Nine Ball

iTrader: (38)

I took the new Corvette to HRP tonight. Weather was in the 80F range and very humid, not really ideal for racing. I'm pretty disappointed with the times I ran tonight, these cars are a pain in the *** to get a good launch out of.

2005 Z51 6-speed
3410 lbs raceweight
car is showroom stock
stock tires at 32 psi in the rears

I tried leaving while slipping the clutch on the first pass (holding at 3K rpm) and the rearend wheelhopped so badly that the entire car shook and my radar detector went flying off of the windshield. That sucked, hello 13.4

Came back around immediately, tried leaving at a lower rpm and easing into it. That didn't work, the car bogged terribly. Ran a 13.2 @ 108 with a horrible 2.3 60' time.

Let the car cool down for 15 minutes, and tried to slip the clutch out holding it at 2K rpm. Slight bog, then slight spin. 13.0 @ 112 mph with a 2.2 60'. 4 mph from just letting the coolant temps get below 200F!?!? Damn GM for making these things run so hot from the factory.

Next pass the coolant temp was back up to 214F. Left the line at 3K rpm slipping, followed by a ton of wheelhop. Powershifted the gears perfectly..... and ran SLOWER! 13.28 @ 109 mph with a 2.3 60'.

Launching a stock Corvette is truly frustrating. I probably need about 10 more passes to figure out how to do it, but it is just damn frustrating. These cars really seem to suffer tremendously when the coolant temps get above 200F. Powershifting the gears, I felt a slight pause (timing being pulled?) between gears. My stock 99 Camaro SS doesn't do that, I went 12.8 @ 104 in it about a month ago (bone stock too).

I have no idea what psi to run these stock tires at. There seemed to be a very fine line between massive spin and wheelhop, or bogging. No middle ground.

Ah well, my C6 is definitely not a 'ringer'

BBM98C5

iTrader: (2)

I have noticed a big difference going from 32 to 27 psi on the street. A lot less wheel spin. I usually run rears at 20 and drop 1 lb at a time till you find where it hooks best at the track. Don't go below 15 lbs though. I think you will be a lot more satisfied with your times with about 18 psi and about a 2000 rpm launch. Just my .02 though.

BrandonSS

iTrader: (1)

18 psi on stock tires? Damn... what size tires come on the vette stock?

Off topic Tony, but if you want PM me with your technique with the 99 SS. I am modded and running 13.1@111 First time ever driving a M6 at the track though.

DrkPhx

iTrader: (15)

Damn that sucks. It seems the the C6's are definitely not in the C5 ZO6 ET range from what I've read so far. I also read they have a heavy-handed torque management system even for the M6's. I would drop the rears to 25 psi and try at least one hard burnout. Last year I ran my TA with 18" Michelin Pilots at the track and managed a 2.0 60 ft only after I dropped the rear pressure and extended my burnouts. I would also ice the intake down between runs, you would be suprised how much it helps on a hot, humid day.

Nine Ball

iTrader: (38)

I plan on installing a 160F thermostat and a manual fan switch. Sucks not being able to hot-lap a car without it boiling over.

I'll play with tire pressure next time, 32 psi definitely didn't work!

BrandonSS: I slipped the clutch out while holding the rpm at 3K, then powershifted each gear at 6100 rpm. 1.80 60', 12.84 @ 104 mph. Stock 99 SS with 38K miles.

BIGBOS

Im hearing there is some sort of torque managment issue with the C6's, even the 6-speeds, cartek seems to know about it and how to get rid of it......but they seemed to have a problem running 13.0's-13.3's, then went down to 12.4's I believe w/just the change

I feel your frustration, I can't get mine out of the hole at all on 19" rims

BBM98C5

iTrader: (2)

It seemed to work for me, I ran a best 13.09@109 in my brothers vette and i had almost all 1.9x 60 foots (a few 2.0x's). This was on a Sumitumo HTRZII 275/40/18.

InsomZ

iTrader: (1)

that raceweight suprises me aren't they suppose to be about z06 weight? but the trap speed is there man all u need is traction.

Richiec77

iTrader: (3)

I beleive I saw somehwere that the reason for the LS2 running Hot is that the Block has less coolant capacity and the Pump moves less Fluid. Block is a Hard Fix, but the Pump might be a change. I'll see if I can dig up the Info so I don't look like I'm speaking out my ***.

