Power Surge
SHO Member
How is your MAF setup? Is it before the turbo? If so, you must recirculate the bypass air (going out your blow off) back into the intake stream.
Turbo project progress pics(rough).
- Thread starter nik97
- Start date
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How is your MAF setup? Is it before the turbo? If so, you must recirculate the bypass air (going out your blow off) back into the intake stream.
A common misconception. These cars are very tolerable of some 'wasted' air. I am sure there are larger issues at play causing his troubles right now, the BOV is likely not one of them.
Power Surge
SHO Member
A common misconception? Come on, Tim. It's tuning 101. If the blow off is after the MAF, it has to be vented back into the intake stream. The MAF has registered that incoming air, and is commanding the fuel to the motor for it. If you dump some of that air before it gets to the motor, you'll have an overly rich condition, surging, and stalling, especially on decel. If you've seen a car that will "tolerate" that, then that's just an oddity. It could be possible to band aid that byproduct by trying to tune a car with less fuel as the air is being vented off, but that's by far a really wrong way to tune.
The correct way would be to recirculate, but with a turbo, you *can* get away with doing this. My system is not optimal, howeve, it works and I don't want to modify the SHO Shop piping. Heck, my 3.5 - 9 PSI spring cranked half way down vents boost at 15 PSI because of placement and my MAF, could really use some straightening vanes in the pipe before it.
Running the BOV after the MAF on a turbo may effect KAM values if you've noticed a hard time getting an accurate tune.
Running the BOV after the MAF on a turbo may effect KAM values if you've noticed a hard time getting an accurate tune.
Power Surge
SHO Member
There's nothing wrong with your setup, it's done the right way. Your blow off is BEFORE the MAF, so your MAF is reading exactly what's going into the motor. My turbo setup is the same way, because my blow off is also before the MAF.
HoustinoJillian
name's JUSTIN
from what i've read tim (toolman) has a very high number of miles, running a setup with metered gas vented to atmosphere. There's been a lot of threads and discussion on this topic. why don't we reopen one of those threads rather than mucking up this progress thread with another debate?
Not meaning to muck up this thread, as I thought it worth pointing out that any problems nik may be having are likely due to something other than an atmospheric BOV.
PowerSurge said:
Sal, my car got 25.6 mpg on it's last long trip (600 miles each way), with not a single check engine light, surge or stall. I am not saying that the 'best and most accurate' way is to vent to atmosphere, but what I am saying, from years and 55k miles of experience, is that a turbocharged Taurus SHO does perfectly fine with a BOV. You can watch look at my datalogs, or watch a quick recording of my wideband if you need further proof.
nik97 - To get back to the matter at hand, it would be in your best interest to build a leak tester. Some PVC caps at each end of your IC tubing, one with a air gauge threaded into it, the other with a schraeder valve threaded into it, will allow you to pressurize your entire intake tract and quickly find any leaks. Unless you have a very large leak, you will not be able to hear it while the car is idling (and in vacuum). But even a very small leak can cause problems like the one you are describing (the biggest reason I would want a BTM just before the TB).
I suppose I should mention that there is no BOV yet so I have a little compressor surge when I let off the throttle. That's only once it's built up a bit of pressure. It bucks and jerks when steady, light throttle cruising... The car died occasionally on decel before the turbo and the MIL would illuminate just before and when it did die. It is a bit more pronounced now but I think my IAC is on it's way out.
Power Surge
SHO Member
If it works on your car, that's cool. But we don't need to be telling people that it's okay to be doing it that way just because it works fine on one or two cars, when it's not the right way to do it. That's how bad information gets spread around on the internet.
You can open a door to a room with a grenade instead of using a doorknob also. You'll still get in that room, but that doesn't mean the grenade was the best method for opening the door
.Power Surge
SHO Member
You really should not be driving the car without a blowoff/bypass. There's no place for the air to go when you close the throttle and the turbo is trying to still stuff air somewhere. You can actually damage the turbocharger from that bucking your feeling.
jthod
Mr. Goodwrench
kzoosho
Holset HX52
Yea you will want to get a bov in there right away. You can run either a recirc or bov .I have a question. what are you using for tuning? if anything?
AFR/FMU for now... Not the greatest but it will keep it "safe" until I get bigger injectors.
Power Surge
SHO Member
So you're using a stock SHO MAF?
kzoosho
Holset HX52
I can almost be certain that you are maxing out that 55mm unit like right now. So the fmu wont keep you safe is the computer cant read the air. You need to look into something to tune with afc tweecer somethin man. Best of luck
I am using a 73mm Pro-M.
^No.
I put the bumper on today and took it for a spin and the buck/****/stall went away completely. The open element filter I am using was exposed directly to the air blowing across the front of my car. No other changes where made. A friend let me borrow his stock RX-7 bypass valve to adapt into my charge tubes to eliminate any compressor surge. I also got a boost gauge and it is set for 2-3psi now so it should be safe to put from place to place until I get the right equipment. I wont hammer it until I have a wideband.
Ahh yes. When I run my MAF without a filter, it will act just like you mentioned, due to the MAF not getting a clean signal. Glad that solved it for you.
DVJ38
New Member
^No.
I put the bumper on today and took it for a spin and the buck/****/stall went away completely. The open element filter I am using was exposed directly to the air blowing across the front of my car. No other changes where made. A friend let me borrow his stock RX-7 bypass valve to adapt into my charge tubes to eliminate any compressor surge. I also got a boost gauge and it is set for 2-3psi now so it should be safe to put from place to place until I get the right equipment. I wont hammer it until I have a wideband.
Pics or ban!
I didn't realize you and Steve were friends?
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