Tuesday, November 3, 2020

Project Warthog: Air flow and losing weight

The first weekend in October was the Uncertain Rally for South-Central District Sidecar Association members and the Texas Ural riders on Caddo Lake. That's in northeast Texas, near Jefferson.

Why Uncertain? Well, that's the name of the small fishing community on Caddo Lake. Seems they could not decide on a name when filing the incorporation papers with the state. So the clerk penciled in uncertain, telling them they could come back later once they decide on a name. No one came back later.

Riding the 260 miles from Cypress to Uncertain on the Warthog was sort of a shakedown run for the rig. The first long distance ride, time to see what further work is needed before tackling Alaska next year...

With over 49 sidecar rigs is attendance, we created quite the spectacle as we rode into Jefferson for lunch. 

Returning home, decided that the rig would run better and maybe even more fuel efficient if I opened up the breathing. The two big heavy OEM mufflers were removed earlier, replaced by one shorter lighter aftermarket exhaust to accommodate the sidecamper. But the air intake is still stock. Ideally one tries to balance the air intake with the exhaust output, creating a more even flow,  more efficiency, better gas mileage. This factory air intake was restricting air flow putting it out of balance with the now easy flow exhaust. 

As seen in this photo from when I bought the bike, under that big shiny chrome Bearclaw resides the air duct to the fuel injectors. That needs to be removed to open up the breathing.

With the Bearclaw removed, one can easily spot the white plastic radiator overflow tank and the grey air duct under the left side of the main gas tank.

After doing some research, ordered a RamAir intake from the UK. Is only natural for these specialty parts to come from the UK, home of Triumph Motorcycles. The RamAir mounts directly on top of the fuel injector intakes, eliminating a lot of factory air ductwork and OEM filter under the gas tank and the seat.

RamAir was installed, but now that OEM plastic radiator overflow tank.... ugly. Has to go. 
Plus it's blocking air flow to the new filter.

Did not want the new foam air filter to be totally exposed to the weather but when I reinstalled the Bearclaw it compressed the foam filter. Surgery was needed, a cut-off grinder was called in. 

A nip-n-tuck here and there...

This looks better to my eye. Have not decided yet to paint it or leave as is. 
Kind of scruffy... that fits with this beasts' branding: Warthog.

See that slender chrome cylinder on the lower left? That's the new radiator overflow tank. 

Again scouring the internet, found an article on replacing the factory overflow tank with one of these chrome tubes. Chrome is never my first choice but was not offered in black. Not too bad to install either. Though refilling with antifreeze and getting all the air bubbles out was a trick.

So what did I accomplish with all of this? Well, the following parts were removed from the bike, shortening the air route from the intake under the seat to the filter to the injector's by about 30+ inches, plus freed up space under the gas tank for the auxiliary fuel line to enter the main tank without worry of binding the line. We lost some weight, not much though as weight is not as issue on the Warthog.
Hopefully with a more balanced air flow fuel economy will improve. 

Speaking of weight, with a heavy duty scales, weighed each of the three wheels to determine weight distribution of the rig. I calculate that fully loaded with gear, fluids and me, the rig will weigh 
around 1800 lbs, whoa.... over 3/4's of a ton????   Maybe rename her the Pot Bellied Pig? 
Or Hippo?

 Yet with the horsepower and torque of this engine, she chugs along easily at 75 mph with a low 3600 rpm in fourth gear . It has a fifth gear that doesn't get used much.

******      ******      ******      ******

While wrenching on the bike decided to address another issue that bothered me. Every time I stepped into the sleeping area, the floor of the camper dropped several inches as its only left side support are the rear shocks on the bike. Rear shocks are designed to drop down when weight is added to the bike, like when a rider gets on and in this case when someone enters the camper. It's called sag and is normal.  But it stresses the camper structure.

There is a square channel on both the front and rear of the camper designed for a winch receiver. Since I eliminated the winch (replaced it with a come-along) that spot has been empty.  Hmmm... I still have the receiver bar...

Looking through the parts boxes and bins, found an aluminum scissor jack that would work like a stabilizer if I could attach it to the receiver bar.  Did just that.

It won't ride back there all the time as dirt and grit would get into the mechanism. But it is quick to slip in, cranks down easily, stores in the tool box. Adds an extra minute to the set up procedure, but now the camper is stable when I step in.

In this photo from above, that ugly blue backrest was rescued off an old Goldwing motorcycle.  That was the third of three backrests I tried out on the Warthog. Liked this one best, gave good wide support, but looked terrible. 
 Is ugly a theme with this rig?????

Once again digging through the parts bins and boxes, found a well worn Alaska Buttpad, (those are sheep skin seat covers). Raked it with a brush to liven it up then took it to the upholstery shop that builds my taller seats for me. They whipped up a sheepskin cover for the backrest... styling and profiling... I like these sheep skin pads as they quickly shed water and dirt, dry fast, allow air to circulate in hot weather and keep you warm in cold weather.  Plus water is not going to damage them.

Little by little the Warthog is turning into a solid adventure touring sidecar rig. 

Next weekend is Houston's BMW Club 50th annual rally at Oak Thicket State Park in Fayetteville, Tx. I plan to take the Warthog there for another trial run. Sleeping in it for two nights. 
Will report details on fuel economy later.

Ride safe my friends, safe distance, mask up.



  1. What an amazing adventure in construction it is even before you go on any real adventures! You are a wizard with your mechanical skills!

    1. Thanks VP, yes eventually this rig will leave the garage for the wild unknown... or as the Alaska tourist bureau calls it, the Last Frontier.

  2. Replies
    1. Undoubtedly a beast, handling can be a challenge... maybe I can rent it out to rodeo bull riders to practice hanging on...

  3. Pretty nice setup. I like the rear stabilizer setup, but 1800#! Wow!

    1. Thanks Richard, was a cheap and easy solution to stabilize the camper. Wish all solution were that easy.

      Yes it weight a lot, but that engine makes it moves with ease. Still need to figure gas mileage to see if more extra fuel will be needed for the Coldfoot - Deadhorse run.

  4. I like the changes and no need for any painting, it looks fine! The weight is quite a lot but with that beast of an engine .....

  5. Thanks Dom, have to watch the wrist twisting to keep gas mileage up.. is so easy to give it a quick twist and be scooted back in the seat. What a rush! Costly, but still a rush.


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