Went to the track today for the first time since last October. Since the last trip, I have headers, utec, and a new longblock. I'm also sporting a brand new set of BFG's.

It was opening day at the track. Surprisingly, there wasn't much of a turnout. So for a while there I could basically just hot-lap. I got 20 runs in 3 hours. This was in Steele Alabama, and temps were in the mid to high seventies. Weather Underground lists it as low seventies, but it was quite a bit warmer than that.

My previous best was a 13.791@102.22, at the same track, in 25 degree weather(about -1666 ft DA). At the time I had a k&n drop-in filter, ztube, and kinetix cats, on all season tires. Since that night, I couldn't get back into the 13's, even with more mods(clutch+flywheel, intake, mrev+, test pipes, exhaust).

My first lesson of the day was that I can't do a burnout. I pulled the brake fuse(stop lamp). From everything that I've read, that should have let me do burnouts. Wrong. I can get the tires to spin, but as soon as I apply the brakes, the ecu cuts engine power immediately. Fortunately I never stalled, so I escaped complete embarrassment. I had to satisfy myself with just spinning the tires a few rotations before I staged.

I started out at 25 psi in the rears. First pass, I dropped the clutch at 3k and bogged. Second pass, I dropped the clutch at 4k and wheel hopped for the first 30 feet or so. Third pass, I feathered the clutch from 4k, and bogged. The first three passes yielded 2.29, 2.35, and 2.20 sixty foots, respectively.

Remember, these were virgin tires. And I couldn't heat them up properly.

After that, I dropped the rears down to 22psi. That really helped out my launch. I tried different rpms, from 3k to 5k. I tried feathering the clutch, throttle, or straight clutch drops. I still haven't figured out which is the best method, but I think 4500 rpm clutch drops were the most effective, at least for tires that weren't very warm.

Another thing I learned today was that I'm right back where I started, in regards to my buddy's SRT4. When we were both completely stock, we ran almost identical times. The few times we lined up on the interstate, we were extremely close, with me pulling *inches*. We installed a stage 2 kit on his car back in January, and he was faster. But after sharif's tune, we're back where we started. If there's any difference, I might pull by 6 inches over 2 gears on the interstate. At the drag strip though, with my DR's, I'm still quicker.

Here are my times from today, in sequence. I'll follow with some observations and comments. Times listed are 60', 1/8th, and 1/4.

Pressure in rears at 25 psi
1: 2.292, 9.246@80.31, 14.111@101.39
2: 2.351, 9.240@80.98, 14.074@102.29
3: 2.206, 9.093@80.99, 13.911@102.48

Changed pressure to 22psi
4: 2.115, 9.111@77.9, 14.053@100.51 - missed 2nd
5: 2.170, 9.068@80.59, 13.920@101.67
6: 2.373, 9.639@78.9, 14.543@101.03 - wheel hopped bad, missed 2nd and tapped limiter in 3rd and 4th
7: 2.274, 9.215@80.58, 14.061@101.83

Changed pressure to 19psi
8: 2.180, 9.022@81.10, 13.856@101.89
9: 2.164, 9.010@81.05, 13.833@101.97
10: 2.121, 8.973@80.68, 13.814@101.48
11: 2.158, 12.157@46.17, 20.789@55 - missed 2nd, cruised the rest of the way
12: 2.103, 9.296@78.56, 14.214@100.39 - missed 2nd again
13: 2.049, 8.875@80.67, 13.711@101.60 - beat my previous personal best
14: 2.049, 8.882@80.75, 13.708@101.99 - new PB
15: 2.099, 9.008@79.95, 13.905@100.72 - had a passenger filming that run
16: 2.151, 11.475@51.37, 18.806@63.55 - missed 2nd and cruised
17: 2.106, 8.941@81.05, 13.781@101.66 - this also beat my previous PB
18: 2.065, 9.263@78.81, 14.279@96.83 - missed 2nd, then missed 4th
19: 2.052, 8.943@80.40, 13.890@98.33 - missed 4th, still got a 13.8
20: 2.140, 9.108@80.05, 13.972@101.14

Of 20 runs, I missed shifts on 7 passes. That's a miss rate of 35%.
Of 20 runs, I had 2 2.3 sixties, 3 2.2's, 10 2.1's, and 5 2.0's.
Of 20 runs, I had 7 14 second passes, 11 13 second passes, and 2 runs where I just cruised after screwing up.
For the day, I trapped 100mph or greater where I didn't miss a shift
Once I dropped the pressure to 19psi, I didn't touch the 14's again unless I missed a shift.
On one run(#15), I hit a 13.9@100 and had a passenger. The guy was maybe 6'1", and around 200lbs.
I had three passes that beat my previous best. Not by a lot, but better nonetheless.

