Well, I have had the car back for awhile since getting a new clutch installed. I had driven about 200-300 easy miles trying to "season" the new clutch and make sure it was "bedded" in properly before making any passes in the car. Last night was supposed to get cold (like down in the 40's). So, I decided that I would go out to HRP to try and make some passes in the car.
Rather than go out and smoke the brand new clutch, I decided that I would take the car out on ET Streets. I have cut about the same 60' on the radials vs the ET Streets, the main difference is that on the ET Streets I can "pop" the clutch rather than "ride it out" like I do on the radials. I think this is much easier on the stock clutch which is what I am after right now. I really don't want to have to put another clutch in anytime soon.
I was able to get in 9 passes from 6:45 to 10:30.
I ran the car with 14psi in the rears. On the first pass I pulled a good burnout since I hadn't used the ET Streets in many months. I staged the car and brought it up to 5000. It was "instant green", so R/T is immaterial. The car acted really stupid at this point. I un-clutched it and it rolled out, but it didn't feel quite right. I went to pull 2nd and discovered why. The clutch was stuck to the floor again. This time it was stuck, and slipping badly. To put it mildly, I was very upset. I chopped throttle, and the clutch pedal sprung back up. I put the car into second and finished that pass. I picked up the slip at the timing tower to find out I had run a whopping 12.842@114.79...
Now I was a bit worried. Was a stock clutch going to be able to hold the car on ET Streets? Why was my clutch acting so stupid. I decided that the possibility was there that perhaps the new clutch needed a good pass to get settled in, and that even though I had made some easy passes on the street, that perhaps the first pass on the new clutch should have been a bit easier.
I let the car cool down, and put it back in line.
For the next pass I was lined up beside an open headered 68 Camaro. I indicated to the official that I didn't want to run that car since I couldn't hear, and besides in many cases I don't run some of those cars since many have a tendency to have way too much motor for way too little chassis. He didn't see things my way and indicated that I had to run this car. Things got a bit heated and he told me if I didn't run that car I would be thrown out of the track. I knew this not to be the case, and that he was the person with whom you indicated if you wanted to line up with someone, etc...
I am supposed to be the next car making a pass, but instead, I now am forced to pull out of line, and I was hot... I went up to the tower to talk to the officials. They directed me to the track manager (Linwood) who was lining up cars in the staging lanes. I went to talk to him. He told me not to worry that what I was doing was exactly what I was supposed to do. He told me to get back in line, and not worry about it. He got on the radio and called the guy I had problems with and explained things to him.
As I pulled back to the line the guy I had the issue with decided it was time to have a stare down contest. So, we stared each other down, and I made my pass... As a side note, I made 8 more passes and declined running several cars. I also set up races with a couple of other Vettes. He didn't give me any more static.
This time I decided to lauch at around 4000 RPM. Went through my usual routine and got the car staged. I launched, and the car bogged. The pass was better, the clutch seemed to stick well, but as I said the car bogged.
The next pass was about he same except I launched the car @ 4500. The car bogged even worse than the launch @ 4000. And, I slowed down a hundredth. But in both passes the clutch seemed to stick with no real hints of slippage. Also, the clutch wasn't getting stinky. The time slip was as follows:
Temperature had started out in the mid 60's with low humidity. As night fall came it began to cool off, but the humidity came up. DA was in the -100s, and was fluctuating up and down but showing a generally downward slope.
I began moving my launch RPMs up on each successive pass. The next pass I went back to my original 5000 RPM, and the clutch stuck with no problem. As in the previous passes the car "hit the tires" resulting in just a bit of wheel spin followed by the car bogging just a bit. The results were better, and I felt like I was moving in the right direction.
A look at the weather station showed that we were looking at about a -460DA. Temperature was about 58F. 78% humidity and the barometer was at 30.08.
The 11.935 was the second best time I had made in the car to date. The 11.933 I had run last year was with a 1.85 60' and the mph was 114.52. That run was with the stock cover on the air box, and on the stock F1SC radials.
