Finally got some plugs pulled - help with reading please!
09-30-2012, 07:51 AM
#1
Finally got some plugs pulled - help with reading please! Only pulling Plug #5 at this event due to time constraints, however, melted the strap on this plug at previous outing and all other were perfect so figure it's the hot one! Set-up on this Run: 78 N2O and 36 Fuel at 48 llbs in dedicated. N2O Pressure of 1040 PSI. Pulling 10 degrees from base timing of 25 degrees. 114 in the dedicated and mix 114/94 in main tank. NGK BR9ES plugs. A/F was 12.8 to 12.5 through the entire run. Outside temp around 65 degrees. Also, given poor track prep at closed airport was using a 2 second ramp from 25% to 100% on the front end so I'm thinking that would create slightly less heat on the run. No times on this run as no timers at this venue but it's been running 10.5s on richer tune. Appreciate everyone's thoughts/opinions!
P.S. I'm thinking still a little rich and I should pull another degree and lean it out a little more.....
P.S. I'm thinking still a little rich and I should pull another degree and lean it out a little more.....
Last edited by CanadianEh!; 09-30-2012 at 07:58 AM.
09-30-2012, 11:13 AM
#2
Launching!
iTrader: (6)
Join Date: Mar 2009
Location: cape coral, fl
Posts: 261
Likes: 0
Received 0 Likes
on
0 Posts
its still a touch rich, how did it run? Your own advise at the end sounds about what I would do, I would actually pull more like 2-3 lean it out a bit more and them start watching the slip to make sure MPH is improving each degree you put back in her, but i think your getting close, remember too little timing hurts nothing but performance too much hurts parts, better to be on the safe side IMO
09-30-2012, 07:13 PM
#5
Thanks for the feedback! its still a touch rich, how did it run? Your own advise at the end sounds about what I would do, I would actually pull more like 2-3 lean it out a bit more and them start watching the slip to make sure MPH is improving each degree you put back in her, but i think your getting close, remember too little timing hurts nothing but performance too much hurts parts, better to be on the safe side IMO
Last edited by CanadianEh!; 10-02-2012 at 06:26 PM.
10-01-2012, 12:19 AM
#6
I seemed really strong at that A/F and timing but no timer at that event to truly guage performance. I did go back out today where I ran the A/F around 13.2 working down to 12.5 by the end of the run on the same timing. That netted me my best time this year on a 200 shot at 10.44 at 131 mph (also best mph). Did not pull plugs today though but I agree it would be smarter to pull more timing.....
My assessment is slightly rich and leave timing as is until fuel adjusted.
10-01-2012, 12:20 AM
#7
its still a touch rich, how did it run? Your own advise at the end sounds about what I would do, I would actually pull more like 2-3 lean it out a bit more and them start watching the slip to make sure MPH is improving each degree you put back in her, but i think your getting close, remember too little timing hurts nothing but performance too much hurts parts, better to be on the safe side IMO
Trending Topics
10-01-2012, 01:10 PM
#8
9 Second Club
iTrader: (11)
Join Date: Oct 2007
Location: South Ga
Posts: 1,828
Likes: 0
Received 0 Likes
on
0 Posts
Still rich, n2o pressure too high (try 950 off the line), pull two degrees when you lean it out, you can always add it back.
fwiw - 15 degrees is fine for that level however just to be safe I suggested pulling two.
fwiw - 15 degrees is fine for that level however just to be safe I suggested pulling two.
10-01-2012, 07:59 PM
#10
Thanks Everyone for the feedback! Thanks to everyone for the great feedback! I'll definately pull a couple of degrees, lean it out slowly, add back timing the same way and read the plugs! I must say a lot has changed from when I started out a few years back aiming for A/F in the 11.7-11.5 range and thinking A/F in the 10s was dead safe! Pulling plugs is the way to go and my senario is the perfect example why. I thought because my base timing was really conservative at 25 degrees and I was pulling 10 degrees (2 more degrees than the rule of thumb of 2 degrees for every 50 rwhp) I was very safe. Turns out my timing mark is just OK as is but likely would have melted a strap if only 8 degrees pulled. Also, the car clearly makes more power leaned out so as long as timing is safe that's a huge bonus! This is starting to get fun again! Again, thanks to everyone who helps out us new guys - I'm sure I speak for everyone when I say it's greatly appreciated!
10-02-2012, 09:18 AM
#11
You're are doing it the right way and seem to have a good handle on it already.
As carter said take your bottle pressure down to 950, take some fuel psi out of the dedicated(try 1psi first) and 2-3* more timing and see what that gets you. That should get you slightly leaner than you are now. Taking the bottle pressure down to 950 may negate the change in fuel psi, but you'll still be working towards a better tune. If it doesn't get you any leaner try taking another .5psi out and see what that gets you. If that gets you in the AFR ball park and fuel ring ball park you were looking for, judge the heat on the strap and start putting .5-1.0 degree back in it and watch the increments on the slip and the MPH to judge whether or not it likes or wants the timing back in it.
I think you're good on the timing you're running now especially with that fuel, but get the fuel ring cleaned up a little more.
I think it's so funny to see guys saying run it at 11.x AFR and when I ask what their plugs look like they say "perfect". Just looking at your fuel ring with the AFR you are running at goes to show that there is no way in hell 11.x AFR will give you a "perfect" plug reading.
As carter said take your bottle pressure down to 950, take some fuel psi out of the dedicated(try 1psi first) and 2-3* more timing and see what that gets you. That should get you slightly leaner than you are now. Taking the bottle pressure down to 950 may negate the change in fuel psi, but you'll still be working towards a better tune. If it doesn't get you any leaner try taking another .5psi out and see what that gets you. If that gets you in the AFR ball park and fuel ring ball park you were looking for, judge the heat on the strap and start putting .5-1.0 degree back in it and watch the increments on the slip and the MPH to judge whether or not it likes or wants the timing back in it.
I think you're good on the timing you're running now especially with that fuel, but get the fuel ring cleaned up a little more.
I think it's so funny to see guys saying run it at 11.x AFR and when I ask what their plugs look like they say "perfect". Just looking at your fuel ring with the AFR you are running at goes to show that there is no way in hell 11.x AFR will give you a "perfect" plug reading.
