Of course you should start with a limited slip differential. The best deal going is the $450 - $500 conversion offered by my pal Pat at Future Auto .The price depends on your transmission. All you need is a good differential to send him. My buddy Seth handles the orders for Pat. Drop him a line at: SETH PRENTISS
I used 4 separate scales to indepently weigh the wheels of my car,
with me in it. I found that there was a load of 200 pounds more on the left
front wheel than on the right front wheel. This condition would make the right
front tire spin more than the left front.
I unhooked the left front swaybar end
(driver's side), and placed a plywood spacer above the swaybar's rubber bushing,
and re-attached it. When you re-attach it, you must put oversized nuts,
acting as spacers, in between the bottom metal bushing cap, and the control arm
that the bolts screw into. These oversized nuts go around the bolts loosely, and
should be the same thickness as the plywood spacer. They keep the rubber bushing
from being crushed when you tighten the stock bolts. There is only one oversized
spacer nut shown in the diagram, but of course you put one on each
side.
This will make the swaybar lift up on the driver's side, and push down on the
passenger's side. The weight difference from right front tire to
left front tire was 60 lbs less with a 5/8" spacer installed.
This set up helps out quite a bit on the street for "medium" launches with
minimum tire spin. At the track, for HARD launches at full power, I put air in
the ONE air shock, which is mounted on the left rear. This transfers more weight
to the lighter right front tire.
Before I leave the track, the
air comes back out of the air shock for excellent street/road
handling.
This set up, with a decent alignment, was good for 1.8 second 60' launches.
Over the 1998 winter I had taller gearing installed in Slugmobile (went from 3.02 gears to 2.65 gears), and I moved the battery to the passenger's side of the car for better weight distribution.
This set up was good for 1.7second 60' launches.
Below I am posting the results of launches made years ago under the same conditions, at the same time of year, at the same track, on 5 YEAR OLD hard 195/60-15 all season radials.
The blue figures show the results of the sway bar shim and air shock. The
pink figures are the results of having moved the
battery and changed to taller gearing. The super quick launch at the bottom is
the result of practice, although I haven't had the chance to practice as much as
I'd like to.
| DATE | Average of Best 3 runs | Best launch |
| 4-13-96 | 2.25 | 2.23 |
| 4-20-96 | 2.24 | 2.22 |
| 5-16-96 | 2.25 | 2.20 |
| 4-21-99 | 2.14 | 2.13 |
| 10-16-99 | didn't make 3 runs | 2.11 |
| 9-1-01 | practice makes perfect | 1.98 |
I tried fresh 205/60-15 all season radials,
along
with a new launch technique, and I cut a 1.982launch!!!
DO THE MATH, and see how well my car would run on street tires if I was healthy enough to go racing more often... (I've only been to the track 2 times since 1999!)I had to lift on the 1.98 launch, because of a lean condition. Look at the following slips and see for yourself how deep in the 12's I'd be on street tires if I didn't have to lift.
.....
.216 off the 60' time equals .432 off the 1/4mile
...that 13.068 would be MID 12's!
So
far I haven't had the chance to beat my old street tired record of 12.96, but I
will soon!
How does Slug's old 12.96
street tired record compare with other daily drivers running street
radials?? See:
QUICK DAILY
DRIVERS
The taller gearing and battery relocation has
paid big dividends with slicks, too! I NO LONGER need big burnouts
to run low 12's!
| Date | Boost Average | 2 Best launches |
| 7-18-97 | 25.5 | 1.81, 1.80 |
| 7-25-97 | 25 | 1.85, 1.86 |
| 8-15-97 | 25 | 1.84, 1.99 |
| 4-30-99 | 26 | 1.79, 1.78 |
In short, balance the load that the 2
front wheels carry, and select gearing that promotes spin-less launches!