Well I have raced a newer 2003 eclipse and have beat them about by half a car lengths in my stock L03. Well tonight have one next to me wasnt even gonna race him he floored it and I stomped it too. Well I heard the turbo spool and I just backed off and saved the gas lol.

I give the guy credit for not having it r*ced out with some big BOV.

Hes just lucky I wasnt in my 88 or Vette lol.

 

A blow off valve is ***** now?

 

of course it is. id be willing to bet that 99% of the cars with BOVs bought them purely for the sound it makes, not for any "safety" benefit

and before i hear the screams of "its good for the turbo", how many turbos do you actually know of that failed ONLY from not having a BOV?

on the other hand, i know of hundreds of turbo cars that run just fine, with no breakage or damage, that have never run a BOV

 

You don't know what you are talking about. But I don't feel like going over this for the 6th time.

 

good cause im sure no one wanted to hear it the first time

BTW- i know the "theory" behind a BOV, i dont need you to explain it to me. and like i said, i know of hundreds of turbo cars NOT running them with absolutely no effect on the turbo bearings. ricers use the whole turbo damage excuse to conceal the real reason they wanted a BOV in the first place... the sound

 

If BOV's never did anything, race cars wouldn't use them. They do. You apparently don't know the whole 'theory'.


Also, the only cars that I know of that don't come with a BOV from the factory are diesels, and old cars with out of date technology.

 

Yeah, all cars in the last 15 years that I've seen turbo from the factory have had a BOV, usually vented to the intake instead of atmosphere, for the sole reason of keeping it quiet. I think its cool, if I had a turbo car, I'd want that sound too.

Its kind of like a lot of guys and their exhaust. I bet a lot of people don't upgrade their exhaust because it would add performance. They do it because it sounded cool. Just take a look at all the guys in the exhaust board asking "which is the loudest exhaust...which exhaust gives me the best tone". Not a whole lot of "which exhaust flows the best" etc.

I'm curious as to what generation Eclipse was raced above. 2nd gen (95-99) that some came stock turbo, or was this a custom jobby on a 3rd gen one (00-04/05 don't remember what year the new style is)?

 

It was a 2nd gen. It looked completly stock and I never heard a BOV driving next to him thats what I ment by it. I know a lot of stickerfied cars have that BOV that goes off every time they shift even if there not at WOT.

 

Every BOV goes off, every time you lift your foot off the gas, you just can't always hear it. Especially on a factory car where it is routed back into the intake.

 

I too, Would put an aftermarket BOV, for the sound! I love the sound of a BOV.

 

the eclipse 2nd gen bov sucks just plain and simple, its plastic. If you do any modding to a 2nd gen eclipse you have to replace the bov with at least a 1st gen bov. Which will cause you to probably replace the intake and upper intercooler pipe that will make the bov sound louder. but then there a some people that vent because they need that mad bov sound yo.

i personally like my bov quiet. sleeper like.

 

lol i'd put one on my turbo car too, and it would probably be pretty loud. it sounds cool.. although it's hard to tell with the other car behind me

 

Hmmmm maybe I oughta put one on my 940 Hmmmmmm I'd be cool then

 

compressor surge sounds 10000x cooler than any blow-off valve ever made, but if I had a turbo car, it'd have a bov simply for the fact that it IS so bad for the turbo.

 

Compressor surge does have an appeal to it, but not when it's on your $800 turbo. Just like neutral drops are cool, in a rental car.

You know what doesn't sound cool when you don't have a BOV? The sound of you falling out of boost every time you shift because the air goes backwards through your turbo and slows it down instead of it being properly vented somewhere else. Not vert cool at all.

 

so what's the difference between a bov and a wastegate?

 

The BOV opens to let pressure out of the charge pipe after the turbo (and usually after the intercooler) and before the throttle plate.

The wastegate opens up before the turbo to let out hot gasses that would otherwise continue to spool the turbo past the point that you want. If it wasn't for a wastegate, your turbo woudl continue to build more boost until you blew a ring, throw a rod, melt a piston, fire a piston through your hood, melt your head, or any combination of these.

