Question about front end travel

Bill Harris · 09-18-2009, 11:37 AM

You want as much travel as you can get, and it is usually limited by the shock travel. On an early Mustang you can get some additional suspension travel by notching the frame rail where the upper control arm hits it at full extension. If you take the shocks off and jack up the front end so that the control arms are at their limit you will see where you can cut a couple of notches in the lip on the frame rail that will allow for further drop. Once that is done you want to take full advantage of the travel by fully extending the shock and modifying the upper mount so that the shock is at full extension just as the upper control arm hits the frame rail. I don't like having the suspension hang from the shock. Once that is accomplished you want to lower the front end (trimming coils from the springs) until you only have about an inch of down-travel on the shock when the car is static and level. Trim the upper control arm rubber bumpers accordingly. That will maximize the amount of front end travel on launch.
You want the shock to be really loose on extension. The Calvert shocks are cheap and work like a charm. If you want adjustables I have some Koni SP1A units that I will let go at a reasonable price.
The other thing you should do is minimize resistance in the control arm and spring perch pivots. Get roller-bearing spring perches and low friction control arm bushings. OpenTracker makes some nice stuff for the Mustangs. Get in touch with Alex Denysenko at www.moneymakerracing.com and he will have you dragging your bumper in no time (with an empty wallet and a couple of busted knuckles).

Michael Pliska · 09-19-2009, 10:12 AM

I'm not a stock racer, but I did stay in a Holiday Inn Express a couple weeks ago...

One thing to remember too is the spring rate. You want as low a spring rate as possible, with the necessary spring length to maintain ride height. By using springs in this manner, you end up with more force from the spring (which is lifting the front end) as it reaches the end of the suspension travel. I know, this isn't all that intuitive. With a higher rate spring, the force-displacement graph is steeper (the force changes more with the same displacement), such that the force has dropped off significantly by the time the travel is used up. The lower rate springs are able to impart more energy into lifting the car during their travel.

Regards,

henrys57wagon · 09-19-2009, 05:35 PM

When I rebuilt the front suspensions on our stockers I ground off all the serrations on the stock control arm bushings inserts so there is no binding, better than leaving the bolts loose, Henry.

Harry 6674 · 09-21-2009, 01:51 PM

Long spring with small wire. Try to get the correct spring rather than cutting coils as that increases your spring rate.

09-18-2009, 11:37 AM	#1
Bill Harris Member Join Date: Mar 2002 Location: Ooltewah, TN Posts: 421 Likes: 13 Liked 26 Times in 13 Posts	Re: Question about front end travel You want as much travel as you can get, and it is usually limited by the shock travel. On an early Mustang you can get some additional suspension travel by notching the frame rail where the upper control arm hits it at full extension. If you take the shocks off and jack up the front end so that the control arms are at their limit you will see where you can cut a couple of notches in the lip on the frame rail that will allow for further drop. Once that is done you want to take full advantage of the travel by fully extending the shock and modifying the upper mount so that the shock is at full extension just as the upper control arm hits the frame rail. I don't like having the suspension hang from the shock. Once that is accomplished you want to lower the front end (trimming coils from the springs) until you only have about an inch of down-travel on the shock when the car is static and level. Trim the upper control arm rubber bumpers accordingly. That will maximize the amount of front end travel on launch. You want the shock to be really loose on extension. The Calvert shocks are cheap and work like a charm. If you want adjustables I have some Koni SP1A units that I will let go at a reasonable price. The other thing you should do is minimize resistance in the control arm and spring perch pivots. Get roller-bearing spring perches and low friction control arm bushings. OpenTracker makes some nice stuff for the Mustangs. Get in touch with Alex Denysenko at www.moneymakerracing.com and he will have you dragging your bumper in no time (with an empty wallet and a couple of busted knuckles). __________________ Bill Harris ex 2172 STK ex 2272 S/S

09-19-2009, 10:12 AM	#2
Michael Pliska Member Join Date: Oct 2008 Location: Happy Valley, OR Posts: 260 Likes: 0 Liked 0 Times in 0 Posts	Re: Question about front end travel I'm not a stock racer, but I did stay in a Holiday Inn Express a couple weeks ago... One thing to remember too is the spring rate. You want as low a spring rate as possible, with the necessary spring length to maintain ride height. By using springs in this manner, you end up with more force from the spring (which is lifting the front end) as it reaches the end of the suspension travel. I know, this isn't all that intuitive. With a higher rate spring, the force-displacement graph is steeper (the force changes more with the same displacement), such that the force has dropped off significantly by the time the travel is used up. The lower rate springs are able to impart more energy into lifting the car during their travel. Regards, __________________ Michael Pliska 643 S/G

09-19-2009, 05:35 PM	#3
henrys57wagon Member Join Date: Jan 2009 Location: Carleton Place, On. Canada Posts: 107 Likes: 5 Liked 0 Times in 0 Posts	Re: Question about front end travel When I rebuilt the front suspensions on our stockers I ground off all the serrations on the stock control arm bushings inserts so there is no binding, better than leaving the bolts loose, Henry. __________________ old 1608 stock racer

09-21-2009, 01:51 PM	#4
Harry 6674 Senior Member Join Date: Dec 2006 Posts: 589 Likes: 0 Liked 0 Times in 0 Posts	Re: Question about front end travel Long spring with small wire. Try to get the correct spring rather than cutting coils as that increases your spring rate.