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Discussion Starter #1 (Edited)
Anyone know why I might be experiencing so much backfiring from this exhaust? My other mods are in my profile for reference, but I don't think any of them would contribute to or cause this....maybe the BOV, but I've got it adjusted to about as hard as it goes.

Thanks for the help, fellas.
 

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Discussion Starter #4
Thanks, fellas. I'll check both tomorrow and report back.
 

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Is the BOV really set for full recirc? If so, why'd you replace the stock BPV in the first place?

What map are you running? Is it one designed to work with the intake?
 

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Discussion Starter #6
The AFR @ WOT + 11.1. AFR peaked at 20.3 during a session of spirited driving (per AP live data). It hovers around 14.5.

As for the BOV, the stock BOV is not reliable at greater than stock boost levels. I know the problems and opnions people have with BOVs. I therefore went with a reputable name (Turbosmart Dual Port "sleeper") and keet it on full recirc (using block-off plate).

Yes, I am using the Stage 2+SFI map, accounting for Cobb's SFI.
 

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lokey said:
The AFR @ WOT + 11.1. AFR peaked at 20.3 during a session of spirited driving (per AP live data). It hovers around 14.5.
You do realize the stock sensor doesn't read below 11.1, right? ;)

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Discussion Starter #8
You do realize the stock sensor doesn't read below 11.1, right? ;)

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So, to get an accurate reading, I need an AFR gauge? Or can I just get a new sensor so my AP reads it correctly when I do need to check it? ....like today. :)
 

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lokey said:
So, to get an accurate reading, I need an AFR gauge? Or can I just get a new sensor so my AP reads it correctly when I do need to check it? ....like today. :)
WBO2. Not sure which ones are compatible with Cobb AP logging.

Innovate LC-1 / AEM UEGO are two popular choices with the OpenECU guys.

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Discussion Starter #10
Cool, thanks. I'll check them out.
 

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innovate wideband O2 here. works good and if you have a laptop you can log with that. i doubt thats your problem though (running rich or lean within the tune). back firing is a vacuum leak somewhere or the BPV "not" recirculating 100%. either way your dumping fuel without enough air to burn it up. if you just installed the TBE then you had to remove a bunch of stuff (TMIC). do a boost leak test first and for most. everyone should have a tester and should check stuff often. it should be just like normal maintenance!
 

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Or can I just get a new sensor so my AP reads it correctly
the AP doesnt read right because its just piggy backing off the OEM sensor which is not a wide band and doesnt read as well. boost, wide band, aos are a MUST for these cars, lol your 1/3 or 2/3's there.
 

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How bad is the back fire? If its a popping noise at shifts it is easily a bad gasket, unless your getting air into the mix (post turbo) the excess fuel wont burn off, so if you have an exhaust leak letting air in after turbo it will ignite causing a popping back fire type noise.
 

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Discussion Starter #14
It's definitely more of a popping than the typical backfire/sputter from the exhaust. It sounds like its coming from where the down meets the mid. However, I got it up on a lift yesterday to check it out and torque it down. Unless, like you said, its bad gasket from Cobb, I'm stumped.

Once the PW TMIC comes in next week, I'll do that install and check for leaks. As far as timing, it seemed to start shorlty after the BOV was put on, so that is now my lead suspect. I just want a BOV that can take 19-20 psi without caausing all of the issues I've read about. I thought Turbosmart would be a "smart" choice. :)
 

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It's definitely more of a popping than the typical backfire/sputter from the exhaust. It sounds like its coming from where the down meets the mid. However, I got it up on a lift yesterday to check it out and torque it down. Unless, like you said, its bad gasket from Cobb, I'm stumped.

Once the PW TMIC comes in next week, I'll do that install and check for leaks. As far as timing, it seemed to start shorlty after the BOV was put on, so that is now my lead suspect. I just want a BOV that can take 19-20 psi without caausing all of the issues I've read about. I thought Turbosmart would be a "smart" choice. :)
Forge Motorsport I've used their products before.. they're rebuildable and very durable. A little expensive, but worth it.
 

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It's definitely more of a popping than the typical backfire/sputter from the exhaust. It sounds like its coming from where the down meets the mid. However, I got it up on a lift yesterday to check it out and torque it down. Unless, like you said, its bad gasket from Cobb, I'm stumped.

Once the PW TMIC comes in next week, I'll do that install and check for leaks. As far as timing, it seemed to start shorlty after the BOV was put on, so that is now my lead suspect. I just want a BOV that can take 19-20 psi without caausing all of the issues I've read about. I thought Turbosmart would be a "smart" choice. :)
Is you BOV venting to atmosphere? If so, that could be the problem, running rich between shifts?
 

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Is it a cobb dp/Cobb cat back? Is it a brand new gasket? The gaskets that come with cat back exhausts are complete crap honestly, I have turned to the double thick from grimmspeed because I had a notorious leak there even with a good gasket I'd get popping.. Now I dont.

It's definitely more of a popping than the typical backfire/sputter from the exhaust. It sounds like its coming from where the down meets the mid. However, I got it up on a lift yesterday to check it out and torque it down. Unless, like you said, its bad gasket from Cobb, I'm stumped.

Once the PW TMIC comes in next week, I'll do that install and check for leaks. As far as timing, it seemed to start shorlty after the BOV was put on, so that is now my lead suspect. I just want a BOV that can take 19-20 psi without caausing all of the issues I've read about. I thought Turbosmart would be a "smart" choice. :)
 

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Discussion Starter #18
I was really on the fence between the Turbosmart and Forge. I'd hate to spend another $200+ bucks on another BOV. Ugh.

BOV is setup for full recirc (using block-off plate). I may be running rich, but I'm not sure, because I'm on the stock AFR sensor (see above). I do smell a little more gas when revving in the garage...? (yes, garage door open)

Yep, its the Cobb DP and CBE. When I get my protune, I'll have them check for leaks.

Do some TBE setups just "pop", regardless of what you do, just due to the increased amount of flow? Just asking.
 

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my tuner actually told me mine was normal with the large injectors and free flowing exhaust, however I still found a bad gasket at DP/MP
 

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Discussion Starter #20
Just talked to my tuner. He said that Cobb's OTS maps are often on the rich side to be safe. That sound right?
 
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