Project Hellraiser 3

Page 29


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Final Specs

(will fill in the blanks as I go)

Highest point on the roof - 81" (same as the old buggy)

Belly to Ground - 24.38" - ( 4" more than the previous buggy)

Wheelbase - 112.5"  (Previous 4 seater was 111

Front Up-travel - 7" (3 more than the old buggy)

Rear Up-travel - 8" (3 more than the old buggy)

Weight: 4155lbs

CAD vs. Reality

Now that the build is done and the buggy has a weekend under it's tires it's time to wrap up the build portion of this project. There will definitely be more updates as I ran out of time for all of my wish list items and further usage will reveal new things to tweak.  As it sits my to-do list is fairly short:

The need for a limit strap on the front axle is really the only unforeseen design issue I missed during the build and stems from the way my shifter cable has to cross under front of the transfer case output on the passenger side.  This routing was not an issue with a fixed carrier bearing driveshaft like my previous chassis used. The two piece driveshaft the new design uses has just enough travel to cause the driveshaft to crush the shifter cable against the transmission cross member when the front axle drops out on the passenger side.  I'll loose a few inches of droop by installing a 18" long limit strap on the passenger side of the axle but it will keep the shifter cable safe.  I still need to research and see if I can come up with a way to loop the cable down and around on the drivers side of the transmission so it is inline with the shift linkage.

After some investigating I found it was fairly simple to re-orient the shifter cable by adding another arm off of the existing shifter linkage.  By maintaining the same distance from the pivot point I was able to get the correct throw required to hit the gear spacing.

With the reconfigured shifter linkage it looks like I can get away with a 20" limit strap on the passenger side so I went ahead and put one on each side.


Design wise I think the low mounted rear radiator is my favorite feature.  While can't do any hot weather testing till later, if it works as it has been it has a ton of advantages such as allowing for a much lower hood line (better visibility), sleeker /shorter nose, easier shock mounting, quieter (than when it was up front), it doesn't blow super hot air on the front occupants (maybe not a bad thing in the winter) and I have full access to the front of the engine. Disadvantages - more coolant onboard (weight) as well as more plumbing connections but honestly any of the above advantages easily trumps both negatives.

On a similar note the relation of the axle/winch/front end turned out really nice in that I don't have to do any sort of elaborate winch cable routing to get it connected to the front axle.  The cable just attaches to the axle and can be used with no need to feed the thimble thru the fairlead. I wish I could honestly claimed I planned it that way, the reality is everybody gets lucky sometimes.  In my case I didn't even look at my attachment options till the day before the test run.

I love the storage space and the utility basket out back came in really handy the whole weekend. I will say the interior storage is harder to access with both the panels and the chassis at ride height but a large part of that is I did not put a second foot hole in the side panel for getting into the rear storage which is an easily fixed oversight. The fluid holder came in handy although I need to come up with a funnel holder that will keep it secured and clean.

 I think the dual Magnaflow mufflers are great motivators when tackling an obstacle but they are louder than I'd like for cruising around. I want to invest in an intercom system and am hoping the headphones will cut down on the noise to and from the trail so for now ear plugs as needed on the longer drives.. 

The ORI struts were always a big concern, I saw them in action when they first appeared on the scene many years ago and they did not seem to work too well as far as stability went. Based on what I have read ORI has made great strides since then and I can happily say they exceeded my expectations.  I chose them mainly to simplify the suspension since they eliminate the need for air bumps and sway bars.  I also had read about their supple ride and was pleasantly surprised that even with my initial best guess nitrogen charge they rode much better than my previous coilover suspension. It is hard to describe the feeling but in small to medium rocky sections where the old coilovers felt harsh and bumpy at lower speeds these felt cushy with nearly no jarring impacts.  From what I understand the downside to these struts is their rebound capabilities: they can't handle multiple large whoops without tuning them to the point where you loose your stability. They handled my typical race to the trail driving style with ease and I knew when my wife commented how nice the buggy rode that I had made the right choice.

Off-road I could not tell much of a difference between these and my old tuned coilover/sway bar setup.  The ORI's articulated nicely and quietly (no spring rattles) and handled the off camber stuff with ease.  On the steep climbs the struts were very predictable with no hint of unloading. When I did get to the point of picking a front tire I could hold that position for as long as I wanted. I have run airshocks in the past and they would hold to a point and then unload quickly due to push off.  I had no sense of that with the ORI's.  I think the most telling situation was when I got the buggy sideways on one of the steep climbs on Jigsaw. As the buggy twisted the momentum rolled the body/suspension towards a roll but it never occurred.  With my old coilovers I would have expected more rocking as the shocks bled off the energy of the downside coils that were compressed as the buggy tilted to the left.

Cabin ergonomics are a bulls eye.  Seat position and angle feels perfect and re-doing the dash for more knee clearance at the last minute was a good decision as getting in and out with boots on requires more room than the shoes or sandals I wore when fabricating this thing.  I was worried about the switches being reachable with the harnesses on but I can easily get every switch with the 4 points engaged.  Both front passengers have more leg room than the previous chassis and you can tell after extended riding periods that you don't feel cramped or specific pressure points due to being wedged into a position. I do need more temporary storage for gloves and stuff, the Poly Performance buggy bag on the passenger side was used quite a bit the first trip out and I will be adding some more bags like it shortly. My wife liked the retractable grab handle I built for her on the passenger side and I even had some left over foam grip material which I used to turn the rear shoulder harness posts into grab handles for the rear seat passenger.

To utilize the space under the dash a bit better I picked up one of these Mastercraft storage bags from Polyperformance. I discovered they came with a slick half turn locking latch setup which worked perfect for my flat panel mounting situation.

