Race Car Tech Discuss anything related to road racing and auto X.

Custom Intake Manifold Plenum sizing

Old 06-23-09, 03:45 PM
  #1  
"your turbo source"
Thread Starter
iTrader: (1)
 
Join Date: Aug 2005
Location: Birmingham, AL
Posts: 246
Likes: 0
Received 0 Likes on 0 Posts
Custom Intake Manifold Plenum sizing

Hello all. I am fabricating an upper plenum on a 13brew upper manifold. Right now the plenum area is around 1.8L. I know on piston engines like 1L-1L ratio. But since we have a 2 stroke engine what is the best sizing for my application?

There aren't many people with experience in this field so I was wondering if any experienced rotary guys could chime in and help.

A little more info on the set up. I will be using a 75mm mustang throttlebody, T72-Q trim turbo. Want to run 25 psi of boost. Big street port REW engine (went up 1/4" and went 11.5mm from the inner coolant seal groove keeping the stock shape). Exhaust port has the bevelled edge completely ported out (not ported up, ported down and the sides of the exhaust port are also ported. Exhaust ports are flush with the exhaust sleeves.

Engine made 440 RWHP and 358 RWTQ at 20 psi on a 62-1 as it sits now. Its in a 84 FB with ford 8.8 rear with 4.88's.

Any help would be greatly appreciated!

Bryan Nickell
BNR Supercars LLC
Bryan@BNR is offline  
Old 06-23-09, 03:53 PM
  #2  
Banned. I got OWNED!!!
 
racerlinkfc's Avatar
 
Join Date: Dec 2006
Location: Palmdale Ca
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
forced induction application you dont really need to worry that much. you still running a stock lower ? ground zero will help you there..
racerlinkfc is offline  
Old 06-23-09, 04:02 PM
  #3  
"your turbo source"
Thread Starter
iTrader: (1)
 
Join Date: Aug 2005
Location: Birmingham, AL
Posts: 246
Likes: 0
Received 0 Likes on 0 Posts
Here are pictures of the manifold right now. It hasn't been cleaned up yet, but it will give you an idea of what I am doing. If I have to cut down on area, I can. But right now I am waiting on the throttlebody to show and I will have it completed. I was going to cut the plenum down to 1.5-1.6L just to be on the safe side. Hopefully Chris Anderson aka Crispeed will chime in .

I also will add I would like to turn 9-10K RPM.
Attached Thumbnails Custom Intake Manifold Plenum sizing-intake-manifold1.jpg   Custom Intake Manifold Plenum sizing-intake-manifold2.jpg  
Bryan@BNR is offline  
Old 06-23-09, 04:23 PM
  #4  
needs more track time
iTrader: (14)
 
gracer7-rx7's Avatar
 
Join Date: Mar 2006
Location: Bay Area CA
Posts: 7,833
Received 14 Likes on 13 Posts
FYI, RotaryGod has a few really good posts on this exact topic in various places on this forum.
gracer7-rx7 is offline  
Old 06-23-09, 06:02 PM
  #5  
"your turbo source"
Thread Starter
iTrader: (1)
 
Join Date: Aug 2005
Location: Birmingham, AL
Posts: 246
Likes: 0
Received 0 Likes on 0 Posts
After media blast
Attached Thumbnails Custom Intake Manifold Plenum sizing-intake-manifold3.jpg  
Bryan@BNR is offline  
Old 06-23-09, 06:07 PM
  #6  
brap brap brap
iTrader: (7)
 
AlexG13B's Avatar
 
Join Date: Jul 2003
Location: Florida
Posts: 2,859
Likes: 0
Received 4 Likes on 4 Posts
ya rotarygod might know a few things or two, smart fellow.
AlexG13B is offline  
Old 06-23-09, 08:14 PM
  #7  
Original Gangster/Rotary!

iTrader: (206)
 
GoodfellaFD3S's Avatar
 
Join Date: Mar 2001
Location: FL-->NJ/NYC again!
Posts: 29,999
Received 136 Likes on 109 Posts
Hm, I think I want one
GoodfellaFD3S is offline  
Old 06-23-09, 08:48 PM
  #8  
Goodfalla Engine Complete
iTrader: (28)
 
Monkman33's Avatar
 
Join Date: May 2005
Location: Kennewick, Washington
Posts: 3,203
Received 11 Likes on 9 Posts
A higher useful redline would be somewhat beneficial for autocrossing... no?
Monkman33 is offline  
Old 06-23-09, 10:19 PM
  #9  
needs more track time
iTrader: (14)
 
gracer7-rx7's Avatar
 
Join Date: Mar 2006
Location: Bay Area CA
Posts: 7,833
Received 14 Likes on 13 Posts
probably not as much as having more low end torque
gracer7-rx7 is offline  
Old 06-24-09, 12:15 AM
  #10  
Goodfalla Engine Complete
iTrader: (28)
 
Monkman33's Avatar
 
Join Date: May 2005
Location: Kennewick, Washington
Posts: 3,203
Received 11 Likes on 9 Posts
Good point. What would an effective way be to do that? retain stock manifold?
Monkman33 is offline  
Old 06-25-09, 10:42 AM
  #11  
"your turbo source"
Thread Starter
iTrader: (1)
 
Join Date: Aug 2005
Location: Birmingham, AL
Posts: 246
Likes: 0
Received 0 Likes on 0 Posts
Alright, well I just put the manifold together and hopefully everything will be okay . I am sure it will all be okay as soon as 7K RPM hits but I wanted to just cut down on R&D process. I am sure the way the manifold is the engine won't lose much bottom end. The throttle body points in the direction of the primary runners. There should be decent air speed moving through to keep the engine somewhat responsive on the bottom.
Bryan@BNR is offline  
Old 06-25-09, 06:16 PM
  #12  
needs more track time
iTrader: (14)
 
gracer7-rx7's Avatar
 
Join Date: Mar 2006
Location: Bay Area CA
Posts: 7,833
Received 14 Likes on 13 Posts
Very cool. Bring on the dyno sheets!
gracer7-rx7 is offline  
Old 06-25-09, 11:42 PM
  #13  
"your turbo source"
Thread Starter
iTrader: (1)
 
Join Date: Aug 2005
Location: Birmingham, AL
Posts: 246
Likes: 0
Received 0 Likes on 0 Posts
I would love to make some good numbers, but you know those wankels. If they aren't 100% right, you blow em! Well most of the time lol. I will try the tuning it here in the next few months. I have a lot of changes. 1000cc pris, added pump, methenol inj, Billet 71/Q trim turbo, this intake manifold and a different exhaust manifold and down pipe....

Just a lot of huge changes that really will require a totally different fuel curve.
Bryan@BNR is offline  
Old 06-25-09, 11:44 PM
  #14  
Original Gangster/Rotary!

iTrader: (206)
 
GoodfellaFD3S's Avatar
 
Join Date: Mar 2001
Location: FL-->NJ/NYC again!
Posts: 29,999
Received 136 Likes on 109 Posts
Autocrossing is for sissies anyway
GoodfellaFD3S is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
C. Ludwig
Single Turbo RX-7's
49
01-30-19 06:31 AM
Engine stand ready
New Member RX-7 Technical
3
08-14-15 10:26 PM


Thread Tools
Search this Thread
Quick Reply: Custom Intake Manifold Plenum sizing


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: