Single Turbo RX-7's Questions about all aspects of single turbo setups.

Downside to baffling blow off valve?

Thread Tools
 
Search this Thread
 
Old 12-01-08, 08:45 PM
  #1  
DJK
Full Member

Thread Starter
iTrader: (2)
 
DJK's Avatar
 
Join Date: Feb 2002
Location: Gulfport MS
Posts: 144
Likes: 0
Received 0 Likes on 0 Posts
Downside to baffling blow off valve?

I know this may seem silly to some but I don't really want to hear my blow off valve anymore, as it attracts a little more attention from cops and other cars around here.

What I was wondering if there would be any negative effects if I were to attach a longer hose (maybe 2ft) on the outlet of the blow off valve and route it somewhere in the engine bay? Would that actually quiet it down? Also, would that affect it's function? Thanks

Jerry
Old 12-02-08, 10:05 AM
  #2  
Eye In The Sky

iTrader: (2)
 
cewrx7r1's Avatar
 
Join Date: Feb 2001
Location: In A Disfunctional World
Posts: 7,895
Likes: 0
Received 114 Likes on 66 Posts
I am assuming you mean WG.
Try a small motorcycle/ATV muffler.
If you route it back to the DP or MP, have it at an angle.
Routing back into the DP can cause a loss from 5-30 HP from what some tuners told me.

If not just get a quieter one.

Last edited by cewrx7r1; 12-02-08 at 10:13 AM.
Old 12-02-08, 10:09 AM
  #3  
Crash Auto?Fix Auto.

iTrader: (3)
 
classicauto's Avatar
 
Join Date: May 2003
Location: Hagersville Ontario
Posts: 7,831
Likes: 0
Received 2 Likes on 2 Posts
Are you talking about your blow off valve, or your wastegate??
Old 12-02-08, 11:50 AM
  #4  
DJK
Full Member

Thread Starter
iTrader: (2)
 
DJK's Avatar
 
Join Date: Feb 2002
Location: Gulfport MS
Posts: 144
Likes: 0
Received 0 Likes on 0 Posts
I am referring to my blow off valve not my wastegate. I Think it is a Greddy blow off valve, not that loud but I still would rather keep this car quiet and under the radar as long as there would be no detrimental effects of running a hose off of the outlet port of the blow off valve.
Old 12-02-08, 11:59 AM
  #5  
Tango Down

iTrader: (3)
 
NoPistons!'s Avatar
 
Join Date: Sep 2008
Location: SC/NC
Posts: 2,895
Likes: 0
Received 1 Like on 1 Post
Just recirc it.

Sell it and buy a synapse and put that biach on recirc. Quiet!
Old 12-02-08, 12:00 PM
  #6  
Crash Auto?Fix Auto.

iTrader: (3)
 
classicauto's Avatar
 
Join Date: May 2003
Location: Hagersville Ontario
Posts: 7,831
Likes: 0
Received 2 Likes on 2 Posts
Well, in that case I'd look into a recirculated setup rather then muffling it. It would be hard to reduce the noise enough to make it worth it while maintaining enough flow for proper funciton of the BOV. A recirc. BOV will basically dump all the pressure to a location that's pre-turbo when it goes off.

I know the greddy Type RS has a recirc. fitting available for it, but you need to do the rest of the plumbing yourself.

http://www.atpturbo.com/Merchant2/me...egory_Code=BOV
Old 12-02-08, 03:18 PM
  #7  
Eats, Sleeps, Dreams Rotary
iTrader: (2)
 
BC-FD3S's Avatar
 
Join Date: Nov 2002
Location: LA, CA
Posts: 3,332
Likes: 0
Received 0 Likes on 0 Posts
buy a HKS SSQV and remove the plastic chrome "peace sign".

I love how mine sounds, super low key.

your first mistake is having a greddy BOV... they're loud. not the kind of bov you want if you want to be low key.
Old 12-02-08, 05:08 PM
  #8  
DJK
Full Member

Thread Starter
iTrader: (2)
 
DJK's Avatar
 
Join Date: Feb 2002
Location: Gulfport MS
Posts: 144
Likes: 0
Received 0 Likes on 0 Posts
I'm not sure what/where you mean to recirculate it. I have a custom cold air intake made of flex tube that would be hard to get back into and maintain a seal. And would that even quiet the blow off valve anyway? I was thinking of attaching something that baffles the sound similar to what they used in stock airbox.

As for the Greddy BOV I would love to replace it with something more quiet, but I don't have that much funds available to change something that really isn't a necessity. Thanks for all the feedback.