 

that sounds like a good time. woohoo melted rods pistons etc etc etc.

 

That description is kind of misleading. A basic understanding of how a turbo works is necessary before trying to figure out what a BOV is. A turbo works on engine load. Without some form of load the turbo won't build boost. The load is provided on the 'hot' or turbine side of the turbo which spins the 'cold' or compressor side of the turbo allowing boost to be produced when spinning fast enough.

A wastegate is located either on the turbine housing ('internally gated') allowing exhaust gas to escape before spinning up the turbine wheel or on the exhaust manifold before the turbo ('externally gated') which usually allows for a much larger amount of gas to escape before reaching the turbo. Externally gated is better for a number of reasons that aren't pertinent right now.

A blow off (pop off, compressor bypass etc) valve is found more often than not on factory cars and almost always on cars with manual transmissions. Many automatic transmission equipped cars such as Grand Nationals do not require one due to the nature of the automatic transmission. An auto when shifting does not disengage the engine from the transmission with a clutch removing load and allowing the compressor to surge potentially damaging your $1400 fp3052. The BOV is located on the 'cold' or compressor side of the turbo as close to the throttle body as possible to allow the compressed gas to escape so that it is not forced back into the turbo after hitting the closed throttle body plate. It is quite necessary and many people with manual transmissions use them on supercharged cars as well as on turbocharged cars so the car does not stumble when shifting or various other driveability issues. The BOV is vacuum sourced and opens when a vacuum is present on the engine.

 

Yes. I'd still put a BOV on an automatic though. If you haven't been mashing the gas, and then let your foot all the way off the pedal before, then you've never driven a car.

 

I would too since it doesn't hurt but it's not 'technically' necessary.

 

I was once checking a website that sold parts for the VR4 and stealth TT. They claimed their loudest vent to atmosphere BOV wasnt necesserily the best and said that their more expensive recirculating model was better.

Is that true or are they just trying to sell their products?

 

Most cars with stock BOV are recirculating, so if you put a BOV that vents to the atmosphere, it messes with your car. The computer is programmed to expect that extra burst of air between shifts. So if you put an open air BOV on the car, it will temporarily spike to a rich condition on shifts and cause the car to stumble. That might be what they are talking about.

Putting an open air BOV on a car that is set up to recirculate just for the sound, indeed makes you a *****.

 

Yeah thats what I was aiming for. Learning something new everyday

 

It's due to the fact that most bovs recirc post maf. It is already metered air that is supposed to be recirculating. If you relocate the maf then it is possible to vent without negative driveability issues.

 

Not entirely true. The 2.4L turbo engines in the Dodge SRT4 and Chrysler PT Cruiser GT come from the factory with a recirculating BOV that is totally silent. Adding an aftermarket BOV, which is recommended when bumping to Stage 1 and above, does not cause the car to stumble at all. Even adding an atmosphere venting BOV to a stock 2.4L turbo won't cause a stumble.

Keep in mind that this particular engine can be a real beast in a small package. With just Stage 1 it makes 240HP and 265lb-ft of torque (compared to most Japanese imports that don't make enough torque to tighten the lugnuts on an American Muscle Car!) and can easily be made to produce 450HP with great reliability, without having to beef the internals. Yes, you need a bigger turbo and the requisite fuel feed, but you don't need to touch the internals. In this configuration, an atmosphere venting BOV is a really good idea.

 

Like Inwo said, none of that has anything to do with why a car will stumble. On a Honda you can have a recirculating, or open air and it won't matter because Honda doesn't use a MAF sensor, like VW for example. Open air or recirculating makes no difference relative to how much power you are making. Also, you shouldn't be surprised that the Neon motors are capable of such high numbers without having to build the motor, most factory forced induction cars are the same way.

DSM, Supra, Cobra, GNX, etc, etc.