OK...I'm about to call it quits on me being able to consistantly improve this rig. Last night was just maddening. Sorry for the long post. Here's the deal. Arrive at track late while driving up stop at different gas station becasue I'm on fumes. Start pumping and realize their gas has 10% ethanol but too late. Get in and realize I have left my Predator on my desk, strike two. Earlier yesterday Wade was nice enough to take a call from me and make sure I had pulled the timing correctly with the Predator, so I'm at the track running the B&G NOS with 2 deg pulled in all three ranges. List of changes from last run. 125 NOS Jet (tank pressure 1000) 100 Fuel Jet (same as last time but bigger NOS jet because I was pig rich last run) .8 sec DynoTune delay switch activated (worked great no spinning) 2 deg retard across all rpm ranges (-2 deg) because KR was hitting some 5's last time at track Added brake duct snorkle to air box AFR from LM-1 on second run attached (10.2-9.9 during run) Temp 76, no wind, no humidity, very nice TN night 1/8 mile track all 60's were 1.76xx First run = 7.89 @88.62 2nd run = 7.95 @ 87.55 3rd run = 7.97 @ 86.70 Track was packed so only 3 runs before bracket racing. Almost 1 hr between runs. Intake manifold stayed very hot all night. Can't remember it staying that hot that long even in much hotter weather. Engine temp was 195-200 at each race. Also, my AFR looks identical to 2 weeks ago even with more NOS. Two weeks ago, same track basically same conditions and with the 100 shot I ran three 7.76's @ 89.xx, so with more NOS and timing pulled I run .2x slower. AAAAAAHHHHHHRRRRR!!! One step forward, two steps back. I really believe I just need to drive up to Cincy and let PPP really dial my rig in correctly. Going back Fri night if the rain holds off. I'm open for forum tuning.
When you say same conditions, what do you mean? Weather, track prep, and a butt load of cars at the track has everything to do with your current runs. I realize you have a bigger shot this time around, but if the humidity and temps were up even 5 degree's, that will throw off your times big time. No worries, you will get there. And yes, a professional tune on a Dyno can only help you. IMO
Yes the easiest solution is to go to PPP for a dyno tune, a dyno tune will always be better than a email tune. The next suggestion is to work with Dave at B&G to dial in your tune. If you are that rich on the fuel, you prob need to knock your fuel jets down at least 3 sizes. After you have a/f ratio in high 11s/low 12s(this is safe you can go leaner but your only increasing odds of problems) then you can modify timing. What kind of timing(Base Spark) were you seeing when you had the KR ? I run about a 66/33 mixture of 93 Octane/116 Octane when I goto the track. I dont wanna give away Daves secrets but Im running over 20 degrees base spark with zero KR on a 62N20 29 Fuel Jets and a a/f ratio of 11.9-12.3 thru the rpm band. The Nitrous makers call that a 175RWHP shot, I personally saw a 130ish RWHP gain from it. The Nitrous Calculators you find online call it a 162bhp shot. Good luck and dont be so fast to jump ship on your original tuner if he is working with you. These things take time and effort, if it was easy everybody would be fast and never blow up.
I just changed jets also 12Secuv...same as you 54nos-24fuel and I am still rich..Bottle pressure was only 800 but almost empty and my A/F was anywhere from 10.6-11.5...I am sure it was inconsistant because of being low on nos...But still we have more room to lean em out...I changed jets last weekend and I have not had time to refill bottle but will soon...
Conditions were that the temp was up probably 5-8 degrees higher but the humidity was much lower than the previous trip, so I was calling it even. Big assumptions, I know. Guy in a 5.7 Maggie and a guy in a SRT-4 were both running the same times as two weeks earlier and I was slower. Not giving up on Dave, just frustrating being a novice tuner and I feel like I'm just bothering him when I call and say "I think I'm lean" or "how do you pull timing". He basically told me he had gotten me as far as he can via emailing data and tunes back and forth. He has been good to work with and I recommend his tunes to all the people I can. I wish I had more data from last night but as I stated in the first post, I left my Predator at home, so all I have is the A/F. I'll go down one more size in the fuel jet and check readings and then lean it out if I'm still in the low 10's on Fri night. Thanks for the feedback. I just needed to vent somewhere. No one around the house or office would get my frustration.
