New Exhaust and I have questions.

[XProjectWaffleX]

okay so I'm new to the civic si. The last Honda I had was a 1996 Honda accord SOHC F22 long block NA.

This is the first vehicle I've ever owned that has a turbo which changes things when it comes to mods. (2019 Honda civic si coupe 1.5L)

Of course the first thing I wanted to do was put an exhaust on it, so here's what I did.

Right behind the CAT after the 3 bolt flange I cut the exhaust and welded on a universal 2 bolt flange to new pipe and pre-existing pipe including the stock exhaust so if I need to go back to it I can.

The exhaust I put on is 3" Straight pipe out the back. No resonator or Mufflers.

I absolutely LOVE the way it sounds, however after having it on for a couple weeks I've been noticing that there's less power on the low end of course because there's less back pressure I figured that would happen. What I did not account for was the effect it would have on the turbo. I've been noticing a lean smell. obviously Honda has changed a lot of things between 1996 and 2019 lol. I'd like to know some thoughts on what is going on. Still very new to the turbo chargers.

Secondly, Just yesterday I got a Boomba Racing BOV. Already installed Drove it around for about an hour and I noticed a rich smell when I'm on the gas but I'm still getting that lean smell at idle.

I don't have a Ktuner or hondata flashpro, and my OBDII reader isn't capable of pulling up any data logs. I'm not throwing any codes but I've been around small engines enough to know when something a little off.

That being said what do you guys think? Am I good to continue driving it like it is until I order a Ktuner? also is there any way for me to pull up any data logs on the screen in the car or is that something Honda doesn't want me to do lol

I can post pics or video if anyone thinks they will find it helpful.

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[KOIVUN1]

First mistake was the BOV. Those are infamous for having absolutely zero benefits on this car. the L15 uses a recirc valve, not a vent to atmosphere, so when the bov vents, the car runs rich because the air that the ECU accounted for is gone out the BOV.

When you say lean smell at idle, do you mean like having it started and sitting in your driveway? Or like idling at a stop light? Because if you mean just after a cold start sitting in the driveway, that's plenty normal for a straight-pipe cat-back. If the smell comes up consistently even after/while driving, that may be another issue.

Take off that bov, and order a tune asap, whether it be hondata or ktuner. I would recommend the ktuner, but i am biased because I have the ktuner v2 and i love everything about it.

I don't think you can pull up data logs natively on the screen in the car, but the ktuner v2 has on board logging and IIRC you can also log while plugged into a laptop with the v1.2 (non-touchscreen). Good luck!

 

[Conor]

While I can't help you with your question, I can tell you to prepare yourself for some negative feedback about your BOV...

 

[XProjectWaffleX]

I appreciate the feedback.

So haha I actually got the BOV for exactly that reason. I wanted to trick the ecu because of the lean smell I was getting. It was an idea I had and I wasn't sure it would work or not.

also I was expecting some negative feedback on the BOV because he's right. the system was designed for a full recirculating valve. the only pros are cool BOV sounds and some extra crackles in the exhaust sounds.

I will be getting the Ktuner v2, my buddy has one and it does everything I need and super easy to flash new maps.

I'm going to drive it around for about 6 hours today just to see how it responds to having the BOV on a little longer then ill probably take it off and resell it after I get the tuner. when I get the ktuner Ill be able to see the air fuel ratio at different intervals and then adjust the fuel trim levels so it's consistent across the board with different levels of boost.

 

[COOL COUPE]

New metal always has a " new metal smell " no? I often wounder if the faster expell of air ( less back pressure ) lessons the fact that the BOV causes a rich condition. A just watched a video of popular BOV s and the torque solutions BOV plate rated the loudest. It also takes advantage of the stock plastic and leaves spring parameters unchanged. I say keep your inner pssst up and going.

 

[Robdog2232]

Dm'd you about the bov

 

[booost]

You're going to get a lot of heat for the BOV. Take that off as the people above me have said and the people below me will certainly say. As far as the smell, unless you're completely catless downpipe this might be a placebo and even then i'm not sure you would smell it in the cabin. You may be like all of us or most of us that overthink stuff, i dont think you're going to feel that much power from just the muffler and resonator deletion. Sorry if this doesn't help but just my 2 cents.

 

[XProjectWaffleX]

New metal always has a " new metal smell " no? I often wounder if the faster expell of air ( less back pressure ) lessons the fact that the BOV causes a rich condition. A just watched a video of popular BOV s and the torque solutions BOV plate rated the loudest. It also takes advantage of the stock plastic and leaves spring parameters unchanged. I say keep your inner pssst up and going.

New metal definitely has a distinct smell to it. However after driving it around for 8 hours a day for 2 weeks straight I would think it would be broken in by now.

