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While I built a Cruzer for speed, if Fast was all I was looking for a Sling TSI would have made a better build. I also wanted a part-time bush plane for the times I want to explore the Northwest off the beaten path. I also wanted to be able to change over quickly so that when I needed to go on a long cross country the change over time could be amortized in time and fuel cost savings for the trip. I am hoping for about a one hour change over to move from one configuration to the other.
So how do you take a plane made to go faster and slow it down? This was my recipe.
1. I added Vortex Generators to all the wing and control surfaces.
2. Ordered custom 4" taller nose gear for clearance.
3. Ordered taller main landing gear springs.
4. Ordered second Nose wheel from Super Duty.
5. Ordered 27.5" Tires and 8" rims from Super Duty. (15 PSI for airports, lower for bush)
6. Ordered new Master Brake Cylinders with intensifiers.
7. Ordered second set of Calipers for dual brakes.
8. Ordered Spacers to allow tires to clear the landing gear.
I just flew with the large tires for the first time last night. The plane looks amazing and the fat tires sure make landing a lot softer even when your screw up and land hard.
I tried with just the single brakes and it is dangerous to have to land short without the dual brakes. Don't even try it. I think both dual brakes and the intensifiers are required for short field operations equipped like this.
I will be reporting over time as I test it but I tell you the plane really changes character when you have to climb up to its level and it sure looks bad-ass!
My next step is connecting the brakes and installing the VG's. I will do some stall test before and after and report the numbers.
I also have information on the build in my blog https://my750cruzer.wordpress.com/
I like the added clearances. Are the main gear spring and the extended nose gear from Zenith (SuperDuty or 801)? What size are those wheels? How many inches taller is the main gear spring?
The nose was custom ordered earlier on when I realized that with flat tire and full stop compression I had 1.5 inches of clearance before prop strike. I wanted much more so I got a +4" tube made by Zenith.
Zenair Canada makes a extra tall tundra gear spring that is also about 4" taller. It is a special order from Zenith as well, but I was luck that they had some in stock.
The front fork and main wheels/tires are what are "stock" for the 750 Super Duty.
The Super Duty tires are 27.5" tall. Not quite as big as the Alaska Bushwheel 31" but less than half the price, last longer and use 8" rims so they clear the brakes without having to buy new axels/hubs.
i have a question regarding your choice of front tire. what is the inside face-to-face dimension of the superduty nose fork?
i am curious because my older generation CH750 STOL fork is a 2-piece 'square' shape and is getting tired, i.e. yielding slightly. since the superduty is still flat topped, i am hoping to gain clearance to run a larger (and wider?) tire. Initially, i would run the existing Carlisle Turf-Glides.
i want to congratulate you on your idaho adventure. sounds like your new set-up is taking you where you want to go - and fast!!
I don't have that information off-hand. You might call Roger and check. I will have to visit the hangar and measure.
Love every bit of this. Well done
Hi Jonathan -
Thank you for sharing the nice work. You also have an excellent blog with detailed information sharing that I really appreciate. Once you have had more time to characterize it, it would be very interesting to know your "speed penalty" from these gargantuan wheels.
Yesterday afternoon I got a chance to give the setup a try and I was getting 92kts at 75% power, compared to 100kts with the small wheels and wheel pants.
The other thing is that at both airports I went to I got off on the first exit. Both were almost always used for landings on the other direction. This beast stops super quick now.
Now that I have had a chance to fly in this setup for a while and play with the prop pitch. I have a setup that works reasonably well to balance out between cruise and climb. At Normal cruiser gross weight (1440) I get better than 1000FPM climb from 600' airport elevation, and cruising long distance at 6500-10500ft altitude I average 100 KTAS with fuel burn ranging from 5 - 5.9 GPH depending on altitude. I lose power higher up, but TAS stays about the same. Once I have managed 104KTAS on 5.7GPH burn for a 3+ hour flight.
I have not had a chance to try it out in hot weather in this configuration, so that might change things. In the end I think with a constant speed prop this would be the perfect compromise for me of range, efficiency, fun and back-country capability.