My IAP manifold cracked.

[lrb_2000]

So yeah.. pretty much lame..

I was making sure everything was still nice and tight on my setup (downpipe bolts, turbo flange, etc..) and I saw what looked to be a little crack.. then looking around, it seemed that a bunch of cracks had developed.... So I took everything off, the turbo, downpipe, and manifold.. Apparently the #4 runner has a small crack at the collector, aswell as the wastegate tube.. it's pretty much lame.. now they're pretty small, So I figure I could just have someone weld them back shut..

Then I took a striaght edge to the head flange, and it's pretty warped, so I'll have to get that resurfaced. And, I figure I should probably slot the flange as well for heat expansion and wrap the runners in header wrap.

Should everything be fine if I do all of this? It happened after about four full throttle 1/4 mile runs.... @ about 10psi on a t3 super 60. So I guess it got pretty hot... I noticed when I tried to get it too boost and it would only hit about 7psi and the wastegate would never open.. I hope everything works out, I mean ****, this is a $700 manifold, it's bull****.

[DammitBobby]

Why not contact IAP and see what they have to say about it. Maybe they will fix it for free or offer you another replacement.

[lrb_2000]

Well, I bought it from another member. Not directly from them. But i'll get ahold of IAP and see.

[wild_maxx]

ahh man that really sucks. IDK how it could crack after only 10 psi and base timing at 16* It shouldn't have been that hot... and the weather outside was around 45-50* so it wasn't even hot.

Def. get ahold of IAP and see what they can do. Even if they charge you to reweld it.. i would send it back to them... since they made they know exactly whats needed.

[Jookmasta]

agreed, contact them with the quickness...........post pics if ya can...............

[C-Kwik]

ahh man that really sucks. IDK how it could crack after only 10 psi and base timing at 16* It shouldn't have been that hot... and the weather outside was around 45-50* so it wasn't even hot.

Def. get ahold of IAP and see what they can do. Even if they charge you to reweld it.. i would send it back to them... since they made they know exactly whats needed.

Overall temp is not necessarily a cause of manifold failure. Unless it's to the point the normal stress put on it overcomes the manifold's strength at a particular temperature. That being said, an excess amount of load on the manifold, and/or heat expansion relief considerations were poor in the manifold design, can easily cause cracking of the manifold. I'd definitely be looking to cut the head flange so each runner has it's own flange(DOHC motor). I would consider removing any bracing that might limit expansion as well.

Based on the warped head flange and crack at the collector, I'd bet this is an expansion relief issue. As far as the wastegate tube, I think the IAP manifold uses a brace. I'd probably get rid of that. You should probably use an exhaust bellow between the wastegate and it's return to the main exhaust if you haven't done so already. The wastegate tubes expands and contracts dependent on when it opens and closes, which is not always inline with the manifold and exhaust system expansion and contractions.

[lrb_2000]

Those were my plans... But you say get rid of the brace to the wastegate flange? Also, there's a brace going from the turbo flange to the head flange.. Get rid of that as well?.

It sucks that such an expensive manifold can have this problem, when people can run a SSAC manifold for years and never have a problem... but this is the first i've seen of this manifold having a problem.

[KATwo40]

SSAC FTW!!!

Sorry your mani cracked. I hope IAP takes care of it for you.

[Florida240sx]

I've had my turbo glowing red after making it from jacksonville to daytona beach in under an hour just had heat paint on it which went away after 2weeks....

[C-Kwik]

Considering the need for the manifold to expand, anything that keeps it from doing so is going to add stress. Personally, I feel bracing is required when there is less thought put into designing a strong manifold with no need for bracing. Keep in mind, expansion in a manifold is enough to crack a cast manifold(revhard). Tubular manis are much more susceptible to stress cracks. Tubular manis are also more sensitive to load from the exhaust system. Make sure to use flexible hangers and that the downpipe is bolting to the turbo without having to stress the parts to get it to bolt up correctly. Perhaps use a bellow anyways even if it does line up to be sure.

[lrb_2000]

It's acually a custom downpipe, and the wastegate is open dump. I didn't buy the manifold from IAP so they don't care. It's fine though, we're going to weld up the cracks, take the bracing off, considing that's where all the cracks are, resurface the flange, slot the flange, and header wrap it. Hopefully it should be fine then.

[C-Kwik]

Doesn't matter if it's custom or not. Just that it adds no stress to the manifold.

[daconkiftador]

thats bad new

[lrb_2000]

Doesn't matter if it's custom or not. Just that it adds no stress to the manifold.

Oh, I know.. I was just saying that it wasn't there downpipe. Because I believe that the dump tube for the wastegate would go into the downpipe. I'm hoping for it to be fixed on monday. Also, where can I find new 5 bolt turbo/downpipe gaskets?

[Chezedik]

Well, if a $700 mani will even crack, then I fill pretty good about my $100 ebay mani. I am still a little better off.

[WDRacing]

First off, I'm sorry to hear your mani cracked...thats a real bummer. When I was learning to weld, I thought I had the WG pipe done awsome, turns out the weld looked beautiful, but had ZERO penetration on the mani side, so the pipe and WG blew off and were hanging from the vac line on the WG nipple...good times.

Bracing, well any metal that contacts another metal is going to increase or decrese that spot's ability to absorb, deflect or disperse the temperature. Bracing is usually used on a manifold where the runners were made out of a thinner walled material. The bends to the collector, added weight of the turbo and vibrations from the exhaust system really put some stress on a manifold. Let alone the tremendous amount of heat that its has to deal with. IIRC the supports go from the T3 flange to the actual head flange. If this is correct it's the best way to use a brace, because both metals should be the same thickness and neither is on the runner itself. The runners being the thinnest part, super heat, then cool..repeat all day. Having a brace on a runner...not somthing I would do unless I was cracking the mani where the runner mates up. A better brace IMO would be somthing to support the entire manifold in a verticle direction. Probably to a motor mount..

Reguardless, the mani should not have cracked like it did. Bracing or no...then again, I don't know how everything is together. If there is a pre-load on the downpipe or any part of the exhaust...the mani will crack very quickly. I'd definitly employ a flex pipe section.

Check out your exhaust, re-weld the cracks and press on.

WD

[Chezedik]

What about a piece of pipe, pressed on both sides. Drill a hole, and use it as a simple brace. What do you think?

[WDRacing]

Where is it going to and from? Jump on AIM queer bait

[Edub1]

I am working with a local muffler shop who is going to weld up all my stuff. I asked him if I will need a flex pipe and he said "absolutely" even a RWD turbo car should have one.

Just looking at the geometry involved, these things have a lot more stress on them than a standard manifold. Look at how much farther the DP is from the block than stock. Because the area of an angle increases with distance the DP will move a much greater distance when the engine twists under load. Plus, the motion is more up & down, & side to side Vs stock which kind of rotates most of the exhaust on it's axis.

Than being said, it sounds like you are looking at a $20 welding job. If they can get to it on the car, what's the big deal?

Have them weld in a flex pipe while you are there.

[lrb_2000]

Where do I want to get the flex pipe welded? On the acual downpipe from the turbo?My setup goes:Turbo - downpipe -SR downpipe -3" test pipe - 3" exhaust.

[Chezedik]

Sorry, I wasn't still on. If I am up and drinking after work, I will get on AIM. BTW, is yours in your profile?

EDIT: I found it, it is.

[GEO]

WTF, Marc told me the manifold would outlast the car.

[Edub1]

In place of the test pip is good.

[WDRacing]

That would probably be the easiest place...

If everything is installed and aligned correctly, then the mani should not have cracked. Its somthing "designed" to be abused. I haven't heard of anyone else having issues yet though. Atleast not that I remember

WD

[lrb_2000]

That would probably be the easiest place...

If everything is installed and aligned correctly, then the mani should not have cracked. Its somthing "designed" to be abused. I haven't heard of anyone else having issues yet though. Atleast not that I remember

WD

I must just suck then.

[wild_maxx]

I don't have a flex section in my exhaust at all for the last 2 years and its been fine. Mine goes turbo--> DP-->3"exhast w/2 pre-mufflers-->muffler

I'm going to add a flex section with my next exhaust system to reduce any stress on the turbo/manifold.