For the next pass I decided to move past my 5000 rpm launch window and look to launch around 5200 or so. The car launched clean, and the pass felt very good. And then tragedy struck. I did something that I haven't done in a long time, and something I have never done in the Z. I missed the 3-4 shift. Here I am cooking along on a textbook and I crunch 4th. I could not believe it. Once I missed it I just pushed the clutch in and coasted the rest of the way down the track. I picked up my time slip which further re-enforced my belief that this was a pretty good pass. Up until I blew it...
One thing I did notice was that the clutch pedal seems to be a bit soft after my burnout. So, I decided to test something which seemed to help a bit. After I pulled my burnout, I would roll up, turn on the pre-stage beam, and then pump the clutch 4 or 5 times. This seemed to help out on pedal firmness.
I brought the car back around for the next pass. Again, I moved my launch rpm up a bit more. I brought it up to about 5500. Again, the car would "hit the tires" as it did on all previous passes. It would spin them for about 10 feet, bog slightly as it hooked and then just move out. I was able to power shift the car without any problem, and I could not hear the car "hit the tires" on any of my other shifts.
The DA for that run was about -412. As I said, it would fluctuate up and down, but showed a general downward trend.
The next pass I was lined up with another Z06. I had a Vortex on it, but was otherwise stock (performance wise). I had given its owner a few tips after his first couple of passes and he had been able to drop over .5 by making a few changes to his driving style. He was quite happy with he cars performance thus far especially since he was able to drop .5 and pick up several MPH.
He rolled all the way in, so as soon as I turned on the second beam the dropped the tree. I was not ready and he just left on me. I was bring the revs up, and just dumped the clutch at about 5500. Instead of "popping" the clutch this was almost more like one of my radial tire launches. I ran the other guy down quickly and ended up beating him by about 3-4 lengths. After the pass he explained that he had missed 4th and had run a 12.80.
I picked up my slip at the timing booth and was pleased to see the following:
They had a couple of kids working the booth, and they just handed me my slip and smiled. No one asked me about a cage the whole night... Life at this point was looking good. The lines were starting to get shorter as it was getting late. This meant my passes were getting closer together. I started to smell a bit of clutch stink, and new it was probably best if I wrapped things up pretty soon.
I lined up for my next pass and decided to launch @ 6000 to see if the car would do any better. It hit the tires and spun about 10ft or so. The rest of the pass felt pretty good. I picked up my slip and was both happy, and just a bit disappointed.
I was .003 away from an 11.79. I know, I know. An 11.80 in a stock Z06 is pretty darn cool. But an 11.70 would have been even cooler. I decided that I would make one more pass for the night in an effort to see if there was an 11.70 in the cards.
I pulled the car around and quickly and got back into line. By this time there were only 1 line of cars left that were lined up to run. They put us in another line, and I was 4th or 5th in that group. They pulled us around and I lined up to make what would hopefully be my best pass yet.
I pulled my burnout, and they dropped the tree. The car hit the tires and spun, but this time I noticed that it hit the tires on every gear change. I knew this meant one of two things either the car was pulling even harder and I was on one whale of a pass, or the track was going away. When I picked up my slip I discovered it to be the latter.
The track was finally getting cold enough that it wasn't going to hook anymore. So, I decided to take the car to the shop and put it up for the night. All in all I was pretty happy with the cars performance. One of the things I did note out there was the Blu-By-U was out there wit his car. He recently installed the VaraRam on his car. We started comparing time slips. Now, keep in mind he was on Drag Radials and I was on ET Streets. But, he was trapping 3 mph faster than me at the 1/8 mile. Most of my times were in the 92's he was trapping 95 and running almost 118mph trap speeds. His ETs were down to mine, but that can be explained by the differences in our launches. I found this to be very interesting. Now, one other thing to consider is that the ET Street @ 14psi does have a lot more rolling resistance than a drag radial. But, I still found 3mph to be quite impressive considering the softer launches.
I guess I will have to wait for that -3500 DA day when it is 45-50 degrees, around 40% humidity, and over 30.xx on the barometer. If I can get one of those days I feel pretty certain a 11.70 or perhaps even an 11.60 can be had...
Gotta love those ET Streets...on launch...and holding the shifts.
Is the new one a Z06 clutch?
Might want to start the regular process of changing out the clutch fluid in the reservoir from the beginning of this clutch's track life. Your pedal will reward the procedure.
