Obx Exhaust Install Thread (how To)

[Auburn T5]

Rather than bury this down in the other thread, I thought I'd start a new one from scratch to show the guys who either have bought this or are planning on buying it how to put it on. It's not hard but I like to document all the work like this in case there are future questions on how to do something.

Exhaust is on. MikeG and I tag teamed it and it was very straight forward with no major problems. A few snags here and there but nothing we couldn't easily work around.

Before the pics come, here are some helpful things you'll need to get this done.

First thing is first, the vband clamps that hold the exhaust pieces together need longer screws! It took a while to get the first one on and we ended up having to use a pair of vice grips to pull the two ends closer together to get enough screw through the other side to put the little nut on. Very frustrating and luckly I had a couple other longer nuts/bolts so we used those on the other 2 clamps. If you don't have any, do yourself a favor and go buy some longer bolts and nuts before doing this. You'll thank me later.. I promise. Alternatively, you could buy some of these instead. (which I plan on doing)

http://store.airflo.com/p206604.html

You'll also need a Sawzall (reciprocating saw) or a hacksaw or dremel with cutting bits. The exhaust or it's hanger at the rear needs to be cut about 8 or 9 inches before the tip to get the stock piece off as the stock exhaust hanger prevents it from being wiggled down over the axle and out of the car. (pic shown later to show where we cut it)

Also, the exhaust hangers for the very back aren't long enough to allow the new muffler to hang. The tip goes UP after it exits the muffler and when we tried to re-attach the hanger's mounting bracket, the tip was hitting the bumper well before it was close to being able to be mounted back up to the frame of the car.

unless you're using the o2 anti fouling trick, you need some wire to extend the rear 02 sensor.

Anyways, last night, I hit the 3 bolts on the turbo holding the factory down pipe with pb blaster. this morning, they required zero effort to remove.

Despite not actually doing things in this order, I'll post pics and what I consider the best order to do things here.

first, pull the factory air box out from under the hood and if you reach down, under the ABS module and on top of the transmission, there's a wire harness tunnel that has 2 different types of connectors. One has a connector with a bracket that flips up and releases the other end of the wire harness. This is for one of the 02 sensors. The other has a red pin that holds the 2 plugs together. If you reach in with a long flat head screwdriver, you can wedge the clip apart and pull the plugs apart. That's the other 02 sensor. Removing these makes removal of the downpipe much easier rather than trying to remove the 02 sensors under the car. I should have hit those with PB blaster also as one of them was stuck pretty good.

Here's the air box removed followed by the 2 plugs. (blurry but shows you what to look for) They're pretty tough to get to unless you have small hands. Don't try to get to them from below... it won't work (at least we couldn't get to em)

Next, there's a plate under the car that goes under the exhaust held on by 4 bolts. Remove that then remove the 2 bolts holding the downpipe and catback's sections together which is just above that plate..

At this point, you can remove the 3 bolts holding the downpipe to the turbo and then slowly and carefully rotate the downpipe around the swaybar and remove it from the car.

To make removing the 2nd half easier, I suggested that rather than trying to shoehorn the exhaust hanger rubber mounts off the hangers, just remove the hangers completely. They are all held on by bolts and come off very easily. (here are 2 of them. there's a 3rd one on the drivers side I didn't get a pic of)

At this point, you can easily pull them off the exhaust, set them aside and grab that saw and hack here.

The only other option I see is to either remove the hangers that are welded to the pipe.

At this point, the exhaust should be out of the car.

HA!

Now it's time to remove the 02 sensors, put some antiseize on them and put them into the new pipes.

next, take the 3 bolts that hold the DP flange to the turbo and after some trial and error, we discovered that the easiest way to get the new downpipe onto the turbo is to thread the studs into the turbo and then screw the nuts down to tighten the flange down. It took a little elbow grease to get them all on but it's a nice tight seal it creates. Do the top two from up top and the bottom bolt is easiest to get to from below.

After the downpipe is nice and tight, its time for the mid section. Since I want to keep the car relatively quiet (it's the wife's) I opted to get a catco brand cat. USA made, high quality and this one had the port for the SAS air pump if needed. Since the 99's don't have them, it was left capped off. I also had my local exhaust shop chop the mid pipe that came with the kit and the cat's ends are a hair wider in diameter than the exhaust pipe is so it slips right in without the need of a slip joint. A couple of 3" band clamps tightened down held the pieces together though I think the front slip joint may need some copper exhaust glue/paste to help seal it up better as the clamp didn't get it tight enough that I couldn't still twist it a little.

Anyways, here's that all up and done. I'd also like to note, thank goodness for that flex joint in the DP. It wasn't totally straight pointing back down the tunnel that the exhaust runs through but once we had the piece with the cat mounted up and the Vband clamp on there, we were easily able to move it around and point it straight. Nothing major... that's what the flex joint is there for. So don't be alarmed if your down pipe exit end isn't pointing straight back.

