2g open dump problem

[Jesse36]

So yesterday I put on my xs-performance open o2 dump. Before I took the old one off, my car was set at 16psi, put the new o2 dump on, didn't adjust anything, all of a sudden my car was pushing 23-24psi with alot of fuel cut. I turned it back down and started from the beginning, got it back to about 14psi then the car lost all power and became a dog. Pulled the plugs, in cylinder 1 and 4 the plugs were pretty much melted. Put new plugs in, but the motor still has no power and shakes a bunch. Any ideas? I'm guessing the timing jumped, but why would my open dump cause this?

 

[Vegas Smith]

Usually if you jump timing you get bent head valves and your car basically won't run at all. Is that what you're experiencing?

 

[1990TSIAWDTALON]

Do a compression test.

 

[gsxeclipse102]

Sounds like you over boosted. Time to check the health of the motor

 

[pauleyman]

if you melted plugs you may have also melted a piston, ring lands etc. Time to do a compression check.

 

[pauleyman]

You open dump likely didn't cause jumped time. Your open dump caused an increase in boost that you didn't expect. lean condition, melted plugs. What other damage is there remains to be seen.

 

[doubleclutch]

"Now me and the mad scientist have to tear apart the block and replace the piston rings you just fried"

 

[Jesse36]

Haven't checked it out completely yet. Car still runs, but runs like shit. Any reason the open dump would cause the car to over boost? From the forums I've read everyone says they are better for eliminating boost creep but I find that hard to believe now because it was all over the place

 

[doubleclutch]

Yes,
you got rid of all your back pressure allowing the turbo to spool up real easy.

 

[Jesse36]

So is there really any gains from an open dump or would a recirculated one be better for power wise because I've heard both good and bad things?

 

[Vegas Smith]

I think a recirculated will never be better but it will be quieter. The more airflow your setup makes the more benefit you will see from an external dump or larger exhaust pipe diameter.

 

[Jesse36]

Ok makes sense. I was worried I'd have troubles with it after all this happened. I'll just leave it on then since I plan on building the motor up anyway.

 

[doubleclutch]

If you think about what your asking, yes there are gains from an open dump. Clearly it allows your turbo to spool faster and utilize more energy from the exhaust (hence the overboost).

The question is if it is a street car do you want your car to sound like crap or not.

 

[gsxeclipse102]

O2 dump has nothing to do with spool of a turbo. The wastegate is closed during spool up. O2 dumps are needed when running a restricted exhaust (small diameter or restrictive muffler) or going for maximum hp. Whenever you change a component on the vehicle ecspecially involving the turbo extra care needs to be taken. At this point op needs to find out his motors condition

 

[Jesse36]

Well right now I have 3 inch straight pipe Apexi exhaust back to a 4 inch thermal can. My goal eventually is to have the car built to 500awhp. The open dump was just something i kinda wanted to try out to see if I like it or not. Honestly, it was kinda cool at first but then it got kind of annoying. So now if I build the motor up, idk if the open dump would be the way to go, or just get an aftermarket recirculated one because of the noise.

 

[doubleclutch]

O2 dump has nothing to do with spool of a turbo. The wastegate is closed during spool up. O2 dumps are needed when running a restricted exhaust (small diameter or restrictive muffler) or going for maximum hp. Whenever you change a component on the vehicle ecspecially involving the turbo extra care needs to be taken. At this point op needs to find out his motors condition

From his description it sounded like he was talking about and exhaust dump, not an o2 dump. An wastegate dump would affect being able to control the turbo if there was a restrictive 02 housing before (i.e. boost creep).

Either way, no dump little boost, after dump a lot of boost. Seems like it affects the spool of the turbo.

 

[Tyeler18]

From his description it sounded like he was talking about and exhaust dump, not an o2 dump. An wastegate dump would affect being able to control the turbo if there was a restrictive 02 housing before (i.e. boost creep).

Either way, no dump little boost, after dump a lot of boost. Seems like it affects the spool of the turbo.

This is incorrect. An open dump would increase the ability for the turbo to bypass exhaust, which decreases pressure on the turbine, which would decrease boost. You're using spool and total system pressure interchangeably and they aren't interchangeable.

 

[Jesse36]

Ok so what would be the best thing to do??

 

[Vegas Smith]

Ok so what would be the best thing to do??

About what?

 

[Jesse36]

Tyler18 said "You're using spool and total system pressure interchangeably and they aren't interchangeable." So would it be smarter to just go back to the stock o2 housing for now or just leave the open dump?

 

[gsxeclipse102]

What are you using to control boost?

 

[Jesse36]

Hallman boost controller

 

[Jesse36]

The car was also a dog when i first put the dump on. Wasn't as quick as it was before

 

[Vegas Smith]

It's not really going to make a difference either way. It's only real purpose it to allow you to run lower boost. It could possibly help reduce backpressure if you really really push your setup hard. When the exhaust gets dumped it basically makes your exhaust high-flowing. Sorry if I'm not explaining this well. just do a search and you'll find a million hits on this.

 

[Jesse36]

Oh ok. Yeah I was just hoping I'd get a power gain out of it but clearly I didn't and messed up the motor in the process ha