Just put it in a vice and tighten until it dents a little and try that. Mine is crushed until the vacuum fitting is hitting the lip underneath it.

 

i dont understand which way it gets crushed, sideways or top the bottom or what, i need a damn picture!

 

i dont understand which way it gets crushed, sideways or top the bottom or what, i need a damn picture!

Top to bottom...

 

Aren't you supposed to hook up a source of vacuum like a Mighty Vac hand pump tester with a gauge on it and pump it up to about 18 psi or thereabouts (while BOV's in a vice putting squeeze on top and bottom) and tighten vice (crushing) so that you see diaphragm just begins to unseat seal at 18 psi vacuum? Or something like that. It's been a while. What you're doing is putting more tension on spring in diaphragm so it doesn't blow open under pressure and release boost at higher psi's.

 

I guess it works but it's still such a ghetto mod.

 

if it works whats wrong with saving a few bucks? its has been proven on some quick cars.

 

if it works whats wrong with saving a few bucks? its has been proven on some quick cars.

There's nothing wrong with it but it is a temporary fix. Kinda like using duct tape. You are damaging the BOV to work beyond what it was designed to do. Sometimes crushing them does more bad than good.

Just like the guys who beat on the frame of their cars to fit a Supra IC in it,yeah it works but in most installs I've seen it looks kinda shoddy IMO.

I'm just not into the jury rigged mods.

 

doesnt have to look good to work

 

There's nothing wrong with it but it is a temporary fix. Kinda like using duct tape. You are damaging the BOV to work beyond what it was designed to do. Sometimes crushing them does more bad than good.

Just like the guys who beat on the frame of their cars to fit a Supra IC in it,yeah it works but in most installs I've seen it looks kinda shoddy IMO.

I'm just not into the jury rigged mods.

You can spend your money on HK$ BOV's or whatever, I'll spend mine where I can put it to good use. There's nothing temp. about it. It holds as much boost as I'll ever want to use on the street. It's not being damaged, it's being "modded" or "custom fabricated".

I guess you'll never want a "big" fmic because in a lot of cases you'll have to cut the front bumper and sheet metal to get it to fit along with the i/c piping.

How do you think all these small time vendors/racers started out when there wasn't anything available? If I can get the same results by spending a little time researching and modding as opposed to looking in a catalogue and buying something I already have that'll work, guess which route I'll take.

I don't mean to offend anyone, but if we all had the money to burn I guess I'd be burning mine on a Skyline or Porsche Turbo.

 

Aren't you supposed to hook up a source of vacuum like a Mighty Vac hand pump tester with a gauge on it and pump it up to about 18 psi or thereabouts (while BOV's in a vice putting squeeze on top and bottom) and tighten vice (crushing) so that you see diaphragm just begins to unseat seal at 18 psi vacuum? Or something like that. It's been a while. What you're doing is putting more tension on spring in diaphragm so it doesn't blow open under pressure and release boost at higher psi's.

It is not ONLY the vacuum that opens a bov. It is the pressure differential between the boosted pipe that it mounts on and the vacuum in the manifold. When you are at WOT the manifold line has similar (almost the same) pressure as the UICP. With equal pressure on both sides of the valve it would only require a couple of pounds of spring pressure to hold it closed (it is a game of tug-a-war). However when you go into partial throttle the the TB will create a slight differance in pressure between the UICP and the manifold, it will now require a little more pressure to keep the valve closed. This may cause the BOV to flutter the extra pressure out. When you are coming off of full boost, and allow the throttle to close completely (take your foot off of the gas) the UICP has say 20psi in it while the manifold has 17inhg of vac. This extreme pressure differential easily overcomes the spring pressure, it forces the BOV to suddenly be blown open by the pressure and simultaniously be sucked open by the vacuum. What I am getting at is that it is a combination of the vacuum and boost that operates the BOV. So to crush a valve so that it required 18 PSI of vacuum alone to open the valve would probably hold more boost at closed throttle than desired. A loose BOV will open to oftenly at partial throttle and hurt performance. A BOV that has to much spring pressure will not allow enouph boost out at partial throttle or closed throttle and you will experience a mild to bad case of turbo surge (excessive turbo wear). I am not sure what the actuall desired spring pressure is ( it will varry slightly from car to car) but I prefer my BOV to be a little tight, this will retain more boost in the system in between gears.

 

Uhhhh yah. Whatever works.

 

Uhhhh yah. Whatever works.

AHHH, the famous words of thousands of people that have inadvertantly blown their engines.

 

Ass-u-me. I've had my '91 Tsi since 10-13-90. It's got 110K miles on the odometer and it's making 311 whp. Daily. On pump gas. Head's never been off. That's at 20 psi. Daily. On pump gas.

 

You can spend your money on HK$ BOV's or whatever, I'll spend mine where I can put it to good use. There's nothing temp. about it. It holds as much boost as I'll ever want to use on the street. It's not being damaged, it's being "modded" or "custom fabricated".

I guess you'll never want a "big" fmic because in a lot of cases you'll have to cut the front bumper and sheet metal to get it to fit along with the i/c piping.

