Swallowing my pride and asking questions...

[LilToTo17]

Not familiar with 27Won, I'll give them a look.

RV6 makes quality downpipes as well and they are releasing their frontpipe soon for a full 3" setup.
https://www.rv6-p.com/rv6-tm-modular-downpipe-for-17-civic-si.html

Sponsored

 

[LilToTo17]

Ok, but why does the bov need to go. I'm all ears as I may certainly have made the wrong assumption and decision in getting one, but would like to learn why. Everything I read lead me to believe that they won't add any performance, but they won't hurt.

It'll make your car run rich

 

[ek5.56]

It'll make your car run rich

Well ain't that a bitch... I appreciate the words of caution guys. I contacted the retailer and requested a refund. I placed the order yesterday so it hadn't even shipped yet, so the refund should be an issue.

 

[erbee]

They gonna hate us for sure .......

 

[Micah]

Well ain't that a bitch... I appreciate the words of caution guys. I contacted the retailer and requested a refund. I placed the other yesterday so it hadn't even shipped yet, so the refund should be an issue.

In a Nutshell...... (I am not a mechanic - nor a tuner, but I've owned a few tuned turbocharged cars, Protege, WRX, EVOX, Mini Cooper, and now Civic)

Our cars are MAF tuned. This means the Mass Air Flow sensor is used to determine how much fuel needs to be added based on the measured metered air which flows past the MAF. An alternative to this would be MAP tuning, Manifold Absolute Pressure. Our car does have a MAP sensor, but the tuning for AFR (Air Fuel Ratio) targeting is based on the MAF with our cars. Arguably MAF is better than MAP, but generally speaking if you want to significantly modify and increase power output.... MAP is the preferred method.

So the issue is essentially..... normally MAF reads air - computer sees air and sends appropriate amount of fuel and the cylinder gets the proper mixture for a good combustion cycle, when the car is in boost, extra air is compressed and thus extra fuel is added to maintain the proper mixture. When you let off the gas, as the throttle plate closes, the pressure in the intake piping overwhelms the vacuum which opens the stock BPV (by pass valve), and that air is re-routed back into the intake track where it will continue to enter the engine before the throttle body closes it's flap. With a BOV in place of a BPV, the air is VTA (vented to atmosphere) which results in far less air making it's way into the engine. This is a big problem since the fuel being sent is still based on that metered air. Now you've got an abundance of fuel, which doesn't mix with enough air and doesn't burn, instead it washes the cylinder walls and pulls oil in the process. This new mixture of oil and fuel gets sent out with the exhaust stroke, which is not good. You've wasted fuel and oil, increased friction, and thrown extra hot fuel/oil mixture on your catalytic element. ALL BAD THINGS.

The good news is, you never put it on your car, you will avoid this. Instead, pick up a CAI or SRI (READ REVIEWS AND CHOOSE WISELY, not all of them are well regarded) and when the BPV does it's thing, the "whoosh" sound you are interested in hearing will be audible. If you do not want to read reviews - go for the PRL Cobra CAI or PRL SRI as they have been extensively tested and validated by many people.

Also, welcome to the forum and welcome to owning a turbocharged car.
Some things to keep in mind.

--Boost is based on load. It is easier to build boost uphill than downhill because of load. Just because you can build boost doesn't mean you should. This means when you are in 5th/6th gear, mashing the throttle is a bad idea as the stress on your engine is higher and the resulting acceleration is going to be less. Downshift to a lower gear.

--Turbochargers are oil cooled, if you wait for the car to warm up before using boost and drive easy for a couple minutes before shutting off your engine, the turbo will last longer. Some turbo's are both oil and water cooled. The same behavior should still apply.

--Turbocharged and Supercharged cars are designed to operate in a variety of elevations with different air density, this means there is some wiggle room from the factory which is why forced induction cars typically respond very well to tuning.

 

[ek5.56]

In a Nutshell...... (I am not a mechanic - nor a tuner, but I've owned a few tuned turbocharged cars, Protege, WRX, EVOX, Mini Cooper, and now Civic)

Our cars are MAF tuned. This means the Mass Air Flow sensor is used to determine how much fuel needs to be added based on the measured metered air which flows past the MAF. An alternative to this would be MAP tuning, Manifold Absolute Pressure. Our car does have a MAP sensor, but the tuning for AFR (Air Fuel Ratio) targeting is based on the MAF with our cars. Arguably MAF is better than MAP, but generally speaking if you want to significantly modify and increase power output.... MAP is the preferred method.

So the issue is essentially..... normally MAF reads air - computer sees air and sends appropriate amount of fuel and the cylinder gets the proper mixture for a good combustion cycle, when the car is in boost, extra air is compressed and thus extra fuel is added to maintain the proper mixture. When you let off the gas, as the throttle plate closes, the pressure in the intake piping overwhelms the vacuum which opens the stock BPV (by pass valve), and that air is re-routed back into the intake track where it will continue to enter the engine before the throttle body closes it's flap. With a BOV in place of a BPV, the air is VTA (vented to atmosphere) which results in far less air making it's way into the engine. This is a big problem since the fuel being sent is still based on that metered air. Now you've got an abundance of fuel, which doesn't mix with enough air and doesn't burn, instead it washes the cylinder walls and pulls oil in the process. This new mixture of oil and fuel gets sent out with the exhaust stroke, which is not good. You've wasted fuel and oil, increased friction, and thrown extra hot fuel/oil mixture on your catalytic element. ALL BAD THINGS.

