good question !!
Pitt 10 sec vids
Melting Slicks
Joined: Dec 2005
Posts: 2,074
Likes: 0
From: Charlotte NC
My 330' times are always about a tenth slower when it noses over and bogs. A good run without it nosing over 4.5x 330' and a nose over run is a 4.6x 330' even with both having 1.5x 60's.
Last edited by Blu; Nov 3, 2008 at 04:09 PM.
Melting Slicks
Joined: Dec 2005
Posts: 2,074
Likes: 0
From: Charlotte NC
How much rwhp are you running ? Sounds like you have gobs of torque to deal with. Your going to have to figure out how to apply the throttle and stick with it. It doesn't sound like tire pressure would help you because you are on both sides of the launch problem. That eighth mile sounds like about 11 flat or high ten.
Pitt
Pitt
My setup is simple and budget PRC 5.3 heads, pat G 230/236 xfi cam, fast 90/90, exhaust and a 3.90 rear end.
Last edited by Blu; Nov 3, 2008 at 04:10 PM.
Le Mans Master
Joined: Aug 2005
Posts: 5,130
Likes: 3
From: Winter Park FL
When I figure it out I'm hoping the nose doesn't come up as much but doesn't fall either.Mother of God. Thats a pretty big loss.
Le Mans Master
Joined: Nov 2003
Posts: 8,308
Likes: 157
From: NJ
Thats what Im running ET streets 26x11.5x17. I can cut 1.5x 60's all day but finding the right method to launch is the tough part to keep it from bogging and nosing over which is murder on my ET. Here is what I mean and this is off the top of my head. All runs in 75+ degree heat.
1.52 60' with it hooking then nosing over bogging
7.13@97
1.64 60' with too much spin but no bog
7.18@98
1.54 60' heavy bog
7.20@98
The last time out(65 degrees at night)
1.55 60' with a little spin but hardly no bog
7.07@100.9
Also yesterday I went 7.30@100 with a heavy spinning 1.73 60'
The nosing over usually kills at least a tenth off the 330' which is murdering my ET and mph. I just got to keep working at it, if I could just dump it I would be all set haha.
1.52 60' with it hooking then nosing over bogging
7.13@97
1.64 60' with too much spin but no bog
7.18@98
1.54 60' heavy bog
7.20@98
The last time out(65 degrees at night)
1.55 60' with a little spin but hardly no bog
7.07@100.9
Also yesterday I went 7.30@100 with a heavy spinning 1.73 60'
The nosing over usually kills at least a tenth off the 330' which is murdering my ET and mph. I just got to keep working at it, if I could just dump it I would be all set haha.
A 700 S/C car can blow thru the bog with big torque down low.
You're car doesn't have the massive torque, so gears,clutch release techniques, and meticulous attention to tire pressure are gonna have to do.
With a very hard hitting dual disc clutch the tires want to spin then bog. I see it all the time, the dreaded spin-bog and a 1.6x result. With a single there are other ways to prevent bog.
So, you will want to try and slip the clutch as much as possible and try and force the tires to spin thru the bog. This may require raising the tire pressure incrementally until the bog goes away.
[I always choose hot tires with more psi over warm tires with less psi]
I also like 16" et streets over 17" et streets but be safe and get skinnies as well.
If the clutch grabs too hard it pulls the motor down. It's a very fine line.
Hope to see you spin.
Last edited by robz; Nov 3, 2008 at 05:39 PM.
Melting Slicks
Joined: Dec 2005
Posts: 2,074
Likes: 0
From: Charlotte NC
Melting Slicks
Joined: Dec 2005
Posts: 2,074
Likes: 0
From: Charlotte NC
As you know you want to prevent bog. We can live with some extra spin.(even 4-5 revolutions)
A 700 S/C car can blow thru the bog with big torque down low.
You're car doesn't have the massive torque, so gears,clutch release techniques, and meticulous attention to tire pressure are gonna have to do.
With a very hard hitting dual disc clutch the tires want to spin then bog. I see it all the time, the dreaded spin-bog and a 1.6x result.
So, you will want to try and slip the clutch as much as possible and try and force the tires to spin thru the bog. This may require raising the tire pressure incrementally until the bog goes away.
[I always choose hot tires with more psi over warm tires with less psi]
I also like 16" et streets over 17" et streets but be safe and get skinnies as well.
If the clutch grabs too hard it pulls the motor down. It's a very fine line.
Hope to see you spin.
A 700 S/C car can blow thru the bog with big torque down low.
You're car doesn't have the massive torque, so gears,clutch release techniques, and meticulous attention to tire pressure are gonna have to do.
With a very hard hitting dual disc clutch the tires want to spin then bog. I see it all the time, the dreaded spin-bog and a 1.6x result.
So, you will want to try and slip the clutch as much as possible and try and force the tires to spin thru the bog. This may require raising the tire pressure incrementally until the bog goes away.
[I always choose hot tires with more psi over warm tires with less psi]
I also like 16" et streets over 17" et streets but be safe and get skinnies as well.
If the clutch grabs too hard it pulls the motor down. It's a very fine line.
