Wow!! Is that a JMF? If it is then I know it's the weld, because it looks like it's bent into place there and not a weld which would be crazy that it blew out there. As for welding on the car, it's super easy to remove the injectors and rail or just get heavy type covering for everything while your welding.
I think it'll be fine once welded if it is on a weld, if it's just blew there due to thin metal that could be another problem. I doubt a JMF or Magnus would crack the metal itself but I have seen it happen to the welds frequently.

You didn't race Vin Diesel did you?

Danger to manifold

That doesn't look like the weld cracked, that looks like the actual metal cracked. Who makes the manifold? It can be welded, but personally I think it is a defective part and I would contact the manufacturer and see what they suggest.

That's fixable. I would take it off and weld it. Welding parts on a vehicle can have bad influences on other parts. A couple that come to mind.......alternator, ecu, tcu...I have personally blown an ecu welding on a truck.
You won't need to retune afterwards, nothing was added or changed except you fixed a leak.

Welcome to DSMs.

Completely fixable, no need for a re-tune after you get it re-welded. However, I am surprised it let go after only 25 psi of pressure. Not unheard of, though.

With all of the heat, pressure, and vibration our parts see, it's no real surprise.

You can have it welded, but it may crack again. I had an intercooler that kept doing that at the seams and after fixing it three times and it happened again I finally gave up. There is a lot of pressure exerted on those flat areas like where yours cracked. Just take the area of one of those flat sides (length x width) and multiply it by your boost pressure (25psi ) and you will quickly see how much pressure is exerted on that side.
I think I'm doing that right. But I'm sure someone will correct me if I'm wrong.
So just guessing here... if that panel (side) is 4" wide and 14" long under 25psi it would be seeing around 1400 lbs of force exerted on that panel. 4x14=56 56x25=1400

GRAVEDIGGER said:

You can have it welded, but it may crack again. I had an intercooler that kept doing that at the seams and after fixing it three times and it happened again I finally gave up. There is a lot of pressure exerted on those flat areas like where yours cracked. Just take the area of one of those flat sides (length x width) and multiply it by your boost pressure (25psi ) and you will quickly see how much pressure is exerted on that side.
I think I'm doing that right. But I'm sure someone will correct me if I'm wrong.
So just guessing here... if that panel (side) is 4" wide and 14" long under 25psi it would be seeing around 1400 lbs of force exerted on that panel. 4x14=56 56x25=1400

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Except for the fact that you're accounting for a distributed load. It would be dependent on the the thinnest point/area of microscopic fracture, combined with the material state (martensite, pearlite, etc.) that would determine the fail point. Pressure would essentially be a constant.

First, thats a jmf knock off you see on ebay that comes in stainless or aluminum. Yours is aluminum.

Second, you can weld it back up but its not a guarantee that it wont crack at another location. That knock off manifold has the plenum seam grounded down after it was welded. Being aluminum, this inherently weakens the all the joints. Your best bet would be to reweld the entire plenum area to prevent another crack from popping up.

Haha I remember the movie quote, but couldn't believe it actually happend to me....Thanks all for the feedback!
Lasthope05- You and I are thinking exactly alike. After some inspection it looks like this may be an ebay knock off. It came in the hatch of the talon when I purchased it so I used it. It was aluminum so I figured it might be legit. That's exactly what it is too, the weld has been ground down to look like a bend.

Now the indecisiveness starts...to have it welded and run it or go back to stock??
I don't want to turn this into a different thread, but maybe the stocker is actually MORE efficient for my 20g supporting mod set-up anyway? Felt like I lost a little low end, but the top end was nice...until it blew.

Jbweld ;$ it'd probably actually work , might not hold forever but temp but other than that you could drive to an exhuast shop and see if they could tig a little bead to seal it

I've had my SMIM welded on the car before a trip to the drag strip and it held. A while later I had some bracing welded over that edge and it didn't crack again until I sold that manifold and head combo.

The welder kept asking if I wanted my floor boards checked.

That can be welded on the car, but here's why you shouldn't:

1) With your manifold being used there are now contaminants (carbon/oil residue) in the metal on the inside, and these will make welding very difficult. You can get lots of little bubbles coming up through the weld and these result in pinhole leaks. This means whoever welds this will want to check over and over again that the leaks are finally sealed (ideally with a pressure test though most places aren't going to set this up easily for your very specific manifold design on a whim without a lot of cost to you). A cheap way to check for leaks is to slosh some liquid on the inside of the plenum near the weld and blow high pressure air at it, and watch for bubbles on the outside.
2) You should add some bracing around the edges. Thicker aluminum folded over the seams, both near the runners but I'd also do the ends of the plenum too, and welded into place. This can virtually eliminate recurrence.

Taking an intake manifold off a car doesn't take much time at all, especially when it's a non-oem one. This will make your welder a lot happier too.

