Turbo vs. non-turbo exhaust gaskets

[vrg3]

I'm going to be pulling my turbo soon, and I may as well install the up-pipe I won at the Feed & Speed as well as install the EGT probe I've had lying around for ages, so I started looking at what gaskets I might need.

I understand it's possible to reuse these gaskets, especially if you apply some kind of gasket coating to them, but for the sake of this discussion let's say I'm going to replace all the gaskets I uncover.

Apparently the exhaust manifold gaskets (between the heads and the manifolds) are different between turbos and non-turbos. Turbos use part number 14038AA000 while non-turbos use part number 44022AA020. The turbo gasket costs more than twice as much as the non-turbo gasket.

Is there a significant difference? Does anybody know if I can get away with saving 10 or 15 bucks here? I searched on NASIOC and apparently a lot of WRX owners seem to believe that 44022AA020 is a cross-pipe gasket (I have no idea where they got that), and a lot of RS owners say that 44022AA020 is the gasket they needed when installing aftermarket headers.

Also, the donut gasket between the downpipe and midpipe... I had thought that turbo and non-turbo exhausts were the same after the downpipe (on turbos) and after the y-pipe (on non-turbos). But apparently they're not? The parts manual lists the donut gasket as 44022AA122 for turbos and 44022AA062 for non-turbos, and the turbo piece lists for more than four times the non-turbo one.

Can anybody who's done a turbo swap comment? I'd like to save the 20 extra bucks if I could.

These are the gasket part numbers I've dug up:

manifold-to-crosspipe (need 2):
44022AA160
manifold-to-head (need 2):
14038AA000 (44022AA020 for non-turbos)
manifold-to-uppipe:
44022AA170
uppipe-to-turbo:
44022AA150
turbo-to-downpipe:
44022AA180
midpipe donut:
44022AA122 (44022AA062 for non-turbos)

[BAC5.2]

For the exhaust thing, ask Steve. I'm sure he would have a good idea of what would fit and what wouldn't.

For the donut gasket, it's possible that the part is the same.

I don't see why you can't ditch the spring bolts and use a regular gasket though?

If you DO want to use the donut gasket (which is a good idea, as the spring bolts are basically a flex-pipe replacement), you should definately get new spring bolts. It's almost a definite that you'll break these. I know I broke mine when I tried unbolting them, and my buddy Keefe broke his when he unbolted the exhaust on his 05 GT Sedan. Another buddy with an 05 GT Wagon broke his spring bolts as well.

I can't imagine that the donut gaskets could be significantly different from turbo to non-turbo. The exhaust is the same diameter, so there shouldn't be much, if any, difference.

[vrg3]

Yeah, good idea -- if Steve doesn't run across this thread on his own and chime in on his own I'll ask him to.

If I got rid of the spring bolts and used a normal gasket, wouldn't I be stressing all the exhaust pipes since they'd be forced to bend because there's no play in the joint?

Yeah, I actually thought the rear part of the exhaust was the same between turbos and non-turbos, but they actually go so far as to have different muffler part numbers too. The midpipes have different part numbers, as well as the gaskets between the midpipes and mufflers. The hangers are the same though.

The FSM says to replace the locknuts at the midpipe joint with new ones any time they're loosened; I didn't know the springs were so easy to break though. According to the parts manual the springs are separate from the bolts, and are actually the same on turbos and non-turbos (bolts are 44059AA010 and springs are 44044AA010). But I can't seem to find the part number for the locknuts.

[BAC5.2]

The exhaust will hang and move with everything in the hangers. Stay away from Kartboy style urethane hangers, and you'll be fine IMO. I doubt you'd be stressing anything by having it bolted together like that. That's how all aftermarket exhausts are setup, and that's how I'm running it. Matt's running it like that, and I doubt CES would sell a kit that wasn't up to par in terms of durability, espically for $1600.

I found out that the donut gasket and spring bolt thing is a twofer in idea.

1) Allows the exhaust to flex around and move, like you said. The pipes can flex at that joint.

2) In the instance of a rear collision, the exhaust will push in, and the donut gasket and spring bolt will cushion the turbo from direct impact. The stock exhaust will move in just enough on the donut gasket and spring bolts for the bumper beam to absorb the impact. Then hangers snap, and the exhaust will drop. Remove the gasket, and it pulls the exhaust back slightly, get rear ended, and the exhaust will still drop off at the hangers.

The springs preload the bolts, and they snap like a postal worker if you don't remove them properly.

Rob told me the proper way to remove them was to undo them evenly, by loosening them slightly one by one (like you would tighten a wheel down, you go little by little).

[evolutionmovement]

I couldn't tell any difference between the head and manifold turbo vs. N/A gaskets and I looked out of curiosity. Granted, the N/A gaskets were used, but the shape, material, and thickness all appeared the same. I don't know the part numbers as I ordered the whole gasket set. The set did come with the two crosspipe and an up pipe gasket - they all looked the same as each other.

Steve

[vrg3]

Hmm.

Thanks, Steve... maybe I'll be a guinea pig and see what happens with the NA manifold gaskets.

In any case, brand new NA gaskets should be better than 120,000-mile-old reused turbo gaskets.

