Project Hellraiser

Page 11

   
 
 

Test Run

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It has been 5 months since I started the motor swap project known as Project Hellraiser and It was finally time for a test run.  After spending the previous day finishing up last minute details I was up bright and early at 4am Sunday morning to load up the buggy. The original body panels fit with a few small modifications to the mounting points, a fresh coat of paint is on the schedule as soon as the monsoon season is over with.

The first test was to see what the motor could do on a clear road.  I was not disappointed, 1st gear flies by really fast and the buggy kicks out the tail end after the 1st to second gear shift.  The blower puts out a solid 5-6 psi moments after the throttle is pushed to the floor. On a really straight road I can use 3rd but at that point you are going scary fast.  I'll have to borrow a gps to see what the actual speed is. To recap, the stock motor is rated at 240hp and 280ft/lbs of torque.  With the modifications I have installed I should be up about 20hp.

Next up was crawling around in 4 low.  The first issue I have is the motor wants to overrun the brakes, especially in reverse.  This problem is really bad right at startup but seems to clear up as the transmission gets warm.  The motor idles up a lot when you initially shift from park to reverse or drive so I think tweaking some of the parameters in the pcm may helps solve some of this issue. 

The articulation tests revealed how close all the clearances are between the front driveshaft and lower link. The shock was an inch away from bottoming out at this point (the air bumps are set to bottom out before the shock when the axle is not articulated). 

About this point my throttle cable had gotten really hard to actuate and started sticking.  It looks like a custom unit that can handle a lot of bends is needed.

Here is a shot showing the passenger side which was left stripped of interior panels so I could keep an eye on the driveshaft while testing.  I was mainly concerned with the driveshaft and front link interferences. You can also see the finished twin stick setup I made.  If you would like to duplicate this setup you can use these detail drawings (in .pdf format).

The final dash layout.  I installed a boost gauge, oil pressure idiot light, transmission temperature gauge and tachometer in the center panel.  Off to the left of the steering wheel is a voltmeter, oil pressure and coolant temperature gauge.  The center consoles has switches for the head lights, rock lights, interior lights, winch enable, winch in/out, ARB, fan override and line lock.

I am running a single line lock that is plumbed into the rear brake lines so I can lock up the rear end when I need to do front digs.

Here's the fix for the sloppy gas pedal.  This is the mount for a billet aluminum gas pedal from Summit Racing.  The bearing surface that the shaft rides on is formed by two small plastic end caps which wallowed out after the first test run. Luckily I was able to find a needle roller bearing in the Mcmaster Carr  catalog that fit inside of the pedal mounting block. After polishing the pedal mounting shaft I was able to slide it into the new bearing and I retained the original plastic bushings to keep dirt out of the inner bearing.  The pedal is now nice and tight and no longer wobbles on the mount.

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Update 8-1-06 - The rig made it thru a complete trail the previous weekend.  I was still experiencing the strange idling issues for the entire trail which made it hard to keep the buggy started.  Despite that I was able to easily crawl most of the obstacles, something I didn't do the last time I ran this particular trail. 

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Oddly enough by the time we finished the trail the idling issues seemed to go away and the transmission started acting like I thought the automatic should.  I could put the transmission in gear and it only took a light touch on the brake pedal to keep the rig from moving.  The only thing I could figure was the PCM had a learning curve and it took a while for it to get used to the load the motor was seeing.

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I did make a small list of things I needed to do, mostly related to easy access storage and the need to gather a few key spare parts.

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