Notices
Series I Aftermarket Performance Modifications Discussion of power adding modifications

Thinking of changing your intake? See what the VFAD does.

Thread Tools
 
Rate Thread
 
Old Aug 21, 2007 | 09:54 AM
  #1  
SureShot's Avatar
Thread Starter
Registered
 
Joined: Jan 2002
Posts: 168
Likes: 0
From: Orange Park FL
Thinking of changing your intake? See what the VFAD does.

Page 7 of this document summarizes how the Renesis intake works.
Note the volumetric efficiency curve from 4500-5500 RPM.

You may download it.

http://208.62.166.66:82/guest/Shop_M...evelopment.pdf

Last edited by SureShot; Aug 21, 2007 at 09:57 AM.
Reply
Old Aug 21, 2007 | 10:22 AM
  #2  
mysql101's Avatar
⎝⏠⏝⏠⎠
 
Joined: Apr 2004
Posts: 8,625
Likes: 5
From: USA
yeah, sdais = engine internals. none of that shows a use or gain for the vfad.
Reply
Old Aug 21, 2007 | 10:50 AM
  #3  
SureShot's Avatar
Thread Starter
Registered
 
Joined: Jan 2002
Posts: 168
Likes: 0
From: Orange Park FL
It's about how "standing wave resonance" dynamically improves the intake.
On the Renesis the VFAD accounts for the bulge in the 4500-5500 range.

The "trombone" rig in the R26B was built to expolit the same principal.

It's not such a big deal in a turbo, but it's a big deal to NA's

Last edited by SureShot; Aug 21, 2007 at 10:56 AM.
Reply
Old Aug 21, 2007 | 11:03 AM
  #4  
mysql101's Avatar
⎝⏠⏝⏠⎠
 
Joined: Apr 2004
Posts: 8,625
Likes: 5
From: USA
btw, this was a good read on this topic:

https://www.rx8club.com/rx-8-discussion-3/new-renesis-utilizes-helmholtz-tuning-5710/
Reply
Old Aug 21, 2007 | 11:34 AM
  #5  
zoom44's Avatar
Administrator
 
Joined: Jul 2002
Posts: 21,958
Likes: 115
From: portland oregon
Originally Posted by SureShot

The "trombone" rig in the R26B was built to expolit the same principal.
i held the r26b rig in my hands in may

rip the vfad out and put in the Racing Beat, Mazdaspeed or AEM intake- 'nuff said.
Reply
Old Aug 21, 2007 | 11:37 AM
  #6  
zoom44's Avatar
Administrator
 
Joined: Jul 2002
Posts: 21,958
Likes: 115
From: portland oregon
oh and actual volumetric efficiency as measured "in the field" by Hymee and discussion of same(its greater than 100% at times)

https://www.rx8club.com/showthread.p...ght=volumetric
Reply
Old Aug 21, 2007 | 12:06 PM
  #7  
SureShot's Avatar
Thread Starter
Registered
 
Joined: Jan 2002
Posts: 168
Likes: 0
From: Orange Park FL
Originally Posted by mysql101
btw, this was a good read on this topic:

https://www.rx8club.com/showthread.php?s=&threadid=5710
^^--Awesome thread - the straight dope.

He even mentions the Exhaust aspects of this concept which I plan to exploit in the near future.

(Now - don't tell the Honda ricers or Stang fanatics.)

-Bill
Reply
Old Aug 21, 2007 | 03:21 PM
  #8  
TeamRX8's Avatar
Registered
iTrader: (25)
 
Joined: Apr 2005
Posts: 26,933
Likes: 2,139
Originally Posted by SureShot
^^--Awesome thread - the straight dope.
like you would know ...
Reply
Old Aug 21, 2007 | 04:48 PM
  #9  
½mv²'s Avatar
printf("</%i pistons",3);
 
Joined: Dec 2006
Posts: 654
Likes: 0
From: I'm a yankee trapped in Houston!!
Damn it...



...now I wanna sit down and start doing math and fabricating ****...



...there goes my weekend!
Reply
Old Aug 21, 2007 | 04:57 PM
  #10  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 27
From: Under my car
VFAD = noise abatement. No performance benefit in removing it.
Reply
Old Aug 21, 2007 | 05:04 PM
  #11  
½mv²'s Avatar
printf("</%i pistons",3);
 
Joined: Dec 2006
Posts: 654
Likes: 0
From: I'm a yankee trapped in Houston!!
Who are you telling that to, MM?
Reply
Old Aug 21, 2007 | 10:49 PM
  #12  
GRGJTSN's Avatar
vV Me on the Dragon Vv
 
Joined: Apr 2007
Posts: 123
Likes: 1
From: Atlanta
Originally Posted by MazdaManiac
VFAD = noise abatement. No performance benefit in removing it.
Exactly.
Reply
Old Aug 22, 2007 | 02:39 AM
  #13  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 27
From: Under my car
Originally Posted by ½mv²
Who are you telling that to, MM?
Anyone who thinks otherwise.
Reply
Old Aug 22, 2007 | 10:15 AM
  #14  
zoom44's Avatar
Administrator
 
Joined: Jul 2002
Posts: 21,958
Likes: 115
From: portland oregon
what other methods are there for noise abatement?
Reply
Old Aug 22, 2007 | 12:19 PM
  #15  
½mv²'s Avatar
printf("</%i pistons",3);
 
Joined: Dec 2006
Posts: 654
Likes: 0
From: I'm a yankee trapped in Houston!!
Unless I read right over it in the linked threads, I don't think anyone has touched on variable-width pipes...


Are there formulas for finding out how the frequency of air changes if a pipe widens or narrows? Rather than using an intake that shortens/grows as RPMS change like the 787B, you could install a rubber tube that stretches/pinches based on engine speed...

...I'm no expert on the subject, so I could be suggesting something completely unfeasable/unhelpful. I still need to sit down with some material and research the subject :\
Reply
Old Aug 22, 2007 | 01:00 PM
  #16  
MazdaManiac's Avatar
Banned
iTrader: (3)
 
Joined: Oct 2003
Posts: 16,386
Likes: 27
From: Under my car
Originally Posted by zoom44
what other methods are there for noise abatement?
On the 8, the VFAD and the intake baffles are the main ones.
The muffler and the lack of torque are two others that come to mind, but that is a different story...
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
jay_tibo
Series I Aftermarket Performance Modifications
22
Sep 13, 2016 08:10 PM
uZu
New Member Forum
13
Dec 30, 2015 12:35 PM
ripigs
RX-8 Parts For Sale/Wanted
5
Aug 2, 2015 10:44 PM
MarkX
New Member Forum
3
Jul 31, 2015 07:50 AM
Belalnabi
New Member Forum
9
Jul 17, 2015 07:48 PM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -5. The time now is 12:34 PM.