Quite a fun day at Sacramento Raceway test-n-tune. Hector (07inferno) and I were the only representatives of the LX/LC nation. I think we represented well. There was supposed to be a track rental in addition to the test-n-tune sponsored by a group of AMG guys. That fell through at the last minute based on some meddling by a guy with a Z06 who crapped on the thread at the Mercedes forum and tried to pull strings with the track manager. Anyways I could have really used a few extra hours and some better prep. I was talking to someone at the track who drag races all around California and he was saying how Sacramento was marginal at best. On to the racing. I got their two hours early and cooled the car down to 118*. I pulled the serpentine belt and waited for the best opportunity to run. It was overcast and in the 40s. First two cars pull out. Hector and an Evo VIII. The Evo runs by himself and busts something half-track (I heard it was his transmission). Hector has to shut down and re-do his burnout. I was glad that wasn't me because I would have had to abort the belt pull run. I watch a few sets of cars go and things seem to be hooking OK. I get up to the line and do my burnout. I hit limp mode but because my car is so damned loud with open headers I can't tell what the problem is and think I've busted something major. I figure out it was just limp mode and restart. I launch and the car is all over the place. The wheels are spinning and with the front sway bar off the front end lifts pretty high while I meander down the track. I get a 12 flat at 120 MPH. I rush back to my pit area with water temp around 190*. I put the belt back on and start up as quick as I can to circulate the coolant. The temp drops rapidly to 160s. My next two runs suck (12.1@121MPH and an aborted run due to wheel spin) and I have an awful 1-2 shift that takes forever. I think there is something majorly wrong with my tranny. I later realize the traction control was still on!! With traction control off I hit 11.27@122MPH (3rd hotlapped run). My new Hoosier 315/35/17s smoke really good on the burnout and in fact so good I cannot see anything for several seconds!!! I hotlap again and with a ****ty launch get 11.776@122MPH I take about 45 minutes to cool down and watch some other cars run. I see an '80s Corvette hit the wall several times half track. Guy isn't hurt but every corner of the car hit the wall as he spun. I guess he was on street tires. I felt the same lane get squirrely at the same spot on my second run. After the cool-off I run a [email protected] with a 1.84 60' Spin, spin, spin. Time to hotlap. I'm not sure if the heatsoak makes the launch more manageable or if it is the repeated heating of the tires that is helping the launch. A few minutes later I run a 11.50@122MPH with a 1.83 60' 10 minutes later and I run a [email protected] (60' timer takes a crap so no idea what my 60' was) Another 10 minutes and I run a 11.37@122MPH with unknown 60' 30 minute cool-down and I run 11.26@122MPH w/ unknown 60' 6 minutes later [email protected] w/ unknown 60' 35 minutes of cool-down, refuel and add 2.5% fuel. [email protected] w/ 1.59 60' 15 minutes later I run 12.15@120MPH w/ unknown 60'. I blow off the tires a few other times but didn't bother to pick up the slips. I consider pulling the belt again but don't want to waste 2 hours on cool down only to have the run go to **** due to wheelspin. The track guys point to my car and tell me to pull over. They show me a pool of oil they think was mine and I spend 15 minutes with the car idling as I try to figure out what is going on. Ends up it wasn't my car - wheh! After being nice and heatsoaked I run [email protected] w/ 1.58 60'. Seven minutes later I do my last run and get my PB: 60' ... 1.573 330' ... 4.598 1/8th ... 7.168 MPH ... 96.589 1000' ... 9.375 ET ... 11.233 MPH ... 122.53 Overall I was a little disappointed but it is progress none-the-less. It would have been nice to have a 60' timer that works the whole time and it would have been nice to have more reliable traction. Hard to be confident launching when you don't know what will happen. Car was loud as hell with open headers and several people told me so. Hopefully I'll get a video of a 11.27 run from one of the AMG guys who was filming there. I may try re-dynoing next week with the catback back on to see the HP/TQ difference between open headers and catback/hi-flows. Congrats to Hector who I think ran a PB of 11.28@126MPH w/ nitrous. DA started at -600 and went up to -160 for my best run.
Nice Jeff! sounded like a hairy day there with people rounding the corners on their cars (or is that typical for Sac?). I was thinking about what you said about putting the belt back on to circulate the coolant as soon as possible. You think that's a good idea? Sounded like you got an almost instant drop of 50*. That would mean that the temp difference of the coolant outside the block was probably more than that. When do you worry about cracking a block? I was just remembering my childhood when you always let it cool down before putting water back in it after a boil over. When you shut the engine off, you've turned off the heat source and it should only cool down from where ever it was at when you turned off the key. I don't think there is any spike or anything after that. Is there any need to cool it down faster?
Not typical of Sac but more typical there than elsewhere. The concern is that there are hot spots in the heads that are above 220* and you want to circulate coolant after a run to alleviate that problem. I know several folks who have done this procedure many times and they haven't had a problem. Start run at 120* or below, burnout, stage and race and temp gets to 180-220* Shut down and circulate coolant.
AMAZING TIMES Jeff!!! Myself and a few other guys are coming to hunt you and your times down and get to the bottom of your special mods, track, and DA I wanna see how a heads/cam/headers charger can beat a supercharged AWD Jeep with my own eyes!
Thanks! You pay for the negative DA at Sac with a lack of traction You'd have the traction advantage for sure with AWD. Really my only standout mods are short tires (25.5" diameter for better gearing), 3600 stall converter and 500 lb weight loss Yeah, most folks can only push the pedal to 10 but I've set mine up to go to 11 Sac gets the negative DA but you have to have a good launch to enjoy it. Thanks. I had you in mind all day yesterday when I thought my tranny blew up several times. Luckily I was mistaken. I hope so.
