PDA

View Full Version : blow off valve



quattro411
08-01-2005, 07:39 PM
i just got my blow off valve and there are no intructions on how to intall. does anyone know how to install it?

mxp
08-01-2005, 08:31 PM
what brand is it ? btw you should really go with a diverter valve instead of a blow off ...

A4ringedONE8T
08-01-2005, 09:04 PM
Originally posted by mxp
what brand is it ? btw you should really go with a diverter valve instead of a blow off ...

BOV's work fine with the 1.8T. Its just a matter of preference.

ncttrnl
08-01-2005, 09:29 PM
Originally posted by A4ringedONE8T
BOV's work fine with the 1.8T. Its just a matter of preference.

Depends on your driving style really... if you like hearing the pssssshhhh noise all the time... you're gonna throw codes eventually but I really don't think its that big an issue. Running rich is good ... unless you're an environmentalist.

Back on track...

What engine do you have so we can provide the proper pictures? 180 or 225?

A4ringedONE8T
08-02-2005, 05:29 AM
Originally posted by ncttrnl
Depends on your driving style really... if you like hearing the pssssshhhh noise all the time... you're gonna throw codes eventually but I really don't think its that big an issue. Running rich is good ... unless you're an environmentalist.

Back on track...

What engine do you have so we can provide the proper pictures? 180 or 225?

I've been running a BOV for 18,000 miles and still no codes! Watch one come on today just because you said that [:)]

EVIL-AUDI
08-02-2005, 08:50 AM
Running rich is not good if you care about your Cat at all. BOV are not meant for the 1.8T becuase of our need for that air you are letting go of. Search if you want real info.

A4ringedONE8T
08-02-2005, 01:17 PM
I've done my homework on this and as much as everyone says no about BOV's on our cars it does not hurt them. If you run an air/fuel map on a factory 1.8T they will run anywhere from 1.6% to 2% rich while underload. Anywhere between 1% and 4% is technically acceptable according to Audi. Myself as well as a tech from my local dealer here spent about 4 hours in my car testing the differences between the Forge 004BOV and the Forge 007P diverter. The results from the BOV were 2.6% rich and the diverter 2.1% rich both being within Audi specs. So everyone's car may be different I give you that but theres is not one single reason anyone can give me that the BOV is hurting or doing anything bad to my car. If you have proof I welcome it but from all my testing and straight from the Audi techs mouth, the BOV is causing nothing out of the ordinary.

EVIL-AUDI
08-02-2005, 02:00 PM
Before I do that, you can resize your sig to fit the forum guidelines. 500x150 is the max.

Daft
08-02-2005, 02:09 PM
I can't believe that in this day and age (let alone the lofty search base we have here) that someone is arguing that an atmosphere vent type blow-off valve is completely fine for use on a MAF equipped car!!!!

Look.

Your car has a MAF. It counts airflow as soon as it enters the air filter. The injectors are waaaaay the hell downstream and they are expecting every molecule of that air to arrive for the combustion process. Every bit of it! As soon as you vent even a small amount of it, your mixture will run lean until the system catches up. Were not talking 3 hours here but, running lean is just plain dangerous on any turbo engine.

There are no magical fuel maps or 50/50 vent/DV valves out there that can prevent this. It's just a fact of science and engineering.

You can sit at your PC and tell us all how you've never had a CEL or a "problem" with your car but, you are running lean everytime you open that valve under boost. Everytime you let off the gas for a hard shift. Period.

Just in case you're wondering how a DV makes any difference, I'll fill in the blanks.

Your DV dumps the active boost pressure right back into the intake path right before the mouth of the turbo. The ensures that the air that was counted before will actually arrive at the combustion chambers when promised. Although this seems like a long delay it isn't. The air will still arrive on time but, it will have allowed the turbo to spin down safely which was the main goal.

I know you have your BOV on the car and you "love it, yada yada yada" but, stop spouting the "BOV Gospel" on here and confusing the newbies. Vented air is lost air. Fuel mixture with less air is leaner. 1 + 1 = 2.

ncttrnl
08-02-2005, 06:45 PM
Fuel with less air is rich

Paul_858
08-02-2005, 06:49 PM
ROFLMAO Daft... Less air = higher fuel to air ratio = rich as Ncttrnl stated

A4ringedONE8T
08-02-2005, 09:07 PM
ncttrnl and Paul_858 thank you for answering that one for me[:)] So DAFT, what again was the downside of a turbo car running RICH?

