Blow off valve!!??

OnyxSky · 05-08-2008, 04:15 PM

Does anyone have a blow off valve? I'm looking to upgrade my intake and want a blow off valve also but I am having a hard time finding anything. HELP!

centric · 05-08-2008, 05:29 PM

Search is your friend.

Bottom line, on a Sky with stock turbo, a BOV vented to atmosphere buys you nothing except worse fuel metering.

Just curious, too, why people like sneezing cars?

|V3nom| · 05-08-2008, 05:55 PM

my car sounds like a birdie when i shift lol.

SupraDOc · 05-08-2008, 06:37 PM

Some people just like blow off valves. That's like asking why does anyone like anything in particular. You are right though, worse fuel metering is almost a given on any stock car. I would imagine you could just weld a flange to the intercooler hard pipe. Tial seems to be the best BOV out.

But bump for an answer though! Anyone change to an aftermarket BOV?

**JohnD** · 05-08-2008, 07:19 PM

If you just want the huffing and puffing, getting rid of the plastic airbox and going with a pipe will get you all the sounds you want...

|V3nom| · 05-10-2008, 06:24 AM

i thought turboed engines had to have a bov to vent pressure or it would blow, what do they have on it now, is it a wastegate or something? i saw something on the exhaust manifold, i thought that was a bov.

Bogie · 05-10-2008, 05:15 PM

Just launch off a few redlights without exceeding the speed limit (oh well...maybe five over) and you will quickly learn the sound of our stock CBV. Nothing like getting an RL Turbo all cranked up an ready to go only to have to lift and brake a few seconds later. It doesn't whistle like a BOV, but it does whistle.

|V3nom| · 05-10-2008, 05:17 PM

i thought a turbocharged vehicle had to have a bov so you dont blow the motor? what relieves the pressure then?

OnyxSky · 05-10-2008, 05:44 PM

Yes... it does whistle... but I'm use to a nice head turning teeeeeeeeeeshhh lol

Bogie · 05-10-2008, 06:25 PM

Quote:

Originally Posted by |V3nom|

i thought a turbocharged vehicle had to have a bov so you dont blow the motor? what relieves the pressure then?

The stock Borg-Warner turbo has a built in bypass valve that relieves pressure. Instead of venting to atmosphere, which makes the big whistle sound, it vents back into the impeller...which helps keep it spinning...reducing turbo lag. It still makes a whistle sound because it is venting from high pressure to lower pressure, but it is contained within the turbo so the whistle is not as pronounced.

|V3nom| · 05-10-2008, 07:52 PM

so would you have to disable the built in bypass valve to run a bov?

Bogie · 05-10-2008, 09:04 PM

Quote:

Originally Posted by |V3nom|

so would you have to disable the built in bypass valve to run a bov?

The problem with a BOV is you would need to ensure it doesn't cause problems with the sensors reading the pressure and air flow. The stock computer uses these measurements in the engine performance feedback. If the sensor detects a certain mass flow and feeds that information to the computer, and then the BOV pops and vents to atmosphere, the computer will be shooting fuel in the cylinders expecting sensor mass flow whereas the actual mass flow will be less. The 02 sensor on the back side will scream "rich", and if it's bad enough might even trigger a turbo fault, check engine code, and lock down the turbo.

So it's not so much the BOV messing up the bypass on the turbo as it is the BOV messing up the mass flow to the engine.

|V3nom| · 05-10-2008, 09:14 PM

gotcha. so unless you get rid of the stock bypass valve and do a lot of fidangling to the intake, its not worth it. is the bypass valve on the turbo manifold itself? i saw something on the end close to the front of the car.

Bogie · 05-10-2008, 09:37 PM

Quote:

Originally Posted by |V3nom|

gotcha. so unless you get rid of the stock bypass valve and do a lot of fidangling to the intake, its not worth it. is the bypass valve on the turbo manifold itself? i saw something on the end close to the front of the car.

The bypass valve is integrated into the turbo itself. It runs from the high pressure out down to the low pressure intake at the impeller.

sidejam · 05-10-2008, 11:08 PM

I wonder if the MAF sensor could be relocated in the intercooler pipe just before the throttle body and then put a BOV between the intercooler and the MAF sensor. I'll just assume that the ECU would freak out if you did that too...

Jay_Sin · 05-11-2008, 02:37 AM

I'll never understand why someone will try to go through so much work just to make something that is good for performance to something that is just ok. I guess having that "my car is turbo" woosh is just too important to consider what's actually better for performance.

xxdjfate76xx · 05-11-2008, 03:35 AM

most jap cars that have the BOV upgraded to an atmospheric one have to end up buying some type of fuel management system to get it to run right... my 240sx would shoot a flame everytime i would shift because it ran a bit rich right when the BOV would go off... not much market out there for the redline right now, so not worth doing (my opinion)

sidejam · 05-11-2008, 04:39 AM

I have an automatic. So, at the track, BOV or diverter valve won't make a difference!

