Suspension Experts - Why does the rearend do this?
09-24-2007, 11:56 PM
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Suspension Experts - Why does the rearend do this? This ended up being a 2.5 60'. In the vid, you can see the rear hit the tires hard and then they hop back up and break loose.
28" MT Streets at 18 PSI, QA1's with the fronts at 1 and the rears at 6. Ran a 1.56 the same night with a bog launch. Thinking about going to a pure slick to see if that will fix it.
http://www.fquick.com/videos/Wheel_Hop/3249
28" MT Streets at 18 PSI, QA1's with the fronts at 1 and the rears at 6. Ran a 1.56 the same night with a bog launch. Thinking about going to a pure slick to see if that will fix it.
http://www.fquick.com/videos/Wheel_Hop/3249
09-25-2007, 01:37 PM
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what all suspension is exactly done? have you played with the rear shocks at all? almost looked like the rears weren't stiff enough, above posted definately has it with no weight transfer
09-25-2007, 07:42 PM
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I need to change that pic in my sig. I took that right after I put the QA1's on just cuz it looked cool. Then I raised the front end up to where it should be.
Even tho it looks like it didn't hook at all, when I look at the vid in slow mo, I can see the rear wheel go down a couple of inches. Then, when the tires hit, it comes back up, goes down one more time, and then blows the tires off.
As for suspension - Spohn tunnel mount adj TA, (-2 on the pinion), UMI adj LCA's with relo brackets, (bottom hole), BMR adj panhard, Spohn drag rear sway bar, 275# springs, front sway removed and a 9 inch with 4.10's. SA QA1's with "R" series on the front.
I need to figure out why the rearend hops back up into the car on high rev launches
Here's a vid of the same night, same setup, and a 4.5k launch as opposed to 5.5k
http://www.fquick.com/videos/Launch/3241
Even tho it looks like it didn't hook at all, when I look at the vid in slow mo, I can see the rear wheel go down a couple of inches. Then, when the tires hit, it comes back up, goes down one more time, and then blows the tires off.
As for suspension - Spohn tunnel mount adj TA, (-2 on the pinion), UMI adj LCA's with relo brackets, (bottom hole), BMR adj panhard, Spohn drag rear sway bar, 275# springs, front sway removed and a 9 inch with 4.10's. SA QA1's with "R" series on the front.
I need to figure out why the rearend hops back up into the car on high rev launches
Here's a vid of the same night, same setup, and a 4.5k launch as opposed to 5.5k
http://www.fquick.com/videos/Launch/3241
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09-25-2007, 10:24 PM
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did you forget to put the rear shocks in ? If not try some LCA brackets ? How about rear springs ?
Originally Posted by chuckyt1
This ended up being a 2.5 60'. In the vid, you can see the rear hit the tires hard and then they hop back up and break loose.
28" MT Streets at 18 PSI, QA1's with the fronts at 1 and the rears at 6. Ran a 1.56 the same night with a bog launch. Thinking about going to a pure slick to see if that will fix it.
http://www.fquick.com/videos/Wheel_Hop/3249
28" MT Streets at 18 PSI, QA1's with the fronts at 1 and the rears at 6. Ran a 1.56 the same night with a bog launch. Thinking about going to a pure slick to see if that will fix it.
http://www.fquick.com/videos/Wheel_Hop/3249
Last edited by LS1curious; 09-25-2007 at 10:48 PM.
09-25-2007, 10:49 PM
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Originally Posted by LS1curious
did you forget to put the rear shocks in ? If not try some LCA brackets
09-25-2007, 10:50 PM
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ok you neeed to quit trying to rev up while dumping clutch....looks like you in the right area for 4500 or so...id try holding it at around 5k and slip the clutch quickly and then leaning into the gas...guy with the worlds fastest stock z06 has a big writeup on how to launch a stick
09-25-2007, 11:05 PM
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Originally Posted by daniel6718
Still want to know why that rear end jumps back up. If I could launch at a little higher rpm, and keep the rear end planted, I could get that 60' down to the low 1.5's or high 1.4's.
09-26-2007, 08:26 AM
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Originally Posted by tektrans
You have no weight transfer whatsoever. Start w/ the stickier tire and from looking at the pic in your sig the front of your car is too low.
+1. Car has no added load to the rear tires. To the OP, I assume the sway if off the car right? Just making sure. -Mark
09-26-2007, 10:02 AM
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09-26-2007, 11:30 AM
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Hey John,
28" MT Streets at 18 PSI, QA1's with the fronts at 1 and the rears at 6. Ran a 1.56 the same night with a bog launch. The 1.56 was the best so far. It'll do 1.6's all night long.
I was going to go tonight, and work on it, but it looks like a Harley Shootout. Might be crowded..
Chuck
Originally Posted by chuckyt1
SA QA1's with "R" series on the front.
Originally Posted by chuckyt1
28" MT Streets at 18 PSI, QA1's with the fronts at 1 and the rears at 6. Ran a 1.56 the same night with a bog launch.
I was going to go tonight, and work on it, but it looks like a Harley Shootout. Might be crowded..
Chuck