Blow off valve

darkseas

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I would be careful with returning Ebay products to China, or at least having that expectation. I purchased the Cusco frame braces on Ebay, and while they were from an Australlian reseller, they shipped from China. When trying to return them, the seller would only allow for their return to the Chinese address and FedEx, UPS, and USPS all would not ship to the particular zip code for some reason.
Was there a problem with the Cusco Frame braces?
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maddmatt02

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@Boomba Racing.. At WOT, or close to it, when you let off the gas and the throttle plate slams shut, the valve will vent the excess boost pressure. But, how much excess boost does the BOV need in order to vent? Example. Let's say I accelerate at partial throttle and build some boost, but not peak. When I ease off the accelerator as I reach my desired cruising speed will the BOV vent the excess boost at this point, or will it be handled by the wastegate? I guess my question boils down to the AFR dilemma. If I am cruising at highway speeds and accelerate to pass someone, then ease off the gas to slow back down, there is still a considerable load on the motor at say 76mph with a constant rpm of around 2500. IF the BOV vents at this point with somewhat of a load on the motor, it seems there would be negative impacts to the ratio. But that's only if it does vent. I know the AFR is ultimately calculated by the wideband O2 sensor on the exhaust, but it does take readings from the MAF, does it not? Hope this makes sense :hmm:
I missed a lot in this thread, must've missed the email about people replying... anyways I'm surprised nobody answered you.

when the throttle plate is open the vacuum line to the BOV and the charge piping/manifold is under the same pressure and the spring keeps the BOV closed. If the throttle plate only slightly closes there shouldn't be enough change in the forces to cause the BOV to open, and if so it would be very minimal compared to a WOT/cut situation because once the two forces/pressures equalize (vacuum line/CP) the spring would slam shut the BOV again but it really depends on how much you stepped on it/how quick you backed off (you mentioned "easing" back off of it). The way I pass someone is WOT, by the time I'm around them I'm going 20-25 over and I let off completely and coast to about 10-15 over and then ease into it and "catch" the car around 5-10 over and in this case, yes it will vent for sure. but just gradually accelerating to speed and gradually backing off once you reach cruising speed, no, the BOV will(should) not open.

also, wastegate never releases boost. It's purpose is once the turbo is spooled and you are hitting targeted boost, you have to allow some of the exhaust gases to bypass the turbine or you will risk spinning the turbo too fast/making too much boost.

I also do not think the MAF is used to calculate AFR at all. well maybe not in the sense you might be thinking. it ultimately gives the car an idea of the air it is getting. the o2 tells the car how much fuel is being burnt with that air, and the ecu can adjust fueling to compensate in whichever direction it needs to go.
 
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maddmatt02

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Just bouncing ideas around.. I have heard of people simply removing the hose from the BPV to the intake and plugging it so the excess boost is vented instead of recirculated. Has anyone tried this?
I haven't looked close but from the design of this BOV and some of the "BOV plates" sold on ebay I'm guessing it wont work like that on this car, but I'll look mine over tomorrow and see if its a possibility.
 

9xArtanisx9

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Just wanted to show you guys how weak and flimsy the stock BPV is. Made from rubber and plastic. Sure the exterior is metal, but get a look at the inside!

Honda Civic 10th gen Blow off valve 32096344301_ef7ff45b3b_k



Honda Civic 10th gen Blow off valve 32215133265_8e7e751dd8_k



Honda Civic 10th gen Blow off valve 32096342481_fa1c3234c4_k



Honda Civic 10th gen Blow off valve 32096727081_f8bc6f220b_k



Honda Civic 10th gen Blow off valve 31405116693_bfb6cf65f9_k



Honda Civic 10th gen Blow off valve 32096725621_e3d3bce79f_k
You don't happen to know where I can get the factory bolts for the factory blow off valve? I know there m6-1.0 X 8mm but I can't find them anywhere..
 


ichii

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You don't happen to know where I can get the factory bolts for the factory blow off valve? I know there m6-1.0 X 8mm but I can't find them anywhere..
I got mine at a local hardware store, they should be able to help you out.
 

9xArtanisx9

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I got mine at a local hardware store, they should be able to help you out.
I went to multiple ones and I couldn't find the exact ones. The bolts are either flat on the top or caved in. The ones from factory slightly bulge out... Any pictures and store name if possible? Thanks!
 

maddmatt02

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I went to multiple ones and I couldn't find the exact ones. The bolts are either flat on the top or caved in. The ones from factory slightly bulge out... Any pictures and store name if possible? Thanks!
If you want them to be that perfect of a match might have to just order from Honda
 
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I thought this was helpful.

