N2O PLug and Tuning Question
08-26-2012, 07:53 AM
#1
N2O PLug and Tuning Question Looks like I will finally be able to pull plugs at some upcoming events. I've been running 78/36 (42 llbs in dedicated) jets and pulling 10 degrees from 25 with 114 octane race gas in the dedicated and 40/60 blend in main tank (114 octane race gas/94 octane). On this set-up A/F on the wideband is 12:5 to 12:0 and with a 1.57 60 ft ran a 10.5 at 130 mph (1/8 = 6.8 at 98.4 mph). I'm thinking the plugs will show close on the fuel and not enough timing. My question is about the NGK plugs. I'm still using the Br9es plugs from when I was running a 250 shot and I'm wondering if I should go down to the 8s. What is the impact of running plugs that are too cold? Also, since I swapped intakes/throttle body and plate from a 92mm to a 102 mm set-up I have to run my fuel jets way smaller on every set-up. For example I was running 78/42with 55 llbs in dedicated on the 92mm and run 78/36 with 42 llbs now. Any ideas why? Appreciate your feedback.
08-26-2012, 11:41 PM
#2
Looks like I will finally be able to pull plugs at some upcoming events. I've been running 78/36 (42 llbs in dedicated) jets and pulling 10 degrees from 25 with 114 octane race gas in the dedicated and 40/60 blend in main tank (114 octane race gas/94 octane). On this set-up A/F on the wideband is 12:5 to 12:0 and with a 1.57 60 ft ran a 10.5 at 130 mph (1/8 = 6.8 at 98.4 mph). I'm thinking the plugs will show close on the fuel and not enough timing. My question is about the NGK plugs. I'm still using the Br9es plugs from when I was running a 250 shot and I'm wondering if I should go down to the 8s. What is the impact of running plugs that are too cold? Also, since I swapped intakes/throttle body and plate from a 92mm to a 102 mm set-up I have to run my fuel jets way smaller on every set-up. For example I was running 78/42with 55 llbs in dedicated on the 92mm and run 78/36 with 42 llbs now. Any ideas why? Appreciate your feedback.
Your 78/42 @ 55 is close to my well tuned 78/44@55.
As you have stated, I have noted the 102 plate also does not seem to put out the same power level as the 92. No matter, I just keep adjusting jets to get where I want it.
Using a 36, looks like you are running about ~150hp nitrous. As such, a 7 plug. But, 8s are what I'm thinking and use for the 78.
08-27-2012, 05:57 PM
#4
Thanks guys! I'll go with the 8s then. I'm also going to weigh the bottle between each run to determine how much N2O is being used. My understanding is that it should take .8 llbs of nitrous on a 10 second run to make 100 HP. With 200 HP that should equate to approx 1.6 llbs + purge so say 1.8-2.0 llbs. That should help me determine if I have a restriction. I am running 6AN lines to the solinoids and have checked the filter + replaced the noids in the spring. My times and mph are similiar to the times I ran on the 200 shot last year though on the 42 fuel jet (+2 degrees more timing) which is puzzling??
