Chargepipe Upgrade Worth It

[Spoolin Montego]

For the FBO guys is upgrading the charge pipe/BOV really worth it? I don't feel like I'm losing any boost through the stock diverter valves but I do get some wierd throttle closures when I let off from 100% throttle in the midrange.

Looking for personal experience from someone who was running full bolt ons and then upgraded the charge pipe.

[RnmEvo9]

If it ain't broke, don't fix it.

[That_1_Guy]

Originally Posted by RnmEvo9

If it ain't broke, don't fix it.

For the N54 guys, this statement is absolutely fine..... for us N55 owners, I would recommend that be the first upgrade.

But, if you go FBO, and have the means.... might as well get a more sturdy, durable (and prettier) pipe, that makes a better swishy noise

[nidfix]

Originally Posted by That_1_Guy

For the N54 guys, this statement is absolutely fine..... for us N55 owners, I would recommend that be the first upgrade.

But, if you go FBO, and have the means.... might as well get a more sturdy, durable (and prettier) pipe, that makes a better swishy noise

Why would it be more recommended for N55 ?
Is it flimsier on N55 ?

[That_1_Guy]

Originally Posted by nidfix

Why would it be more recommended for N55 ?
Is it flimsier on N55 ?

Yes, by far. N55 has plenty of owners who have experience "Cracks and breaks" at high boost levels. From just a simple crack causing boost leak, to some serious cases of it snapping off.

A lot of N55 owners will tell you that it is the first thing you should do. But then again, N54 is different.

[nidfix]

Originally Posted by That_1_Guy

Yes, by far. N55 has plenty of owners who have experience "Cracks and breaks" at high boost levels. From just a simple crack causing boost leak, to some serious cases of it snapping off.

A lot of N55 owners will tell you that it is the first thing you should do. But then again, N54 is different.

Thank you for the reply.
Do you believe it necessary even if the car is stock ?

[RimasRS]

Originally Posted by nidfix

Thank you for the reply.
Do you believe it necessary even if the car is stock ?

There was a cases when for example 1M was stock and it broke off the CP.

But I think stock car should handle just fine...

[That_1_Guy]

Stock, no. You're fine.

[nidfix]

Thank you !

[chrisko]

Sorry if this is a bit irrelevant to the whole discussion but I can't seem to find an answer anywhere. I came from a subaru and whenever you got a BOV, you needed to get tuned for it otherwise it would act quite silly.

Do you also need a tune for a BOV on our cars? Apologize if the question is dumb.

Thanks!

[Ian///M]

Originally Posted by chrisko

Do you also need a tune for a BOV on our cars? Apologize if the question is dumb.

Thanks!

No tune required.

[Tee-Dub]

What charge pipe is my question! I ordered my COBB today and have been looking at charge pipes and intercoolers all day. Can't make up my mind.

[chrisko]

Originally Posted by Ian///M

No tune required.

I assumed so since I couldn't find any info regarding BOV and tune.

Thanks a ton for your response.

[chrisko]

Originally Posted by Tee-Dub

What charge pipe is my question! I ordered my COBB today and have been looking at charge pipes and intercoolers all day. Can't make up my mind.

From what I've seen around, seems like majority vote is on this: http://www.evolutionracewerks.com/node/190

[Tee-Dub]

Yeah, I've been leaning towards the ER, although mine is an N54, so different CP than what you posted a link to.

[Ian///M]

Originally Posted by chrisko

I assumed so since I couldn't find any info regarding BOV and tune.

Thanks a ton for your response.

Don't expect any performance gain. Simply that the stock CP can cause problems, but most are fine. IMO, if it breaks, replace it, else leave be.

Another 1M member had a blown engine and was denied warranty due to aftermarket CP fitted.

[That_1_Guy]

Originally Posted by Ian///M

Don't expect any performance gain. Simply that the stock CP can cause problems, but most are fine. IMO, if it breaks, replace it, else leave be.

Another 1M member had a blown engine and was denied warranty due to aftermarket CP fitted.

That would not fly with me. Unless you can show me how a better fitted part assisted in breaking the car, you won't just deny warranty. But hey, guess there are always horror stories.

[chrisko]

Originally Posted by That_1_Guy

That would not fly with me. Unless you can show me how a better fitted part assisted in breaking the car, you won't just deny warranty. But hey, guess there are always horror stories.

I'd probably switch back to stock CP before taking it back in for warranty

[Colt]

Originally Posted by chrisko

From what I've seen around, seems like majority vote is on this: http://www.evolutionracewerks.com/node/190

Love my ER CP. I'd go with them or ETS, IMO

[Freon]

Originally Posted by chrisko

Sorry if this is a bit irrelevant to the whole discussion but I can't seem to find an answer anywhere. I came from a subaru and whenever you got a BOV, you needed to get tuned for it otherwise it would act quite silly.

Do you also need a tune for a BOV on our cars? Apologize if the question is dumb.

On a Subaru or the N55, the fueling is MAF based. The air is "metered" as it passes the MAF sensor, so the engine computer injects fuel as if that air was going into the cylinders. If it is instead dumped back out to the atmosphere instead of recirculated into the intake, the car still injects that fuel and the car goes rich. It has absolutely no way to "know" that air was dumped. There's no "tune" fix for that either. It is a system design error.

