shock absorber travel

Shocks, Springs, Brakes, Frame, Body Work, etc

Moderator: Team

Post Reply
chevy art
Pro
Pro
Posts: 430
Joined: Mon Jul 14, 2008 10:56 am
Location:

shock absorber travel

Post by chevy art »

HAVE A SET OF STRANGE COILOVER SHOCKS, SINGLE ADJUSTABLE WITH SPHERICAL ROD ENDS. THEY ARE 12" CLOSED ANDS 17 1/4" OPENED, GIVING ME 5 1/4" OF TRAVEL. I WANT TO USE THEM ON MY 67 NOVA DRAG CAR ALONG WITH CALVERT 2 PIECE MONOLEAF SPRINGS AND THE CAL TRACK TRACTION BARS. I WANT TO SET THE SHOCK RIDE HEIGTH AT 13 1/4, THEREBY GIVING ME 4 FULL INCHES OF EXTENSION. I HAVE 14 INCH SLICKS ON THE CAR AND A 5,0000 STALL AND TRANNY BRAKE. I WILL COME OUT AROUND THE 5,000 RPM MARK. DO YOU THINK THE 4 INCHES OF EXTENSION WILL BE ENOUGH WITH THE SETUP I JUST DESCRIBED. I WORRY THIS WILL NOT BE ENOUGH EXTENSION AND IT WILL UNLOAD THE TIRES AND MAYBE BE UNSAFE. WHAT DO YOU GUYS THINK OF THIS SETUP. ALL SUGGESTIONS WOULD BE APPRECIATED. IS THERE ANY PARTICULAR SHOCK ADJUSTMENT THAT WILL HELP THIS SETUP? THANKS ART
Greenlight
Pro
Pro
Posts: 415
Joined: Wed Feb 16, 2005 10:37 pm
Location:

Re: shock absorber travel

Post by Greenlight »

Four inches will/should be more than enough travel. Ultimately, you don't want to see much separation or compression of the rear suspension to the body during launch. Three inches of shock travel will usually suffice. The other consideration is the shock travel caused by the rear axle rotation (pinion angle change). This will differ based on whether you install the shocks in the front or in the rear of the rear axle, and how far from the axle centerline (fore or aft) they are installed. I would guess that the typical rear axle rotation (pinion angle change) would be around 2 to 4 degrees.

Check out a few YouTube videos of NHRA Stockers (which mostly use Caltracs) and you will note that the rear of the car seldom separate more than about 1 inch.
Project Greenlight
chevy art
Pro
Pro
Posts: 430
Joined: Mon Jul 14, 2008 10:56 am
Location:

Re: shock absorber travel

Post by chevy art »

thanks greenlight. i needed a little re-assurance before using these nice shocks. calvert had told me that his setup onlu allows about 2 degrees up pinion movement, so that part should be OK, and the shocks are mounted just clearing the backbrace on my ford 9 inch rear. any other suggestions now thaT YOU KNOW MY COMPLETE SETUP. ALSO CALVERT SAYS THAT HIS LEAF SPRINGS DONT ALLOW TOO MUCH REAR END UP MOVEMENT, SO HOPEFULLY YOU ARE RIGHT ABOUT ONLY GETTING ABOUT 3 INCHES OF SEPARATION. THANKS AGAIN ART PETERSON IN NY
Post Reply