3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.
Sponsored by:

Injector diffusers and aftermarket injectors

Thread Tools
 
Search this Thread
 
Old 06-16-13, 10:49 AM
  #1  
Brap..
Thread Starter
iTrader: (2)
 
Mitchocalypse's Avatar
 
Join Date: Jul 2010
Location: Alberta, Canada
Posts: 449
Likes: 0
Received 1 Like on 1 Post
Injector diffusers and aftermarket injectors

I will be using ID 1000 primaries and 2000 secondaries. I have the FFE cup things that they sit in (cant remember exactly what they're called)

Are diffusers recommended? I know they can break and damage the engine but im not sure if I should just leave them at this point
Old 06-16-13, 12:03 PM
  #2  
Non Runner

iTrader: (3)
 
Ceylon's Avatar
 
Join Date: Mar 2008
Location: Somerset, England
Posts: 2,209
Received 276 Likes on 145 Posts
Most people say the spray pattern is good enough on the IDs not to need diffusers.
Old 06-16-13, 04:20 PM
  #3  
Form follows function

iTrader: (8)
 
Speed of light's Avatar
 
Join Date: Oct 2004
Location: Now in Arizona
Posts: 1,203
Received 33 Likes on 21 Posts
The spray pattern isn't the only factor, the diffuser creates a low pressure area downstream of itself which helps flash the fuel into vapor and improves the homogenization of the mixture.
Old 06-16-13, 04:25 PM
  #4  
Old [Sch|F]ool

 
peejay's Avatar
 
Join Date: May 2001
Location: Cleveland, Ohio, USA
Posts: 12,506
Received 416 Likes on 296 Posts
At least for the primaries, it also stops the injector pattern before it can cross through the air stream like an air door. Having no diffuser on the primary should hurt airflow.
Old 06-16-13, 09:42 PM
  #5  
rotorhead

iTrader: (3)
 
arghx's Avatar
 
Join Date: Aug 2004
Location: cold
Posts: 16,182
Received 429 Likes on 263 Posts
I've been thinking about this issue and I'd like to give 1 for vote for the diffusers not being that important relative to the risk of sucking one in and blowing a motor. Granted, that seems to happen rarely, so use your best judgment.

I haven't inspected the pattern on the ID injectors, but basically all the new style ones use a series of small holes to spray from the nozzle. On the old style injectors, it's one or maybe two bigger holes that need extra help to vaporize the fuel. Also, the air atomization ports help as well.
Old 06-17-13, 12:52 PM
  #6  
Sponsor
iTrader: (41)
 
IRPerformance's Avatar
 
Join Date: Apr 2003
Location: NJ
Posts: 11,347
Received 317 Likes on 190 Posts
The o-ringed inserts are designed to be run without the diffusers. Don't use them. they become brittle, crack, and fall into the motor causing damage.
Old 06-17-13, 02:01 PM
  #7  
Torqueless Wonder

iTrader: (1)
 
cptpain's Avatar
 
Join Date: Oct 2004
Location: Texas
Posts: 2,020
Likes: 0
Received 3 Likes on 3 Posts
ID's have a significantly improved spray pattern than the common injectors we're used to seeing on our rotaries.

there is no need for the diffusers, and as Rotary Experiment Seven has said, you can't use them anyway.

I've seen ID 725 and ID1000's used as primaries and they hold a rock solid idle. Some people even use a much higher static fuel pressure.
Old 06-17-13, 09:26 PM
  #8  
10-8-10-8

 
SA3R's Avatar
 
Join Date: Jan 2012
Location: Australia
Posts: 845
Likes: 0
Received 9 Likes on 7 Posts
I have seen a plastic diffuser fall into a 13B before. Nothing happened.

Timeline:
Tore it apart for rebuild, all diffusers were present.
Bolted it back together with its diffusers under the stock injectors.

Tore it apart over a year later because the owner then wanted to go single turbo, fancier seals, etc. Was still running fine.
Noted one diffuser was now gone. Engine had been running fine regardless.

This tells me that A. I dont think they have a huge effect on performance.
B. It clearly must have swallowed a diffuser while running. It kept running and did not cause damage. Nobody noticed until it was pulled apart one day.
Old 06-18-13, 11:44 AM
  #9  
Sponsor
iTrader: (41)
 
IRPerformance's Avatar
 
Join Date: Apr 2003
Location: NJ
Posts: 11,347
Received 317 Likes on 190 Posts
You got lucky. I've seen at least 3 motors that chipped a seal when part of an injector diffuser fell into the motor.
Old 06-18-13, 12:14 PM
  #10  
Senior Member

iTrader: (9)
 
socks's Avatar
 
Join Date: Nov 2009
Location: Greenville, SC
Posts: 366
Likes: 0
Received 9 Likes on 6 Posts
I specifically asked full function about this, and they were definitive. Do not use the diffusers with the ID injectors.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bryancmatthews
Power FC Forum
14
10-05-15 08:49 PM
ZacMan
Build Threads
4
09-19-15 09:20 PM
mulcryant
2nd Generation Specific (1986-1992)
10
09-09-15 05:24 PM
dillrx7
Single Turbo RX-7's
3
09-07-15 09:38 AM



Quick Reply: Injector diffusers and aftermarket injectors



All times are GMT -5. The time now is 04:12 PM.