[Edub1]

My guy runs a muffler shop for years, I can't see any reason in the world to second guess the guy.

[C-Kwik]

First off, I'm sorry to hear your mani cracked...thats a real bummer. When I was learning to weld, I thought I had the WG pipe done awsome, turns out the weld looked beautiful, but had ZERO penetration on the mani side, so the pipe and WG blew off and were hanging from the vac line on the WG nipple...good times.

Bracing, well any metal that contacts another metal is going to increase or decrese that spot's ability to absorb, deflect or disperse the temperature. Bracing is usually used on a manifold where the runners were made out of a thinner walled material. The bends to the collector, added weight of the turbo and vibrations from the exhaust system really put some stress on a manifold. Let alone the tremendous amount of heat that its has to deal with. IIRC the supports go from the T3 flange to the actual head flange. If this is correct it's the best way to use a brace, because both metals should be the same thickness and neither is on the runner itself. The runners being the thinnest part, super heat, then cool..repeat all day. Having a brace on a runner...not somthing I would do unless I was cracking the mani where the runner mates up. A better brace IMO would be somthing to support the entire manifold in a verticle direction. Probably to a motor mount..

Reguardless, the mani should not have cracked like it did. Bracing or no...then again, I don't know how everything is together. If there is a pre-load on the downpipe or any part of the exhaust...the mani will crack very quickly. I'd definitly employ a flex pipe section.

Check out your exhaust, re-weld the cracks and press on.

WD

I got a better rookie welding story. On my first car, a 1983 Toyota Celica GT-S, I decided to make my own short shifter(seeing as how noone made one for it). I found a used lever at pick-a-part for $15.00. I completely took it apart and tried a few things, eventually coming up with a design that cut out a 2 inch section at the base of the shifter about an inch from the fulcrum and rewelded it together. It held for about 2 weeks when I had a run-in with some old VW beetle. We took off from a light and I pulled ahead immediately, only to shift to second and have the whole dame thing break off at the lowest weld. All this while my female passenger was laughing her *** off. And she continued to laugh the whole way home as I had to shift with about 1 inch of shifter. I got much more of a short shifter than I had anticipated. My dad later saw my welding work and laughed at it as well before fixing it for me. I leave welding to professionals now.

As far as bracing goes, even if you attach them to flanges, the runners will want to expand more than the brace since the runners see more heat. This would be more of an issue with stainless steel than mild steel as it expands more for a given temperature change, but whether or not anything will crack depends on many factors.

Heating and cooling in that of itself is not the issue. It's when different parts of the manifold heat and cool at different rates and to different temperatures at the same time. The most common problem being when the runners are hotter than the head flange, it tends to want to bow the head flange and the head flange will prevent the runners from expanding. This puts stress on the head flange and the collector. The other one is the wastegate tube(both before and after the wastegate).The header and exhaust will see heat generally relative to engine load but always see some level of heat constantly. Wastegates will be cooler while the WG is closed and then begine to heat up as it opens. How much it opens can also be a factor here. It's at a different temp than the manifold and the exhaust very often and goes through heat cycles at different times.

There is actually one concept I've heard about thin-walled mani's being less prone to cracking. The thinner walls have more uniform heat through the wall thickness and has less chance of cracking. Though, I'd speculate this is more in the runners themselves and would still require considerations for expansion. The concept seems somewhat valid though. Think of welding cast iron. It's generally thick and therefore prohibits the use of arc wedling as the local temperature at the weld gets so much higher than the rest of the part. Even a gas weld requires the part be heated up to keep temperatures more even and requires a long staged cool-down period. Too much of a difference in temps across such a thick part will cause the part to crack while cooling down after being welded.

[daconkiftador]

Yeah I always thought the megan racing SR downpipe with the flex-tubing wasnt a bad idea.. if nothing else, just for extra security and or forgiveness.

Than I was told it was just a FWD thing to have flex-tubing =/ because of the way the motor torques.

[lrb_2000]

Yeah I always thought the megan racing SR downpipe with the flex-tubing wasnt a bad idea.. if nothing else, just for extra security and or forgiveness.

Than I was told it was just a FWD thing to have flex-tubing =/ because of the way the motor torques.

Which is why you shouldn't listen to me.