I transferred the hole pattern onto a sheet of paper, then transferred it to the center pane in the buggy.  After drilling a bunch of 1/8 diameter holes I used rivets to attach the tabs that came with the bag, then attached the bag to the tabs.


Sealing up the passenger compartment paid off in less dust and heat being able to enter not to mention it just looks nicer. The front headers are ceramic coated and the exhaust tubing under the floors is wrapped.  Despite not having any heat reflective materials on the body panels I never felt any engine/transmission heat either of the two days were drove around which compared favorably with the old buggy which would get toasty even on a cold winter day.  The one thing I did stick to the floors was some self adhesive anti-slip mats I found at a local Harbor Freight store.  I was worried they would not stick well but so far so good.  Worst case I will rivet them to the floor panels. Rear visibility is limited but no worse than my previous rig,  you can't really get much with a rear seat in the way anyways. 

I can't believe I forgot the cup holders!  The passenger side Polyperformance buggy bag has an integrated cup holder but I did not have room for a bag on the drivers side or in back by the 3rd seat so I bought some of their "Candola" drink holders.  The drivers was mounted on the side of the shifter tower and the 3rd seat drink holder attached to the tube to the left of the seat. $20 later and problem solved.

Speaking of the 3rd seat, the single panel ATV seat heater made by Wamseats fit the PRP Preemie seat perfectly in the "seat" area (could also have been put in the "back" area).  I wired the control up on a moveable bracket next to the seat so Cameron can select high or low settings as desired.

I can't say much power wise since I didn't really open it up on the roads, was too busy with everything else. Throttle response was real snappy on the trail and there was ample torque to launch the climbs in second despite the larger tires. I did notice the max boost pressure was down a bit despite the smaller pulley, most likely due to the ported blower.  I also don't recall ever seeing any timing pulled when accelerating which bodes well for the modifications I installed.   I was running a can of octane boost just to be safe, I may try a straight tank of 91 and see if the timing remains stable on acceleration.  I do plan on getting the engine/PCM tuned and dyno'd to ensure everything is running as it should.

Fast forward a week later.  Further testing showed I was only making 4, maybe 5 psi of boost at best. Ever since shortly firing up this motor I have heard a hissing which I thought was the intake. Turns out it was one of the vacuum plugs I used to block one of the unused S/C ports which had blown out. This would explain why I wasn't seeing much boost the first test run. I am still only seeing 4, maybe 5 psi with a 3.3" pulley. That seems way to low. I know you drop a little boost from porting but 8psi to 4 is a huge drop. Going to pay more attention to this tomorrow when we are out. If it doesn't look like I am loosing boost somewhere else not sure what else to do. I don't like how this 97 blower has the little tower coming off of it with the two ports. I did not have a new o-ring to put on it when I rebuilt everything and am not convinced this connection is holding up to the pressure. The 98+ blowers eliminated this connection.

I did have problems with the flanges on the new rear axle shafts working their way loose. I ended up turning the body of the hub down slightly so the bolt heads could seat square to the flange without hitting the radius that was left from the initial machining process.  The rub marks are where the bolt still interferes with the hub body when you first start tightening them.  I did not want to turn the entire hub body down since the sealing surface between the hub body and cap was not very big to begin with.

The original battery box was swapped out for this Artec unit that fit my battery better.  The original box was meant for a Group 34 Optima but halfway thru the project when my 2 year old Optima battery died in my Jeep I decided I was done with that brand and the premature failures I had experienced with their batteries the last few years.

With the camshaft break in complete I drained the oil and removed the oil filter from the stock location and installed my remote oil filter and oil accumulator. I managed to find a 1/4 NPT to -6 adapter that had an extra 1/8 NPT port for my low oil pressure light sender (installed on the accumulator outlet).  I am omitting the engine oil cooler for now since the cooling system worked very well on the test runs. I have the option to add a cooler if further hot weather testing shows it is needed.

My solution for onboard air is a dedicated compressor with a 100% duty cycle.  I chose a Viaair 350C for it's compact size and duty cycle.  The new compressor found a home above the ARB compressor.  If my ARB ever fails me on a road trip I'd like to be able to re-configure and use the Viaair as a last resort. To aid in getting tires back up a surge tank is helpful.  After some measuring I found a place for one of Viaair's half gallon tanks under my second cooler.  A larger one would be better but I wanted it tucked away.  To help compensate I am using a 145psi pressure switch so I can charge the tank up pretty good.

I re-used the air chuck I fabricated for my last buggy.  The best spot seemed to be next to the passenger seat since it was about mid chassis and should keep the chuck cleaner.

The switch for the Viaair compressor found a home under the dash.  After some further testing I also found the electronic fan controller was not activating the secondary fan like it was supposed to so I wired the relay trigger for that one to another switch. This will be temporary till I have time to dig into the wiring loom to find the PCM fan trigger wires (there is one high and one low negative trigger coming off the PCM). The bad oil pressure gauge turned out to actually be the gauge which I discovered after I ordered and installed a new sender.  I had a feeling I should have just ordered a completely new gauge.  Not wanting to spring for another $80 Autometer gauge I Picked up a $20 LED gauge from Harbor Freight.  I am actually pretty impressed with it's build quality and I like the larger sweep.

I also forgot the hard stop for the gas pedal so I cut down a 5/8 threaded coupling and welded it to the pedal mounting plate.  To get the position just right I tie wrapped the pedal to the mount, ensured the throttle body was bottomed out on the stops, then welded the hard stop to the plate.

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