I see you pulled 2 degrees??I think you need -4 on a 125shot..Also with your intake staying so warm would also be a factor.I have seen 6.1s loose somwhere between 20-30hp due to heat soak..
Vent all you want Jimmy, that is another reason we are here man... Hang in there man, it will all come together eventually. Just make sure you have fun doing it.
jimmy - go visit the boys over at PPP and i am sure they will get you dialed in. i still think that some other "variables" might have slipped into the equation for you on your last track visit. hang in there, i am sure you will get things figured out soon enough!!!
You have an A/F gauge and are not relying on the datalogs right?Because they are not an accurate representation of the actual A/F. I also find up to a 125 shot with race gas that I leave the timing alone and let the knock sensors pull it back.
I can relate...JMatt said not to worry about KR...I only had about 1.5 KR ..N/A...and have not logged on spray...But just when I thought my A/F was perfect 12.2-12.7....in 30-40 degree temps...The weather broke here now 60-70degree days and my A/F is arond mid 11's...So now I have to get a nice day and start pulling fuel and keep an eye on timing...Is any KR acceptable on spray?...JMatt knows his stuff and I trust him..I would just hate to do something wrong and toast my motor...
I don't have the LM-1 mounted where I can watch it when I drag so yes I have been relying on the data log. I've had someone ride with me on back road sprints and watch it but not since I added the NOS. I've also got a DynoTune A/F Lean Kill Switch but I can't get it to synch up with the LM-1. I've tried different settings on the LM-1 programming but have not found the right combination yet. I've been running so rich I have not worried about being too lean yet. I'm not going anywhere. With my mods and the NOS I will find high 11's in the 1/4 and low 7's in the 1/8. I'm addicted to the attention the Jeep gets at any track, even running high 7's and 12's!
What kinda timing(Base) do you see when spraying the 125 ? If you have a N20 tune, you shouldnt need to pull timing. I personally have seen as much as 8 degrees KR but usually run between 1-2 degrees KR. I do know that my knock sensors have been desensitized as well, my ass did pucker the few times I saw 8 degrees KR. I pulled the plugs on the drivers side and saw no signs of detonation. Try datalogging Base spark and Cylinder #1 as well as KR and a/f ratios.
62 N2O, 26 Fuel. 11.8-12.2 AFR Don't waste your time hitting spray is your bottle pressure is less than 925. With 800 PSI inthe bottle, you just ran pig rich, which bogs you down. With my old setup, I only ran 3 times on each 10 pound bottle. Now, with a 15 pound bottle, I might run 4 times, but that's the maximum. I also take a jump box to the track because between all the time spent trying to keep the bottle warm and running the fans trying to keep the engine and trans cool, I've needed a jumpstart more than once. Don't underestimate how long it will take to heat the bottle. The more empty the bottle, the longer it will take to heat it and build pressure. When you can't build enough pressure, you're too low in the bottle to be useful anyway.
Hey Matt, My bottle has never shown under 900 PSI and I've made 10 1/8 mile runs (5 w/100 shot & 5 w/125 shot). My NOS vendor put my bottle in a freezer for an hour and said he was able to get 11lbs in by doing that. Do you think something is wrong with my pressure gauge? I can go out to the Jeep right now and open the valve and have 900 PSI without turning on the heat pad after all those runs. Also, what do you guys pay for NOS? Mine was $5/lbs.
I do have the B&G NOS tune. I'll log this data Fri night if it does not rain. Might even have to find a Sat track if it rains Fri. I want to put all this input to use. Thanks again.
Are you using a Zex bottle heater?If you are ditch it for a better one.I use a DynoTune Heavy Duty heater.The Zex heater is almost useless for keeping pressure up.
