2.1 60 fts...help!
#1
Racer
Thread Starter
2.1 60 fts...help!
I really need to get my launch right. On 28 x 10 Hoosiers.
Can anyone critique these runs?
2.1 60 ft 95.95 mph, 2.0 60 ft 96 mph.
What would it do in a 1/4 mile with 1.6 60 fts?
Thanks!
Can anyone critique these runs?
2.1 60 ft 95.95 mph, 2.0 60 ft 96 mph.
What would it do in a 1/4 mile with 1.6 60 fts?
Thanks!
#5
Racer
Thread Starter
I'm pretty sure they were spinning. I reviewed the logs and I was launching at 3400 rpm.
I bogged one run.
Does the 2.0 and 2.1 60 ft with 96 mph mean if I can get 1.6 I'd be around 99 mph?
I bogged one run.
Does the 2.0 and 2.1 60 ft with 96 mph mean if I can get 1.6 I'd be around 99 mph?
#6
Pro
Doubtful you'll gain any mph, depending on how bad you spun you might lose mph when you hook but get there quicker, gotta try what you can to make it work. Idea is to launch as hard as you can without spinning the tires. If your on old tires and the compound is hard that could be one thing, try different tire pressures, try varying your launch rpm to see what works best, try just leaving off idle and taking it slightly easy, sometimes what may feel slower will get you a better ET because you hook.
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SVT_Z06 (09-19-2016)
#7
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Doubtful you'll gain any mph, depending on how bad you spun you might lose mph when you hook but get there quicker, gotta try what you can to make it work. Idea is to launch as hard as you can without spinning the tires. If your on old tires and the compound is hard that could be one thing, try different tire pressures, try varying your launch rpm to see what works best, try just leaving off idle and taking it slightly easy, sometimes what may feel slower will get you a better ET because you hook.
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SVT_Z06 (09-19-2016)
#8
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When logging, look at your wheel speed and rpm. This will give you a good picture of the launch. In addition, get some video of the launch showing a full side shot of the car. (A good vid will be from the side with the videographer standing slightly behind and angling toward the front.) The entire car should take up the frame. Since the Hoosier slicks are white lettered, you will definitely see how much spin you get.
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SVT_Z06 (09-19-2016)
#9
Racer
Thread Starter
When logging, look at your wheel speed and rpm. This will give you a good picture of the launch. In addition, get some video of the launch showing a full side shot of the car. (A good vid will be from the side with the videographer standing slightly behind and angling toward the front.) The entire car should take up the frame. Since the Hoosier slicks are white lettered, you will definitely see how much spin you get.
I guess the good thing is I was consistent all night with same 60fts and mph. Time to break those habits.
I reviewed my logs and it looks like I'm shifting 1-2 at 5500 rpm. 2-3 at 6200. Too low?
#11
Your reaction time was .228 better/faster. Add your reaction time to his ET, 8.161 vs your 8.132. He was quicker but you had .228 head start that he couldn't overcome.
#12
Racer
Thread Starter
#13
Safety Car
What gears are you running? What other mods are done to the car? A 28" tire is pretty tall unless you've got an aggressive gear. If you're launching at 3400rpm I'm guessing your bogging vs. spinning unless you're not heating up the tires or the track prep is absolutely horrible.
#14
Burning Brakes
If your running a full slick at 17psi, that's way to much. I'd start at 12psi and see where your at. I ran a 28 X 10.5W at 11psi in a 3200 lb car. I run my drag radials at 17-18psi.
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SVT_Z06 (09-19-2016)
#15
Racer
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What gears are you running? What other mods are done to the car? A 28" tire is pretty tall unless you've got an aggressive gear. If you're launching at 3400rpm I'm guessing your bogging vs. spinning unless you're not heating up the tires or the track prep is absolutely horrible.
Hmmm...you got me thinking about the tire height now. I do have 555R's that I can try.
#16
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#17
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That is a very aggressive slick especially with stock gearing. 17-18 psi is not too high based on your mods. I would be very careful at 12 psi. If you dead hook, you may break something.
You first need to determine if you are bogging or spinning and then adjust accordingly. Small 1 psi increments are better.
You first need to determine if you are bogging or spinning and then adjust accordingly. Small 1 psi increments are better.
#18
Burning Brakes
I figured 12psi was conservative. Breaking shafts comes with racing. I've been as low as 10 & 1/4 on a full 28 inch slick. My cars got a built 9inch and the car 60 foots 1.27-1.28 so I'm not worried about breaking anything. It did sway a tad bit tho. I'm on a drag radial these days. In my mustang so it's kinda night and day in a corvette
Last edited by junk c5; 09-19-2016 at 09:33 PM.
#19
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I figured 12psi was conservative. Breaking shafts comes with racing. I've been as low as 10 & 1/4 on a full 28 inch slick. My cars got a built 9inch and the car 60 foots 1.27-1.28 so I'm not worried about breaking anything. It did sway a tad bit tho. I'm on a drag radial these days. In my mustang so it's kinda night and day in a corvette
Last edited by GARY2004Z06; 09-20-2016 at 08:24 AM.
#20
Racer
Thread Starter
It indeed is a very different world and much more costly when something lets go. (If only a CV axle lets go, consider yourself lucky. A good rear runs around $3500 and is a pain to install.) The OP's car should really be on a 26" bias ply tire as most manual trans N/A Vettes should be. We have run low pressures at around 10.5 psi on some setups with certain track conditions; however, we have also been in the mid to high 1.3s on both 26" and 28" tires with pressures ranging from 12.5 to 15.5 psi. If your car is a stick car and it sixties in the 1.2s, that is fantastic. That is extremely hard to do in a stick Vette.
I have 305 35 18 555rs that are 3 months old that I will try on the track (26")
Should I start with 15 psi hot with the 555rs?