Blow off valve

Okay.. which one of you on here did this? Anybody planning to install one? Thoughts? I know my truck isn't a "race car" by any means, but personally I like the sound

 

Sounds fake and hopefully it is.

 

lol, I kinda like it. Why not show off your turbos!

 

CBV is a part of any turbo engine.

 

OP is asking who is going to install an external for "sound".

 

The mod is probably rerouting the excess air from the fresh air intake to atmosphere. Or using K&N or other "zero restriction" air filter, it makes CBV's WOOOSH pretty loud.

 

Now that i think about it. Might get annoying real quick while on long road trips sounding like a giant semi truck.. or a boosted supra lol.. I'm not on tiktok so i thought maybe he'd be on here to share his setup

 

Resembles my truck, but not me. I’d do it though, why no

 

Correct, hence my "external". Instead of recirc, it goes to atmosphere.

 

My buddy has a GTI with a LOUD intake. It does not get annoying at all on long drives. You only hear it when you want to.

 

He probably just disconneted the return hose and capped the intake. On the Ecoboost trucks you could literally cap the intake with a rubber cap from a chair leg and vent the stock BOV to atmosphere.

Swapping the BOV to a mechanical aftermarket unit is probably not a good idea. The stock unit is probably electronic and probably gets used for more than just blowing off excess pressure.

 

I wouldn't do it. That sound seems cool when you just hear it go by or hop in a car for a quick drive. Driving daily it would get old really fast.

 

Can someone School me on the mechanics here:

Isn’t there a corresponding relationship between the pressure release at a BOV and the RPM drop at shift change?

I would assume that you would get a lot less blow off sound (assuming a loud BOV) with a higher number of transmission gears (like a 10 speed) because the gear shift patterns are designed to keep the turbos spinning and boost pressure more even.

 

When the throttle closes, there's still a lot of inertia of the spinning turbine wheel, which continues to push fresh air. That causes a quick pressure buildup. CBV's job is to release the excess pressure to somewhere else. Releasing it to atmosphere is not very efficient (the air is filtered and metered), so usually it goes back to the compressor.

The turbo operation is electronically/pneumatically controlled by the engine computer, so most of the time your turbo engine works as a poor natural aspiration engine, without boost. This is what makes a turbo engine efficient: when the power is not needed, the engine does not develop boost. No boost (or very little of it), no pressure release via CBV, no wooosh!

The next smart thing in the turbo's control is a wastegate. It is electronically/pneumatically controlled as well: the computer can "ask" the wastegate to open and divert gases away from the hot half of the turbine wheel. This happens, for example, every time transmission decides to shift gears. Transmission computer has a dedicated electric line that asks the engine to reduce power while the transmission is shifting. The engine than commands the throttle to close partially and also it opens the wastegate (not always, only if the turbine is spinning fast enough, i.e. there's boost). By the time the throttle really closes and intake pressure is ready to build up, there's not much energy left in turbine to compress enough air that can trigger CBV. No pressure, no woosh, so it does not annoy you very often.

 

The guy just disconnected the hose at the diverter valve. Saw he said it in one of the comments. Wouldn’t suggest this route tho. It’ll cause afr to go rich when coming off throttle and may even cause cel if untuned.
Pic of diverter valves off my truck. And the hose that needs to be disconnect and capped.


I’m waiting for an intake system and it’ll give it same effect but without the vent to atmosphere. Just won’t be as loud as vent to atmosphere. My Evo X was pretty loud though even with stock diverter valve and just aftermarket intake. Can really hear the bov out of the air filter. But evo X is also running 25psi of boost. The stock air box is hiding all the noise. If you wanna be real cheap, remove the air box and put a cone filter.

 

I think you need an open top box to really hear it. I am running an S&B intake on my truck and you would never know it from stock. It's a conical filter inside of the factory lower box and S&B upper cover.

 

Yeah. If it’s in an enclosed box. Won’t really hear it, since the box will muffle all the sound. Has to be exposed intake like this from my evo to really hear it.

 

https://youtu.be/jqOryebN6T8

 

Pretty sure it won't. Where it recirculates to is after the MAF sensor anyway. Truck has no idea if the recirculated air is there or not.

Edit: JB4 confirms this in that video as well posted above.

 

Problem with disconnecting the line on this truck, is ALL the air is metered. So when it blows off and the system can’t account for it, codes will become active.

This guy, is a Toyota diagnostic technician pretty in depth break down of the whole truck but he explains the whole turbo blow off rather well. Worth a watch.

https://youtu.be/EKRlBoj0s7E

 

I think I would get one just to take me back to my old Dodge Neon SRT sound I used to roll with. That car was scary fast.

 

I am fairly certain these trucks dont use a maf. They are load based tuning so they depend on a MAP sensor and a bunch of volumetric efficiency equations in the pcm to calculate the air mass going into the engine.

I would guess they might also have factory wideband O2 sensors and can keep the afr perfectly dialed.

i bet the sensors near the air boxes are pressure sensors so they can infer turbo pressure ratios, speed and efficiency.

But you are right, because the air mass calculation happens due to the MAP sensor, VTA mods wont bother it.

 

This should be coming out next week. $200

 

We need more info and/or sneak peek photos.

 

That’s a big no for me. It’d be fine if it was an STI, Evo, Supra, Golf R, or even an old SRT-4, but not on a full sized pickup. To me it seems incredibly “rice” and out of place on a truck; but in the end people can do whatever they’d like.

 

They sure were! I didn’t have the Neon, I had it’s heavy counterpart. But damn did that thing move, especially with mods.

 

I agree. Only thing I saw was from YouTube.

 

While I served my friend had a suped up SRT4.. Tungsten motor mounts are the onea that stuck to my head and had more mods than I cared to remember, but had me white knuckling the door handle...

 

My friend had a BOV on a focus. it was all fun and games until he pulled up next to a dump truck with air brakes one day. "Hey, sounds like he wants to race" ruined all his fun!

 

the V35 engines use MAFs.