HELP NEEDED URGENT INTAKE EXPLOSION MAYBE BACKFIRE

[Hwarangdo]

Hello
I'm a team member of Universidad Central de Venezuela, we have a problem in our team.
We have a Intake of carbon fiber and when we try to swith our car it blow in the intake and exhaust.
We Think it was a back fire.
We are in Brooklyn Michigan, and we are looking for a solution.
If anybody have an idea, please contact us

[Hwarangdo]

Hello
I'm a team member of Universidad Central de Venezuela, we have a problem in our team.
We have a Intake of carbon fiber and when we try to swith our car it blow in the intake and exhaust.
We Think it was a back fire.
We are in Brooklyn Michigan, and we are looking for a solution.
If anybody have an idea, please contact us

[J. Vinella]

This is the exact reason we have switched to aluminum. Mainly poor design on our part for epoxy in peel.

If you can save the nozzle and runners you could maybe bend up some sheet pieces and weld or epoxy them together. Without knowing the damage it is hard to give advice. Some pictures would help.

Best of luck.

[Thrainer]

John, what reason? Because aluminium is stronger than CFRP?

Hwarangdo, maybe you can explain your old design and what happened. If your CFRP intake is not stiff enough, you can add a core and make it a sandwich. This is much more effecient than adding layers of CF.

Thomas

[J. Vinella]

Our manufacturing process led us to have a seam on the inside of the plenum. When a backfire happened inside the intake the seam effectively went into peel. Epoxies typically work great in shear but are shit in peel, you need something like rubber cement for that.

The intake we had was easy to layup but has this one terrible design flaw. Without seeing Hwarangdo's I cannot speak to the reason for his failed, but two part plenums with seams are common and easy enough...

[A Richards]

That happens a lot, and to lots of teams. I've seen it happen twice, once right in my face and its not much fun at all. We usually wear safety glasses or dont look at the engine when we start it cause you never know when it may happen. They 'usually' blow when your having trouble starting your engine thats slightly warm. You crank the guts out of it, let it sit with the intake valve open. That fills the intake with fuel vapour and when you hit the starter button........... BOOM. Dont think that alloy intakes wont blow up either. As for blowing the exhaust, not really sure how that happens?? You did bolt in on right??

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">

Hwarangdo, maybe you can explain your old design and what happened. If your CFRP intake is not stiff enough, you can add a core and make it a sandwich. This is much more effecient than adding layers of CF.

</div></BLOCKQUOTE>

Could not agree more. I said that exactly on the forum about a year back and got shoot to pieces for it. Unfortunatly with the any plenum we've every made it hasn't been joined as a sandwich panel and it still able to fail. If you intake dosn't suck in under throttle then its probably stiff enough anyway.


The Moral to this story is get your engine starting properly and it 'should not' happen. All the stories that i've heard of this occuring is when they said team is having trouble starting their car. Before my time some clown decided that it would be a good idea to spray aerostart into the intake, didnt end well.....

A good trick to get you by in the mean time, that is before your car starts easy, is to pull the plug lead off it after a few failed attempts to start and crank it over to clear vapour and fuel out of the engine. It should also go with out saying that you remove the injector plug as well http://fsae.com/groupee_common/emoticons/icon_smile.gif


Ash.

[A Richards]

Sorry think I read your message wrong, dont worry if your intake hasnt exploded in your face yet it probably soon will. Try looking at ignition timing.

[Mark TMV]

In the future you could try incorporating a valve or a plug that would "pop" in case of a backfire to save you from having to make a new intake...

[Mikey Antonakakis]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mark TMV:
In the future you could try incorporating a valve or a plug that would "pop" in case of a backfire to save you from having to make a new intake... </div></BLOCKQUOTE>
What if you installed this valve backwards so that under vacuum the intake sucks in more air, past the restictor? You wouldn't be breaking any rules, would you?? http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif

[Joe the plumber]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mikey Antonakakis:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mark TMV:
In the future you could try incorporating a valve or a plug that would "pop" in case of a backfire to save you from having to make a new intake... </div></BLOCKQUOTE>
What if you installed this valve backwards so that under vacuum the intake sucks in more air, past the restictor? You wouldn't be breaking any rules, would you?? http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif </div></BLOCKQUOTE>


Sure hope you are not serious, cause if you are you need to look at the rules before comp starts.

[Mikey Antonakakis]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Joe the plumber:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mikey Antonakakis:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mark TMV:
In the future you could try incorporating a valve or a plug that would "pop" in case of a backfire to save you from having to make a new intake... </div></BLOCKQUOTE>
What if you installed this valve backwards so that under vacuum the intake sucks in more air, past the restictor? You wouldn't be breaking any rules, would you?? http://fsae.com/groupee_common/emoticons/icon_rolleyes.gif </div></BLOCKQUOTE>


Sure hope you are not serious, cause if you are you need to look at the rules before comp starts. </div></BLOCKQUOTE>
...hence the rolling eyes

[jpusb]

que paso brother escribe Juan Pablo de la USB jefe de motor del 2008 voy a escribir en ingles pa que los del foro no se arrechen

It all depends on the damage the explosion made to the intake. If your plenum cracked you can always bond it back together with magic stuff, epoxys and CF layers. You can attach aluminium sheet metal pieces to the plenum to reinforce the whole thing.
What I would do is make a new plenum out of aluminium, weld it somewhere near where you are staying (radiator workshops or something) and do the attachements with the rest of the intake (runners and restrictor) outside the plenum.
If you need to, do not pay attention to smoothness in the plenum build, weld, and attachement to the runners, and pay even less attention to look, just get the thing running and to be ready for tech and try to retune as best as you can the thing so that the driver won't be battling with the engine to drive the car around.

Last year we brought like 3 different intake manifolds with us to the competition, just in case, but we didn't do so this year. Anyway, if you need anything we're staying at the Four Points hotel, Ann Arbor.

Good luck with that

[Steve O]

Hwarangdo I interpreted your problem different from everyone else: I am reading this as you want to fix the backfiring issue not that your intake is destroyed. If this is the case this problem is caused by the way some ECU's handle the falling edge signal when they turn on and how your coil is referenced relative to your ECU. There are two quick and easy ways you can handle it:

1) Put your ignition coil on a relay that is turned on with your ECU and place a slight delay cap in front of the relay to make sure the ECU is in its ready to start state before your coil is charged up.

2) The simple way: put a relay on your coil and put a manual switch to switch it on after you switch on your ECU. The downside to this is that you still have to remember to switch everything in the right order or you will end up with the backfiring issue again. An alternative although probably not a great last minute solution is to get a 3 position switch that is make before break. Position 1 - ECU off / Coil off; Position 2 - ECU on / Coil off; Position 3 - ECU on/ Coil on. The make before break is an important part of this switch or else your ecu will switch off between 2 and 3, again causing the same problem.

An alternative potential 3rd solution other than switching your coil separate from your ECU (that may or may not work depending on your ecu and coil) is to set your reference and ground pin on your coil to the reference pin on your ECU. This means that your reference is not chassis ground, it is the ECU's 0V equivalent to ground that does not change when the ecu switches on and off. For a last minute solution I recommend the first 2 suggestions though!

Good Luck,

Steve