It sounds like it is best to stick with the diverted/recirculating valve. Could the fuel calculation problem with a Blow-off valve be corrected with a reflashed ECU?
I agree. I was absolutely tempted to get one and even ordered it. After doing more research I decided to cancel the order.

I recently replaced the catalytic converter on my daily car which the cat was only 2 years old. I installed a cold air intake because it sounds awsome but without tuning it because I couldn't for my ECU, causing it to burn rich and melt the catalytic converter. I would think a check engine light would tell me something about air fuel ration is wack but it didn't and eventually, P0420 code which can be caused by as little as 5% inefficiency. Note that the catalyic converter is one of the more priciest parts of the car, not to mention the other hassles like by the time the cat fails you have frozen bolts, frozen O2 sensor, confined space so limited ability to use a proper torque wrench, ect ect.

I think the fuel calculation problem can be corrected but the flash would have to be specific to the amount of air blown off to atmosphere which varies with blow off valves but never as reliable as OE. Even if the blow off valve damage is very small, the numbers add up, how many years off the lifespan of the catalytic converter would it remove? I bought a Civic for reliability, so I'm going to keep it reliable.

I think Engineering Explained draws out this rich condition pretty well.
 

hfpdohc

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I agree. I was absolutely tempted to get one and even ordered it. After doing more research I decided to cancel the order.

I recently replaced the catalytic converter on my daily car which the cat was only 2 years old. I installed a cold air intake because it sounds awsome but without tuning it because I couldn't for my ECU, causing it to burn rich and melt the catalytic converter. I would think a check engine light would tell me something about air fuel ration is wack but it didn't and eventually, P0420 code which can be caused by as little as 5% inefficiency. Note that the catalyic converter is one of the more priciest parts of the car, not to mention the other hassles like by the time the cat fails you have frozen bolts, frozen O2 sensor, confined space so limited ability to use a proper torque wrench, ect ect.

I think the fuel calculation problem can be corrected but the flash would have to be specific to the amount of air blown off to atmosphere which varies with blow off valves but never as reliable as OE. Even if the blow off valve damage is very small, the numbers add up, how many years off the lifespan of the catalytic converter would it remove? I bought a Civic for reliability, so I'm going to keep it reliable.

I think Engineering Explained draws out this rich condition pretty well.
wich car are you talking about(civic turbo ?)
 


Boomba Racing

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There's been a lot discussion since we have released our BOV if the piece makes your car run rich or not. In this video we decide to show everyone what happens.

The results are in, let them speak for themselves!

We performed simulated street driving under partial acceleration runs and shifting to see what happens when you let off the gas and shift when running our Vent To Atmosphere BOV.

The spring pressure we use in our BOV was carefully chosen so that the vehicle's operation is not negatively impacted from running this BOV. There is no stuttering, no increased turbo lag, and no check engine lights from running our BOV. The stock BPV features very poor construction and is made from cheap plastic and rubber and features a very flimsy spring. Our valve has aircraft grade billet aluminum, a brass piston, and Viton O-rings and is tested to 100 PSI to ensure leak free operation. All of our BOVs also carry a lifetime warranty to the original owner.
 

Snoopyslr

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There is not near enough data displayed to arrive at the conclusion that your BOV stays within "safe parameters".

Why didn't you include boost levels, throttle position, and time duration?
 

sniper

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I'm running the Boomba BOV and like it (though I wish it were louder... or I should stop listening to music lol) and I wish I had MT, so I could actually let off gas/shift. Having the CVT, it doesn't vent unless I let off gas :(

Is the dyno measuring the AFR from the exhaust or something? If it's just reading the sensors in the car, then isn't it getting the reading from before venting?
 
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There is not near enough data displayed to arrive at the conclusion that your BOV stays within "safe parameters".

Why didn't you include boost levels, throttle position, and time duration?
I agree the information doesn't prove anything is within safe parameters. Anything past 15.0 is running lean, so there's a massive spike in lean mixture in the info provided. Might be alright for a while but multiply the lean spike hundreds of times a day for a decade or two and see what happens, this lean condition would increase temperature, and even slightly the greater the wear.

Take for example if you have an all stock Civic driven for 20 years, what parts failed and why? The heat wear over the lifespan of the car made its toll and it's completely stock. Now factor in lean condition mods, you can definitely say there would be a significantly greater amount of wear and tear.

Check engine lights won't turn on for wrong air fuel ratio it will only turn on if the related sensors completely fail. The car is designed to adjust to fuel to variations of airflow. It wouldn't make sense for check engine light to come on because you live in high or lower elevations.

Anyhow, people can do what they want. If in 10 years they're okay with more wear and tear for the sake of sounding cooler that's their choice. If voiding the manufacture warranty before it ends is fine with the car owner that's their choice too.
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