Intake manifold explosion! Alcohol possible cause?
Originally Posted by Fourdoor
#4 How much are you offereing? I thought of having it repaired and then selling it, but if it failed again the buyer would fined some way to blame me.... if you want to purchase it "as is" and do your own repair PM me with an offer 
Keith
Keith
Actually the 3rd or 4th one of these I have seen, its not that uncommon.
http://www.4g63hp.com/forums/attachm...5&d=1135914298
http://www.4g63hp.com/forums/attachm...6&d=1135914304
http://www.4g63hp.com/forums/attachm...5&d=1135914298
http://www.4g63hp.com/forums/attachm...6&d=1135914304
Thread Starter
Joined: Oct 2003
Posts: 2,702
Likes: 4
From: Rosedale, IN
Originally Posted by TheGVR4kid
How come the velocity stacks don't look like the pretty CNC'd one that they've always advertised?
Originally Posted by dryad001
My thoughts exactly.
Keith
This is probably due to the methanol puddling in your intake. The meth would not have necessarily been consumed in the explosion, the explosion could have blown out the available o2 which would result in the left over meth in the intake.
This was obviously caused by some sort of backfire, I really don't care to speculate how it happened. One thing to keep in mind though, when instances like this happen it is not a bad thing to have your intake manifold blow apart like this. Something has to be the weak link when this happens. Whether it's an intercooler endtank, intake manifold, pressure making it's way through the turbo, or a ring land on one of your pistons. Take your pic on what you'd rather have. Personally I'd like to see the intake manifold or intercooler let go.
I agree. This appears to be a result of a backfire.
Keep in mind that modern port injected manifolds (including aftermarket jobs) are designed to be run dry. When injecting any liquid, some puddling should be expected. Likewise, unlike the stock setup, the mixture in the manifold is explosive, and is subject to ignition if something causes a sparkplug to fire at the wrong time (i.e. while the intake valve is open). When this happens, the explosion will cause a rupture of the weakest link, which in this case is the manifold weld. The force of the explosion is also probably to blame for the failed injector o-rings, but the weld gave because the leakage past the o-rings wasn't enough to contain the pressure the resulted from the explosion.
It might not be a bad idea to check the TB and the integrity of that shaft seal, and vacuum lines as well.
Keep in mind that modern port injected manifolds (including aftermarket jobs) are designed to be run dry. When injecting any liquid, some puddling should be expected. Likewise, unlike the stock setup, the mixture in the manifold is explosive, and is subject to ignition if something causes a sparkplug to fire at the wrong time (i.e. while the intake valve is open). When this happens, the explosion will cause a rupture of the weakest link, which in this case is the manifold weld. The force of the explosion is also probably to blame for the failed injector o-rings, but the weld gave because the leakage past the o-rings wasn't enough to contain the pressure the resulted from the explosion.
It might not be a bad idea to check the TB and the integrity of that shaft seal, and vacuum lines as well.
I had the same thing happen to my weapon R intake manifold at GT Live. I was running around 30psi. same setup too... GT35r with alky.
It didn't blow apart as bad as yours but it blew open in multiple places though... Like along all the stacks and plenums!
It didn't blow apart as bad as yours but it blew open in multiple places though... Like along all the stacks and plenums!
Newbie
Joined: Oct 2006
Posts: 82
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From: Toronto
Meth
Methanol injection explosions, are actually very common these days, as the popularity of Meth injection rises. Meth injection backfires behave exactly like a nitrous backfire.
When you load up the intake manifold with fuel, and you have a rich misfire, you will experience just this.
Clear evidence is the birthing of the plenum, only an sudden tremendous amount of force could have caused that.
With small backfires, the plenum usualy retains its integrity resulting in only small amounts of distortion. You can never how bad your backfire will be, all you know is BANG, and your car is usually bouncing off the rev limiter. The best thing to do is program in fail safes through your engine management, and gradualy step it in, making sure to not run too rich, always making sure your ignition system is in optimum condition.
That was an early model there in the pic, newer plenum's have added features to protect you in case of large backfires. extar features include: internal welding, thicker material, and external bracing as well. They have been tested to 130psi of pressure, on the bench with using nitrogen. The have a hard time sealing gaskets past 90 psi.
When you load up the intake manifold with fuel, and you have a rich misfire, you will experience just this.
Clear evidence is the birthing of the plenum, only an sudden tremendous amount of force could have caused that.
With small backfires, the plenum usualy retains its integrity resulting in only small amounts of distortion. You can never how bad your backfire will be, all you know is BANG, and your car is usually bouncing off the rev limiter. The best thing to do is program in fail safes through your engine management, and gradualy step it in, making sure to not run too rich, always making sure your ignition system is in optimum condition.
That was an early model there in the pic, newer plenum's have added features to protect you in case of large backfires. extar features include: internal welding, thicker material, and external bracing as well. They have been tested to 130psi of pressure, on the bench with using nitrogen. The have a hard time sealing gaskets past 90 psi.
Newbie
Joined: Dec 2003
Posts: 55
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That is in no way Magnus's Fault...
Welds are not to blame.
What happened was as marco stated a rich misfire..
It could also have been a lean backfire. Both cause tremendous amounts of force in the intake manifolds.
i have datalogged upto 84psi in one of my intakes before it blew apart like a can of sardines. It's a good thing the intake went as i have seen even worse conditions. It could travel all the way back to the turbo and kick the nut off the comp wheel and destroy your turbo. I rather weld up a new intake then replace expensive turbo's or other parts...
Welds are not to blame.
What happened was as marco stated a rich misfire..
It could also have been a lean backfire. Both cause tremendous amounts of force in the intake manifolds.
i have datalogged upto 84psi in one of my intakes before it blew apart like a can of sardines. It's a good thing the intake went as i have seen even worse conditions. It could travel all the way back to the turbo and kick the nut off the comp wheel and destroy your turbo. I rather weld up a new intake then replace expensive turbo's or other parts...
