WOT loud pop! Worries me.

wrxrick · 06-29-2008, 09:58 AM

Last night I was testing some WOT pulls for my new alky kit. My mods are as follows:

Open ECU professional tune
SMC Alcohol Injection
Turboback exhaust
GM Boost solenoid
Walbro Fuel Pump

I was doing a WOT pull last night and I noticed near the end of fourth gear at about 6,500rpms I heard a very loud pop. The strange thing is, is that no power was lost. I actually was able to keep going to 7,000rpms and even pushed it a little in 5th gear. It seems as though everything is fine. The sound seemed similar to someone taking a 12" wooden ruler and smacked it against a wooden school desk. Not sure what it was. Any ideas?

Again, no power loss, nothing. Car runs great. Just heard a loud pop from the engine bay at WOT.

wrxrick · 06-29-2008, 10:43 AM

Just spoke to a buddy of mine. Says it was intake backfire.

***520*** · 06-29-2008, 10:44 AM

IDK what intake backfire is, but check your IC hoses.

***sti_kris*** · 06-29-2008, 10:56 AM

intake backfire is do to an ignition issue i believe. friend of mine is having that problem but it is in a camaro.

wrxrick · 06-29-2008, 03:14 PM

How often do STi owners typically change out their plugs?

minorthreats · 06-29-2008, 03:54 PM

Quote:

Originally Posted by wrxrick

How often do STi owners typically change out their plugs?

too early...

***sti_kris*** · 06-29-2008, 04:16 PM

i need to change mine...

minorthreats · 06-29-2008, 04:34 PM

Quote:

Originally Posted by sti_kris

i need to change mine...

me to

**tyler_sti** · 06-29-2008, 04:42 PM

It's probly just a normal backfire. My invidia n1 would backfire at high rpms all the time. What are you're afr's between shifts?

wrxrick · 06-29-2008, 09:17 PM

^^^It wasn't an afterfire. It was a backfire.

An afterfire goes out the exhaust. A backfire goes up though the intake manifold.

I'm going to change my plugs. Actually, Subaru is going to change them. I hope they are under warranty. I'm not sure exactly how much they will charge for the labor and parts.

Anyway. I'm fairly confident that this was a backfire issue. I'm pretty sure it is not piston related or otherwise internally related since the car still has power and no smoke is exiting the exhaust. Since I'm on the alky all the time now, should I get stock plugs? Or aftermarket? And will I need to get re-tuned with aftermarket?

Thanks.

**boondocksaint** · 06-30-2008, 04:49 AM

Quote:

Originally Posted by wrxrick

Last night I was testing some WOT pulls for my new alky kit. My mods are as follows:

Open ECU professional tune
SMC Alcohol Injection
Turboback exhaust
GM Boost solenoid
Walbro Fuel Pump

Quote:

Originally Posted by wrxrick

I'm going to change my plugs. Actually, Subaru is going to change them. I hope they are under warranty. I'm not sure exactly how much they will charge for the labor and parts.

Anyway. I'm fairly confident that this was a backfire issue. I'm pretty sure it is not piston related or otherwise internally related since the car still has power and no smoke is exiting the exhaust. Since I'm on the alky all the time now, should I get stock plugs? Or aftermarket? And will I need to get re-tuned with aftermarket?

Thanks.

Sorry, I couldn't resist.

I cannot answer the plug question. Check the tuning forum.

limited777 · 06-30-2008, 04:59 AM

Quote:

Originally Posted by boondocksaint

Sorry, I couldn't resist.

my dealer specifically told me unless I was running a Big Turbo or MBC they would warrantee the car regardless unless clearly the issue was directly related to my part but they are really cool about that stuff.

**boondocksaint** · 06-30-2008, 05:14 AM

Quote:

Originally Posted by limited777

my dealer specifically told me unless I was running a Big Turbo or MBC they would warrantee the car regardless unless clearly the issue was directly related to my part but they are really cool about that stuff.

Good to know there are such dealerships.

limited777 · 06-30-2008, 06:23 AM

Quote:

Originally Posted by boondocksaint

Good to know there are such dealerships.

on the other had my other friends dealership is building his 30r setup and tuning it haha. Sick right

ninjaboy76 · 07-01-2008, 07:11 PM

Again, what are your AFRs at WOT? An intake backfire usually happens when you have to much fuel and it isn't getting burnt. You may be tuned to rich with the alky injection.