In my 25 passes on Nov 15th, I changed the fluid four times to keep the pedal normal. On Monday morning, the fluid is black and gooey. Heat from launches will do that. So I'll change it daily until it stays clear. Mine now has 125 burnouts and launches.
Ranger - Thanks. The clutch is a stock unit replaced under the Tech Line bulletin. I agree. I have a gallon of Castrol GT LMA that I will be using to freshen up the clutch fluid. I am considering building a bleeder to attach to the stock bleeder setup. I think I may extend the bleeder so it comes out of the bottom somewhere. That way I can slide under the car and crack the bleeder and just change all the fluid at one time.
Z06nut - Thanks also... I'm ready for time travel. If I do it, I'm going back to cash out of all my tech stocks....
Damn, I tried everything I could....dropped tire pressure, changed rpm launch, long burnout/short burnout....I sucked off the line. My worst 60fts ever on the 275/40 bfgs.
But gees, the car was trapping like an animal. I had 3 consecutive runs of +95/+118 traps. I managed an 11.98 on a 1.94 60ft and an 11.95 on a 1.87 60ft. Car trapped 95.47 tops in the 1/8 and 118.71 in the 1/4. Too bad I wasted that power with poor launches...
__________________
'06 MS Z06
11.31 at 123, 1.80 60ft
showroom stock
Fabulous evening at the track! Congratulations on new best. I kept looking for a late night post last night and thought you had decided that it wasn't going to be cool enough. 6000 launch Wow
Sorrry I missed it.
tommy
I went back out tonight looking for an 11.79. But tonight did not start out very well. I was rolling the car back in my shop, and the door was open. Well, you can guess the result. I caught it on the stairs and cracked the corner of the door. To say that I was highly upset with myself would be an understatement.
I went ahead and went to the track anyway. The air felt really poor. Temps were supposed to be in the 40's, and it was in the low 70's. The sun was beginning to set, and temps were coming down, but humidity was on the way up.
I got there early, and drove the car through tech quickly. I went ahead and put it in the lanes. There were very few peope there, so it was already moving. In fact I was trying to drop the pressure in the tires while the line was moving.
Anyway, I didn't get much chance to cool the car. I pulled up and was waved through. I pulled my burnout and staged the car. I left at around 5000 and the car bogged as I left. I got to the end and picked up my slip. The lady waved me over to the side to talk to the tech guys (the track nazis were handing out slips tonight). Of course who did I get to talk to, the guy I had my run in with the last time.
He was actually cool. He looked at me and said, "you know what you need". He handed me my slip and I drove off. I weighed the car, it scaled at 3216 with me in it tonight which is inline with what I have seen before.
You only get two sub 11's with the "track nazis" so I planned to hit the brakes unless it was a very good run.
My next pass I launched the car at 6000. The car left pretty good and spun the tires slightly. But it still had a bit of a bog. I jammed the brakes and got into the ABS going through the finish line.
I didn't get any nasty comments when I picked up my slip.
That 60' was my best to date. This was about a 11.8x pass if I hadn't lifted in looking at other similar slips. The air quality just wasn't geoing to gat any better, and the temps won't be in the 40's till tomorrow moring. So I decided to make one last Banzai pass and go home early.
I cooled the car and the lanes began to fill up. Where there had only been 3 lanes filled, now 9 lanes were filled. So I put my car in line after about a 30 minute cool down. Temps were at 174 degrees. So it was cool enough if everything else would cooperate.
I finally go my turn, and I went for broke. I decided that this pass I would go ahead and try to launch at 6500 and see if I could overcome some of the poor air quality by launching harder. The car stuck hard it didn't spin. But, it did bog a bit leaving. So, the ET Street is just too much tire for a stock Z06. It hooks really hard, but it either needs more power or more gear so it doesn't bog leaving. I could combat this by slipping the clutch, but if I am going to do that, I will simply switch back to radials.
I picked up my slip and the first question was "where is your firejacket?"along with order to "go home" for the night. The slip was anticlimactic at best.
AutoForums.com is the premier network of enthusiast-owned
enthusiast-operated automotive communities.
We operate more than 100 automotive forums where our users consult peers for shopping information and advice, and share
experiences and opinions as a community.
. Can't wait for that ride.
[/IMG] Notice at super sonic speeds your car turns EB.
Linear Mode