Are you saying the manifold-to-uppipe gasket looked to be the same as the manifold-to-crosspipe gaskets? Cuz the manifold-to-uppipe gasket costs a few bucks less than the manifold-to-crosspipe gaskets.

[evolutionmovement]

Shit, I can't find them now, but yeah, the three gaskets appeared identical when I looked. I briefly wondered if there was a difference as I wouldn't be able to tell. Dammit, now I can't find them. They're somewhere in this mess ...

Steve

[vrg3]

Woah. Maybe I'll just get three manifold-to-uppipe gaskets then!

If you can find them to compare them again, that'd be awesome. Don't stress about it though.

[legacy92ej22t]

I didn't really read through all the above post, I just kind of scanned them, so if I say something that has been covered then sorry.

The cross-pipe to manifold gaskets are smaller then the up-pipe to manifold gasket. The manifold to cross-pipe gasket is part # 44022aa160

I don't have my part # for the up-pipe to manifold gasket anymore because I already used it.

The manifold to head gasket is part # 44022aa020

In terms of the donut gasket in the exhaust pipe, I thought that the turbo had a .25" larger diameter exhaust. Is that wrong? If it is then ignore me but if it isn't wrong then that's why they would have different part #'s.

Vikash- Are you going to replace all these gaskets just for kicks? Really all you need is a new DP to turbo gasket, up-pipe to turbo gasket, up-pipe to manifold gasket, and the donut. You don't have to remove the manifold or crosspipe at all. It'd be cool to replace them all though since you're down there but you definitely don't have to, especially if money is a concern.

[BAC5.2]

Matt - I think both exhausts are 2.25", not positive though.

Vikash - Make sure you have a sawzall when you do the install. The bolt holding my downpipe to the tranny would NOT come out, and I had to hack the bracket.

[vrg3]

Matt - Okay, so I can't use a manifold-to-uppipe gasket instead of the manifold-to-crosspipe gaskets. Thanks for clarifying.

So did you use part number 44022AA020 for the manifold-to-head gasket? Cuz that's the non-turbo part... I think I'm going to try it anyway, but if you already successfully did that'll be good to know.

If the turbo's exhaust were a quarter inch larger, that would certainly explain all the stuff being different... I just always thought people who did turbo swaps kept their stock exhaust from the midpipe back...

I realize I won't need to remove the manifolds for the turbo swap, but I think I want to put an EGT probe right where the nice flat spot is on the driver side manifold. I want to know if anything funny is happening with cylinder 4. I changed the plugs recently and the #4 plug had oil all over it... I don't know what to make of that, though; the compression test came out okay (just under 150 psi in each cylinder).

Phil - I don't have a Sawzall, but I do have an angle grinder and a bunch of hacksaws, as well as a Dremel... hopefully I'll be okay, even if it takes me a little longer.

Can someone confirm or refute that turbo have a larger-diameter exhaust than non-turbos?

[evolutionmovement]

Hm, I wonder if I didn't get an extra gasket and one missing ... Well, at least I don't have to worry about it for a while, but I wish I could find them so I could tell you for sure, dammit.

It's possible the manifold to head gasket has a slightly different ID as I didn't match them on top of each other, however, the heads are the same for turbo and N/A with some extra machining process for the right side on the turbos.

How much oil is it? Valve seals wouldn't effect compression, but shouldn't be bad enough to cover the plug. Does it still fire?

Steve

[vrg3]

It wasn't a lot of oil, but it seems odd to me that there would be any wet oil at all on a spark plug that came out of a running engine. I think it still fires, because I haven't really noticed any weird running or anything like that... and I haven't noticed any smoke out the tailpipe or anything.

[evolutionmovement]

I recommend a thorough engine cleaning with Sea Foam or whatever to be safe. I wonder if you have carbon building up. Mine was fine (I have to assume good compression as it ran great until the valve actually went), but used oil. I think carbon build up prevented efficient heat sinking through the seat. If I had regularly cleaned the engine out, I bet it would still be fine.

Steve

[vrg3]

I do Seafoam the engine periodically... just before taking those plugs out I actually did run Seafoam through the intake, crankcase, and fuel system.

The thing is -- my engine doesn't seem to consume oil. I don't ever need to add oil between changes; I check and it's just where I left it.

[BAC5.2]

That's really Odd Vikash, my #4 had oil on it as well.

Well, what was scary, was that I had oil in the spark plug well (I stuck the wrench in there, and when I pulled it out, it was dirty, although it did just sort of look like a little bit of oil and some water.

Compression test came out perfect. 155psi in every cylinder. The plug looked fine to me, no oil or anything on it, but goddamn were my plugs fouled up.

[vrg3]

You may have gotten some coolant in there if your coolant tank ever broke. It helps if you properly apply dielectric grease, but a deluge of hot coolant is a lot to stand up to. The coolant probably carried some engine bay grease and grime in with it.

Your plugs were probably fouled up from running ridiculously rich.

[legacy92ej22t]

Matt - Okay, so I can't use a manifold-to-uppipe gasket instead of the manifold-to-crosspipe gaskets. Thanks for clarifying.

No problem.

