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

pulsing boost at transition to secondairy turbo

Old 06-13-07, 01:36 PM
  #1  
slo
registered user

Thread Starter
iTrader: (1)
 
slo's Avatar
 
Join Date: Jan 2006
Location: San Diego
Posts: 2,469
Likes: 0
Received 0 Likes on 0 Posts
pulsing boost at transition to secondairy turbo

Car is running simplified sequential off a haltech. What would cause the boost to pulse rapidly after the second turbo comes online. datalog of map looks like the teeth of a saw.

Also the pulsing starts just after the transition, and continues getting worst as the rpm go up.

It did this when stock (stock computer, stock turbo controll setup).

Could this be a bad turbo contoll actuator?
Old 06-13-07, 03:31 PM
  #2  
Cheap Bastard

iTrader: (2)
 
adam c's Avatar
 
Join Date: Sep 2002
Location: San Luis Obispo, Ca
Posts: 8,370
Received 50 Likes on 42 Posts
Have you done anything to the precontrol hose? Replaced it? Removed the pill? Installed a boost controller?
Old 06-13-07, 04:03 PM
  #3  
RX7 lover

 
BobfisH's Avatar
 
Join Date: Jun 2005
Location: UK
Posts: 1,160
Likes: 0
Received 2 Likes on 1 Post
What boost gauge do you have?

My car had a blitz boost gauge in it and i didnt have this problem. Now i do, but ive since had the car remapped with a decat and a few other bits and installed a defi boost gauge.

ive bene told that the defi gauges are very sensitve and are supposed to come with a little dampener thing that stops this from happening?
Old 06-13-07, 05:19 PM
  #4  
slo
registered user

Thread Starter
iTrader: (1)
 
slo's Avatar
 
Join Date: Jan 2006
Location: San Diego
Posts: 2,469
Likes: 0
Received 0 Likes on 0 Posts
I think your onto something, so the precontroll could be causing this problem.

Let me guess, if the second turbo isn't spooled when the y pipe valve and TC bring both turbo's online the boost will flow to the other turbo, and somehow the y pipe valve is fluttering after that point as a result.

This has nothing to do with what boost gauge I have...

Originally Posted by adam c
Have you done anything to the precontrol hose? Replaced it? Removed the pill? Installed a boost controller?
Old 06-13-07, 05:28 PM
  #5  
Moderator

iTrader: (7)
 
dgeesaman's Avatar
 
Join Date: May 2002
Location: Fort Kickass
Posts: 12,302
Received 16 Likes on 15 Posts
Another guy found that this problem was a clogged cat.
Old 06-13-07, 08:26 PM
  #6  
Senior Member

 
YOUWSH's Avatar
 
Join Date: Apr 2004
Location: Sydney Australia
Posts: 558
Likes: 0
Received 0 Likes on 0 Posts
What exactly does pulsing boost mean?

I'm having abit of problem usually on 3rd gear after about 5k rpm with the car cutting out slightly as I approach red line. Like the car stutters and cuts out for a slight second so is this pulsing or just purely fuel cut? Better yet how do I fix this?
Old 06-14-07, 12:35 AM
  #7  
Cheap Bastard

iTrader: (2)
 
adam c's Avatar
 
Join Date: Sep 2002
Location: San Luis Obispo, Ca
Posts: 8,370
Received 50 Likes on 42 Posts
Originally Posted by slo
I think your onto something, so the precontroll could be causing this problem.........
Could be, but you didn't answer my questions.
Old 06-14-07, 11:08 AM
  #8  
slo
registered user

Thread Starter
iTrader: (1)
 
slo's Avatar
 
Join Date: Jan 2006
Location: San Diego
Posts: 2,469
Likes: 0
Received 0 Likes on 0 Posts
Well to answer your question, I am controlling the pre control with a haltech, but I set it to return the pre control actuator to closed at the transition point.


Originally Posted by adam c
Could be, but you didn't answer my questions.
Old 06-14-07, 11:12 AM
  #9  
Mr. Links

iTrader: (1)
 
Mahjik's Avatar
 
Join Date: Aug 2001
Location: Kansas City, MO
Posts: 27,595
Received 40 Likes on 26 Posts
Here's an overview of the system:

http://www.autosportracetech.com/RX-...erOverview.htm

Just make sure you are emulating something similar.
Old 06-14-07, 12:48 PM
  #10  
slo
registered user

Thread Starter
iTrader: (1)
 
slo's Avatar
 
Join Date: Jan 2006
Location: San Diego
Posts: 2,469
Likes: 0
Received 0 Likes on 0 Posts
Thanks for the link, I could potentially set it up exactly like that.

So I think I need to move the control solenoids to between the wastegate and pre control actuators rather than have them in the stock locations.

And acording to this link the pre controll stays open after the changeover.

Also I am controling the CCV and CRV with the same output (they seem to have the same paramaters, so why not) it seems to me mazda didn't do it because it has the tendancy to make honking noises in some ranges depending on what the pre controll is set at.
Old 06-14-07, 05:01 PM
  #11  
Cheap Bastard

iTrader: (2)
 
adam c's Avatar
 
Join Date: Sep 2002
Location: San Luis Obispo, Ca
Posts: 8,370
Received 50 Likes on 42 Posts
Originally Posted by slo
Well to answer your question, I am controlling the pre control with a haltech, but I set it to return the pre control actuator to closed at the transition point.
I suggest that you reinstall an OEM precontrol line (with a pill in it), and only use the haltech to control boost on the wastegate.
Old 06-14-07, 06:23 PM
  #12  
slo
registered user

Thread Starter
iTrader: (1)
 
slo's Avatar
 
Join Date: Jan 2006
Location: San Diego
Posts: 2,469
Likes: 0
Received 0 Likes on 0 Posts
Even with the oem pil, I don't have an OEM computer installed to controll the pre-controll solenoid. what I have on the haltech is a 3d map that gives duty cycle based on boost and rpm.

I may set it up just as you are suggesting, I might experiment some. The haltech with a trim module and easy dataloging makes it very easy to experiment.

Originally Posted by adam c
I suggest that you reinstall an OEM precontrol line (with a pill in it), and only use the haltech to control boost on the wastegate.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
cristoDathird
Introduce yourself
28
05-30-19 08:47 PM
C. Ludwig
Single Turbo RX-7's
49
01-30-19 06:31 AM
incubuseva
2nd Generation Specific (1986-1992)
14
09-03-15 12:37 PM


Thread Tools
Search this Thread
Quick Reply: pulsing boost at transition to secondairy turbo



All times are GMT -5. The time now is 08:18 PM.