Hellraiser 4 Chassis Plans





Check out the Project Hellraiser 4

build for my conversion of my 3

 seater to a 4 seater.

Weight as shown is 3800lbs

Hellraiser 4 Chassis's done up as a 2 seaters.

6.0l LS2 w/ Turbo 400 Trans


This is my completed 4 seater variant which I am happy to say works as good if not better than the old 3 seater variant. The biggest difference is the added 3" of wheelbase, which if you have seen my videos you know that wheelbase is a plus on the verticals.  Here is a video of the 4 seater climbing the S&M waterfall and the last fall on Matrix.   If you are worried that a 4 seater can't perform like a 2 seater, don't.


 This model is shown with PRP standard bench seat out back.  Full sized seats could be used by stretching the rear portion further back. As you can see the front portion remains the same as the BMP chassis while the rear gets wider and the roof extended. There is roughly 12" of legroom for the rear seats and they sit up off the floor giving your legs a place to go (instead of sitting on a flat floor).

  This chassis design is only 5 inches longer than my BMP chassis gains most of the passenger room via the wider rear end and a custom gas tank out back which allows the rear seats to have a decent amount of legroom. It looks like there will be ample storage both above the gas tank and below the rear seats. Wheelbase shown above is 111" although shorter is possible as shown below.

Specs:  Outside of rocker to outside of rocker is 58.2", outside of door bar to outside of door bar is 53.6".  Belly to highest point on the roof is 54" and length from front bumper to rear most tube is 138.4". Estimated chassis weight is 300-350lbs depending on bracing.

Advantages of my designs include:

The ability to pull the transmission and transfer case without pulling the motor (via the lower skid plate).

No bars near your head (unlike many homebuilt chassis designs).

A cockpit that is big enough to keep you from hanging outside of the chassis when seated.

A suspension that works excellent for both crawling and climbing.

Motors - As per the FAQ:

Suzuki: 1.3, 1.6 or 2.0l motor should fit with a Samurai or Sidekick 5 speed and Samurai transfer case.  I used to run a Toyota 5 speed transmission (85 4x4 Pickup) mated to a 1.6 16v motor via an SOS Ringr adapter. A stock Samurai radiator fits perfect up front.

Toyota: 22re (2.2l), 2rz (2.4l), 3.4l, 2rz(2.4l) or 3rz (2.7l) motor found in various Toyota pickups could also be used with a 5 speed transmission and dual Toyota transfer cases. If you run an automatic a 3.4l Toyota V6 should also fit.

Domestic: A Pontiac 3.8l V6, Chevy 4.3l V6, Chevy 4.8/5.3/5.7/6.0/LT1, Ford 5.0l to name a few. An automatic transmission is preferred as it makes the drive train length shorter and allows you to push the motor back to leave enough room up front for a good sized radiator. A 26 x 19" double pass Ron Davis radiator fits if you lay it back at an angle (this particular radiator keeps my supercharged 3.8l motor plenty cool). A manual transmission will work but wheelbase will need to be 102" or above.

Larger motors have been installed by other builders (including big blocks).  Really if you think about it the difference between a 4.3 V6 and 5.3 V8 is only a few inches in length and the chassis is very easy to modify if you want to make the fenders a bit wider to accommodate whatever it is you want to use to power this chassis.

Pictures and build up notes for a Supercharged 3.8l install can be seen here.

Axles: I am running Toyota truck axles from an 85 4x4.  Pretty much any solid axle can be made to fit.  I have personally run 1985 Toyota truck axles as well as narrowed D60's (60" wms to wms) under this chassis.

Suspension: The skies the limit. I ran a dual triangulated 4 link front and rear utilizing 2.0" coilovers and provide the numbers to duplicate this link setup. Wheelbase in the plans is approximately 111" and with 39" tires the belly is approximately 23" above the ground. The wheelbase and belly clearance can be changed to suit your needs. For further suspension information see the FAQ.

Steering: Full hydraulic via a double ended steering ram.  A single ended steering ram could be used but you will need to modify the front link setup.

Tires:  With the Toyota axles and 2" backspacing on the rims up to a 39" tire should fit fine.  A narrow 42" tire also fits. With full width axles a tire larger than 42" in diameter could be used.

The plans you will receive are laser printed on 11 x 17 sized sheets of paper.  I have broken down the entire chassis into stages and include a suggested order of assembly guide to help you build your chassis.  The guide lists how I would tackle the chassis build and notes when you should mock up major systems and suggests other systems that need to be considered at that stage.

Things to keep in mind:

1. I make no warranties of any kind for the performance or durability of this chassis.  You are buying plans only. If you chose to fabricate something using these plans you assume all risk in the fabrication and operation of the project.

2.  You will need a basic knowledge of tube bending and access to a tube bender, welder, chop saw, etc. Access to a plasma cutter or cutting torch would be very helpful but is not required.  The chassis is designed around 1 5/8 tubing with a bend radius of 4.5"***.  Larger tubing  or bend radii could be used with some adjustments to the initial tube lengths.  there are no bends over 90 degrees.

*** It has been brought to my attention that the 4.5" radius die is no longer available from JD2. See the FAQ here for information on compensating for different die sizes. It is actually a very quick and easy adjustment to accommodate larger bend radius dies.

3.  The plans are meant to be a guide.  Since there is no way to get the bends to match the plans %100 expect to have to make small adjustments.  The plans do have suggested cut lengths and start points for the bends.  It will be your responsibility to cope the tube ends.  In spots where there are straight braces I usually provide a recommended tube size and length, however in most cases your best bet is to measure the distance between the nodes to determine the actual cut length.

4.  The plans only cover the dimensions of the basic chassis.  This means gussets, mounting tabs, suspension related mounts on the axles, body panels, component mounts, and all interior mounting tubing, etc are your responsibility. 

5.  I will include a recommended list of material for the basic chassis.  You may want to purchase additional material if you would like to leave extra material on the cuts or if you feel you may have to re-do a section of tubing.

For costing purposes I used approximately (8) 20ft sticks of 1.625 x .120 DOM, and (2) 20ft sticks of the following: 1.50 x .095 and 1.50 x .120 for the main chassis bracing. To save money you can get away with using HREW for any piece of tubing that does not contact rocks.

The plans cost $120 which includes all drawings on 11 x 17 paper; shipping is included in that price to any address in the Continental US.  I do not offer electronic versions. I accept Zelle as payment, email sales@azrockcrawler.com for payment information. I used to accept PayPal but as of 12/9/2020 I am no longer accepting payment from that "service".

All packages ship USPS, please allow 1-2 weeks for domestic orders although actual ship times are usually much faster.

International customers please read -

As of 10-30-2020 I will only ship to the US. I apologize for the inconvenience but I no longer have any faith in the postal services of other countries.

  Answers to the most common questions -

I do not offer an electronic version of the plans.

I do not accept PayPal for any orders as of 12-9-2020