Quote:

Originally Posted by limited777

my dealer specifically told me unless I was running a Big Turbo or MBC they would warrantee the car regardless unless clearly the issue was directly related to my part but they are really cool about that stuff.

That's convienent until something goes wrong, then it will be easy for them to point the finger at your aftermarket mods. I wonder how nice they will be if they have to replace your motor?

06-29-2008, 09:58 AM	#1
wrxrick Junior STI Driver Car: 05 Subaru WRX STi Fav Mod: Tune Posts: 184 Join Date: Feb 2006 Trader Rating: (0)	WOT loud pop! Worries me. Last night I was testing some WOT pulls for my new alky kit. My mods are as follows: Open ECU professional tune SMC Alcohol Injection Turboback exhaust GM Boost solenoid Walbro Fuel Pump I was doing a WOT pull last night and I noticed near the end of fourth gear at about 6,500rpms I heard a very loud pop. The strange thing is, is that no power was lost. I actually was able to keep going to 7,000rpms and even pushed it a little in 5th gear. It seems as though everything is fine. The sound seemed similar to someone taking a 12" wooden ruler and smacked it against a wooden school desk. Not sure what it was. Any ideas? Again, no power loss, nothing. Car runs great. Just heard a loud pop from the engine bay at WOT. This ad is not endorsed by this member. Please register or login to hide this ad.

06-29-2008, 10:43 AM	#2
wrxrick Junior STI Driver Car: 05 Subaru WRX STi Fav Mod: Tune Posts: 184 Join Date: Feb 2006 Trader Rating: (0)	Re: WOT loud pop! Worries me. Just spoke to a buddy of mine. Says it was intake backfire.

06-29-2008, 10:44 AM	#3
*520* STi > EVO... Wait what??? Car: 03 EVO Fav Mod: stock :( Location: Michigan / Saint Louis Posts: 12,397 Join Date: Oct 2005 Trader Rating: (1)	Re: WOT loud pop! Worries me. IDK what intake backfire is, but check your IC hoses.

06-29-2008, 10:56 AM	#4
*sti_kris* its all in the curves Car: 05 CMG STI Fav Mod: Aps 3.5" TBE Location: Austin, Tx Posts: 841 Join Date: Apr 2008 Trader Rating: (0)	Re: WOT loud pop! Worries me. intake backfire is do to an ignition issue i believe. friend of mine is having that problem but it is in a camaro.

06-29-2008, 03:14 PM	#5
wrxrick Junior STI Driver Car: 05 Subaru WRX STi Fav Mod: Tune Posts: 184 Join Date: Feb 2006 Trader Rating: (0)	Re: WOT loud pop! Worries me. How often do STi owners typically change out their plugs?

06-29-2008, 04:16 PM	#7
*sti_kris* its all in the curves Car: 05 CMG STI Fav Mod: Aps 3.5" TBE Location: Austin, Tx Posts: 841 Join Date: Apr 2008 Trader Rating: (0)	Re: WOT loud pop! Worries me. i need to change mine...

06-29-2008, 04:42 PM	#9
tyler_sti Gold Member Car: '07 CMG STI Fav Mod: Not knowing how to "spell" hah Location: los angeles Posts: 3,736 Join Date: Aug 2006 Trader Rating: (15)	Re: WOT loud pop! Worries me. It's probly just a normal backfire. My invidia n1 would backfire at high rpms all the time. What are you're afr's between shifts?

06-29-2008, 09:17 PM	#10
wrxrick Junior STI Driver Car: 05 Subaru WRX STi Fav Mod: Tune Posts: 184 Join Date: Feb 2006 Trader Rating: (0)	Re: WOT loud pop! Worries me. ^^^It wasn't an afterfire. It was a backfire. An afterfire goes out the exhaust. A backfire goes up though the intake manifold. I'm going to change my plugs. Actually, Subaru is going to change them. I hope they are under warranty. I'm not sure exactly how much they will charge for the labor and parts. Anyway. I'm fairly confident that this was a backfire issue. I'm pretty sure it is not piston related or otherwise internally related since the car still has power and no smoke is exiting the exhaust. Since I'm on the alky all the time now, should I get stock plugs? Or aftermarket? And will I need to get re-tuned with aftermarket? Thanks.