CLOSE CALL! HAHAH

The next piece is fairly straight forward. The hanger bracket and rubber hangers slip onto the new hangers and then just loosely screw the bolts back in that hold the exhaust hanger brackets to the frame of the car so that you have a bit of wiggle room to make sure you get the next Vband clamp on and tightened on. Once you do, tighten down the hanger brackets into the car's frame.

For the final piece, as I mentioned earlier, you have a choice here... as some have mentioned, the tip does come out a bit too far and though we could have hacked it off and just taken it to a shop to do or simply slapped a generic tip onto it, we've done neither just yet. Since the mounting bracket wouldn't have bolted back up to the car as the tip was hitting the bumper, we could have either gone out to try and find longer rubber exhaust hangers or zip tied the hangers up to the hanger bracket.

In true Heebspeed glory, we opted for the super deluxe platinum Eddie Bauer edition zip ties to hold the final piece in place. Actually the Vband clamp is helping that but YES when we take it to get the tip shortened a bit (it's really not THAT bad) we'll have them put longer hangers on.

There were 2 places that were going to make contact with metal so rather than hearing exhaust rattle, I employed my anti exhaust rattle trick by cutting up an old turbo hose section and zip tied it around the pipe. One place is where the pipe humps over the axle.

The other is where the center plate with 4 bolts in the middle of the car is. The pipe was touching that plate so I put a piece of the hose there also.

That should be it. If you're wanting to retain the 02 sensor's bung and have opted for a cat, you'll have to clip the 4 wires for the rear sensor and extend them out with more wire. Then re-attach the two 02 sensor plugs, put the air box back in and fire it up.

Driving impressions

I really like the way it sounds. It's very very calm until you get on it and even then, it's not that loud. Very civilized. As I mentioned to mike and my wife (who was riding to make sure it wasn't too loud...like she had a choice to decide if she wanted to leave it on or not ) I mentioned to them that the actual tone of the exhaust is nearly identical to the stock setup. I know the cat has quieted it down a bit more. It's like it just makes the stock exhaust a bit louder. When you're sitting there at idle and just low/no boost cruising, it's practically like stock. I was impressed. When you get on it though, it wakes up and has a nice smooth note that's loud enough to let people know it's not a stock exhaust but not so loud to draw all the attention (unlike mine )

As far as new power goes, even with the ECU throwing a P1171 (maf sensor I believe...ha! Imagine that Mike!) even with that code which very well could be putting the car in a reduced state of performance, it has improved power. It doesn't run out of steam as the rpm's climb past 4500 like it used to.

For $400 + $50 for the cat and $40 to have the mid section pipe cut to size, wide band bung added for a future wideband system and the band clamps for the cat joints, I'm very pleased with the results. I guess next on the list is to get some better Vband clamps, seal up that slip area where the DP enters the cat and either get longer exhaust hangers or go to autozone or O'Rly and get a new rolled edge tip that's a little smaller. Just cut the pipe where the current tip is and slip the new one on.

Anyways, like I told mike, it was much more straight forward than when we did my swaybar and endlinks and though it wasn't totally straight forward and a perfect fit, for the quality of the work and great sound that's kept the car civilized sounding, I'm very pleased. The little setbacks were minor inconveniences and I think for you guys who are planning on doing this, going into the install knowing some of the things that took us by surprise or gave us a bit more trouble than we anticipated, planning ahead for these things will make life easier. And having a 2nd set of hands really helps too.

Oh and one final thing... the exhaust stinks like burning something. I think it's the cat's core heating up and burning off the stuff inside and I know the metal has to cure or whatever it does. Just driving a mile to mikes house and back had the exhaust's down pipe a deep gold color it had changed to. Bling bling! Hopefully the stink won't last too long. I remember mine stunk like crazy too.

I'll try and get a video up tomorrow or sometime this week. If you just hear a stock exhaust and imagine it a little louder, that's what it's like. Nothing shocking or vastly different. I'm sure without a cat, it'd be louder though.

*** UPDATED ***

The center plate with 4 bolts should not be put back onto the car. It offers little to no structural reinforcement and was the biggest source for exhaust rattle. Unless you want to wrap you mid pipe with exhaust wrap to try and prevent metal on metal contact, I'd suggest just not putting this back on. It appears as if it's sole purpose on the car was to cover volvo's butt if the center joint on the stock exhaust were to fail, it would prevent the exhaust from dragging on the ground. Decent Vband clamps should ensure this doesn't happen...not to mention all the exhaust hangers pretty much hold it tight up under the car anyways. So once I removed the plate, rattling has nearly totally been eliminated.