Of the 20 runs, I had 5 passes where I broke into the 8's in the 1/8th. I haven't been in the 8's since the last time I saw the 13's in December of 05. Two of those were 8.8's.

I'm averaging 21mph in the last half of the track. Less than I had hoped.

Now, I mentioned that the temps were in the mid to high 70's. Weather underground states they were in the low 70's. To calculate density altitude, I used the figure of 75 degrees. That puts the DA at 1955 feet. The last time I hit 13's, the DA was -1666ft.

My traps aren't anywhere close to what I'd hoped for. I was hoping for 103's. There's a lot left in the sixty foot, but I think that's it on power. I might pick up another mph if I run it in the forties or fifties, but not more than that.

The sixty has at least another 2 tenths in it, putting it in the mid 1.8's. I just have to figure out how to do a burnout. If I can pull a 1.8, then that should put me at a high 13.4 or low 13.5. If I pick up another 1 or 2 mph in the cooler temps, AND cut some 1.8 sixty foots, I might even run a low 13.4 or a high 13.3.

But I'm tired of setting goals and not meeting them. I should just be happy with what I'm running now.

 

WOW, 13.7 at 102 in 1900 elevation!
Time to dyno the beast.

 

Already have. Info here.

 

Trey,

Congrats on the new best. The DA definitely wasn't helping you. Regarding the burnout, have you tried disconnecting the yaw sensor under the center console? When you unplug the yaw sensor, it turns off the TC and stability control, but leaves the ABS on. There's also another brake sensor you can unplug by the ABS acuator.

As for the launch, you're probably going to have to up that launch rpm even higher. I'd be shooting for 5000-5500rpm with a little slip for the first 5 to 10 feet. It's abusive, but you need that torque multiplication to launch because the car doesn't have a whole lot of torque to begin with. I use to launch my Maxima at 5000-5500rpms with DRs and streets tires, stock 110+K mile clutch no less.

 

Thanks for the feedback Dave. Do you think there's another 2 tenths left in the 60 foot, with a proper burnout and higher rpm launch?

And I'm not too worried about my clutch right now. This clutchmasters is a beast, at least compared to stock. I ran 20 times Saturday with no complaints from the clutch. And on the way up there, I did something I've never done before on the interstate: I topped out 4th gear. I powershifted from 4th to 5th at 7k rpms, and the clutch acted perfectly. I even caused the slip light to come on

 

Under the right conditions, track prep, and launch rpm, upper 1.8 60 foots and 13.3-13.4s@~103mph should be attainable. Since you've now got the right tires and a strong clutch, the issue now becomes the half shafts. It's the luck of the draw. Some guys launch their Zs at 6000rpms with over 300wtq and don't have a problem and some guys launch a 4,500rpms on slicks and mostly stock power and snap them. The trick is to slip the clutch a bit on the higher launch to take that initial driveline snap out of the equation. A clutch dump on sticky tires is almost always a recipe for disaster.

 

Nice runs Trey, are you running the BFG drag radials? If so they need to be heated up quite a bit and then you will get your sub 2.0 60 foot times.

 

great times I can't wait to get into the 13s...my PB of 14.002 kills I was that close

 

Thanks man. Yeah, I'm running BFG DR's. I know I have to heat them up, but I have to figure out how to override the ecu's cut before I can do burnouts.

And Kenny, I have some advice. Plenty of people told me to get some wheels and DR's. I always planned on doing so, but first I wanted to see how far my traps would go all motor. It turns out that I picked up very little mph. If I had it to do all over again, I would have gone with wheels+DR's much earlier.

So go ahead and get you a set. Like DaveB and many others have said, DR's will be the single most cost-effective mod to bring down your ET.

 

Congrats on your new personal best! 20 runs in 3 hrs sounds like you had some fun You can definetely improve on your times with a better 60'. I like to feather the clutch a few feet out of the hole. You can try 4000 rpms and experiment from there. But, let me worn you that you can really shorten the life of your clutch by doing this. I'm envious that you got to unwind and have some fun. Our local tracks don't open till April

Bobby

 

^^^ah, but see that happens when you live in the tundra.

Our tracks here are only closed about 2.5 months *maybe* a little more.

 

Let me know your best launch technique on the BFGs. I just put some 265/40/18s on my stock 18s. I only had 4 runs.
First run, I feathered the clutch at 2500 rpms...2.2' (weak launch)
2nd run, I feathered at 3000rpms...2.0' (bogged)
3rd run, I dropped the clutch at 3000rpms...2.0' (bogged)
4th run, I dropped the clutch at 4000rpms...2.2' (spun)

I know I can get a 1.8' on DRs if I can managed 2.0' on street tires. Good luck on your quest.

 

nice & plenty of room for improvements

 

badboy when r u gonna take off work so we can go to the track