which will cover the build up of one of these chassis.
Estimated Chassis weight - 325 lbs
Guy Paananen's HR3 Chassis
Front mounted radiator.
8.1L, 4L80e & NP205 fit with minor mods to the sub frame.
Decided to put the radiator in back.
My latest design is another 3 seater chassis.
It differs from my older 3 seater design in a few key areas, the
biggest being the rear mounted radiator. With the radiator mounted
in the back the chassis gains a sleeker appearance up front due to a
lower hood line, this affords better front visibility as well as
more potential suspension up travel.
The passenger compartment
is also few inches wider despite the overall width being narrower
due to the elimination of the outer nerf bars. The seating
arrangement places the rear child's seat in the center with entry and
exit via the passenger window area. A mid-sized child seat (or such
as a PRP Pre-teen) should also fit for future expansion. With some
changes to the roof you should be able to get a full sized seat in
back although you will want to modify the C-pillars for side entry.
The slightly larger size is more apparent when comparing this new 3 seater
design to my older 4 seater designs (very similar to the BMP 3 seater).
Ample storage is provided via a basket above the rear mounted fuel cell as well
as the areas to the left and right of the rear seat.
3 Seater overlayed onto the Hellrasier Pickup
Customizing the chassis is very straightforward and I note in the
prints where certain dimensions effect important parameters such as
chassis width, belly height, etc. I also feel this chassis would
make an excellent 2 seater if you want a good go fast chassis with
ample passenger space. Eliminating the rear set and moving the
radiator up provides a ton of room for fluid coolers out back and
the rear storage basket would make a nice platform for a spare tire
Outside of rocker to outside of rocker is 55.62", outside of door bar
to outside of door bar is also 55.62". Belly to highest point on the
roof is 53.62" and length from front bumper to rear most tube is
139". Estimated chassis weight is 300-350lbs depending on bracing.
The wheelbase shown is 110", I'd recommend sticking with 108-115"
As always some of the advantages of my designs include:
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.
As a bonus I will be making available to
purchasers of my plans the .dxf files for the suspension brackets
and other water jet parts I had made (like the rear storage basket).
These can be given to a local laser or water jet cutter so you can
work around the brackets like I did or you can try cutting them by
hand. I just ask that the files only be used by the end user
and not distributed in any other form or used for financial gain. I
will include a link to the files with the chassis blueprints.
Pretty much anything can be made to fit. 4
cylinders are no problem and most 60 degree V6's are actually more
compact than a lot of the inline 4's currently out there (Suzuki
1.3/1.6, Toyota 2.4/2.7l, etc). About the only engines that
would give me pause are 90 degree V8's like a Ford 5.4L or 4.6L
since they are so darn wide. That said It is
easy to make adjustments to the chassis so if you did have a blown
5.4L and wanted it in the chassis you could as long as you were
willing to put up with a wider front end. Inline 6's present
another problem - length. You'd have to stretch the nose of
each chassis a few inches (assuming a front mounted radiator) except
for the BMP 2 seater which was designed with a Jeep 4.0l drive train in
If you go with a rear mounted radiator you should be
able to fit just about anything.
For reference my 3.8L/904/D300 is roughly 54" long (pulleys to
rear output), 28" Tall (oil pan to top of motor) and 22" wide at the valve
Axles: Whatever you
Suspension: The skies the limit. I ran a
dual triangulated 4 link front and
rear utilizing 16" travel ORI struts and provide the numbers to duplicate
this link setup. Wheelbase in the plans is
approximately 110" and with 42" 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.
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
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
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. You can use my buildups to fill in the blanks or to give
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 (10) 20ft sticks of 1.50 x .120
DOM, and (3) 20ft sticks of the following: 1.50 x .120 and 1.00 x .095 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. I will
budget as I work thru my project, it contains the most accurate
lists of costs I have seen yet on what goes into a buggy.
The plans cost $120 which includes all drawings on 11 x 17 paper; shipping is
included in that price to any address in the
I do not offer electronic versions. I accept Zelle as payment, email
email@example.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
I do not accept PayPal for any orders as of