Besides, if you look at any high horsepower import, they're usually running BOV. I'll assume there must be a reason for it...

Jay_Sin · 05-11-2008, 11:44 AM

Quote:

Originally Posted by sidejam

I have an automatic. So, at the track, BOV or diverter valve won't make a difference!

Besides, if you look at any high horsepower import, they're usually running BOV. I'll assume there must be a reason for it...

Because their engine is tuned for it. Ours are not. Ours is also designed for our turbo, so an aftermarket BOV isn't going to do much unless you swap to a larger turbo and you are able to tune it properly. Other then that, it is just a waste of time.

Like stated several times before, go with a CAI. It make the BOV much more audible, and actually help with hp instead of making it worse without a tune.

sidejam · 05-11-2008, 01:24 PM

I guess the biggest advantage of a BOV is that at part throttle, it stays closed. With the DV, with just a little bit of vacuum, it will be open. I think a happy medium would be to put in an aftermarket BOV, but have it vent back to the intake. You'd still get most of the noise of a BOV, but it wouldn't throw any codes. I believe that what Dejon is doing on their turbo kits.

|V3nom| · 05-11-2008, 04:20 PM

so whats the little metal part coming off the exhaust manifold by the turbo?

OnyxSky · 05-11-2008, 05:45 PM

Wow... well... I was looking for the quick answer like my srt-4... bought a part for 60 bucks and it sounded saaaaaweeeet. I guess I will be happy with the little sound we have now.

Jay_Sin · 05-13-2008, 11:30 PM

Quote:

Originally Posted by |V3nom|

so whats the little metal part coming off the exhaust manifold by the turbo?

Probably the wastegate. Other then that I don't have a Sky yet so I don't know if there are any other metal things coming off the manifold.

05-08-2008, 04:15 PM	#1 (permalink)
OnyxSky Member Join Date: Aug 2007 Location: Enfield, CT Posts: 24 My Photos: (4)	Blow off valve!!?? Does anyone have a blow off valve? I'm looking to upgrade my intake and want a blow off valve also but I am having a hard time finding anything. HELP! __________________ ~Mark 2008, Onyx Black, Redline, 5 speed Chrome Wheels, all the extras, 3m Bra, delivered 8/30/07!

05-08-2008, 05:29 PM	#2 (permalink)
centric Member Join Date: Mar 2008 Location: Los Angeles, CA Posts: 19 My Photos: (0)	Search is your friend. Bottom line, on a Sky with stock turbo, a BOV vented to atmosphere buys you nothing except worse fuel metering. Just curious, too, why people like sneezing cars? __________________ Cars: 08 Sky Redline, 03 Viper SRT-10, 00 Prowler, 68 Mustang Convertible (302), 68 Mustang Fastback (347), 66 Corvette 427/425 Convertible

05-08-2008, 06:37 PM	#4 (permalink)
SupraDOc Member Join Date: Feb 2008 Location: Virginia Beach, VA Posts: 7 My Photos: (0)	Some people just like blow off valves. That's like asking why does anyone like anything in particular. You are right though, worse fuel metering is almost a given on any stock car. I would imagine you could just weld a flange to the intercooler hard pipe. Tial seems to be the best BOV out. But bump for an answer though! Anyone change to an aftermarket BOV? __________________ 1995 Toyota Supra Twin Turbo Targa (Baltic Blue) 1 of 45 [BPU] 2008 Saturn Sky Redline (White w/ Red Leather) 2004 Subaru Impreza STi [GT30R] - 470AWHP 430TQ 11.83 @ 119.74 (1.81 60ft) [RIP] 1994 Toyota Supra Turbo [BPU] - 375.2RWHP 406.4TQ [SOLD]

05-08-2008, 07:19 PM	#5 (permalink)
JohnD First 2000 Sr. Member Join Date: Apr 2006 Location: SoCal Posts: 3,475 My Photos: (73)	If you just want the huffing and puffing, getting rid of the plastic airbox and going with a pipe will get you all the sounds you want... __________________ First:"BABY"* Silver Pearl 9 May 06* Then:"SPIRIT"* Black Onyx Red Line 25 Oct 06* Check out My Photos!

05-10-2008, 05:15 PM	#7 (permalink)
Bogie Senior Member Join Date: Aug 2007 Location: Northern, VA Posts: 2,278 My Photos: (0)	Just launch off a few redlights without exceeding the speed limit (oh well...maybe five over) and you will quickly learn the sound of our stock CBV. Nothing like getting an RL Turbo all cranked up an ready to go only to have to lift and brake a few seconds later. It doesn't whistle like a BOV, but it does whistle. __________________ 2008 Redline Black Onyx Black/Red Leather Monsoon 6 Disc Spoiler French Transmission Snagged 8/31/07 Belle? That's my car Alizée? That's my avatar Me? Forty something male skydriver

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05-08-2008, 05:55 PM	#3 (permalink)
\|V3nom\| Senior Member Join Date: May 2008 Location: Denham Springs, LA Posts: 244 My Photos: (0)	my car sounds like a birdie when i shift lol.