The good news is, you never put it on your car, you will avoid this. Instead, pick up a CAI or SRI (READ REVIEWS AND CHOOSE WISELY, not all of them are well regarded) and when the BPV does it's thing, the "whoosh" sound you are interested in hearing will be audible. If you do not want to read reviews - go for the PRL Cobra CAI or PRL SRI as they have been extensively tested and validated by many people.

Also, welcome to the forum and welcome to owning a turbocharged car.
Some things to keep in mind.

--Boost is based on load. It is easier to build boost uphill than downhill because of load. Just because you can build boost doesn't mean you should. This means when you are in 5th/6th gear, mashing the throttle is a bad idea as the stress on your engine is higher and the resulting acceleration is going to be less. Downshift to a lower gear.

--Turbochargers are oil cooled, if you wait for the car to warm up before using boost and drive easy for a couple minutes before shutting off your engine, the turbo will last longer. Some turbo's are both oil and water cooled. The same behavior should still apply.

--Turbocharged and Supercharged cars are designed to operate in a variety of elevations with different air density, this means there is some wiggle room from the factory which is why forced induction cars typically respond very well to tuning.

This is a great write up, thank you. Makes perfect sense when you lay it out like that. So from what I gather based on this info, if I were to add a bov, I’d get the “pssh” noise, but I get a smoky stinky exhaust and be doing long term harm to my cyclinders and other areas I’m sure. And for some more money I can achieve the same noise by adding a cai, except now I’m not only getting the turbo sound, I’m getting the other sounds of the cai and increased performance. Sounds reasonable enough to me. I’ve settled on a cai, but want to check out the 27won before pulling the trigger on the prl. Thanks again

 

[LilToTo17]

This is a great write up, thank you. Makes perfect sense when you lay it out like that. So from what I gather based on this info, if I were to add a bov, I’d get the “pssh” noise, but I get a smoky stinky exhaust and be doing long term harm to my cyclinders and other areas I’m sure. And for some more money I can achieve the same noise by adding a cai, except now I’m not only getting the turbo sound, I’m getting the other sounds of the cai and increased performance. Sounds reasonable enough to me. I’ve settled on a cai, but want to check out the 27won before pulling the trigger on the prl. Thanks again

Well you might be waiting a while more if you order from PRL as they just sent out their bulk orders of intercoolers and cold air intakes. I have an Injen CAI but just ordered my 27won CAI and will not regret it as this intake is still pulling cool air from the fender well and the enclosed box where the filter lies rejects heat so technically it is a CAI

 

[RunningHot2017]

Ok, but why does the bov need to go. I'm all ears as I may certainly have made the wrong assumption and decision in getting one, but would like to learn why. Everything I read lead me to believe that they won't add any performance, but they won't hurt.

Not normally no but the Honda 1.5 Turbo is designed with a recirculating valve. Its not really meant to vent to atmosphere. Vit did some research awhile back and saw that it messed with the fuel trims. I cant really remember what else came from that thread, but thats most of it.

Edit: uhh, what Micah said.

 

[17siturb0]

If the V2 unit for Ktuner is to much, get the V1, better set of tires, rear Hasport mount, Prl downpipe, Prl intercooler and Prl cold air intake.

Now if you want to put all that power down, upgrade your clutch, I recommend the fx300. That’s the majority of it right there.

*edit return the BOV its a pile of sh!T

 

[ek5.56]

KTuner is $449, not $6-700. If you're going to just do one mod this is the one to do. Intake will set you back a couple of hundred and will net you a whopping 3-4 HP on an otherwise stock car.

I was referring to the v2. Im seeing them for $649.99

 

[Micah]

I was referring to the v2. Im seeing them for $649.99

Save your money and just get the v1 or v1.2. you can use a smartphone or your factory entertainment screen to run the software and monitor the same stuff you would see on the screen.

Also consider purchasing your tuning device used. There is typically zero wear and tear on them. I purchased my Hondata used for $500 shipped. You can find people selling ktuner v1 and v2 on this forum.

 

[a c i d.f l y]

I was referring to the v2. Im seeing them for $649.99

There's zero difference between the tune applied to your car between a v1.2 and 2.0. The Smartphone ap with Ktuner feature set is $4.99, so you don't even need a laptop. The Ktuner is seriously the best $455 (with ap) you can spend on your car right now.

After that, TIRES. A good set of rubber changes the whole feel and performance of the car. After that, if ya wanna get crazy go for an intercooler, downpipe, and maybe a CAI. Get a SRI if you just want a little extra growl coming from your engine bay.

 

[HondadSi]

Also if you want to save money you can look for used ktuners and or flashpros on forums.

 

[T_A_H]

First things I got for my Si:

Window tint
All weather floor mats

Actually those were the last things I got for my Si

 

[Luckyarmpit]

Welcome to the forums. First, you don't need to swallow your pride to ask questions. This is how we learn.

As others have said, the Boomba BOV is a bad idea because of how eloquently @Micah explained. If you want that turbo sound, install a SRi or CAI kit. I installed the Injen kit and opted for the full CAI. And yes, to answer your question, you remove the stock resonator box when you install the CAI kit. You clearly hear the hiss of incoming air and the psssshhhhh when the BOV operates.

Sponsored