Paul_858
08-02-2005, 09:17 PM
exhaust tips turning black quicker, inefficient performance, waste of fuel, potential emissions issues.

A4ringedONE8T
08-02-2005, 09:29 PM
Originally posted by Paul_858
exhaust tips turning black quicker, inefficient performance, waste of fuel, potential emissions issues.

Wash my car every other day, Couldn't tell because APR's software is making my timing screwy, still getting 20 in the city and 30 on the highway, cats cleaned out [hail] I have answers for them all [:D]

And BTW I'm not telling anyone to run a BOV just mearly stating that I have not had any problems with mine and have no reason to dismiss them from an Audi's mod lost after dealing with them first hand. If you PERSONALLY have used a BOV on a 1.8T and had problems please post up because I would like to investigate what you have found, perhaps I am missing something. But until then I love my BOV and all of you guys on here. [az]

Daft
08-03-2005, 08:29 AM
Honestly, I have no idea why I went off on the lean thing. That was a major brain fart. I appologize for the mistake.

With that being said, this still doesn't mean that the BOV is a useful part on a MAF powered car.

Running rich can be looked at as "desirable" when you're getting up near redline and combustion temps are highest.

However, it should be noted that running rich does a whole lot more than "making your bumper black".

The piston tops, the valve seats, the turbine wheel and the exhaust runners will all develop a nice black cake of buildup. Oxygen sensors and the catalytic converter will receive the same as Paul indicated. As the final result your bumper will receive whatever soot is left.

The performance increase of a BOV over an aftermarket DV is minimal at best in terms of responsiveness. In sum, I can't see the value of this responsiveness versus the coating of carbon fouling that will result from the venting process.

The only way to put a BOV on your 1.8T and not see these rich surges is to get away from the MAF setup. For example, a car using a MAP system wouldn't be affected.

Eitherway, you guys obviously enjoy the soot in your engines, I recommend you ask your families for a case of seafom for Christmas.

Keep on scrubbing!

EVIL-AUDI
08-03-2005, 08:37 AM
No one can ever fault Daft for making one mistake. He is by far the most knowledgeable person on this board.

ncttrnl
08-03-2005, 10:20 AM
You know what... I run a DV. I run it because I don't want that damned noise. I'm not too worried about running a little rich when I lift off throttle.

I know there is this whole big thing about BOVs being bad for our engines because we use a MAF. I know plenty of people that use BOVs and never even see a check engine light. The bigger issue with BOVs is that they are a boost leak all the time if they aren't adjusted properly.

Now if he said he was going to go and put a manual boost controller in place of his N75 and clamp his wastgate shut, I would jump in and say not to do it. He's just asking how to install a part that might clog his cats in 50K miles or might leave some deposits in his engine besides all the crap from the PCV system.

I think my responses have been pretty even keeled and I certainly have not been spouting "BOV Gospel". If I have then I would call your responses "BOV FUD". If he likes the thing and it runs a little rich then whatever. He can get someone to clear his CEL if he gets one.

I'm rambling...

Point of all this is...
A) its his car
B) its not ideal but its not horrid
C) its his car

TT18T
08-04-2005, 03:19 AM
i think the sound from my forge 007p is good enuf for me. :)

EVIL-AUDI
08-04-2005, 08:34 AM
EVOMS BPV is plenty also

AudiGuy666
08-20-2005, 07:18 PM
BOV's suck
They are annoying and useless.

jeremy@matrix
08-23-2005, 09:02 PM
We would HIGHLY suggest running a BPV on any MAF-equipped vehicle; Forge 007P is what we prefer.

Fast01TT
08-23-2005, 10:58 PM
i had a greddy bov, it wasnt adjusted correctly but yea it ran really rich. however, it didnt sound that bad (kinda like my forge 007).

AudiGuy666
08-26-2005, 11:29 PM
Originally posted by Fast01TT
i had a greddy bov, it wasnt adjusted correctly but yea it ran really rich. however, it didnt sound that bad (kinda like my forge 007).


I doubt it sounds like a 007.