Thursday, June 24, 2010

Mopar Front Suspension Upgrade

TRACK STATSTemperature 72 -76F; barometer 30.05; 0-2 mph crosswind; 45 percent humidtyRUNLaunch RPMShift RPM60’1/4 ET1/4 MPH11500 - Shakedown run58001.9611.94101.07022500 - Stock front end - 18 PSI - 36 total timing58001.72no data no data32500 - Hot Lap58001.71no datano data 42500 - New front end - same tune - 18 PSI58001.64no data no data52500 - Hot Lap58001.66no datano data DIFFERENCE .08

Technical Info

Owner: Moe Keys, Blue Bell, Pennsylvania

Car: 1968 Dodge Coronet 500 Convertible

Engine: .060 over 413

Cam: Comp 504 lift

Intake: M1

Carb: Holley 750 HP

Trans: 727 / 3500 TCI converter

Rear: 4.10 8 ¾

If you spend any amount of time at the track, you generally see engines tweaked to peak performance. Properly tuned and tweaked from carb to timing curve, there are definitely rewards gained in focusing on these areas, but that doesn’t mean you should get “tunnel vision” and forget the rest of the car. Traction is king on the track, so attention is naturally focused on the rear suspension, but how often do you think about the front suspension in relation to elapsed time down the quarter mile?

If you do consider this aspect of the total package, there are several schools of thought, old school, new school and everything in between. The simple fact is that the front suspension has a lot to do with getting your car to clock optimum 60-foot times. For instance, unhooking the sway bar for more suspension travel is one change people make; let’s take a little closer look at theory behind doing that. Why? The bushings that do a good job locating the bar, and hold it in place during cornering, also means that it doesn’t fall down easily when the front end rises during a hit on slicks.

Those bushings create friction; removing that friction by unhooking the bar will aid faster suspension travel. Now imagine that same principle being used for the upper control arms, ball joints, and strut rods. While doing a rebuild, you can clearly see the bind in the strut rods and friction in the bushings of the control arms before your torsion bar is installed – it takes some serious effort to move the front end – it is far from friction free!

There are some tricks that guys have used for years, such as applying a lubricant on the control arm bushings to get them to move easy, or putting a double nut on the lower shock mount (to back off the shock mount to avoid the bind at the lower control arm); some racers prefer selecting junkyard shocks that are shot to help in the transfer. The list goes on and on.

Our test was a simple one. Modern technology has eliminated a lot of the friction points we used to have to work around. While putting one of these front ends together, you can immediately feel the difference. We are talking about the adjustable upper control arms and adjustable strut rods ; coupled with QA1 shocks, we wanted to determine what benefits result with this recipe of parts.

We have to thank Moe Keys for beating up his beautiful ’68 Coronet 500. Moe had just replaced the motor in his convertible and had no idea what it would run. Well, for a mild build, he sure knocked it out of the park! Moe ran mid 11’s right off the bat and for the safety of himself and others, since the droptop had no cage, Moe did a series of 60-foot runs for our timing tests. Since the testing was to see the effect of these parts on the first 60-foot times anyway, the situation worked out very well. Thanks again from Mopar Enthusiast to Moe for thrashing his ride and wrenching this effort; lets get this car out on the track and burn some rubber!

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