If you were under boost, the 5th injector was firing fuel into the throttle body. That means the air going into the intake manifold also had fuel in it. At the right mixture, this could easily be ignited and the intake will become, in effect, a combustion chamber. That's what I believe happened. I doubt that 8 or 9 PSI could explode the plastic intake. But 100 PSI certainly could, as in a fuel-air explosion.

The question is, what set it off? It could have been the previous racing heated up the intake valves to the point where the fuel-air stream was ignited in the intake port and the explosion propigated back into the manifold.

This would be a very interesting question to pose to John Conchie.

Just a thought...

 

thats a good point there, i was all worried but i forgot they are spraying fuel into the intake on the alpine kit which i will not be so hopefully my 2.4 manifold will be fine on about 10 psi or whatever

 

Actually if you ask john, the stock intake manifold cannot take anymore then about 10-11psi then it does exactly what happened to my car(i could very well have been pushing that after my exhaust was done). thats how i know it was because of the boost pressure. That could have happened, but i dont believe so, because i have pushed my car MUCH harder then that. I will be talkin to him, but i plan on replacing the stock plastic one, as should anyone that buys the kit who is going to beat their car up. I run my car WOT all the time, doing so to a PLASTIC manifold is going to put a lot of strain on it. After 3000 miles of being beat, im not surprised it blew up.

Just a thought...

 

are you positive it wasn't a fuel puddle/backfire??

 

i really havent heard any storys like that from other bossted ecotec that uses the same intake maniflod, i ran my car hard but it threw a rod just driving half ass. i plan on pickin up a saab manifold

 

how did this happen?

the is the first story I've ever heard of any Ecotec guys blowing their plastic manifold due to boost levels...I'm not so sure about that one.

 

Dude, it has nothing to do with your manifold being plastic...

Your manifold "exploded" like Lewi-SS just said...fuel puddling. Like rollerman had a fuel puddling issue with his nitrous wet kit...you're essentially doing the same thing.

Think about physics...

In order for there to be a explosion, there has to be something that is actually explosive and a ignitor. Air pressure by itself (even with a hot intake manifold) isn't going to make your manifold explode. Like Lewi-SS said, in order for air pressure to make your manifold pop off, you'd have to be pushing some astronomical amount of pressure to where the bolts physically come loose and pop off. It's coming off because it can't handle the pressure being presented. A explosion is totally different.

Another thing to think about is how does your extra injector operate. On a engine, the intake valves open, the fuel injectors spray, then shuts off, valves close. On your extra injector, is it staying CONSTANTLY open? I know everything happens very fast but this is something to think about. If it is staying constantly open, this doesn't suprise me that you're having a fuel puddling issue.

Overall, air pressure isn't the cause of this and for someone to tell you this makes me think something is wrong. Air pressure isn't going to cause a explosion or even a hole in your manifold. No disrespect to whoever John is but I think they need to think about that statement to you with more research. I know people who are running larger turbochargers than you on the stock 2.2 manifold (on j-bodies) with over 10 PSI of boost pressure and NEVER had a problem manifold wise.

Pressure isn't the culprate...fuel is.

 

yay some one lied to you about your manifold. yay for fuel puddling

 

The extra injector is triggered when boost reaches a certain point and the duty cycle is varied based on boost (both variables are adjustable). I do believe it's not timed to intake cycle. Therefore it is providing fuel to the intake stream constantly. This is the same as all N2O systems. Generally at higher flow there is little or no puddling. I've seen engine swaps into Gen I Neons that are firing the port injectors 180% out and it makes surprisingly little difference. The fuel just "hangs around" for a brief fraction of a second waiting for the valve to open. It idles a bit rough, but at higher RPM it's pretty much normal.

N2) puddling is much more dangerous than fuel puddling. Fuel puddles generally aren't ignitable, but vapor is, which is why I wondered if there was a hot spot or backfire. 10 PSI+ might eventually split the plastic intake manifold (more from pressure cycling than anything - plastic will fatigue much like aluminum sheet) but an explosion would be unlikely.

This "John" we talk about owns Alpine. He has a tememdous amount of experience at turbocharging numerous gas and diesel engines. I will probably ask him about the explosion issue.

Dude, I saw your engine Saturday. If you don't want it, can I have it? It's truely amazing! Oh, not to make light of it - truely a sad occurence, my condolences and all, sorry for your loss. But if I ever grenade an engine, I hope it's as creative as yours! It makes the hydraulic lock pics from a few months ago look like a minor scratch! Hopefully you'll be up and running again in short order.

 

if you ran out of money, i wouldn't put the turbo on yet... what if something DOES happen? basically you're screwed, you'll be without a car until you get that money saved up. being that you're going to pretty much be the first boosted 2.4, that we know of atleast, you may run into undiscovered problems since no one else has done this... no money for fixing it = don't put the turbo on.

i think this is quite sad... the first person to get a turbo blows his manifold... not looking very promising at all...

 

Duane whats up man...i have seen this with nitrous setup many times or it has been know to be called "dragon's breath"...

Usually on nitrous it is a puddling issue OR pre-ignition as the cylinders are glowing hot and you have vapors lingering around and boom...at WOT or cruising or what ever if there is fumes and some sort or spark or heat to ignite it then you will have this issue...

All it boils down to was the tune...tune was fine on his setup before...then Duane went to a bigger exhaust and was not "Re-Tuned" for the change so the ecm was only being safe and adding fuel as it is instructed to...

Manifold i have seen pushed to 15psi with no issue's...simply put this was caused by a tuning issue...very simple fix and lesson learned...

 

actually I think thats one blown motor and one blown manifold...

 

well i hope the 2.4 can do this a little better with the stronger parts used in it...i'm gonna attempt it either way i guess. i was shooting for 270whp but i think i might tune for a little less till i know its safe.

 

i should have the manifold off today or tomorrow, we will see what happened, ill have pics too. and the manifold didnt get blown off the bolts. it just split at the seems.

 

my supercharged cobalt > your turbocharged cobalt.....what the point of doing the turbo when my car is still going to destroy yours all day long??? to beat ricers and civics?? and other 160hp cars?? i dont get it?? y not just buy a fast car in the first place?

 

Because we crave abuse from SS/SC owners who are full of themselves...

The blown motor had nothing to do with the turbo...

 

wow your cool ..... i still believe it puddled in the mani and it backfired tho man

 

you bought a mid 14 second car, and you're saying why not just buy a fast car in the first place?? if you had a z06 you can say something like that, but you bought a cobalt and this statement really shows how ignorant you are.

 

thats not what I hear...what happened then

 

Thats funny because i destroy SS/SCs and redlines. I dynoed 212/224 in denver. Im 2500ft lower then that now. Which means you dont have **** on my car. Im sorry you had to spend 24k and i've spent MAYBE 15k.

 

Sway, was there a actual explosion or did you happen to notice a crack?

 

it was just a crack at the seams. It "poped", sounded exactly like a balloon under my hood. The manifold doubles back on itself right? well it seemed like it popped at the bottom, and just seperated back towards the intake of the engine like someone pryed it back. Ill have pics tomorrow, i just didnt want to take crappy ones when it was dark.

 

got my car for 18000 and have put 3000 into it and i dynoed at 279 whp so come get some from your turbo 2.2 and to what D4 said i own a 2000 corvette as one of my other cars and i have a 2002 yukon denali so i can say whatever i want sir!!!! hahahahha and 2.2 will be slow no matter how hard you guys try!!!!

 

so what if it is "slow" in the grand scheme of things? how does that affect you in any way, and why does it seem to bother you?

 

Did this happen when you were under full acceleration?

A pop to me sounds like a explosion.