You're going to get a lot of heat for the BOV. Take that off as the people above me have said and the people below me will certainly say. As far as the smell, unless you're completely catless downpipe this might be a placebo and even then i'm not sure you would smell it in the cabin. You may be like all of us or most of us that overthink stuff, i dont think you're going to feel that much power from just the muffler and resonator deletion. Sorry if this doesn't help but just my 2 cents.

As far as power goes I can 100% tell that there is power loss on the low end, which isn't a problem. I mean it's not like the motor is built or anything I was expecting the car to react that way. All stock internals and the factory tune. Maybe I was just thinking Honda's ECU was smart enough at this point to automatically bump up the fuel levels at lower RPM to account for the excessive air flow.

Also to be 100% honest with you, I didn't even realize the stock down pipe had a CAT on it so it probably has more back pressure than I thought it did. That extra little filter + the turbo would explain why I'm not a turtle on take off.

From just testing yesterday I can tell it's running just slightly lean until I shift from first, after that the full release to atmosphere BOV's "RICHNESS" effect takes over and greatly overpowers the leanness so much to the point yes I smell it in the cabin.

that being said I'm considering switching to a BOV spacer plate like COOL COUPE was talking about or even a hybrid BOV. That way the intake is getting at least some of the air the ECU is expecting lessening the richness effect.

What are your thoughts? I know this is like trying to screw in a Philips head screw with a Flat head screw driver and isn't the best solution for what I'm dealing with. But for the time being until I'm able to get a tuner I would much rather run rich than lean.

 

[booost]

New metal definitely has a distinct smell to it. However after driving it around for 8 hours a day for 2 weeks straight I would think it would be broken in by now.



As far as power goes I can 100% tell that there is power loss on the low end, which isn't a problem. I mean it's not like the motor is built or anything I was expecting the car to react that way. All stock internals and the factory tune. Maybe I was just thinking Honda's ECU was smart enough at this point to automatically bump up the fuel levels at lower RPM to account for the excessive air flow.

Also to be 100% honest with you, I didn't even realize the stock down pipe had a CAT on it so it probably has more back pressure than I thought it did. That extra little filter + the turbo would explain why I'm not a turtle on take off.

From just testing yesterday I can tell it's running just slightly lean until I shift from first, after that the full release to atmosphere BOV's "RICHNESS" effect takes over and greatly overpowers the leanness so much to the point yes I smell it in the cabin.

that being said I'm considering switching to a BOV spacer plate like COOL COUPE was talking about or even a hybrid BOV. That way the intake is getting at least some of the air the ECU is expecting lessening the richness effect.

What are your thoughts? I know this is like trying to screw in a Philips head screw with a Flat head screw driver and isn't the best solution for what I'm dealing with. But for the time being until I'm able to get a tuner I would much rather run rich than lean.

To my knowledge, the ECU is going to try to recalibrate itself as much as it can. The BOV you'll run more rich but you'll suffer from a bunch of possible things can go wrong by using it. People have had oil dilution with gas and a whole bunch of messes. It's just not the car for a BOV, plate or anything unless you're swapping ecu's and ditching your MAF sensor. An intake will get you the same sound and will be much more beneficial long term.

 

[XProjectWaffleX]

To my knowledge, the ECU is going to try to recalibrate itself as much as it can. The BOV you'll run more rich but you'll suffer from a bunch of possible things can go wrong by using it. People have had oil dilution with gas and a whole bunch of messes. It's just not the car for a BOV, plate or anything unless you're swapping ecu's and ditching your MAF sensor. An intake will get you the same sound and will be much more beneficial long term.

I see. In that case what would you recommend for an intake. I'm in AZ and it almost never rains here so I'm open to options.

 

[booost]

I see. In that case what would you recommend for an intake. I'm in AZ and it almost never rains here so I'm open to options.

I have the 27WON but a lot of people love the PRL CAI—just make sure to get the street MAF edition

 

[XProjectWaffleX]

I'll definitely look into it

 

[COOL COUPE]

It's interesting that the response is always ... Get the PRL short ram. It sounds the same. Yada yada yada bla bla bla. Bottom line is that the short ram does more harm than good over the stock set up. The plate is wicked nasty in hot weather. The Honda parameters hype up the boost in hot weather to maintain the base level hp and tq. In 95 degree weather for you want a short ram? I get a serious sounding pppssssttttt ! Juvenile for sure!

 

[arpypat]

It's interesting that the response is always ... Get the PRL short ram. It sounds the same. Yada yada yada bla bla bla. Bottom line is that the short ram does more harm than good over the stock set up. The plate is wicked nasty in hot weather. The Honda parameters hype up the boost in hot weather to maintain the base level hp and tq. In 95 degree weather for you want a short ram? I get a serious sounding pppssssttttt ! Juvenile for sure!

Only on civicx does an exhaust thread turn into a BOV thread

And who said to get a PRL short ram? one person @booost said he has the 27won CAI and that ppl love PRL CAI...

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