the 14mm (5 degree) ratcheting wrench saved me a lot of time getting those rusty bolts out.


Once I loosened the bolts, I came in with an impact driver and removed them all, I used a small one as it is not that strong and I wanted to avoid stripping things. You are probably laughing at me for wearing that respirator, but I have an oil leak in the transmission and it stinks. That mixed with Simple Green totally sucks, you can tell I am not a tough guy when it comes to this lol




I put these back in, but I will replace them with new ones ASAP, I don't want to have problems removing them in the future…


I left the nuts in the DP to hold it in place and started removing the o2 sensor bracket (you can do it when you remove the midpipe, I didn't know this until after I brought it down)


Push the sensor out through the inside of the car


Remove bolts to midpipe



Remove the rear bracing to get the midpipe out


3/4" socket should work


Bracing removed, give it a good clean mine was nasty


By the way, I found that stinking oil leak. It looks like it's coming out of that wire, I believe it's the back-up light sensor???? I don't know...


This is what was in my face all day, yuck.


Out with the old:


And in with the new:



I hung the exhaust first, use Simple Green as a lubricant to insert the exhaust hangers


Then I installed the Downpipe, and lastly the midpipe, put a new o2 sensor in and tightened everything down.


I haven't taken the car out for a spin yet but the sound is awesome and I love it, next up is my intercooler and the rest of the FMLE package. You can now return to my build thread here Project -Zero Four-

[mayday1]

Is your downpipe from flyin-miata?    I got mine a couple months ago and it doesn't look like yours.
The cat in my FM downpipe is shiny stainless steel and smaller, while yours is covered with a heat shield.
(I think the cat covered with a heat shield is more OEM looking and more likely to pass the visual part of the smog test).

[MSMzer04]

Yes I got my Downpipe from FM ordereded it last year around the Holidays, not sure if they have changed it. Btw are you in CA? The Cat is not part of visual inspection here, they actually look at the serial number on it  to determine whether it's a legal cat or not .

[TheBigChill]

That's a nice write-up.  Good job.   

Regarding the broken universal joint socket:  Instead of using that type you have, try this:  http://www.amazon.com/Sunex-3301-8-Inch-Impact-Universal/dp/B000RLMRD0/ref=sr_1_2?ie=UTF8&qid=1456924128&sr=8-2&keywords=universal+3%2F8+impact+socket

[MSMzer04]

Thanks for posting the link! And I looked for impact universal joints and sockets but could not find at any store in my area. Had I known, I would have ordered that from Amazon ahead of time. Now the question is, will it fit in the tight space and awkward pipe angle? I don't know how much bigger that one is compared to the craftsman brand I used.

[TheBigChill]

Thanks for posting the link! And I looked for impact universal joints and sockets but could not find at any store in my area. Had I known, I would have ordered that from Amazon ahead of time. Now the question is, will it fit in the tight space and awkward pipe angle? I don't know how much bigger that one is compared to the craftsman brand I used.

I used that same unit for my downpipe install.  Worked a treat, especially combined with a 10" wobble extension.

[mayday1]

I didn't have a u-joint that fits, so I started with a couple of wobble extensions plus regular extensions, but there was
too much slop and turning the rachet didn't turn the nuts.  So I went to HarborFreight and got a long 20"? extension
and that did it for me.

My DP doesn't have a heatshield, I wonder if there should be one to avoid fire if I park
on dry grass.  I took a picture of it but I don't know how to attach a picture in my reply though.

[SilverMiataRacer]

I took a picture of it but I don't know how to attach a picture in my reply though.

http://www.mazda-speed.com/forum2/index.php/topic,20220.0.html

[mayday1]

Thanks SMR for the posting instruction.

I sent the picture of my downpipe to FlyinMiata and promptly got a reply that mine doesn't look
like what it should look like, they'll investigate.

Very strange! 

[mayday1]

Went home during lunch and checked.  My cat has a heatshield on the top, but not on the bottom.
Seems wrong to me, without a heatshield  facing the ground,  parking a hot car on tall, dry grass
may start a grass fire.  It almost happpen to me in the past, my old VW's cat heatshield fell off from rust and it scorched
the grass below, fortunately I was sitting in the car and smelled the smell and stomped out the impending fire.

[MSMzer04]

It's good that you bring this up, when I wired my o2 sensor I taped the wires together while I search for a butt connector that is appropriate for this application. I haven't found anything that withstands temperatures above 300* would any connector be good enough?

[mayday1]

I think if your O2 wiring and connectors are not touching the hot downpipe, and if you can wrap something like aluminium
foil (but more permanent and less hacky) around the plastic connector to spread the heat, you should be OK. 

Does your cat have a heat shield on both sides of the cat, or only on one side?

[millsj]

I've got the fm down pipe and the heat shield is on the top. I recently had to do a trackside repair because the heat shield had completely come loose. All four corners had broken at the spot welds. I now bring drill bits and self tapping screws to the track.    Luckily a neighbor with a stacker trailer full of tools was able to help me out.

[04-VR-_Speed]

MSMzer04, hope you won't mind a small FYI...
Mazda Workshop manual recommends removing self locking nuts by hand, impact wrench may shear off studs.

BOLT TORQUE values are in ft - lbf
O₂ sensor (new gasket) - 30
3ea. self locking nuts (replace) - 33
2ea.(rear downpipe & mid pipe flange) nuts - 38
2ea. front brace - 75
6ea. undercarriage bracing front 2 - 75, rear 4 - 29
2ea. rear frame rail brace - 17
6ea. rear cross member brace - 75
[I could not find any info on that silver undertray that's under the oil pan/trans.]