So did you use part number 44022AA020 for the manifold-to-head gasket? Cuz that's the non-turbo part... I think I'm going to try it anyway, but if you already successfully did that'll be good to know.

I didn't use it yet. That's just the gasket that Jon sent me with the cross-pipe. I never looked it up to see if it were different then the turbo or NA. Hmmm, I wonder. I say ask to see both at the Suby dealer and compare, then report your findings to the rest of us.

I realize I won't need to remove the manifolds for the turbo swap, but I think I want to put an EGT probe right where the nice flat spot is on the driver side manifold. I want to know if anything funny is happening with cylinder 4. I changed the plugs recently and the #4 plug had oil all over it... I don't know what to make of that, though; the compression test came out okay (just under 150 psi in each cylinder).

AH, right on, that's probably a really good idea. That's a bit scarey that you're getting oil on the #4 plug.

[vrg3]

Good idea -- I'll try seeing if my local dealer has both parts in stock.

Yeah, I don't know what's going on with that oil... Last time I did a tuneup the plug was clean.

This is probably unrelated, but when I removed that plug, it came out without its crush washer. The crush washer stayed down in the spark plug well and I actually ended up getting it out by kind of threading the compression tester into it and then pulling.

I dunno. I'll probably pull that plug out after a few hundred miles and inspect it.

[vrg3]

Okay, now, having actually gone through these parts I have a better understanding of what's going on.

Here's what I've found:

I ended up just replacing the manifold-to-head gaskets, the manifold-to-uppipe gasket, the uppipe-to-turbo gasket, and the turbo-to-downpipe gasket. I still need to do something about the donut.

The joint between the downpipe and midpipe is a flex joint. The downpipe has a portion that sticks out and actually goes into the midpipe. A graphite "donut" gasket fits onto this portion and allows the joint to seal even when the two pipes aren't lined up perfectly. The two bolts that hold the joint together are shaped specially to hold springs, and when properly assembled the springs allow some give that allows this whole joint to flex. As Phil says, it's basically a replacement for a flex-pipe. Some aftermarket downpipes end in a flat flange and thus eliminate the flex joint; with these you have to use a conventional gasket and rely on flex in the hangers. Others allow you to keep the flex joint, but even with these you have the choice of switching to the flat gasket and rigid fasteners.

The springs, bolts, and nuts are all separate pieces. If my information is correct, the spring is part number 44044AA010. The bolt is 44059AA010, and the nut is 802008270. These are the same on all modern Subarus, turbo and non-turbo alike.

The donut gasket is apparently different but I have yet to compare them.

I don't like the idea of the entire exhaust being rigidly connected to the engine, so I'm trying to get a replacement pair of nuts and bolts (I had to cut through the bolts because of rust) and a gasket (mine flaked apart). For now, I have a pair of 3/8" bolts and a bunch of aluminum foil stuffed in there.

The turbo and non-turbo manifold-to-head gaskets did appear different to me. The turbo ones are made like the crosspipe, uppipe, and downpipe gaskets: they look like they're made from sheets of stainless steel. The non-turbo ones have that kind of dimpled appearance. I guess the turbo ones are supposedly capable of withstanding higher temperatures and/or pressures. I put non-turbo ones on my car this time around though. I expect they'll do okay; it looks like in addition to MSR, a lot of vendors out there actually sell non-turbo manifold gaskets in their "uppipe gasket kits," including dealerships like Exeter Subaru.

The manifold-to-uppipe gasket is indeed smaller than the manifold-to-crosspipe gasket.

I'm going to try to pay a visit to my local dealer sometime soon and hopefully they'll have both donut gaskets in stock so I can compare them.

[originalcyn]

So, this thread is a million years old, but i'm planning on replacing my exhaust manifold gaskets. I bought a set of fel pro gaskets from napa, and the box indicated that it works for both the turbo version and the N/A version. Did we ever get confirmation on this? And if we did, what does everyone think about this set vs the fel pros?

http://www.grimmspeed.com/catalog/produ ... ucts_id=32

[Legacy777]

The multi layer steel gaskets seem to be the "standard" for turbo engine applications because they hold up to the heat better than the composite gaskets, but that doesn't mean the composite ones won't work. What kind are the fel pro gaskets?

[originalcyn]

Josh,

Thanks for getting back to me. I really want to have this done on Friday, but If I don't order the grimmspeed ones soon enough I might not have time.

This is the Fel-pro set.
http://www.amazon.com/Fel-Pro-MS95088-M ... B000C2CK5Y

The box says it replaces no: 14038-aa000

This apparently includes (according to the box) 1.8 Sohc ej18e 93-96, 2.2 sohc ej22e 90-96 and 2.2 Turbo sohc ej22t 90-95.

I'm NA, so i don't think it will hurt, i'm just not certain it's necessary though.

If the Grimmspeed ones are going to last longer or whatever, i'd rather go with them. I doubt there's going to be any actual performance benefit to them, but i wouldn't mind a higher quality gasket for a couple bucks more.

[Legacy777]

If it's just for a non-turbo setup, the fel pro ones will be more than fine.

[originalcyn]

Ok, awesome. Thanks!