Jerry
Old 12-02-08, 05:43 PM
  #9  
Rotary Enthusiast

iTrader: (3)
 
wackaloo13's Avatar
 
Join Date: Jan 2007
Location: st. louis
Posts: 1,000
Likes: 0
Received 0 Likes on 0 Posts
recirculate it back into the intake crack pre turbo but after the filter. That should reduce alot of the noise. Just trade your greddy bov for the type S model, you can just connect a hose to it and dump it back into your CAI
Old 12-03-08, 09:06 PM
  #10  
Eye In The Sky

iTrader: (2)
 
cewrx7r1's Avatar
 
Join Date: Feb 2001
Location: In A Disfunctional World
Posts: 7,895
Likes: 0
Received 114 Likes on 66 Posts
Why did you buy a FD in the first place? It is always draws attention.
Injoy it!
Old 12-04-08, 10:50 PM
  #11  
DJK
Full Member

Thread Starter
iTrader: (2)
 
DJK's Avatar
 
Join Date: Feb 2002
Location: Gulfport MS
Posts: 144
Likes: 0
Received 0 Likes on 0 Posts
I didn't buy the FD for attention. I was in high school when it came out and besides loving the look I thought it was an awesome performance platform just to start with. The extra noise just draws even more attention than I want, and to tell you the truth I really don't like the blow off valve that much anyway... I can deal with it if I have to though.

As far a dumping the blow off back into my intake it looks like that is going to something pretty challenging as far as keeping a seal on the intake tube. It is aluminum flex tubing and probably won't quiet it that much even if it keeps a good seal. I also covered the flex tube with a thermal blanket from DEI, keeps the tube from heat soak and I seem to see lower and much more consistent intake temps since I did that. Thanks
Old 12-05-08, 01:05 AM
  #12  
Rotary Motoring

iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 8,217
Received 765 Likes on 507 Posts
Yeah, I have an old Greddy type RS blow off valve as well and it is annoying.

It sounds fine at full boost when it just chuffs, but it is all whistles and giggles at low boost and I have a very responsive turbo so it is a constant cacophony.

I tried tightening up the BOV so it basically only vented at high boost, but the turbo didn't like that much.

I took the BOV apart and ported it to remove all the sharp edges,/ bell mouthed the exit and put a small K&N filter on the end, but it only helped a little bit.

What is a nice quite BOV that opens with a weak enough vacuum signal for a rotary?

And yesh: unlike any FD ever, my car is sleeperish :P

Old 12-05-08, 08:33 AM
  #13  
Crash Auto?Fix Auto.

iTrader: (3)
 
classicauto's Avatar
 
Join Date: May 2003
Location: Hagersville Ontario
Posts: 7,831
Likes: 0
Received 2 Likes on 2 Posts
Originally Posted by DJK
As far a dumping the blow off back into my intake it looks like that is going to something pretty challenging as far as keeping a seal on the intake tube. It is aluminum flex tubing and probably won't quiet it that much even if it keeps a good seal. I also covered the flex tube with a thermal blanket from DEI, keeps the tube from heat soak and I seem to see lower and much more consistent intake temps since I did that. Thanks
Ahh I see. But which is going to be noisier? A wide open BOV? Or a recirc'd one with a leak around the intake tube?

Most OEM turbo cars are setup with a recirc. of some description, but if you're not willign to go to the lengths to make it work, or to switch to a BOV that's "less loud" (they'll all still vent a large volume of air, and it'll still make noise) then sucking it up is your only option

Personally, I wouldn't plumb it into your flex tube if you're bent on keeping it - what does your air filter look like? (presuming this is a single turbo car) If it's a KN style with a flat plastic top - there's a perfect entry point. Don't worry too much about the length of hose inbetween the BOV and intake, it won't matter much.
Old 12-05-08, 10:11 AM
  #14  
DJK
Full Member

Thread Starter
iTrader: (2)
 
DJK's Avatar
 
Join Date: Feb 2002
Location: Gulfport MS
Posts: 144
Likes: 0
Received 0 Likes on 0 Posts
It is a single turbo car and it does have a KN filter on it, and that might be a good idea to try and recirculate it back through the top of the filter. Thanks for the idea. I hope it keeps a good seal and is quiet, otherwise I'll need to get a new filter. Probably worth a shot, thanks again for the suggestion.

Jerry
Old 12-06-08, 11:36 PM
  #15  
Eye In The Sky

iTrader: (2)
 
cewrx7r1's Avatar
 
Join Date: Feb 2001
Location: In A Disfunctional World
Posts: 7,895
Likes: 0
Received 114 Likes on 66 Posts
FOTU and FOTK.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Smokeyfb33
Old School and Other Rotary
10
10-01-15 12:10 PM



Quick Reply: Downside to baffling blow off valve?



All times are GMT -5. The time now is 11:06 PM.