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

Harm of a restrictive intake

Thread Tools
 
Search this Thread
 
Old Mar 3, 2015 | 10:11 AM
  #1  
Tem120's Avatar
Thread Starter
Rotary Freak
Tenured Member 05 Years
iTrader: (5)
 
Joined: Sep 2011
Posts: 2,824
Likes: 6
From: Miami
Harm of a restrictive intake

So I had some old 20 year old apexi intakes the filters were ancient and because of my intercooler they honestly didnt FIT .


So I decided to make my own intakes . made a heat shield , put a couple of 2.5 inch filters and got a bit of ducting for it .

And yeah intake temps even dropped a couple C on the Power FC . BUT using the same settings the car boosts 1psi less then it did before . and it seems maybe to my imagination that it also takes a bit longer to spool


So I'm curious .. What the consensus is . on a more restrictive intake

it did help a bit with boost creep which I had haha .

But since the intake is restrictive I imagine its putting more stress on the compressor wheel ...

is the more restrictive intake a good solution for the boost creep , or should I change my intake setup to something better flowing . and just deal with my boost creep ( boost creep is not dangerous it creeps up to 14 psi from my preset 12 by redline , BUt I have plenty of fuel for it )
Reply
Old Mar 3, 2015 | 10:21 AM
  #2  
j9fd3s's Avatar
Moderator
Community Builder
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Mar 2001
Posts: 31,819
Likes: 3,223
From: https://www2.mazda.com/en/100th/
a little intake restriction is probably better than boost creep...

the turbo is working a little harder, if you plotted where you were on a compressor map, the intake restriction adds to the pressure ratio, so the turbo is going to run a higher pressure ratio, all things equal, which they aren't, as boost dropped too...
Reply
Old Mar 5, 2015 | 10:46 AM
  #3  
gracer7-rx7's Avatar
needs more track time
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (16)
 
Joined: Mar 2006
Posts: 9,750
Likes: 788
From: Bay Area CA
Originally Posted by j9fd3s
a little intake restriction is probably better than boost creep...

the turbo is working a little harder, if you plotted where you were on a compressor map, the intake restriction adds to the pressure ratio, so the turbo is going to run a higher pressure ratio, all things equal, which they aren't, as boost dropped too...

+1 on a little restriction being better than boost creep.

Don't over think it. It won't have an impact on reliability. I would often re-install the stock airbox on my turbo rotaries in the winter when I lived in cold weather so that boost could be controlled. Otherwise it would spike and creep like a ****.
Reply
Old Mar 5, 2015 | 11:07 AM
  #4  
arghx's Avatar
rotorhead
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Aug 2004
Posts: 16,205
Likes: 460
From: cold
Originally Posted by j9fd3s
a little intake restriction is probably better than boost creep...

The turbo is working a little harder, if you plotted where you were on a compressor map, the intake restriction adds to the pressure ratio, so the turbo is going to run a higher pressure ratio, all things equal, which they aren't, as boost dropped too...
+1
Reply
Old Mar 5, 2015 | 05:32 PM
  #5  
adam c's Avatar
Cheap Bastard
iTrader: (2)
 
Joined: Sep 2002
Posts: 8,370
Likes: 50
From: San Luis Obispo, Ca
If your boost only goes to 14 psi at redline, and you have pleanty of fuel, I dont think you should be concerned. Thats not boost creep.
Reply
Old Mar 5, 2015 | 07:35 PM
  #6  
SA3R's Avatar
10-8-10-8
Tenured Member: 10 Years
 
Joined: Jan 2012
Posts: 848
Likes: 12
From: Australia
Originally Posted by adam c
If your boost only goes to 14 psi at redline, and you have pleanty of fuel, I dont think you should be concerned. Thats not boost creep.
I'm not doubting you Adam, but on a stock system (stock ECU & injectors), isn't the stock pattern

10psi on primary turbo... 4500rpm secondary turbo kicks in, 8psi.... then back to 10psi. Then 8psi to redline.

If the literature is correct and it is 8psi until redline (after secondary turbo is online) then 14psi at redline represents around a 6psi overboost situation?
Reply
Old Mar 6, 2015 | 08:26 AM
  #7  
adam c's Avatar
Cheap Bastard
iTrader: (2)
 
Joined: Sep 2002
Posts: 8,370
Likes: 50
From: San Luis Obispo, Ca
From the information given, this doesnt look like a stock system: Intakes, PFC, intercooler, increased fuel cpapcity. I assumed some exhaust mods that are not listed.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Jeff20B
1st Generation Specific (1979-1985)
73
Sep 16, 2018 07:16 PM
stickmantijuana
3rd Generation Specific (1993-2002)
13
Jan 9, 2018 11:19 AM




All times are GMT -5. The time now is 08:36 PM.