Another nitrous question

Old 10-06-2008, 04:17 PM
  #1  
jwhitehead
Junior Member
SHOW GUEST
Thread Starter
 
Join Date: Mar 2006
Posts: 8
Default Another nitrous question

have a 502 with a fogger, timing set @ 36, retard set @ 12, 1050 dominator with 88 front and rear jets,everything new, set up 300 shot, bottle full with 900 p.s.i. engine back fires thru headers , shut engine down. Checked plugs, electrode in porcelin on some plugs had started to melt.

set up 250 shot increased bottle pressure to 1100 p.s.i. car ran 1.16 / 60 foot, 5.38 @ 127 mph.

SB2 406 small block ran this good, what am I missing?????
jwhitehead is offline  
Old 10-06-2008, 04:24 PM
  #2  
bjuice
Administrator
RACING JUNKIE
 
bjuice's Avatar
 
Join Date: Apr 2003
Location: Greenville s.c.
Posts: 3,239
Default

You gotta run a cooler Plug..2 levels cooler then all motor plug,,you also need to close up the gap from 25/26...i have see Big inch NOS motors running 22 gaps.
also have you manually checked your timing retard to make sure its pulling the timing out when you pull the trigger? (critical)

Next how are you feeding the fuel to the motor and Nos ?..did you wet flow the Nos to make sure your fuel pressure is holding upon activation ?

No doubt you got some detonating going on there.



Brian
__________________
Bjuice..

"I'M YOUR HUCKLEBERRY ! "
bjuice is offline  
Old 10-06-2008, 04:32 PM
  #3  
jwhitehead
Junior Member
SHOW GUEST
Thread Starter
 
Join Date: Mar 2006
Posts: 8
Default another nitrous question

I am running AR3933,.035 gap, fuel pressure is set @ 10 p.s.i. with fuel pump running and fuel flowing thru return line to cell.

Un sure about retard, was working with small block. will check.
jwhitehead is offline  
Old 10-06-2008, 04:51 PM
  #4  
bjuice
Administrator
RACING JUNKIE
 
bjuice's Avatar
 
Join Date: Apr 2003
Location: Greenville s.c.
Posts: 3,239
Default

for starters you need to be running an AR3932 Plug and close that gap to 25 for starters.

Next have someone pull the trigger on the Nos ( just test the selenoid)..make sure Nos is not live nor fuel or Nos is dumped in motor.. while car is idling (3k) see if timing is being pulled out ( with timing light) when trigger is pulled...you will see it back up on the balancer.


i can tell you have not flowed the Nos by your post...thats ok many do not know how to properly flow a (wot) Free flow...i don't know if i can explain it good enough for you in a post...
What concerns me next is what kind of fuel pump you got supplying the Motor and Nos ?..then what kind of igintion you running ( crank trigger) ???

if your not running a BG 400 or Magnafuel Prostar 500 or some comparable fuel pump..chance are you don't have near enough pump to support a 300 shot on a 502 ( in one pump)...

my advise to you..is don't run any more NOS until you know for sure rthe things i have posted...youll burn that bad boy down in a skinny minute with a 250/300 shot..

there's alot more to running Nos Safely than what one thinks ?
__________________
Bjuice..

"I'M YOUR HUCKLEBERRY ! "
bjuice is offline  
Old 10-06-2008, 07:07 PM
  #5  
lookingaround
Senior Member
RACING JUNKIE
 
Join Date: Feb 2006
Location: Lenoir City Tennessee
Posts: 865
Default

i use to run a holley blue pump just for my NOS. when we set the pressure we set it on 3 or 5 pounds free flowing on a 250 shot. like Brian said go 2 steps colder on plug too. Brian is it 2 degree's timing retard for every 100 horse of NOS? its been since 98 since i have raced are used any
lookingaround is offline  
Old 10-06-2008, 07:15 PM
  #6  
hammertime
Senior Member
RACING JUNKIE
 
Join Date: May 2003
Location: Coldwater, MI
Posts: 2,998
Default

Originally Posted by lookingaround
i use to run a holley blue pump just for my NOS. when we set the pressure we set it on 3 or 5 pounds free flowing on a 250 shot. like Brian said go 2 steps colder on plug too. Brian is it 2 degree's timing retard for every 100 horse of NOS? its been since 98 since i have raced are used any
I pull 4 per 100
hammertime is offline  
Old 10-07-2008, 04:58 AM
  #7  
gimmemud
Senior Member
MASTER BUILDER
 
Join Date: Apr 2006
Location: Ms.
Posts: 191
Default

What jets do you have in fogger, nos and fuel? Which zozzles, annular or 90*

The AR3933 plug should be fine, I run that plug with 2 foggers and they are just right, have tried 3932's and they were too cold.
gimmemud is offline  
Old 10-07-2008, 02:13 PM
  #8  
jwhitehead
Junior Member
SHOW GUEST
Thread Starter
 
Join Date: Mar 2006
Posts: 8
Default another nitrous question

Thanks all,

the nitrous/fuel jets are 28/28 , the fuel pump is a BG 400 mounted at the front of the car plumbed with #12 an braided lines to a fuel log, #12 feed the carb and #10 feed the fuel solenoids.
jwhitehead is offline  
Old 10-07-2008, 02:27 PM
  #9  
ARUSSELL
Senior Member
MASTER BUILDER
 
Join Date: Mar 2008
Posts: 192
Default

I was hurting plugs then went to a .018 gap and colder, running great.
ARUSSELL is offline  
Old 10-07-2008, 02:39 PM
  #10  
bjuice
Administrator
RACING JUNKIE
 
bjuice's Avatar
 
Join Date: Apr 2003
Location: Greenville s.c.
Posts: 3,239
Default

Originally Posted by lookingaround
i use to run a holley blue pump just for my NOS. when we set the pressure we set it on 3 or 5 pounds free flowing on a 250 shot. like Brian said go 2 steps colder on plug too. Brian is it 2 degree's timing retard for every 100 horse of NOS? its been since 98 since i have raced are used any
hammer is dead on what Nos recommends..2 degrees per 50hp...
i was overkill when i ran my Nos..i free flowed at 6 psi, with a HOBB switch.
__________________
Bjuice..

"I'M YOUR HUCKLEBERRY ! "
bjuice is offline  

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information