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2.1 60 fts...help!

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Old 09-17-2016, 03:57 AM
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SVT_Z06
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Default 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!





Old 09-17-2016, 07:36 AM
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GARY2004Z06
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Should go mid 11s in the high 11x.xx range depending on mods and weather.
Old 09-17-2016, 04:53 PM
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Thanks, Gary.

I think I need some new slicks or maybe need to launch higher. I had them at 17 psi. Maybe that's too high. Shooting for a 7.3 or 7.4.
Old 09-17-2016, 08:38 PM
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Were you still spinning the tires or hooking & bogging? There's a ton left on the table just in the 60'
Old 09-17-2016, 09:39 PM
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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?
Old 09-18-2016, 07:28 AM
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Originally Posted by SVT_Z06
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?
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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Old 09-18-2016, 07:52 AM
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Originally Posted by mcshocks
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.
You need a little tire spin and/or clutch slip on a launch. DRs need only clutch slip. Actually on a slick, you need several revolutions of spin for a proper launch. A little spin helps mitigate the bog.
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Old 09-18-2016, 08:02 AM
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Originally Posted by SVT_Z06
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?
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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Old 09-18-2016, 10:36 AM
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Originally Posted by GARY2004Z06
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.
Will do. Thanks again for the tip.

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?
Old 09-18-2016, 01:18 PM
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Im also confused how I beat this evo (had an 'LOL V8' license plate)

Old 09-18-2016, 04:12 PM
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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.
Old 09-18-2016, 04:17 PM
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Originally Posted by Millenium Z06
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.
Awesome explanation. Thank you very much!
Old 09-19-2016, 02:04 PM
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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.
Old 09-19-2016, 04:33 PM
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Originally Posted by SVT_Z06
Thanks, Gary.

I think I need some new slicks or maybe need to launch higher. I had them at 17 psi. Maybe that's too high. Shooting for a 7.3 or 7.4.
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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Old 09-19-2016, 08:30 PM
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Originally Posted by MVR 155
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.
I'm running stock Z06 gearing.

Hmmm...you got me thinking about the tire height now. I do have 555R's that I can try.
Old 09-19-2016, 08:31 PM
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Originally Posted by junk c5
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.
Ok, I will try 12 psi hot and see if that helps. Thanks!
Old 09-19-2016, 09:14 PM
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Originally Posted by SVT_Z06
Ok, I will try 12 psi hot and see if that helps. Thanks!
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.

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To 2.1 60 fts...help!

Old 09-19-2016, 09:28 PM
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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 junk c5; 09-19-2016 at 09:33 PM.
Old 09-20-2016, 08:24 AM
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Originally Posted by junk c5
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
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.

Last edited by GARY2004Z06; 09-20-2016 at 08:24 AM.
Old 09-20-2016, 09:47 AM
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Originally Posted by GARY2004Z06
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.
Thanks you, Gary!

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?


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