It's never really finished.
Previous Page

I have been enjoying driving buggy
and not having to do fabrication every weekend but there are still some small
tasks that I need to finish up. As shown above I am mocking up some
fenders for the rig to better protect some of the wiring and air cleaner from
the elements. Still not 100% sure on the final shape of the panels but
this setup is the front runner.


Another little project I completed was getting the
passenger OS (Oh sh!#!) handle mounted. I no longer had a 1" round tube to
attach the handle to on the dash so I welded a pair of tabs to a piece of
1" tubing and attached it to the firewall tubing.



I bought 2 air bumps for the front
of Project
Hellraiser to try them out and see what kind of difference they would
make. I was worried the ride quality would be compromised since I was
adding in another dampener but my concerns were unfounded. The addition of
the air bumps to the front suspension really smoothed out the bumps so the only
jarring hits you could feel when driving at speed down dirt roads were the rear
polyurethane bump stops when they bottomed out. It was time to get rid of the old
polyurethane bump
stops. This little project highlights how handy a plasma cutter can be. With surgical precision I was able to cut out the old bump stop mount
and at the same time carve a pocket for the new air bump can while saving the
original gusseting.

The new air bump in
place. These are the same as the front, Fox 2.0" x 4"
travel. The only issue I encountered was when I went to install the air
bump into the can, I could only get the air bump about 3/4 of the way into the
can before it stopped solid. I tried a little coaxing with a hammer and then
dropping the rig on the air bump to push it to it's seated position to no avail.
The final solution was to split the can, I made a small cut going from the top
of the can to the tail of the "X" in the logo. The air bumps
slid right into place after that.
After a few runs I determined the
air bumps were still a little too stiff with the default nitrogen pressure so I
lowered the nitrogen charge to 150psi. This change has made the ride a bit
smoother and I no longer notice the bumpstops contacting the bump pads when
driving at slow speeds.

It has been a year and I finally
tried using the lower adjustment hole on the axle bridge. This change lowered the rear upper link approximately 1.5".
In theory this adjustment reduces the rear anti-squat about 30%, lowers the roll center height about 2" and
increases the roll axis 2 degrees, After driving several trails I noticed the
rig climbs better and the little bit of hop I would experience on really
vertical obstacles is gone. Overall I like the change and was surprised I
could notice such a small adjustment. The
specs on the original setup can be seen here.
Update 11-2-06 - I had a few
issues with the motor cutting out at full throttle. The first thought was
a fuel delivery problem but after replacing the 43gph pump with an 80gph pump
the problem remained. A scan of the PCM showed a random cylinder misfire
code. I did a little research and made a list of all the things I could
try to eliminate this code. The first things I tried were a different set
of spark plugs, pulling and cleaning the MAF and adding a ground wire to the
coil pack assembly. One of these things did the trick and the buggy ran really
good for several trips. The last time out I got a slight hesitation and a
backfire when driving at speed to and from the trails, hopefully a one time occurrence.

I have also had all sorts of
transmission related problems. So far they all seem to have been related
to a shoddy rebuild. For starters the transmission chewed up one of the
bands due to the band not having been adjusted properly after the first rebuild.
I had a transmission shop clean out the transmission and replace the bands but
there was still a lot of debris floating around in the system causing some of
the valves to stick when the transmission was cold (note the debris on the
filter shown in the first picture above). I also had some fluid
leakage from the torque converter.

Due to the leakage and the
knowledge that I would most likely never get all the debris out of the torque
converter I went ahead and ordered a new torque convert from Art Carr. This
particular converter is designed specifically for rockcrawling and is designed
to spin up faster, provide more torque multiplication than a typical converter
and should generate less heat. All of these things are possible due to the
converter being custom tailored to my buggies gearing and power output. It took
3 weeks to receive the first converter and unfortunately it would not work with
my motor. I sent my original converter back with the incorrect converter
and waited another 3 weeks before a new unit arrived. Art Carr ended up
using the motor side of my old converter to get the proper pilot for the motor
end but the internals are still their custom formula.
For reference the tear down
to get the transmission disconnected from the motor takes about 6 hours and
consists of pulling most of the interior out, removing the seats, floors, lower
belly pan, both drive shafts, transfer case, battery and a few other things I am
forgetting. I was able to roll the transmission over as it sat on the
lower link cross member so it did not have to be pulled from the vehicle.
I installed a new filter and then sealed up the transmission pan with some right
stuff sealant and a new gasket.
After a few runs with the new converter installed I feel some
differences compared to the original torque converter. First, the rig is
easier to hold at a stop when in high and low range. Part of that is due to a
higher stall speed, we aimed for 2500rpms with this converter and I have no idea
what the original was. Second, the transmission temperatures stay a bit
cooler than before. I could easily get the temperatures up to 240+ deg
with some spirited driving but now they hang closer to 220 deg. Third, the
engine does feel like it has more torque. I notice this effect the most
when crawling. Lastly the motor definitely feels like it spools up faster from a
dead stop. There was a slight lag before which feels like it is nearly
gone when attempting steep waterfalls.
Next
Page