Project Hellraiser

Page 13

   
 
 

Year End Update

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The rig has been getting used pretty extensively this fall with no major issues to speak of.  The small issues involve a few panels screws that worked their way loose and a brake caliper bolt I have to tighten after every run.  I also am still getting a hesitation on acceleration which I thought I took care of.  I foresee some more parts swapping to track down the engine miss.  Future repairs include replacing the ARB compressor, after nearly 7 years of service the little unit tends to pop it's circuit breaker if it is on for more than a minute. I'd like to swap it out for a Viair 100% duty cycle compressor if there is enough room.   

Performance wise I am very happy with the rig.  I am down to a short list of obstacles I have yet to drive and feel I am to the point where the tires are holding me back.  The Irok's have proven to be a great all around tire this past 18 months and still have over 60% of their original tread left but they just don't compare to the competition compound tires some of the other guys are running. I see the rigs with the red label Krawlers making the same obstacles using less throttle than I have to which sure looks like it is easier on their rigs.  I experimented with some circle track tire softener on my Irok's in an effort to soften up the rubber to provide more grip.  After about 8 applications over the course of a year I think the softener helped but it only seems to effect the top layer of rubber so after a few runs the extra grip seems to dissipate.  

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The 3.8l motor continues to impress me.  I had a few people tell me early on in my swap that a 4.3 would have been a better choice since they make more torque than the 3.8l but I just don't see it.  This motor pushing tall 42" tires will take a V8 with smaller tires off the line and stay ahead.  I really don't see a 4.3 keeping up but I'll gladly race a built one when I find it. The big advantage seems to be the blower which keeps the motor pulling hard in all the gears. I know Jack told me his 5.0 pulls hard in 1st but not so hard in 2nd.  We did some high speed runs and the 3.8l pulled hard enough that I didn't even go to redline instead opting to shift at about 5k at 1st and 2nd as seen in this video.  Again, no complaints on the power.  

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The speed of the rig actually prompted me to put a second set of 100 watt lights on the nose of the buggy.  At night a single set was not bright enough for the speeds this thing is capable of.

A lot of people ask me how heavy the new motor is and if the weight adversely affected performance. Since the block and heads are cast iron this motor has to weigh at least 450lbs. I admit at first I was concerned about the extra weight but my fears were unfounded.  The rig easily does stuff I had to hammer the old rig to do thanks to the hp and torque. If anything the rig feels more balanced which is mostly due to being able to move the motor and drive train further back into the chassis. If I ever did want to drop some more weight I noticed ZZperformance is coming out with a set of aluminum heads for this motor.

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I have now fully adjusted to the automatic transmission.  Since it is manually shifted I still get to row thru the gears which was the most enjoyable part of the 5 speed except now I don't have to mess with a clutch and the shifts are instant. I modified the shifter by cutting the gate between neutral and 1st gear.  This allows me to go from either 1st or 2nd gear straight to reverse in the event the buggy starts to go over backwards. 

One small chassis change I need to make which will help with smoother throttle modulation is adding a foot rest for my left foot. There are times where the seat belts are the only thing holding me in and without being able to steady my body against the floor or chassis I get some inadvertent foot movements with the right foot on the gas pedal.

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Another big eye opener was the ability to do front digs.  I knew it was useful for turning but it is even more useful for getting your front end to climb really steep or undercut obstacles. A common scenario is nosing down to a wall (possibly undercut), when your front tires hit the wall the rear tires actually fight the front tires efforts to climb by pushing them into the wall causing the drive train to load up.  Trying the same thing but disengaging the rear end allows the front to climb much easier without all the drive train load caused by the front tires getting mashed into the obstacle.  As shown in this video, I use front wheel drive to get the tires started up the undercut wall, then engage the rear axle as the front tires start climbing.  This tactic is also handy when you get a tire pinched to where the rig won't move.  Disengaging the end that is not pinched and then trying to free the tire has worked quite well in many instances even though it seems counter-intuitive. 

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I recently added a storage shelf over the fuel cell which freed up my second cooler mount by allowing me to tie down my gear bag out back. Future upgrades include replacing the steel upper links with aluminum links and beefing up the front axles. Right now the stock front 35 spline axles and u-joints have shown no signs of wear but I can see the day coming where I push them too far.  I already ordered and received a set of the Longfield 300m u-joints and plan on getting a set of Alloy USA chromoly axles on order soon.  The plan is to swap the beefier axles in and use the stockers for spares. Other than that I plan on getting out as much as possible this wheeling season and maybe someday getting around to finishing up the front fender panels. 

Update - 12-26-06 - Time for some end of the year maintenance.  Going from front to rear I set out to inspect every bolt and component on the buggy in anticipation of a busy couple of weeks just after the start of the new year. I discovered a bent rod end on one of the front upper links.  This is the kind of thing that is much better to fix in the garage then on the trail after the rod end has broken. This particular rod end was 5 years old originating from my first 4 link on my yellow Samurai.

Out back I noticed some cracking on one of the supports on the upper link mount bridge.  This particular section was built by the previous owner but I am pretty sure the cracking is recent. I cleaned up the paint with a wire wheel and then re-welded the joint.

I also received some new, brighter LED modules for X-mas so I set about installing those.

I also got a set of aluminum upper links for X-mas to match the lowers.  These links are 7 lbs lighter than the steel pair they replaced.

I found a replacement for my old ARB compressor, the compressor pictured above was spotted in a Pep Boys ad for $59 ($49 after rebate). It looked familiar so I did a quick search and came up with some really good reviews. Basically they used to sell this compressor with a cig lighter power connector but it blew fuses like crazy. The auto parts stores blew them out for $25 and then they disappeared from the market.  It appears like they are now selling them again but this time with clamps to hook it directly to the battery. Part #MF-1050.

Compressor review.  Zuk tested these things against a $250 Viair and it worked better. You can run them 30 minutes at a time (40 max) before they recommend a cool down so this should work great for the occasional tire fill. I hooked mine up tonight and it seems to move way more air than the old ARB compressor. I plan on plumbing it in so it fills my old compressor tank. I want to be able to swap out two wires and have the old one running again (as a backup if needed).

The new compressor was installed behind my passenger seat.  I have used it for two trips now and it fills the ARB tank in half the time the original compressor took.  I also had to fill a tire on the trail and this compressor made short work of the task. The only real obstacles I had to overcome on the install was dealing with the metric connections.  To get a leak free connection I ended up JB welding a metric to npt adapter into the compressor head, the adapter threaded into the head but I could not get it sealed no matter how far I screwed it in.

The bolt on the caliper that always worked loose also got a closer inspection.  After a once over I noticed the spacer that the caliper rode on was cracked in half.  I turned a new spacer on the lathe at work to replace teh broken one.

The last mod before the end of the year will be a set of sticky competition tires.  I am hoping to have them installed before our clubs annual New Years campout.

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