Oh. I use to run my Nitto 450's at 17 PSI to get 1.9/2.0 60's I did the same 60's with E.T. Streets until I got a Stall.

FEAR THE LS1

iTrader: (1)

I don't think the General intended the C6 to be much a 1/4 mile car off the show room floor, like you said its going to be a challenge to find that sweet spot for launching the car. However, I'd like to see you do a 4 wheel drift through an Apex in any Fbody, the C6 is a corning **** compared to any Camaro. I test drove one and the sales guy was like "have at it" I took that bitch for a ride let me tell you. I'n first gear I was getting alot of wheel hop from every light I took off from (that was disappointing), but in 2nd-4th gear the car pulled nice. I had the most fun sliding around corners and I even got to do a little drifting on the goodyears coming around an onramp to the highway, took that 25mph ramp at about 50mph sliding. No way I would ever try that in my Camaro.

With a few modification to the rear suspension I think you could get that C6 to go 1.8 60' consistantly on street tires. Some MT radials would be nice too. I cannot wait till my C6 gets here, I've been driving a damn Tahoe everyday for almost 2 years now....ugh

Lee

Nine Ball

iTrader: (38)

They weigh approximately 100 lbs more than a Z06 (3015 for Z06). Plus I weigh 192 lbs, and had approx 3/4 tank of gas.

CHRISPY

haha you'll get it quicker, the vettes just take getting used to.

Nautilus

iTrader: (15)

I took my uncle's to the track a few weeks ago. Bone stock with only 250 miles. I ran consistent 110 mph, but I had the same problem. I never got a good launch, if I left a little too light the car would just bog and if i was a little to heavy I would get no traction. I made three runs and I just couldn't find a a good way to leave the line. My best was a 13.4 at 110 with a 2.2 60ft time. All three runs were right there within a 1/2 mph and 1/10 and my 60ft times were 2.2 & 2.3.

The other problem.....every run was made with the temp reading over 200 and one was at 220.

The car is a 6-speed, but not a Z-51. I wasn't impressed with the car when I first drove it and the track numbers just backed up my first impression.

It's going to eastside for a catback, cai, 160 t-stat and tuning, then it's headed back to the track.

SSnakekiller

iTrader: (8)

Why not just do this: https://ls1tech.com/forums/corvette-performance/294974-c5-hard-launch-pic.html

lol j/k. Man that sucks. I've been thinking about a C6 but I dunno now. If I got one I would probably not touch it (warranty) and expect it to easily run high 12's. Im sure it will get stronger as you break it in more, but like Lee said, the car is not meant for launching, its meant for pullin G's.

PA Z06

Tony
I was talking to a friend at the track on tuesday who got a new c6, his times were pretty bad at first 13.5 ish and he took his car to cartex, and had a switch installed to help control traction, he was complaining that it felt as though the computer was holding something back, he did the switch and bam he was into the high 12s, hope that helps, when i get a second ill look for more info on the name of the switch

BIGBOS

Its the torque management issue, I'm not exactly sure how it works w/the 6-speeds though....

Patman

One of my biggest problems with my car at the strip is that when traction is good, it just bogs off the line, even with a full throttle off idle launch. If you torque it up it'll just spin like mad though, it's impossible to find that fine line.

So I get my best times when the track is sticky but not super sticky, so that when I launch the tires are just on the edge of spinning. I have TM removed, and I'm going to get it dyno tuned again soon and I'll see if they can lean it out a little bit off idle (I think it's running too rich off idle, causing a lot of the bog)

Mine really shouldn't bog considering it's got 3.15 gears. My LT1 with 3.23 gears never bogged like this one does. It just falls flat on it's face for the first 300ft off the line. It would easily run 12.9s if it didn't bog.

I've got the coolant issue solved though, even with the stock thermo I never see it go over 194F thanks to having the fans set to come on lower. (in fact, they both run at all times except on the highway)

Louis

iTrader: (7)

I dont care about the launch, I care about hitting the brakes at the end, and making the first turn in, beating the previous cars to the time slip booth

Bad Habit Bird

iTrader: (12)

Your Formula wasn't either but in the end it all seemed to work out for you

I will be keeping an eye on what you do with this vette, I will be getting mine next year and I can't decide what type of setup to run

Nine Ball

iTrader: (38)

ordered today from Cartek:

Torque Management Module
Fan Switch Module
160F Thermostat

I'll install the stuff and go back to the track, probably after Power Tour.

Tony