Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by: KPower

Stupid knock

Thread Tools
 
Search this Thread
 
Old 05-19-2009, 06:34 PM
  #1  
Elite Member
Thread Starter
iTrader: (30)
 
levnubhin's Avatar
 
Join Date: Aug 2007
Location: Va Beach
Posts: 7,329
Total Cats: 12
Default Stupid knock

Boost it set at 18.5 psi and I keep getting knock and a hesitation at high rpm's. AFR's are low 11s with 93 fuel. I started with the top map below before upping the boost and had no knock. Now with the higher boost I have the knock. I changed the spark to what you see in the lower map and still have knock. Anyone have any ideas besides lowering boost?
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote

Last edited by levnubhin; 03-12-2010 at 03:50 PM.
levnubhin is offline  
Old 05-19-2009, 06:51 PM
  #2  
Elite Member
iTrader: (1)
 
richyvrlimited's Avatar
 
Join Date: Jun 2006
Location: Warrington/Birmingham
Posts: 2,642
Total Cats: 42
Default

18.5 psi is what 220kpa? the timing's barely/not changed at that level...

Try a more drastic cull of timing, it's easier to control a fire than put it out
richyvrlimited is offline  
Old 05-19-2009, 08:19 PM
  #3  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,493
Total Cats: 4,080
Default

16* is around what most us stockers run at 12-14psi, just fwiw.
Braineack is offline  
Old 05-19-2009, 09:00 PM
  #4  
Elite Member
Thread Starter
iTrader: (30)
 
levnubhin's Avatar
 
Join Date: Aug 2007
Location: Va Beach
Posts: 7,329
Total Cats: 12
Default

So I should pull even more spark?
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
levnubhin is offline  
Old 05-19-2009, 09:41 PM
  #5  
Elite Member
iTrader: (2)
 
240_to_miata's Avatar
 
Join Date: May 2007
Location: Cromwell, Connecticut
Posts: 2,604
Total Cats: 16
Default

pull until u stop knocking to see where ur at. Do you have knocksensems?
240_to_miata is offline  
Old 05-20-2009, 05:48 AM
  #6  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

19psi on pump gas might just be too much.
Savington is offline  
Old 05-20-2009, 06:25 AM
  #7  
Elite Member
iTrader: (13)
 
Fireindc's Avatar
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 6,603
Total Cats: 564
Default

Time for WI =)
Fireindc is offline  
Old 05-20-2009, 07:48 AM
  #8  
Elite Member
Thread Starter
iTrader: (30)
 
levnubhin's Avatar
 
Join Date: Aug 2007
Location: Va Beach
Posts: 7,329
Total Cats: 12
Default

Originally Posted by Savington
19psi on pump gas might just be too much.
Originally Posted by Fireindc
Time for WI =)


That's what I was afraid of because even with a spark map close to DIY's base map I was getting knock.

I guess I'll just have to settle for 16 psi.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
levnubhin is offline  
Old 05-20-2009, 09:19 AM
  #9  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,493
Total Cats: 4,080
Default

or run race gas or WI.
Braineack is offline  
Old 05-20-2009, 09:42 AM
  #10  
Elite Member
iTrader: (9)
 
Saml01's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 5,710
Total Cats: 3
Default

Bad gas maybe? You are on the east coast so it should be a problem.

If you are getting knock on the DIY map then it might be something worse. Are you sure your mechanical timing is correct?

The DIY map is so damn conservative, I have no idea how you can develop knock on it.
Saml01 is offline  
Old 05-20-2009, 09:58 AM
  #11  
Elite Member
iTrader: (10)
 
leatherface24's Avatar
 
Join Date: Dec 2006
Location: Pembroke Pines
Posts: 4,064
Total Cats: 10
Default

try a gallon of toulene when you get to about half a tank. stuff works awesome on my MSM
leatherface24 is offline  
Old 05-20-2009, 10:05 AM
  #12  
Elite Member
Thread Starter
iTrader: (30)
 
levnubhin's Avatar
 
Join Date: Aug 2007
Location: Va Beach
Posts: 7,329
Total Cats: 12
Default

Originally Posted by leatherface24
try a gallon of toulene when you get to about half a tank. stuff works awesome on my MSM
I really doubt that will work, we're talking 18-19 psi here.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
levnubhin is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Rick02R
WTB
3
01-03-2016 07:18 PM
skidude
Insert BS here
150
11-25-2015 02:42 PM
matthewdesigns
Suspension, Brakes, Drivetrain
1
10-10-2015 02:07 AM
elior77
MEGAsquirt
30
09-23-2015 06:38 PM



Quick Reply: Stupid knock



All times are GMT -4. The time now is 07:09 AM.