Rear Suspension Video - Page 2

Bobby Fazio · 08-10-2013, 08:57 AM

What causes everything to compress on the right rear and not on the left rear? We took out all preload for this weekend and that still didn't prevent it.

Jeff Lee · 08-10-2013, 10:14 AM

All RWD cars with a solid rear axle, as viewed from the rear, the engine twists clockwise and the rear end twists counter clockwise.
A drag car need to keep the left & right drive tire planted equally. Whether by pre-load on a 3 or 4 link, traction bars, air bags, anti-roll bars or springs and shocks is up to you. But "balanced" L/R adjustments can't work due to the nature of the rear axle twist on launch.

FED 387 · 08-10-2013, 10:19 AM

coupla things come to mind here--ya might want to switch springs and or shocks side to side not both at the same time but first say the springs see if it does it then the shocks try the same thing---- have you scaled the car to see how much each corner weighs?? might not weigh the same side to side---looking at the pic of the rearend it appears that the left is planting harder than the left=== but when you look at the 2 pix from the right front it appears that the right is planting more than the left---does the car go straight when it leaves ??

FED 387 · 08-10-2013, 10:22 AM

I meant to say the left spring is extended more than the right not planting the tire as hard--FED387

Tony Curcio · 08-10-2013, 10:40 AM

Having the right side squat and the other rise is commonly seen on Chevelles with a factory four link. This is because the instant center is too low.

In your case, raising the front mount of the ladder bar will bring the instant center up and back. After doing this, you may find that shock adjustments are a lot more effective.

Bobby Fazio · 08-10-2013, 10:52 AM

Can't thank you guys enough for the input! To answer a previous question, yes we have had the car scaled numerous times but it does not seem to do much other than get the car to leave straight. It's kind of difficult to get equal weights on both tires and the ride heights to be similar side to side. It doesn't help with this squat problem nor improve the weight transfer issue but it looks like everyone agrees that I need to raise the ladder bar to move the IC.

Might be SS/LA soon!! This car is worse than a woman!

Hudlow66 · 08-10-2013, 11:49 AM

I believe it's been mentioned before but if you've got room (and rules permit), an anti-roll bar would make a nice addition.

Jeff Lee · 08-10-2013, 12:43 PM

Quote:

Originally Posted by Bobby Fazio

Can't thank you guys enough for the input! To answer a previous question, yes we have had the car scaled numerous times but it does not seem to do much other than get the car to leave straight. It's kind of difficult to get equal weights on both tires and the ride heights to be similar side to side. It doesn't help with this squat problem nor improve the weight transfer issue but it looks like everyone agrees that I need to raise the ladder bar to move the IC.

Might be SS/LA soon!! This car is worse than a woman!

Well, you would be a woman if you put an automatic in it!
And all the principal of suspension tune would apply with a more feminine transmission.
Have you ever looked under Kips Mustang? Very interesting ladder bar arrangement.

Hudlow66 · 08-10-2013, 03:02 PM

*Like* ^^^^

K Stubbs · 08-10-2013, 05:34 PM

You definitely need an Anti Roll bar. This will eliminate the twist and keep one side from doing something different than the other.

08-10-2013, 08:57 AM	#11
Bobby Fazio VIP Member Join Date: Nov 2009 Location: Egg Harbor Township, NJ Posts: 1,464 Likes: 1,416 Liked 4,355 Times in 498 Posts	Re: Rear Suspension Video What causes everything to compress on the right rear and not on the left rear? We took out all preload for this weekend and that still didn't prevent it. Attached Thumbnails __________________ '65 Mustang SS/L & L/SA DriverInterviews.com \| App.DragInsights.com

08-10-2013, 10:14 AM	#12
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 3 Times in 3 Posts	Re: Rear Suspension Video All RWD cars with a solid rear axle, as viewed from the rear, the engine twists clockwise and the rear end twists counter clockwise. A drag car need to keep the left & right drive tire planted equally. Whether by pre-load on a 3 or 4 link, traction bars, air bags, anti-roll bars or springs and shocks is up to you. But "balanced" L/R adjustments can't work due to the nature of the rear axle twist on launch. __________________ Jeff Lee 7494 D/S '70 AMX

08-10-2013, 10:19 AM	#13
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,400 Likes: 482 Liked 320 Times in 172 Posts	Re: Rear Suspension Video coupla things come to mind here--ya might want to switch springs and or shocks side to side not both at the same time but first say the springs see if it does it then the shocks try the same thing---- have you scaled the car to see how much each corner weighs?? might not weigh the same side to side---looking at the pic of the rearend it appears that the left is planting harder than the left=== but when you look at the 2 pix from the right front it appears that the right is planting more than the left---does the car go straight when it leaves ??

08-10-2013, 10:22 AM	#14
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,400 Likes: 482 Liked 320 Times in 172 Posts	Re: Rear Suspension Video I meant to say the left spring is extended more than the right not planting the tire as hard--FED387

08-10-2013, 10:40 AM	#15
Tony Curcio Member Join Date: Mar 2002 Location: West Chester, PA Posts: 271 Likes: 1 Liked 4 Times in 1 Post	Re: Rear Suspension Video Having the right side squat and the other rise is commonly seen on Chevelles with a factory four link. This is because the instant center is too low. In your case, raising the front mount of the ladder bar will bring the instant center up and back. After doing this, you may find that shock adjustments are a lot more effective. __________________ Tony Curcio 1860 STK

08-10-2013, 10:52 AM	#16
Bobby Fazio VIP Member Join Date: Nov 2009 Location: Egg Harbor Township, NJ Posts: 1,464 Likes: 1,416 Liked 4,355 Times in 498 Posts	Re: Rear Suspension Video Can't thank you guys enough for the input! To answer a previous question, yes we have had the car scaled numerous times but it does not seem to do much other than get the car to leave straight. It's kind of difficult to get equal weights on both tires and the ride heights to be similar side to side. It doesn't help with this squat problem nor improve the weight transfer issue but it looks like everyone agrees that I need to raise the ladder bar to move the IC. Might be SS/LA soon!! This car is worse than a woman! __________________ '65 Mustang SS/L & L/SA DriverInterviews.com \| App.DragInsights.com

08-10-2013, 11:49 AM	#17
Hudlow66 Junior Member Join Date: Apr 2011 Location: Spokane Valley, WA Posts: 59 Likes: 0 Liked 0 Times in 0 Posts	Re: Rear Suspension Video I believe it's been mentioned before but if you've got room (and rules permit), an anti-roll bar would make a nice addition. __________________ Phil Hudlow 6678 (S/C, S/G, ET-PRO)

08-10-2013, 03:02 PM	#19
Hudlow66 Junior Member Join Date: Apr 2011 Location: Spokane Valley, WA Posts: 59 Likes: 0 Liked 0 Times in 0 Posts	Re: Rear Suspension Video Like ^^^^ __________________ Phil Hudlow 6678 (S/C, S/G, ET-PRO)

08-10-2013, 05:34 PM	#20
K Stubbs Member Join Date: Aug 2008 Location: Benton, Arkansas Posts: 402 Likes: 0 Liked 20 Times in 3 Posts	Re: Rear Suspension Video You definitely need an Anti Roll bar. This will eliminate the twist and keep one side from doing something different than the other.