The FMIC I'll be installing will require minimal cutting of the bumper and will not hurt the structural integrity of the existing piece. There are several FMIC kits that are fine for what I want to achieve and they don't require hacking the piss out of the front end.

Crushing a BOV is a ghetto mod period even if it works. I plan on pushing about 22psi so I do have to spend some cash on a good BOV and TEC sells a nice HKS racing bypass for around $175 which to me is a good price.
"Crushing" isn't an exact science and I'm sure there are cases of a crushed BOV failing but I doubt anybody would post it here.


I also don't use aqurium valves as boost controllers either,yeah they work but also people have blown engines up with 'em too.

I guess you mod within your budget and that's cool but if you can afford it then I'd opt for quality pieces instead of hack jobs.

 

Ass-u-me. I've had my '91 Tsi since 10-13-90. It's got 110K miles on the odometer and it's making 311 whp. Daily. On pump gas. Head's never been off. That's at 20 psi. Daily. On pump gas.

You're the exception not the rule so good for you.

All car brands have their factory freaks that hold up to abuse or are faster than the norm.

 

Maybe you ought to check out my profile for a list of my mods.

 

Ass-u-me. I've had my '91 Tsi since 10-13-90. It's got 110K miles on the odometer and it's making 311 whp. Daily. On pump gas. Head's never been off. That's at 20 psi. Daily. On pump gas.

I'm with ya. I've been doing this since ~1997 with similar mods as you. Only difference is I have a mkiv smic and a 190lph pump.

 

Maybe you ought to check out my profile for a list of my mods.

What I meant was I put my cash where it was necessary and used what I could because I could.

"Crushing a BOV is a ghetto mod period even if it works."
"I guess you mod within your budget and that's cool but if you can afford it then I'd opt for quality pieces instead of hack jobs."

I don't believe in "ghetto" or "hack jobs". Just because someone doesn't have the cash to burn but has the ingenuity to modify a part , I wouldn't hold it against them but I would applaud their ability to satisfy their need and desire for speed.

This subject is getting old and drawn out. To each his own.zzzz

 

Hey,if it works for you then go for it. I can tell you don't have a hack job car and you do have some nice parts on it I was just giving my opinion.
I'm gonna spend the extra money on a proper BOV but when my stock one does start to not hold boost I might experiment with crushing just to see how much boost I can hold with it and then put on the HKS one. I'm not really into the crushing mod but I am curious.

When does the stock BOV start to leak? I've personally had mine to 19psi with no leaks but by April I'm planning on 22psi.

 

ok if he's pushing the stock BOV past what it was designed for then his stock BOV is useless anyways. crushing it is free, if it works fine, then great, you just saved yourself $175. If it doesn't work, oh well, looks like you will have to buy a new BOV. I don't see how he has anything to lose by crushing the BOV.

come on people, this is a DSM board, we're not snotty supra owners or anything. we use what works, not what's most expensive.

 

come on people, this is a DSM board, we're not snotty supra owners or anything. we use what works, not what's most expensive.

AMEN!

 

Lets stay on the topic of how to crush the bov guys.

 

i have a spare 1g bov laying around so im gonna probably do the vfaq way. I think its like 50 bux for the kit on dejontool site, i was a little confused by the way they have it layed out. It says 50 bux then right after it says 10. It looks like it should be 50 dollars but i cant see how it should be so im tempted to say its only 10 dollars. Has anyone actually ordered it and done it.

 

i dont think a crushed 1g BOV is a "ghetto mod"

alot of local guys tat run 22+psi run a cruchsed 1g BOV.. oh did mention their running high 11s or low 12s? hmmm ghetto mod eh? i guess you call it ghetto because it dosnet have that PSSSHHHHH sound... oh well i guess to some people the nice PSHHHH sounds is more of a priority than spending that $100++ for nice sounding BOV than putting that $$ into other mods.

 

i dont think a crushed 1g BOV is a "ghetto mod"

alot of local guys tat run 22+psi run a cruchsed 1g BOV.. oh did mention their running high 11s or low 12s? hmmm ghetto mod eh? i guess you call it ghetto because it dosnet have that PSSSHHHHH sound... oh well i guess to some people the nice PSHHHH sounds is more of a priority than spending that $100++ for nice sounding BOV than putting that $$ into other mods.

It's just my opinion guys and you don't have to jump all over me for it.

BTW the HKS BOV sounds pretty much like the stock one but is adjustable and cost about $50 less than the Greddy one that everybody just raves about.
Owning a DSM also doesn't mean you have to mod as cheaply as possible. I'm just not afraid to spend a little more money for quality parts and yes,I don't mind a little bit of *bling* when I open the hood.

Speaking of trying to save a little money,I posted a thread a while back about a $75 fuel pump from Napa that flowed at the same 255lph as the Walbros do and I got zero replies. What's that all about? I guess if I posted something about Altezzas or "which deodorant I use" (the stupidest thread on the board ) I would have had 50 responses by now.

Sometimes this board is a little frustrating but I still love most everybody on it.