newbie turbo tech question...help me out

[fasTTA707]

ok... blowoff valves sound REALLY COOL hahaha.... they're one of the only things that make alot of rice rockets tolerable for me.... but my question is what do they do and should you have one or not?

i've heard "the only way a blowoff valve is useful is if you also have a stand alone fuel system, otherwise the blowoff valve creates a hp loss"

i have no clue, i just know it sounds cool but have no idea what its really for. could anybody help me out? is this something that would be beneficial on a tta or is this just a rice rocket accessory? let me know, thanks alot.

 

[Slow91z]

WOW...who fed you the line about stand alone fuel system???A blow-off valve has NOTHING to do with the fuel system.

Ok check it out...When you let off of the gas the ait has to go somewhere (you know the air under boost in the up-pipe??)...On a stock car it blows back through the turbo and out of the air filter (creates the mutant pigeon sound our cars make) and spins the turbo backwards...This isn't real good on the bearing in your turbo.

Now most people think that unless you have a manual transmission this does nothing for you (I disagree, but I don't want to start that argument again)...I will NOT add horsepower, but it will sound cool and extend the life of your turbo...With a manual tranny your car will actually spool faster between gears because the turbo will keep spinning the correct direction, and not have to reverse it's self.

 

[fly89gta]

What he said...

but I like the mutant pigeon sound

 

[Lee_Burough]

If you want some cheap entertainment, do a search on "BOV"

This issue, more than any other in the Buick community, causes more polarization than any car related issue I can think of (except maybe the power plate).

Some, if not most, reliable TR experts say adimantly that we don't need a BOV. I believe that.

Now, why did I buy one? I bought one because of the way I drive my car. If I was only running a quarter mile there would be no question.

But, I do most of my driving within a mile of my house: WOT bursts to 65-70 mph and then a firm application of the brakes (that gives me enough data on Tlink to go home and analyze it and make some tweaks with the T+).

My stock turbo made quite a bit of noise as the air pressure danced with the turbine wheel and tried to turn it backwards. I wanted to prolong the life of my new turbo, so I'm trying a BOV to soften the ten cycles of WOT & brakes I do each time I go out on the streets.

If you don't drive like that, a BOV can't help. If you do drive like that....It might or might not help your turbo's longevity.

If you buy a BOV, make it the last thing you purchase: Its prolly the last thing you really need.

 

[fly89gta]

Yeah I'm getting one too because of my driving style. On the gas hard then off real quick...a TE60 isn't exactly a small turbo and moves quite a bit of air...I'd rather have it last as long as possible

 

[Razor]

We can usually tell how young someone is by the questions asked

Dont need a BOV unless you want to possibly have it leak sometime in the future. As to the turbo theory as it pertains to our cars, plenty of stock turbo's well over 200K miles without issue.

If you want to go through the welding, fabbing, questions(whats that), expense, and possibly having it leak cuasing a MAF reading/blm issue, then have at it.

Had you car had a huge front mount and long piping.. then yes. But on a stock IC car.. not needed.

Start reading through posts, and go to GNttype.org lots of reading there.. The search button will answer probably all of your questions as well.

Get the car, get it running rite, learn it, then start modifying it. Do not modify till its at 100% correct, failure to do so will leave you with so many questions it will make your head spin. And nobody to be able and correct issues you may have created. These are just words of experience dealing with these somewhat finiky cars.

Theyre real easy when you know what your doing, a real chore when you dont.

Even for some of us that have a grasp on tuning them, some can be a real handful/headache/heartache.

You ordered your scanmaster yet.. your gonna need it.

 

[1badTTA]

Originally posted by Slow91z
Ok check it out...When you let off of the gas the ait has to go somewhere (you know the air under boost in the up-pipe??)...On a stock car it blows back through the turbo and out of the air filter (creates the mutant pigeon sound our cars make) and spins the turbo backwards...This isn't real good on the bearing in your turbo.

OK, a little misinformation here. (where is the BS flag?) Your turbo will not spin backwards and the sound you hear isn't air flowing backwards. What you hear is the wastegate fluttering due to an overpressurization of the line connecting it to the turbo body. When you let off quickly alot of pressure does build up in between the turbo and throttle body whick will send an overboost signal to the wastegate opening it rapidly which allows the exhaust gas to bypass the the turbine putting less of a load on the compressor wheel which in turn reduces the boost in the compressor housing enough to allow the wastegate to close and then another another boost spike occurs causing the cycle to start over again. Still no air flowing backward or turbo spinning backwards, just sudden slowing of the turbo at an eneven rate.

Anyways, a BOV isn't needed in a TR due to the auto tranny, but it might add some life to the turbo. Either way, it won't make you any faster except for the weight savings it provides to your wallet.

 

[GTABurnout]

went through this a while ago, but still put one on have had no problems with it, and I feel it is a needed item for a street driven and slightly raced TTA. If you want to do one don't listen to all the haters out there because I have had nore people ask to see my set up then they would like to admit.

SO you're not alone although some guys will make you feel that way...

Email me if you want to see pics...

 

[Slow91z]

Originally posted by 1badTTA
OK, a little misinformation here. (where is the BS flag?) Your turbo will not spin backwards and the sound you hear isn't air flowing backwards. What you hear is the wastegate fluttering due to an overpressurization of the line connecting it to the turbo body. When you let off quickly alot of pressure does build up in between the turbo and throttle body whick will send an overboost signal to the wastegate opening it rapidly which allows the exhaust gas to bypass the the turbine putting less of a load on the compressor wheel which in turn reduces the boost in the compressor housing enough to allow the wastegate to close and then another another boost spike occurs causing the cycle to start over again. Still no air flowing backward or turbo spinning backwards, just sudden slowing of the turbo at an eneven rate.

Anyways, a BOV isn't needed in a TR due to the auto tranny, but it might add some life to the turbo. Either way, it won't make you any faster except for the weight savings it provides to your wallet.

I'm just explaining it the way it was explained to me.

 

[fasTTA707]

hey guys thanks alot i really appreciate the input... i didn't mean to start any arguments i was just hoping to gain some knowledge from people who have been working with the cars for a long time and know them very well, and i did gain alot of knowledge from reading this post but i'm still unsure of what i wanna do lol... but i AM gonna take the advice of the people who said if i DO add a bov make it my last priority...that will give me more time to learn and make an educated decision for myself. i guess the first thing i'll do is get a scantool and start reading up on the car. thanks again.

 

[1badTTA]

Originally posted by GTABurnout
went through this a while ago, but still put one on have had no problems with it, and I feel it is a needed item for a street driven and slightly raced TTA. If you want to do one don't listen to all the haters out there because I have had nore people ask to see my set up then they would like to admit.

SO you're not alone although some guys will make you feel that way...

Email me if you want to see pics...

I am not being a "Hater", I am just trying to inform someone who asked a question. I agree that a BOV is useful for protection of a high dollar turbo but IMHO is completely worthless on a stock or very mild (TA49-PT51) turbo as it will run around $200 for the BOV and will probably not extend the life of the turbo as much as saving the $200 for a rebuild. fasTTA707 came on not even knowing how a BOV really works much less if it would be benificial for him so I was just trying to help out a new guy save a few bucks and put it where it needed to go which is a scantool.

 

[Slow91z]

I have to agree, scantool WAY before a BOV.