How many of you drag your Z?

[cuisinartvette]

Any tips on how these cars do/don't like to be launched? Going to run her tomorrow night to get some baseline numbers before the mods start...
Not expecting too much, as the air is terrible where I run and it will probably be pretty warm.

[Scoob]

I can't offer much in the way of tips as the 1/4 isn't my thing so I only do it for fun. I put the shocks on "tour" and launch at about 2k.

[Aurora40]

I was launching the car around 4000-4500 rpm when I took it to the strip. I'm no expert either, but I was going by advice I'd heard here (or on corvetteforum?). It worked well, don't dump the clutch, but modulate the launch using it. It wasn't hard on the car and was sort of easy to control. Easier than gas and dump, for sure. If I dump it at about 2000 rpm, it breaks loose badly.

[Z Factor]

Any tips on how these cars do/don't like to be launched? Going to run her tomorrow night to get some baseline numbers before the mods start...
Not expecting too much, as the air is terrible where I run and it will probably be pretty warm.


My post is predicated on the assumption that you will be launching it at the track.

In my book, it is very important that we get our terms on the same page. I use several methods depending on what I am up against, and the track conditions. I feather my clutch (also know as "slipping the clutch") at fairly high RPM's to not bog the engine or break traction. Specifically, I hold rpms around 4500-5000 - feather the clutch to contact, get the car moving while adjusting the clutch and throttle to prevent the car from bogging, and prevent it from spinning the tires for greatest traction. I'm sure 5000 sounds high, but keep in mind that the LT5's secondaries don't come into play until 3000-3500 rpm's. If you were to "dump" the clutch at even 3-3.5k you would probably break traction so feathering is the way to get moving for best times.

:cheers:

[cuisinartvette]

My post is predicated on the assumption that you will be launching it at the track

Yes-I don't know that there's much life left in it, but I may give it a go anyways. As long as I don't smoke the clutch completely and can get home I'm happy. I thought I'd try walking it out of the hole once, then leaving from a higher RPM-Should I avoid the burnout box with new tires? I'm guessing a lot of water may be thrown up in the wheelwell? Running my auto is a cakewalk, thought I could benefit from you guys' experience. Track is about 3000 ft. elevation, DA is usually pretty lousy. I'll have some timeslips tonight!

[Aurora40]

Depending on how it's set up, you can probably do a quick burn-out without using the water. Just drive around it and smoke 'em a tad past the water. I'd do at least some kind of burn out to clean any crud off the tires. You'll probably pick up a lot of crap on the way back from your run when the tires are hot.

[WB9MCW]

cuisinartvette WHEN U GET UR NEW CLUTCH GO CERAMIC RACE FROM CAROLINA CLUTCH WITH A ALUM. FLYWHEEL!!! I DID AND I PUT UP WITH THE GEAR RATTLE(IT IS A TRUE PAIN IN THE EAR) BUT I HAVE GREAT A LAUNCH NOW AT 3500 RPM. JIMO!!!

[cuisinartvette]

Well, bad news.

Two runs, both 13.8, one @103 and 104 mph. 2.22 and 2.25 60'. Some tirespin in first thru third...Here's the kicker:

3000 ft elevation
5500 DA
28% humidity

I suspect the lousy air had everything to do with this and my need for traction.Everything there was running SLOW. Even the modded turbo Subarus couldn't break into the 13'. They usually runwell up there. Felt good to whip an LS2 by a full second and destroy a brand new GT though!

Part of me blames the air/traction and the other part of me wants to dump both the vettes...

[Z Factor]

Well, bad news.

Two runs, both 13.8, one @103 and 104 mph. 2.22 and 2.25 60'. Some tirespin in first thru third...Here's the kicker:

3000 ft elevation
5500 DA
28% humidity


I suspect the lousy air had everything to do with this and my need for traction.Everything there was running SLOW. Even the modded turbo Subarus couldn't break into the 13'. They usually runwell up there. Felt good to whip an LS2 by a full second and destroy a brand new GT though!

Part of me blames the air/traction and the other part of me wants to dump both the vettes...

Everything considered, I'd say the conditions had a lot to do with it so don't sell the vettes.

What rubber were you wearing?

[cuisinartvette]

New Sumitomos, 28 lbs. I didn't expect them to hook real well to start with; Leaving at any higher rpm seemed like a waste. Maybe I'll try again, but I was hoping for at least a low 13 at that altitude with that DA. There's more in it, just have to try a track at lower elevation with a stickier tire. 13.8 is pathetic IMO....

[Aurora40]

what does "5500 DA" mean? What was the air temperature? I'd think 3,000' plays a bit of a part. 104mph isn't too bad especially if the atmosphere wasn't good. I'm guessing the 4.09 gears don't help improve your trap, just ET.

Also, two runs isn't that many unless you are good at it already. I ran around 13.6-13.4 for the first few runs I made on my one trip to the track. It wasn't until my last run (of about 6-8 runs) that I hit a 13.2. I imagine if I'd kept running I probably could have done better than that also.

[Jeffvette]

what does "5500 DA" mean?

Density Altitude
Originally developed from formulas used by aircraft pilots to calculate lift, this relative performance altitude when calculated for racing includes additional compensation for the effects of humidity on engine performance.

[cuisinartvette]

First run I left at about 2000;second one about 1500-Didn't slip it bad, nor dump it-Maybe I expect too much. I'm going to try another track when it cools off, see how it goes. Yes, more seat time should help, too. First run made some respectable shifts-Didn't want to miss at 7000 rpm;second run I hit all gears perfectly short of speedshifting. It was a blast, though I have to admit!

i didnt' get the air temp;Guessing around 80ish-I noticed 1/2 hour after leaving the track it cooled off outside and my readut said 77

[cuisinartvette]

For the member that was curious to how it ran, here's the poop...

http://img.photobucket.com/albums/v224/kalthoff1/Scan10008.jpghttp://img.photobucket.com/albums/v224/kalthoff1/Scan10007.jpg

[ShawnZR-1]

I've dragged my Z about 10 times now just for the fun of it. The absolute best I've ever done is 12.96@111MPH. That was at Beach Bend too!

My 60's are abismal, 2.2+ but that is on street tires. I can dial in a 13.2 and be damn sure I'd hit that all day long without breaking out.