ACE Header/Overpipe, and STI Engine Mounts: Looking for Tips
 

Hey folks. I've never done any of this stuff on a car before, so I'm just looking for some tips before I get started. I have installed coilovers, swapped to a BBK, installed a catback, and done other stuff, so I consider myself mechanically competent, but I've not done these mods specifically ever before.

A few questions:

1. Sounds like all I really need to do is remove the medal skid plate (and maybe the fiberglass one as well) in order to make everything "accessible" under the car.

2. Do I need any special tools, and are there any special precautions I need to take, when removing the O2 sensor(s)? Still unsure if it's one or two sensors I'll be removing. It's just one, right? I keep hearing the wires are fragile, and the sensors are sensitive. Will a normal wrench/socket work for removing these?

3. Removing the header sounds simple enough - undo a bunch of bolts. I know it won't be because the car has seen 5 salty winters, and almost 70,000 miles, so I'm sure lots of PB blaster will be involved (hopefully nothing more), but the physical removal sounds simple enough.

4. Engine mounts: I've never "jacked" an engine before. It's my understanding that as long as I unbolt it from the two mounts, I don't need to do anything else before jacking it up a few inches? How high can I safely jack it up without breaking anything? And what is a safe jack point? This probably makes me the most nervous. After that, sounds like I just unbolt the stock engine mounts and bolt in the STI ones, and then lower the engine back down.

5. Can someone tell me (or point me to a thread) that has all of the torque specs for both the mounts and the header/overpipe?

6. Any other tips/tricks I should know before getting my hands dirty? Any tools I should acquire in advance?

I appreciate the insight. Thanks!

Unsure if aftermarket headers will have different torque specs but here's the OEM ones.

Yeah, this assumes it doesn't come with its own torque specs. I haven't received it yet (it's coming Friday.)

There is a special 02 sensor removal socket tool you can purchase. It essentially is missing a chunk from one side, I'd buy one ( harbor freight has them). if you have corrosion on the header bolts, you may want a small handheld propane torch to put heat on those bolts. Heat helps so much when removing stubborn rusted bolts. Also helps to keep them from snapping.

I don't know enough about the other sections to give you proper advice, so I'll keep my thoughts to myself.

With that many miles and salt I would consider getting OEM replacement O2 sensors that way you don't have to fuss with the originals which could likely get damaged removing anyway

I just acquired a small butane torch, so we have that now! And should something like this work for the O2 sensors?

https://www.amazon.com/ARES-70039-8-.../dp/B01C4OB3XC

You'll want one that has a 6 sided socket fitting, like this - that matches our 02 socket housing size. I think we're 7/8ths or something

Yeah those O2 sensors are going to be real tough to remove, get the specialty tool ahead of time or some extra sensors you can return if need be. The header is straightforward; if youve done a catback and suspension stuff you will be fine there. For the overpipe? A bit tougher for sure and I can't advise here.

I would personally skip the engine mounts, unless yours are shredded.

As far as the o2 sensor, I just use a closed/box end 7/8" (I think) wrench, no need for the "special tool" which is just a socket with a cut out for the wire. The o2 connector will fit thru the 7/8 wrench hole. You could also use a 7/8 tubing wrench which has a slot to pass the wire thru but still give you 5 sides of contact on the nut of the o2 sensor...just don't use a regular open end wrench.

See this post for some good reading on the header install/removal
http://www.ft86club.com/forums/showthread.php?t=73146

Good luck with the rust! :(

Already ordered the STI mounts. CSG "recommends" them due to the reduced clearance from the ACE setup, and a friend of mine with the same header highly recommended stiffer mounts. Since mine are approaching 70,000 miles and the car is driven on rutted Chicago roads, autocrossed, and ice raced, it probably doesn't hurt to do them, and I understand they're MUCH easier to do with the header removed, so now sounds like the best time.

the stock header nuts will be accessible enough to use an impact if thats your chosen method (i used a 3/8 drive battery impact on mine). however when i installed my aftermarket header there was 1 nut i couldn't get to with anything but a wrench. maybe your wont have that issue. OEM torque specs will be 22ft/lbs, no reason the aftermarket header should require anything differnt than that.

I unplugged my o2 sensors and pulled them out with the header and just took them off with a regular wrench with zero issues. however, no snow/ice here so no salt. ymmv

I did sti mount and ace header. Both 02 sensors are in header and will need swapping over. Although like supertom mentioned at 70k miles and salty winters you might as well get fresh new 02s.

Header / overpipe is pretty straight forward although easier and more wiggle room with engine slightly lifted. So perfect time to do mounts. Only thing I did (not sure if necessary but I took off the intake box before jacking engine up to do mounts). Was able to jack engine up enough to get mounts out no problem.

Stock mounts are really soft engine rocks a lot even new. So definitely a good idea to swap. STI mounts are perfect for a DD I didn’t notice any NVH at all.

Also don’t forget to hammer down the skid plate there is a “bubble” on the plate right under header. It looks like a good 1/4” clearance but under load when engine rocks it will rub and you will hear it.

Ah, point taken! Let us know how the install goes and if you notice any improvements afterwards!

Official ACE installation guide