[Justin R32]

Awesome write-up! I have no questions...you answered them all!

I hope to get mine on next weekend.

I'm going CATless, so I hope it's not TOO loud.

[UnknownSoldier]

really good write up and it looks fantastic.

[Auburn T5]

maybe it'll find it's way to bay 13 (along with my axle swap write up)

[AaronD81]

Awesome write-up! I have no questions...you answered them all!

I hope to get mine on next weekend.

I'm going CATless, so I hope it's not TOO loud.

I am much happier after adding a cat. I ran it for about 2 weeks without one and it droned pretty badly during partial throttle acceleration. If you decide you want a cat to quiet it down later it's really easy to take out the straight pipe after the DP. I cut the pipe and added the cat in about 2 hours.

[TBM]

Excellent write-up. However, I'm taking my OBX exhaust to a shop and let them do everything since I'll also be installing a hi-flow Magnaflow cat along with a bung for the SAS. Anything specific I should be letting the exhaust shop know apart from the things you mentioned?

Looking forward to the video/sound clips...

[volvotron]

Good write up.

Anyone reading this that has a straight outlet downpipe for sale, PM me.

[Yosser]

Thanks for the excellent write up :)

[Auburn T5]

Anything specific I should be letting the exhaust shop know apart from the things you mentioned?

not really... just spend a little bit more money on some high quality Vband clamps to hold the sections together, make sure they weld in that extra bung on the DP for an 02 sensor. Make them mark where to weld it because if they weld it in the wrong spot, the sensor won't fit as it would hit the frame of the car.

Make sure they anti-seize everything also. There's nothing worse than having to do work on the car a year or two down the road only to discover rustedbolts that break or strip.

That's really all I can think of. For a shop, this should be a walk in the park.

[Mossback]

Thank you for the write up. It will help a bunch when mine goes in! :D

[Auburn T5]

**UPDATE**

Apparently this exhaust gets a LOT hotter than the exhaust I had on my mustang. It was hot enough to melt the rubber intercooler hose I had slipped between the exhaust pipe just before the cat there to prevent it from rattling against the flat (4 bolt) plate under the pipe.

I had some spare samco hose that supposedly has a better tolerance to heat. My guess is that it will suffer the same fate but without SOMETHING there to absorb the vibrations, it's incredibly annoying and though I'm sure the plate could temporarily be removed, I don't want to chance it right now.

New Vband clamps will most likely be ordered in a week or so. And I'm guessing I may look around town to see if I can find some exhaust wrap on the cheap to wrap around the pipe there at that plate, where it humps over the rear sway bar and at the section of downpipe which appears to be barely clearing the swaybar (maybe a centimeter of clearance). If you're using the IPD sway, I'd say plan ahead in case your DP has this same super close fit and get some exhaust wrap to keep handy just in case.

[tozovr]

Great write up man...As I'm looking at the pics of the disassembly I couldn't help think that something was wrong. I was right. No rust. Damn you and your Alabama climate!! I did my O2s this weekend here in Maine..the front was cake...the rear, because of that plate, was a HUGE PITA. Captive nuts. Fawking ingenious. I'd like to bust some teeth on the Engineer that thought that would be a good idea!!! LOL!

[Yellow95]

Drew- You can safely toss that plate under the middle of the car. I dont have it on any car except the Olice and it still has the stock exhaust. I need to find an answer for the metal on metal contact at the rear. Cant really get in there with a hammer or I would "modify" it myself.

Gary

[sconeman]

**UPDATE**

Apparently this exhaust gets a LOT hotter than the exhaust I had on my mustang. It was hot enough to melt the rubber intercooler hose I had slipped between the exhaust pipe just before the cat there to prevent it from rattling against the flat (4 bolt) plate under the pipe.

I had some spare samco hose that supposedly has a better tolerance to heat. My guess is that it will suffer the same fate but without SOMETHING there to absorb the vibrations, it's incredibly annoying and though I'm sure the plate could temporarily be removed, I don't want to chance it right now.

New Vband clamps will most likely be ordered in a week or so. And I'm guessing I may look around town to see if I can find some exhaust wrap on the cheap to wrap around the pipe there at that plate, where it humps over the rear sway bar and at the section of downpipe which appears to be barely clearing the swaybar (maybe a centimeter of clearance). If you're using the IPD sway, I'd say plan ahead in case your DP has this same super close fit and get some exhaust wrap to keep handy just in case.

Not kidding I was just going to write a question about this because.

My exhaust tip get hot enough to burn my leg..which I have done a couple of times since installing my exhaust.

[Auburn T5]

I may get some exhaust wrap and wrap those parts where they're rattling (and remove that center plate) and then use a piece of the silicone around the wrapped part as I would assume it won't get nearly as hot then.