Make sure when this is re-welded that the head flange is re-checked for flatness. Welding around the runners can result in odd and unexpected warping that can deform the flange. Once deformed you can end up with a leak at the head, or worse have the flange start deforming the runners/plenum when torqued down and that can lead to really fast cracks in the plenum again (this exact scenario happened to me and took me a long time figure out what was going on).

It cracked because the joint was butted the wrong way. For outside corner joints it needs to be prepped like a V and where it cracked looks like it was an edge weld and cracked in the middle of it.

On top of that they ground down the weld.

Too add to TSIAWD666 in general aluminum does not like to be ben on tight radiai. I think the min bend radius is like 5X the material thickness. Different alloys have different charachteristics. If this is a china piece I'm sure it's mystery meat, so who know what it is.

Also the boost makes a lot of constant force in the intake trying to blow it up, but that's not the culprit. It's the sonic activity in the ports that make that thing vibrate like a drum head. That sharp corner is a stress concentration, and it gets fatigued first. Round manifolds are better than square in this respect.

Wow, thanks for all the great info. Gotta say, I think I'm headed back to the stocker and ponying up for the re-tune now.
A nice shiny bay does little for me when I have to keep pulling it off and having it welded up or constantly worry about boost leaks. At that point I would just invest in a quality SMIM.
When I did the boost leak test with soapy water I saw bubbles all around the throttle body bolts and they are torqued to spec and the gasket is new... so maybe the flat part of the SMIM that bolts to the throttle body is already warped.
So...folks that have had a SMIM and went back to stock....did your butt dyno say it was dissapointing in terms of top end loss? I honestly was expecting more out of the set up at 25psi...but it never felt fantastic...who knows maybe I had a little crack all along and we never noticed it.

On my old HX35 setup I went from stock to a short runner big plenum manifold and didn't really notice a gain. Theroetically that setup should have benefitted more from a good intake than yours. I wouldn't sweat it, you have much lower hanging fruit.

Awesome....

I can't get the stocker on and re-tuned until next week says my tuner. Last thing I'm wondering is if the car is driveable with no negative results until then? When I say driveable I mean basically enough to get it one hour away to the tuner shop?

I know that I "CAN" drive it and the AFR's are just a bit lean at idle (15.5-16.1), and fine everywhere else (I was expecing them to be richer in boost, but they are around 11.1) because I drove it all the way home not knowing about the crack. I could have had this crack a while, who knows. I never noticed anything as far as performance loss I don't think, but I had nothing to compare too, this happened shorlty after I got the car back from upgrades and tune. I just yesterday felt the top end shudder during a pull and my idle started getting weaker than normal on start up so that sparked the BLT.

But, I'm interested to now know a little more HOW the crack is affecting performance exactly. I'm honestly not sure how/if the ProEFI compensates when there is a leak in the manifold. I know the basic concept of a boost leak is letting in unmetered air at vac and pushing air out of the crack in boost, but is there a difference in where the leak is at? For example, the stock MAF metered the air prior to going into the turbo. The ProEfi can't be doing that because I have no sensors in my intake pipe. So where does the ProEfi measure the air and if there is a crack in the intake manifold how does it compensate for it? I'm sure this requires an answer above my knowledge base, but I basically just want to make sure I'm not hurting things getting this to the tuner.

Are you speed density? I have driven my car with the intercooler pipe blown off, and it drove just fine. I also don't use closed loop.
If you're speed density, the fuel is metered by what the map sensor is reported.

I would assume ProEfi runs on speed density because I'm bypassing the stock MAF. The stock MAF is only there right now because I haven't replaced my dejon intake pipe yet and the filter doesnt attach directly to the intake pipe without the stock MAF adapter...it's not even plugged in. I do have an aftermarket sensor of some sort mounted on my upper intercooler pipe so that must either be reading volume or temp of the intake air.

Just an fyi for others that have this happen....JB weld aluminum epoxy holds 30psi on a BLT all day long and the car has power again. Not going to be a permanent fix (looks like hell on the SMIM with a blob of JB weld), but this will definitely get you buy until you have the time/funds to get it fixed right.

More reasons to remove the manifold to fix it:

1) To properly fix the crack, you'll need to terminate it. You'll need to stop drill on both ends. This will put some amount of debris in the manifold that you'll need to clean out.

2) You'll want to leak test it afterward and leak testing on a bench is easier and generally more effective.


That whole edge looks bad though. Looks like you'll soon be dealing with more cracking. If I were you, I'd put the stock manifold back on until I could afford a properly build SMIM.

99gst_racer said:

More reasons to remove the manifold to fix it:

1) To properly fix the crack, you'll need to terminate it. You'll need to stop drill on both ends. This will put some amount of debris in the manifold that you'll need to clean out.

2) You'll want to leak test it afterward and leak testing on a bench is easier and generally more effective.


That whole edge looks bad though. Looks like you'll soon be dealing with more cracking. If I were you, I'd put the stock manifold back on until I could afford a properly build SMIM.

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don't worry, he jb welded it and he didn't say anywhere the brand of the manifold so it's obviously ebay. he posted in his journal earlier

@Bastard likes his low hanging fruit