I was thinking on adding a BOV to my s40T5. I know my T5 doesn't produce nearly enough pressure to require a BOV, its just for the "PSH" sound.

Upon learning about BOVs, I read that if you add one to your car, your stock ECU will still expect air, and will pump too much fuel in, cause stalling (aka somthing bad, that sounds like will create a lot of problems I shouldn't be worrying about in a 6 month yr old car)

Does this mean I will have to modify my ECU in order to not create problems? Think I'm better off just not potentialy voiding my 7r/100k warrenty?

I could always make the PSH sound myself haha

Thanks

 

I for one have a BOV on a 1999 s70 awd. My car is an automatic as well. I do not stall ever.

What you heard is uderly stupid IMO. No need to modify the ECU. I had my BOV on when I was running between 5-7 PSI stock, worked fine.

You will run into maybe a problem of running too RICH or too LEAN. Which IMO for a split second is ok.

I suggest an HKS SSQV, I wouldn't get a Turbo XS Type H-RFL, I have this one and they are known to leak. Get the HKS SSQV.

If you want more boost get an ECU upgrade from like SpeedTuning USA, Upsolute, IPD, RICA, Inmotion, Etc... Then you will hear the BOV better.

 

what do you mean my runnning too rich or lean?

also about Speed Tunning USA,
that guy only lives about 40 minutes from me, its being the cheapest ECU upgrade and not having to do any ECU shipping is kinda nice. But I remember reading on the forums though that an ECU upgrade will actually decrease your HP if your car is an Automatic ( Thank god for Geartronic). I think you wrote it if I remember. How is that possible?

Even luckier for me, an Upsolute dealer is very close to me. Including installation, I save $5 (neglegible) by using Upsolute. Which do you recommend?

 

At least when dynoed you will lose HP. Because there is a drivetrain loss of about 25%. Now for actual driving I don't know if there is an actual loss of Hp.

I would suggest looking up on Wikipedia or Howstuffworks or whatever it is what running RICH and LEAN means. Searching is the key to your learning.

 

Read This


Rich and Lean meaning
"Every new car, and most cars produced after 1980, have an oxygen sensor. The sensor is part of the emissions control system and feeds data to the engine management computer. The goal of the sensor is to help the engine run as efficiently as possible and also to produce as few emissions as possible.

A gasoline engine burns gasoline in the presence of oxygen (see How Car Engines Work for complete details). It turns out that there is a particular ratio of air and gasoline that is "perfect," and that ratio is 14.7:1 (different fuels have different perfect ratios -- the ratio depends on the amount of hydrogen and carbon found in a given amount of fuel). If there is less air than this perfect ratio, then there will be fuel left over after combustion. This is called a rich mixture. Rich mixtures are bad because the unburned fuel creates pollution. If there is more air than this perfect ratio, then there is excess oxygen. This is called a lean mixture. A lean mixture tends to produce more nitrogen-oxide pollutants, and, in some cases, it can cause poor performance and even engine damage.

The oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures. The mechanism in most sensors involves a chemical reaction that generates a voltage (see the patents below for details). The engine's computer looks at the voltage to determine if the mixture is rich or lean, and adjusts the amount of fuel entering the engine accordingly.

The reason why the engine needs the oxygen sensor is because the amount of oxygen that the engine can pull in depends on all sorts of things, such as the altitude, the temperature of the air, the temperature of the engine, the barometric pressure, the load on the engine, etc.

When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. Your car performs poorly and uses more fuel than it needs to. "

 

thanks for the link, after reading that I definately don't want to put a BOV in. Its a split second but for a new car rather not take chances for a "psh" sound.

But, I really am considering getting an ECU anyways. That still doesn't make sense of how you would get a 25% driveterian loss in an AT but not a MT? How do you get a driveterain loss at all? The ECU for volvo assumes premium fuel so that the engine can run faster without damage.
Put simply though, acceleration will be faster in real life driving conditions right? If it went down that would mean ECU upgrades are worthless pieces of crap.

 

No it doesn't mean they are worthless at all.

I could tell a huge difference on the street when driving. My boost was raised from the 5-7 PSI stock to 12PSI. I have the SpeedTuning USA 12PSI program upgrade.

However you know you will be running RICH or LEAN most likely with just an ECU upgrade done. So really your not going to get away with the problem unless you do some serious tuning.

If you want to watch your A/F ratio's you want a Wideband O2 sensor, not a Narrow band.