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-   -   Simple BOV Question. (https://www.rx7club.com/single-turbo-rx-7s-23/simple-bov-question-602369/)

tandolla 12-04-06 02:33 AM

Simple BOV Question.
 
alright i know if your put the BOV on the TB side you get better performance. and if you put it on the Turbo Side you save the turbo..

but my question is .. how much of the turbo do you save if you mount it on the Turbo Side..

i was planning on mounting on the TB side for performance.. but if mounting it on the TB side will ware out my Turbo Alot quicker then i will put it on Turbo side.. ?

dubulup 12-04-06 11:17 AM

if you want performance...mount it in the trash.

if you want it...mount it where ever you want.

PhatManBUD 12-04-06 11:30 AM

hahaha

tandolla 12-04-06 02:36 PM

umm.. real mature.. it was a simple question. that obviously you dont know so i dont know why you even toook the time to read it..

RacerXtreme7 12-04-06 02:44 PM

He read your post, I think he is a BOV non-believer and is just trivializing your post/question. Just mount it near your TB, its better performance and placeing it near your turbo isn't necessarily better for the turbo. Theres other factors most don't think about like dampening and other things that make mounting it by the tb the best location.

~Mike...............

tandolla 12-04-06 03:16 PM

thank you i appreciate it. :)

dubulup 12-04-06 04:05 PM


Originally Posted by tandolla
umm.. real mature.. it was a simple question. that obviously you dont know so i dont know why you even toook the time to read it..

I do know, and I was being 100% serious...sorry about the tone. I should have said, "mount it in the 'for sale' section"...the trash sounded kind of harsh.

there are 100's of posts debating this very issue...all three locations.

hondahater 12-04-06 04:18 PM

so is yours mounted in the trash? I do believe you are the second only to riceracing that doesn't "believe" in blow off valves that I've heard of. There must be some sort of good evidance to disban the otherwise wide spread idea that the bov is good for your turbo. Not trying to be a prick just wondering what your reason is for not liking it. Would be much obliged if you could elaborate for me.

edit: you gotta come down to lake charles one day so I can see your mighty fine fd :)

tandolla 12-04-06 04:21 PM


just wondering what your reason is for not liking it. Would be much obliged if you could elaborate for me.
+1

dubulup 12-04-06 04:47 PM


Originally Posted by tandolla
i was planning on mounting on the TB side for performance..

Figure'd he wanted an answer that gave the most performance. When people, who know more than me, talk...I listen, be it Rick Engman, Carlos Lopez, Bryan Nickell, howard coleman, or Peter @ R.I.C.E. Racing...


Originally Posted by RICE RACING
BOV's are only fitted as OEM noise reduction device when fitted in plumb back mode.

BOV's casue charge loss in piping and circuit cars can and have gone slower when fitted with a dump valve due to needing to fill back up charge piping upon re throttle application.

I eliminate BOV's on every car I own or work on be it Mazda rotaries or big hp 2JZ supra's, I have never had a turbocharger fail due to not running a BOV. On the other hand have had lots of techincal problems with cars fitted with BOV's and also general losses of performance ;)

Have data logs ranging back 7 years on every format from Autronic to Motec to stand alone loggers that show no performance gains when running one of these stupid devices on a motor vehicle. Its one of the biggest single cons on the aftermarket performance sectors ever.

BTW F1 never used BOV's, even when allot of the engine suppliers had OEM road cars running with them........ The truth is they do very little if anything measureable for perfomance and they do absolutley nothing for increasing turbocharger life, in fact they do the exact opposite if they do fail or leak they can cause turbocharger overspeeding, probably why they were never used in F1 ;)

Fuel engergy is what keeps turbines spining either that or working in a complete or partial vacum, we dont and cant achieve partial vacumes but we do introduce fuel into the turbine section,once this is shut (on closed throttle) off the compressor slows dramaticaly BOV or not.

7 years and probaly 100 000km and up to 36psi boost speaking here across a plethora of vehicles. My SP FD RX7 only runs 16psi of boost but I have not had one issue at all in 8000km of driving and testing since removing BOV's infact only thign thats changed is that the car is more responsive and faster as a result.



Originally Posted by RICE RACING
The fuel energy comment is not anti lag, it was not meant to read that way it was more meant that the only "normal" thing that gives a turbocharger energy is heat form combustion (temperature) and flow rate of gases over the turbine wheel. When you eliminate both these things (I.E. closed throttle and decel injector cut) amazingly the turbo slows down amazingly quickly with or without a BOV it makes no damn difference.

The admission of atomspheric particles or atmosphere slows any turbine system down very dramaticaly, the ONLY thing that can keep it sustained at any rate worth mentioning (aside form normal combustion on WOT) is running in a vacum and that my friends does not happen on anything but a lab type vacume system using in industry or a university. We rebuild turbo molecular pumps and I have seen this first hand ;)

What does happen though in a negative way is that when running a BOV you dump all that hard work that was done by the compressor and loose all volume of compressed particles in the charge plumbing and charge cooler and this is a negative aspect since you have a lag to build this pressure back up on a re opening throttle. Turbine speed has greatly diminished since there is nothing to drive it since you lifted off anyway and the presence of atmospheric air pressure on the inlet of the turbocharger massively slows down the turbine/compressor anyway BOV equipped or not so its a net loss. This is why they were never used in serious competition at the top level.

