Posts by gearhead

    JRI's and most other shocks are filled with oil... If air were used, under compression the oil might diesel... It just has to go over 22:1 That would shoot off your suspension. There have been some unfortunate incidents in China where regular office chair cylinders dieseled, firing the piston/bracket assembly up through the seat killing the user. Most of the office chair shock and adjustable height cylinders use a silicone based oil (non-flammable) as the "valve" attached to the adjustment lever allows outside air in and out. With automotive shocks, the oil can be a non-flammable oil, but that might not have the best damping qualities so don't count on it.

    A big 200+ pound Yost -- I use it to press bearing races into an old Harley transmission. It's big enough that I can put the whole trans in it to gently press them in. It would also come in handy if I had to disassemble/reassemble and align 3-piece Harley flywheels. So far, I haven't had to disassemble a Harley engine to that extent . Yet. Great tapered ball ends on the handle. No worry about pinched fingers.



    You need a P300 NIOSH rated mask for it to be effective. These are frequently used by auto body paint shops and pesticide applicators. Some disposable masks will also filter to 1/3'd micron -- but they can make breathing difficult with strenuous activity. A sneeze can spread a communicable coronavirus for 7 feet... Bus? Train? Plane? Wear a P300 rated mask even if it makes you look like an idiot. Most cheap disposable masks are for protecting other people from your spittle -- not the other way 'round. And, if you sneeze wearing a cheap mask -- it won't do other people much good anyway. At best, cheap masks are just a physical restraint to prevent you from touching your face/mouth often, one of the main ways you get virus infections. The Wuhan "novel" coronavirus has a long 14 day incubation period where people often have no symptoms but can still communicate the disease... A very difficult bug to isolate.

    I'd use a brush to remove the rust, then I'd put a very thin coat of paint over the area -- not an encapsulator which might hide any future corrosion... The Slingshot framework doesn't have any excess structure... If a weld joint is rusting, I'd want to see it right away. Basically, treat it like you would a motorcycle frame.

    If you've got the Pro-Charger Supercharger, you're one of the few who has one... Before changing the exhaust, I'd check with the guy who did the ECU reprogram to see if there's enough fuel to cover the flow change. Most supercharger maps run rich, so there should be enough margin, but I'd check just in case. I'd also check the MAP sensor (typically changed to a 2-bar MAP sensor) to make sure that it's a secure mounting. DDM sells clips to hold these securely in the Slingshot manifold to avoid leaks or detachment.

    There's a nice cool place to the left of the steering column with nice holes through the firewall for wire bundles or tubing.




    The holes in the firewall are behind the instrument cluster. You can easily see the routing path from the engine compartment by placing a flashlight up behind the instrument cluster.


    This location stays nice and cool. If your boost controller has buttons for quick-spooling or boost defeat, you'll be able to reach them from your seat. This is the closest "cool" location to the intake manifold -- so you can keep your vacuum sense line as short as possible.

    There's an unused manifold hose bib covered with a vacuum cap on the stock manifold. These can be used for BOV's or anything needing manifold pressure. I've attached a pic with it circled in red below.


    Just my 2 cents... I'd contact Bob at http://mefiburn.com/slingshottune.asp as he did the tunes for Alpha. You might also check that the MAP sensor (a 2-bar sensor which was adapted to fit in the stock location) is secure and not leaking. DDM sells a plastic bracket which will secure 2-bar map sensors in the Slingshot manifold.


    I've got an Alpha supercharger, and I used Brisk RR14S spark plugs gapped down to 18 thousanths to prevent spark blow-out at high RPMs and boost.

    N2 does have a larger atomic radii as a gas than O2. But, the main reason 100% N2 is used in aircraft tires is the pressure... The loads on these tires are high and the tires are small -- so these tires are often kept close to 200 PSI. Some things will spontaneously combust in 250+ PSI air (at standard room temps) -- hence the use of 100% N2. This is due to the increase in O2 partial pressure. Sometimes this is referred to as "dieseling". Look up "fire piston" and watch videos of people using a simple plunger with a bit of cotton on the end as a lighter. People have been killed by poorly designed or faulty office chairs, where the pneumatic cylinder diesels and shoots the piston rod up through the chair (and whoever happens to be sitting on it). This is the reason a lot of the gas pistons/cylinders use non-combustible silicon oils and are nitrogen charged, to avoid dieseling explosions.


    All that said, if your tire is at 4+ ATM, the partial pressure of O2 in the tire can be equivalent to 100% O2 at standard atmospheric pressure. Hence, the reason air released from a tire smells like rotten eggs -- that O2 has been oxidizing your tire from the inside out. Some of the pressure reduction in a tire is the O2 being consumed by rubber compounds/oils in the tire (oxidation). I've used 100% N2 in my tires for decades. Science? I'm an engineer and a pilot.

    There are safety equipment choices -- and then there are insurance choices... If anyone were to take a ride with me in my Slingshot, they'd probably be the most insured they've ever been... I've got a $4M policy. For good reason. Out here in Kalifornia, most of the Hospital ER's have been closed (guess why). An acquaintance of mine had a solo accident on a bicycle in Irvine/Costa Mesa and he had to get med-evac'd out in a damned helicopter. That short copter ride set him back $10K+ and that's before the doctors even got started... An accident at higher speeds in a Slingshot or car involving multiple people -- the costs can get staggering quickly. Not to mention that many cities like Huntington Beach charge a hefty fee for accidents in their city, to cover the costs of their first-responders.

    I've used a HANS device, along with 5-point restraints... This is probably OK if you're on a racetrack -- where you're not going through intersections... A HANS device prevents you from swiveling your head to check cross-traffic. And you can forget about leaning out and taking a quick glance at what's behind you. I tried using a mirror strapped to the wrist of my left hand -- but it was simply too awkward.


    The standard 3-point safety belt on a Slingshot does allow your upper torso to pivot inwards (towards the center console) on high-G deceleration. This will avert neck snaps as your head stays in-line with your upper torso. But it also allows your helmet to smash into the steering wheel. I figure, as long as it's my helmet and not my head it's something I can live with.