Hope to see you spin.
Next outing I will start with more tire pressure and see if that helps it spin through the bog. I know my car has a 10 in it with cool weather and getting the launch worked out, just got to perfect it for those right conditions.
Just ran the figures to see what the DA was at the time of the run and I came up with 1751 feet at the time I ran the 7.13, now give me some of this -DA weather haha.
Last edited by Blu; Nov 3, 2008 at 04:40 PM.
Thread Starter
Le Mans Master
Joined: Aug 2007
Posts: 6,473
Likes: 297
From: Orange Park FL
As you know you want to prevent bog. We can live with some extra spin.(even 4-5 revolutions)
A 700 S/C car can blow thru the bog with big torque down low.
You're car doesn't have the massive torque, so gears,clutch release techniques, and meticulous attention to tire pressure are gonna have to do.
With a very hard hitting dual disc clutch the tires want to spin then bog. I see it all the time, the dreaded spin-bog and a 1.6x result.
So, you will want to try and slip the clutch as much as possible and try and force the tires to spin thru the bog. This may require raising the tire pressure incrementally until the bog goes away.
[I always choose hot tires with more psi over warm tires with less psi]
I also like 16" et streets over 17" et streets but be safe and get skinnies as well.
If the clutch grabs too hard it pulls the motor down. It's a very fine line.
Hope to see you spin.
A 700 S/C car can blow thru the bog with big torque down low.
You're car doesn't have the massive torque, so gears,clutch release techniques, and meticulous attention to tire pressure are gonna have to do.
With a very hard hitting dual disc clutch the tires want to spin then bog. I see it all the time, the dreaded spin-bog and a 1.6x result.
So, you will want to try and slip the clutch as much as possible and try and force the tires to spin thru the bog. This may require raising the tire pressure incrementally until the bog goes away.
[I always choose hot tires with more psi over warm tires with less psi]
I also like 16" et streets over 17" et streets but be safe and get skinnies as well.
If the clutch grabs too hard it pulls the motor down. It's a very fine line.
Hope to see you spin.
Pitt
Le Mans Master
Joined: Sep 2006
Posts: 9,105
Likes: 166
From: PA
One thing I cant get figured out is this. How do you get enough runs to figure these things out without beating the crap out of your car, slipping and slipping and slipping your clutch, enough time to play with tire pressure, let the car cool, how many hot laps to do in a row, track prep is different every time you go to a track and weather. Car may be stronger, may be down a little for the weather, Track may be hooking and it may not. I go down and get 3-5 runs on average in a nite. I usually like a 2 hot lap cool for 30-45min and go again.
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Thread Starter
Le Mans Master
Joined: Aug 2007
Posts: 6,473
Likes: 297
From: Orange Park FL
One thing I cant get figured out is this. How do you get enough runs to figure these things out without beating the crap out of your car, slipping and slipping and slipping your clutch, enough time to play with tire pressure, let the car cool, how many hot laps to do in a row, track prep is different every time you go to a track and weather. Car may be stronger, may be down a little for the weather, Track may be hooking and it may not. I go down and get 3-5 runs on average in a nite. I usually like a 2 hot lap cool for 30-45min and go again.
Melting Slicks
Joined: Dec 2005
Posts: 2,074
Likes: 0
From: Charlotte NC
One thing I cant get figured out is this. How do you get enough runs to figure these things out without beating the crap out of your car, slipping and slipping and slipping your clutch, enough time to play with tire pressure, let the car cool, how many hot laps to do in a row, track prep is different every time you go to a track and weather. Car may be stronger, may be down a little for the weather, Track may be hooking and it may not. I go down and get 3-5 runs on average in a nite. I usually like a 2 hot lap cool for 30-45min and go again.
Thread Starter
Le Mans Master
Joined: Aug 2007
Posts: 6,473
Likes: 297
From: Orange Park FL
One thing I cant get figured out is this. How do you get enough runs to figure these things out without beating the crap out of your car, slipping and slipping and slipping your clutch, enough time to play with tire pressure, let the car cool, how many hot laps to do in a row, track prep is different every time you go to a track and weather. Car may be stronger, may be down a little for the weather, Track may be hooking and it may not. I go down and get 3-5 runs on average in a nite. I usually like a 2 hot lap cool for 30-45min and go again.
I have been keeping my tire pressure and launch rpm the same since the last couple passes at BG, and just playing with the throttle/clutch slip to get rid of spin. I just could not get consistant trying to guess pressure and rpm all the time. Everything I did created spin...and I never ever had the bog. That would have really blown me away.
You better take out the Ricers Bruce...for Gods sake..we are all counting on you !!
Pitt
Thread Starter
Le Mans Master
Joined: Aug 2007
Posts: 6,473
Likes: 297
From: Orange Park FL
Thanks.
What pissed me off is the back up run. I have a hard time slipping the clutch long enough and when I don't she bites hard and hops. That is an instant loss...from 1.47 sixty to 1.57 sixty. That would have been another 10.6 back up run. I do that 1 out of every 3 runs.
Pitt