The worst part is that after the oxygen sensor detects that rich spike, the ECU try to pull fuel, and then the car goes lean. This can be bad. You shift, go rich, ECU tries to compensate, you punch the gas, car goes lean. Not good. In situations such as full throttle, part throttle, full throttle you can easily cause the engine to knock due to the lean condition at high throttle. Oxygen sensors are not fast enough to deal with this. If they were, you wouldn't need any MAF or even speed density.

There's really no way to tune this out on a Subaru or N55, but people love their ridiculous noise making external dump blow off valves, so there is a falsehood spread that you are ok as long as it is tuned for so tuners can take money in to "fix" it. But there's no actual way to tune this problem out, and I'd be more than happy to have an open debate with anyone who disagrees. It's a system design flaw to dump metered air. The real fixes would be to relocate the MAF between the blow off valve and throttle (which is a huge undertaking and really only done for big turbo cars, and comes with its own host of problems), or switch to speed-density fueling like the N54, which again is not always simple. I see no circumstance where you should do this just because you want a noise making device so the car sounds cool.

I highly recommend against ever using a blow off valve that dumps air out of the system on any car with a mass airflow sensor. Not even 50/50 valves that recirculate at first, but open dump on larger throttle reductions. You've just made the flaw smaller, but it is still a flaw.

N54, good to go, doesn't really matter as it uses speed density fueling. Use whatever blow off valve style you want. You may want to adjust the spring on the blow off valve itself to give you the best behavior. There are pros and cons to tighter or looser release. N55, stick with a full recirculating setup where the air released from the charge pipe is routed back into the intake.

I still tend to think the tune itself really doesn't have too much effect.

For the record, I tuned dozens if not hundreds of Subarus for years from around 2004-2008, and was heavily involved in OpenECU, and wrote an actual speed-density patch for the 32bit Renesas CPU that is now widely used in many EJ257 turbo that are tuned using OpenECU.

[chrisko]

Originally Posted by Freon

On a Subaru or the N55, the fueling is MAF based. The air is "metered" as it passes the MAF sensor, so the engine computer injects fuel as if that air was going into the cylinders. If it is instead dumped back out to the atmosphere instead of recirculated into the intake, the car still injects that fuel and the car goes rich. It has absolutely no way to "know" that air was dumped. There's no "tune" fix for that either. It is a system design error.

The worst part is that after the oxygen sensor detects that rich spike, the ECU try to pull fuel, and then the car goes lean. This can be bad. You shift, go rich, ECU tries to compensate, you punch the gas, car goes lean. Not good. In situations such as full throttle, part throttle, full throttle you can easily cause the engine to knock due to the lean condition at high throttle. Oxygen sensors are not fast enough to deal with this. If they were, you wouldn't need any MAF or even speed density.

There's really no way to tune this out on a Subaru or N55, but people love their ridiculous noise making external dump blow off valves, so there is a falsehood spread that you are ok as long as it is tuned for so tuners can take money in to "fix" it. But there's no actual way to tune this problem out, and I'd be more than happy to have an open debate with anyone who disagrees. It's a system design flaw to dump metered air. The real fixes would be to relocate the MAF between the blow off valve and throttle (which is a huge undertaking and really only done for big turbo cars, and comes with its own host of problems), or switch to speed-density fueling like the N54, which again is not always simple. I see no circumstance where you should do this just because you want a noise making device so the car sounds cool.

I highly recommend against ever using a blow off valve that dumps air out of the system on any car with a mass airflow sensor. Not even 50/50 valves that recirculate at first, but open dump on larger throttle reductions. You've just made the flaw smaller, but it is still a flaw.

N54, good to go, doesn't really matter as it uses speed density fueling. Use whatever blow off valve style you want. You may want to adjust the spring on the blow off valve itself to give you the best behavior. There are pros and cons to tighter or looser release. N55, stick with a full recirculating setup where the air released from the charge pipe is routed back into the intake.

I still tend to think the tune itself really doesn't have too much effect.

For the record, I tuned dozens if not hundreds of Subarus for years from around 2004-2008, and was heavily involved in OpenECU, and wrote an actual speed-density patch for the 32bit Renesas CPU that is now widely used in many EJ257 turbo that are tuned using OpenECU.

Thanks for the great info, you definitely seem quite knowledgeable in the subject and it all makes sense. I remember on my Subaru I never really had any issues with the BOV besides when it was "unntuned." It wouldn't idle. I always did open-source as well (bugeye 2003 w/ EJ257). But do you think the jerk from releasing throttle midboost would be due to the BOV? I remember it always did that but I always assumed it was backpressure buildup from the turbo.

After reading this, I think I may stick with the BPV

[Jcp135]

Originally Posted by Tee-Dub

What charge pipe is my question! I ordered my COBB today and have been looking at charge pipes and intercoolers all day. Can't make up my mind.

I was trying my new Cobb Acces Port yesterday, changing between maps and my charge pipe broke. I will go with ER.