The next biggest falicy is turbo failure, well I single handidly have proved that to be utter garbage but you dont need to take my word for it simple research will prove to you that turbochargers did not fail any sooner before the mass marketing of BOV's and they have not yet shown one scrap of evidence to prove what physics there is to back up their claims of increased reliability, they do however have a ton of scare tactics and adhominem argument to back up a baseless case though.

So far as practical fact I have no BOV's on my FD and it loves it ;) I am constantly on 1.06kg/cm boost and have experienced no one single issue with many thousands of miles of hard driving and testing so far, car definatley has more pull between gear changes but so has every car that I have removed BOV's from.

No my BOV is mounted on the Cold Side IC pipe...if I hadn't welded it there, I'd probably run without it. I might try to cap it?!?!

I'll come to lake charles...just as soon as I get the car back together ;)
http://i7.photobucket.com/albums/y28...p/DSC08205.jpg

dubulup 12-04-06 04:51 PM


Originally Posted by dubulup
Figure'd he wanted an answer that gave the most performance. When people, who know more than me, talk...I listen, be it Rick Engman, Carlos Lopez, Bryan Nickell, howard coleman, or Peter @ R.I.C.E. Racing...






No my BOV is mounted on the Cold Side IC pipe...if I hadn't welded it there, I'd probably run without it. I might try to cap it?!?!

I'll come to lake charles...just as soon as I get the car back together ;)
http://i7.photobucket.com/albums/y28...p/DSC08205.jpg


EDIT: http://rapidshare.de/files/10639230/ricesp.mpg.html <--a lap in his SP RX-7

dubulup 12-04-06 04:52 PM

http://rapidshare.de/files/10639230/ricesp.mpg.html <--a lap in his [RR] SP RX-7

dubulup 12-04-06 04:53 PM

SHIT! they took away the edit button...I'm an idiot

dubulup 12-04-06 04:54 PM

LOL I think this is a better link > http://mugenpower.net/rx7c/ricesp.mpg

hondahater 12-04-06 05:10 PM

cool, downloading the video now. I'm the same way, I consider myself a newb even though I know more than the average person when it comes to rotaries but there is so much to learn and I only know what I know so saying I know everything or even a small amount is just dumb. Lol, your car looks like mine right now except my motor is apart as well. Hopefully will have everything back together and ready to run for the steve kan tunning in mid january, of course thats being very optomistic :)

Heisenberg 12-04-06 05:11 PM


Originally Posted by dubulup
LOL I think this is a better link > http://mugenpower.net/rx7c/ricesp.mpg

Nice!!:icon_tup:

ronbros3 12-04-06 05:19 PM

Is it true that there are more FDs without engines in them, than there is running on the street Ron

dubulup 12-04-06 05:25 PM

don't know...since I've owned mine. The engine has been in more than out, I hope.

ronbros3 12-04-06 05:35 PM

I know what you mean, I got two FDs in my shop, no engines in both. OH well, time and money!! Ron

hondahater 12-04-06 05:39 PM

these aren't hondas. You can't just slap it together and expect it to be a reliable car. If you have a career like most of us then it takes time to get the beast just how you want it. I don't mind. It makes it just that much better when it's finally together.

edit: I understand the consept of not having a bov now but why would most if not all turbo charged cars come standard with bov's if it doesn't do anything good? One thing I've learned to do is trust auto manufactures because of the time and money that has gone into R&D.

dubulup 12-05-06 08:11 AM


Originally Posted by RICE RACING
BOV's are only fitted as OEM noise reduction device when fitted in plumb back mode.

probably makes a quiet shift, especially when plumbed in...I don't really hear compressor surge on RICE's car in the video, or anything terrible happening during shifts for that matter.

I believe, he was running sequential twins without the CRV as well.

CarbonR1 12-05-06 10:49 AM

BOV's are primarily in the OEM to reduce the noise from compressor surge. They are even used on diesel motors that have no throttling lose. When running without one, it theoretically the hardest on the thrust bearing/BB cartridge because when the throttle is closed, it tends to want to put an axial load on the rotating assembly towards the turbine side. This is due to the pressure being on the turbine side acting underneath the wheel to put the whole assembly in an quick axial load.

I don't think it would be possible to feel something like this from the driver's seat, because it happens so quickly. Also, it is not practical to compare DD turbo systems to racing turbocharging. For the sake of performance, reliability is often compromised. The turbos used in high racing applications are rebuilt after each race, so who would care if it was hard on the bearing system?

I'm not a fan of the BOV sound, but they are there for a reason, even if performance is a bit lower.

-Kevin

ikari899 12-05-06 11:09 AM

im going to have to agree with carbonR1 please run a BOV... your turbo will thank you.

Whizbang 12-05-06 11:33 AM


Originally Posted by tandolla
alright i know if your put the BOV on the TB side you get better performance. and if you put it on the Turbo Side you save the turbo..


mmm...misconseptions.

dubulup 12-05-06 11:50 AM


Originally Posted by Low Impedance
mmm...misconseptions.

my entire point of responding to this thread...


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