07-09-2016 MPC Real Street |
Subject: 07-09-2016 MPC Real Street by rklessdriver on 2016/7/11 19:10:32 I have been planning to treat this race as a test session for the entire month since our last race. The overfueling condition when the nitrous kit is activated has been a problem from day one since I had this fogger built. It has been solidly stuck in the 10.XX AFR range despite 3 different carburetors and regardless of what I flow the fuel pressure at. I joked at the last race that I was so tired of seeing it rich on the AFR nmeter and plugs looking like crap after every pass that I going to take the 31N jet out, put the 36N jet in and leave the 22F jet in..... I wasn't quite that brave. I put the recommended 36N and 26F jets in and set fuel pressure to 6 psi to start. My first round qualifying pass didn't go very good. I forgot to air the tires down... remembered that there was 25pis in the rear tires about the time I hit the burnout box.... Sure enough the car blew the tires off instantly. I peddled and got the car hooked up and watched the AFR meter all the way down.... 10.5 AFR showing entire run. Q1 - 6.19@121MPH. 1.46 60ft. Came back and dropped the fuel jet down. Ready for Q2 with a 36N 24F @ 6psi. Managed to remember to air the tires down to 17.5psi for Q2. The car acts very funny going up on the trans brake... stumbles bad and takes a second to clear out.... I have to sit there after the tree comes down and hold the car for a second before I let it go. Car left like a pig, felt kinda slow and sure enough 11.3-11.6 AFR showing the entire run. At least we are making some progress on the tune up. Q2 - 5.60@124MPH 1.30 60ft. Good enough for 7th on the ladder. So I go back and decide to try and drop fuel pressure. Gonna make a big move from 6psi to 4 psi and see if I can get the AFR to show in the 12's for first round eliminations. I got nothing to loose as I'm up against a car capable of running 5.30's. For whatever reason the car backfires going up on the trans brake and catches the carburetor on fire... well that sucks. Unbuckle my belts so I can reach the hood latch. Track and my crew guy get the fire out and I happen to notice that thru all the commotion by crew/track guys opening the hood and what not, the car didn't move out the lights, so the timer hasn't started yet.... Well lets make a test hit! I fire the engine back up put it on the brake and let it go.... car feels like a rocketship.... then instantly rattles the tires (like BAD wheel hop). I stay in it glancing at the AFR meter all the way to the line.... 11.6 AFR is the highest I saw. E1 - 5.75@122MPH... 1.38 60ft. Like an idiot, I'm not even buckled in... yep in my haste I forgot to put my 5pt harness back on. I go talk to the track guy about making a test run after E2. They say I'm good to go, so I go back and take some more jet out of the nitrous kit.... You guessed it. 36N 22F@6psi. Just what I jokingly threatened to do a month ago. The car comes up on the brake fine this time, and I when I let it go it takes off. Feels like a rocket ship for sure this time.... very small power wheelie to about 40ft out.... Nice and straight and I can tell just from the sound of the engine that its running good. glance at the AFR meter and 12.5 AFR in low gear, 13.05 AFR on shift recovery for a millisecond then back to 12.6ish in high gear. I am ecstatic at the big end of the track waiting on my crew guy to get there with the 4 wheeler to pull it back to the pit. He pulls up and hands me the slip. E2 Test pass - 5.67@125.6MPH. 1.32 60ft. I am shocked because it felt like so much better of a pass, but the clocks don't lie.... Finally we have the MPH we have been looking for... but now the 60ft sucks. Video of the race is here on Youtube. Give it a like as the guy comes to most of our races and has started posting the videos up and he sure makes it easier for me to show everybody else what we are doing out there. https://www.youtube.com/watch?v=Ae2fM7QQgNs Next race is going to be a challenge working on getting that 60ft back in the low 1.2X's... but if I can the car is going to fly.... Hope to see a few 5.40 time slip's. Thanks Gurus. Will |