Gizmo Questions
After talking with a friend about the gizmo we came up with some other things to ponder...and the Possible shortcomings?
1) The bypass line on the Gizmo does not seem to be thermostat controlled. If so, the coolant that flows through the bypass line, when the Gizmo t-stat is open, does NOT flow thru the coolers.. This takes away from the cooling capacity of the sled...ie the ability to shed heat.
2) The "cold shot" that seems to be the focus of the design still occurs on cold start up after sitting for more than a couple of hours outdoors or on initial start-up in the morning... the Gizmo does not do anything about this.
3) I'm as concerned about the "Hot Shot" that the engine gets which, IMO, may be worsened by the Gizmo.
If you have been sitting for a while, the t-stat in the Gizmo is closed by design. The Gizmo gets it "temp signal" at the thermostat-bulb from the cold coolant that has been chilling in the coolers as reported.... with a very small amount of bypass water around the gizmo.
If someone sits and eats a 15 min lunch... the Gizmo t-stat is closed as reported above... upon start-up, if someone goes for an immediate "rip up the hill", the Gizmo will take some time (who knows what this is during operation) to come up to temp as the coolers are only getting this small amount of coolant through the coolers to blend the temps and get the coolers up to temp.
Well on the rip up the hill, the engine thermo is open... and the bypass is flowing 95% of the coolant Until the thermo in the Gizmo cracks-open.
IMO,in this scenario, the engine temps will skyrocket and cause the ECU to go into protection mode... pulling timing and adding fuel. This could pose a problem on a tough climb or technical sidehill above obstacles if the sled hesitates or looses power in this mode.
This fast ramp up of temps before the Gizmo opens is what I'm calling "hot shot"
You will still need to let the sled warm up to temp with the Gizmo installed which some people seem to forget about.
4) The engines and control systems were designed to work at lower temps...
Going into it blindly saying "it seems to work for me" and that the temp thing does not "seem" to be causing the engine to go into protection mode is not showing the whole picture.
...IMO It would be good to see some track dyno numbers running the gizmo for long times (say 5 minutes) at varying throttle positions with the sled operating above 150 degrees... and at what temps the engines seem to be pulling power or putting the sled into protective mode.
5) On the standard RMK's... Redneck is recommending disconnection the fwd tunnel heat exchanger so the bypass can be hooked into the Gizmo. The stock bulkhead cooler is plumbed so that the bypass flow REMAINS cooled during operation.
It is removed, I assume, because there would be no way to run this cooler in the bypass line with out the "cold shot" from that cooler.
In a Gizmo install into a std RMK, the coolant should be routed through this cooler in series with the other cooler.
5) On the Pro RMK's (compared to the Dragons)... the cooling system is smaller in both surface area and liquid capacity.
Diminishing the flow through the tunnel coolers by the amount of liquid that flows through the Bypass-Line is taking away from an already small cooling sytem that was flow/capacity optimized for the engine....Probably more noticeable on a turbo sled.
We have not really come into the warm season yet. But those coastal riders that I know, in this last 50 degree heat-wave have been seeing, have their bone-stock PRO's temp at 150-170+ on the hardpack trail with scratchers down. Riding next to the same length Dragons at 120-135 degrees with scratchers down.
This has to make you wonder about the cooling capacity of a PRO RMK since the cooling arrangements are identical in the two sleds with the only difference being the size of the coolers (larger on the Dragons) and the holes in the snow flap that keep the valuable snow-spray inside the tunnel and not out the holes.
cheers boys!