05-10-2008, 06:24 AM	#6 (permalink)
\|V3nom\| Senior Member Join Date: May 2008 Location: Denham Springs, LA Posts: 244 My Photos: (0)	i thought turboed engines had to have a bov to vent pressure or it would blow, what do they have on it now, is it a wastegate or something? i saw something on the exhaust manifold, i thought that was a bov.

05-10-2008, 05:17 PM	#8 (permalink)
\|V3nom\| Senior Member Join Date: May 2008 Location: Denham Springs, LA Posts: 244 My Photos: (0)	i thought a turbocharged vehicle had to have a bov so you dont blow the motor? what relieves the pressure then?

05-10-2008, 05:44 PM	#9 (permalink)
OnyxSky Member Join Date: Aug 2007 Location: Enfield, CT Posts: 24 My Photos: (4)	Yes... it does whistle... but I'm use to a nice head turning teeeeeeeeeeshhh lol __________________ ~Mark 2008, Onyx Black, Redline, 5 speed Chrome Wheels, all the extras, 3m Bra, delivered 8/30/07!

05-10-2008, 07:52 PM	#11 (permalink)
\|V3nom\| Senior Member Join Date: May 2008 Location: Denham Springs, LA Posts: 244 My Photos: (0)	so would you have to disable the built in bypass valve to run a bov?

05-10-2008, 09:14 PM	#13 (permalink)
\|V3nom\| Senior Member Join Date: May 2008 Location: Denham Springs, LA Posts: 244 My Photos: (0)	gotcha. so unless you get rid of the stock bypass valve and do a lot of fidangling to the intake, its not worth it. is the bypass valve on the turbo manifold itself? i saw something on the end close to the front of the car.

05-10-2008, 11:08 PM	#15 (permalink)
sidejam Senior Member Join Date: Nov 2007 Location: Calgary Posts: 237 My Photos: (0)	I wonder if the MAF sensor could be relocated in the intercooler pipe just before the throttle body and then put a BOV between the intercooler and the MAF sensor. I'll just assume that the ECU would freak out if you did that too...

05-11-2008, 02:37 AM	#16 (permalink)
Jay_Sin Senior Member Join Date: Oct 2007 Location: Bismarck, ND Posts: 173 My Photos: (0)	I'll never understand why someone will try to go through so much work just to make something that is good for performance to something that is just ok. I guess having that "my car is turbo" woosh is just too important to consider what's actually better for performance. __________________ Future Solsitce Owner

05-11-2008, 03:35 AM	#17 (permalink)
xxdjfate76xx Member Join Date: Feb 2008 Location: Miami, FL Posts: 63 My Photos: (0)	most jap cars that have the BOV upgraded to an atmospheric one have to end up buying some type of fuel management system to get it to run right... my 240sx would shoot a flame everytime i would shift because it ran a bit rich right when the BOV would go off... not much market out there for the redline right now, so not worth doing (my opinion) __________________ 8000K HID Headlights 3000K HID Fog Lights Opel Grill Badges/Emblems Dejon Intake Dejon BOV Spring Dejon Pipes Magnaflow Exhaust 18" Staggered Gravana J2 Rims Eibach Pro Lowering Springs DDM Works Pro-beam Wastegate Mod Bypass Mod Westers tune

05-11-2008, 04:39 AM	#18 (permalink)
sidejam Senior Member Join Date: Nov 2007 Location: Calgary Posts: 237 My Photos: (0)	I have an automatic. So, at the track, BOV or diverter valve won't make a difference! Besides, if you look at any high horsepower import, they're usually running BOV. I'll assume there must be a reason for it...

05-11-2008, 01:24 PM	#20 (permalink)
sidejam Senior Member Join Date: Nov 2007 Location: Calgary Posts: 237 My Photos: (0)	I guess the biggest advantage of a BOV is that at part throttle, it stays closed. With the DV, with just a little bit of vacuum, it will be open. I think a happy medium would be to put in an aftermarket BOV, but have it vent back to the intake. You'd still get most of the noise of a BOV, but it wouldn't throw any codes. I believe that what Dejon is doing on their turbo kits.

05-11-2008, 04:20 PM	#21 (permalink)
\|V3nom\| Senior Member Join Date: May 2008 Location: Denham Springs, LA Posts: 244 My Photos: (0)	so whats the little metal part coming off the exhaust manifold by the turbo?

05-11-2008, 05:45 PM	#22 (permalink)
OnyxSky Member Join Date: Aug 2007 Location: Enfield, CT Posts: 24 My Photos: (4)	wow Wow... well... I was looking for the quick answer like my srt-4... bought a part for 60 bucks and it sounded saaaaaweeeet. I guess I will be happy with the little sound we have now. __________________ ~Mark 2008, Onyx Black, Redline, 5 speed Chrome Wheels, all the extras, 3m Bra, delivered 8/30/07!