Hi,
I just wanted to tell all about some of my improvements to the cooling system both H2O and oil and the new fuel system on the RW.
I have managed to gain 3" more MAP by this improvement.
the gist of the idea and I have since validated the improvements by very experienced flight instructors is delete the belt driven fan, it takes about 10HP to drive that fan, thus the power saving.
1- I replace the radiator by a more efficient radiator used in racing.
2- I totally cover the top of the radiator with a shroud which has a bum shape deflector in the middle of it.
    This stops all the hot engine air from being forced through the radiator as in the stock setup, the internal deflector changes the incoming air from 2 x side scops to travelling                      downwards.
3- I fully enclose the bottom of the radiator with another shroud in which I mount 2 x 11" dia electric fans, these fans are controlled by a thermostat mounted in the radiator that turns       the fans on / off as needed. Trials has shown that in the hover the fans cycle on off but once in forward flight the fans remain off as the two side scoops capture enough air to keep       temperatures stable.
4- I also delete the standard oil tank that the coolant runs through with an oil only tank and then I install an air to oil cooler in the bottom of the tub fed air by a NACA scoop, behind    the oil cooler I mount 2 x 5" electric fans that again do the job in the hover and the NACA scoop does the job in forward flight.
5- I also delete the entire fuel system and replace with a TBI, this needs the exec90 carbi manifold which I invert and add a Y manifold to mount the TBI below the fuel tanks so no fuel pumps are needed, the TBI has a fuel mixture adjustment in the cabin (same as in a fixed wing setup) so the engine can be tuned to suit the day temp pressure etc to get the most out of it, I run a fuel mixture gauge which samples the exhaust gasses to display the reading on the instrument in the consol.
6- I also install the air filter in the tup to feed directly into the TBI, (cold air induction)
7- I fit a fuel sump and modify (shorten) the stock RW fuel filter and on off valve this gives me a large fuel sump to test when doing the daily fuel drain test for water.
I also do a lot of other modifications and get made special parts that are hard to find

         

Wow, that is quite the mod there @Graeme Smith , 3" great work! Thanks for sharing it here! What was the weight comparison before/after with fluids?

(12-27-2025, 02:54 AM)Jared Hartzell Wrote: Wow, that is quite the mod there @Graeme Smith , 3" great work! Thanks for sharing it here! What was the weight comparison before/after with fluids?

Never thought to re weigh, but the cooling system changes would be approx no difference, but getting rid of the fuel pumps and the FADEC and all its wiring will be a saving overall

(12-27-2025, 03:14 AM)Graeme Smith Wrote:

(12-27-2025, 02:54 AM)Jared Hartzell Wrote: Wow, that is quite the mod there @Graeme Smith , 3" great work! Thanks for sharing it here! What was the weight comparison before/after with fluids?

Never thought to re weigh, but the cooling system changes would be approx no difference, but getting rid of the fuel pumps and the FADEC and all its wiring will be a saving overall

Really like all your Mods Graeme.  If I was building from scratch, I think I would do this as well.  On my ship, I removed the FADEC's and run a FuelTec computer closed loop Turbo on a Joe Huff modified engine, so mixture is automatically controlled for best performance.  For oil cooling I removed the stock oil cooler from it's location and added a Derale 15840 Hyper Dual-Cool Remote Cooler on the right side.  Living in south Texas, I also added a secondary oil cooler in the belly with a scoop for forward flight as well as a fan.  For water cooling, there is also a secondary water radiator under the copilot's seat with a fan ejecting down.  Plus, the turbo has a radiator for the intercooler up on the aft portion of the mast above the water reservoir with it's own fan.    Lot of stuff that I think if I went with your airflow modifications, It would be better.

(12-27-2025, 01:54 PM)Tim Morris Wrote:

(12-27-2025, 03:14 AM)Graeme Smith Wrote:

(12-27-2025, 02:54 AM)Jared Hartzell Wrote: Wow, that is quite the mod there @Graeme Smith , 3" great work! Thanks for sharing it here! What was the weight comparison before/after with fluids?

Never thought to re weigh, but the cooling system changes would be approx no difference, but getting rid of the fuel pumps and the FADEC and all its wiring will be a saving overall

Really like all your Mods Graeme.  If I was building from scratch, I think I would do this as well.  On my ship, I removed the FADEC's and run a FuelTec computer closed loop Turbo on a Joe Huff modified engine, so mixture is automatically controlled for best performance.  For oil cooling I removed the stock oil cooler from it's location and added a Derale 15840 Hyper Dual-Cool Remote Cooler on the right side.  Living in south Texas, I also added a secondary oil cooler in the belly with a scoop for forward flight as well as a fan.  For water cooling, there is also a secondary water radiator under the copilot's seat with a fan ejecting down.  Plus, the turbo has a radiator for the intercooler up on the aft portion of the mast above the water reservoir with it's own fan.    Lot of stuff that I think if I went with your airflow modifications, It would be better.

(12-28-2025, 01:41 AM)Graeme Smith Wrote:

(12-27-2025, 01:54 PM)Tim Morris Wrote:

(12-27-2025, 03:14 AM)Graeme Smith Wrote:

(12-27-2025, 02:54 AM)Jared Hartzell Wrote: Wow, that is quite the mod there @Graeme Smith , 3" great work! Thanks for sharing it here! What was the weight comparison before/after with fluids?

Never thought to re weigh, but the cooling system changes would be approx no difference, but getting rid of the fuel pumps and the FADEC and all its wiring will be a saving overall

Really like all your Mods Graeme.  If I was building from scratch, I think I would do this as well.  On my ship, I removed the FADEC's and run a FuelTec computer closed loop Turbo on a Joe Huff modified engine, so mixture is automatically controlled for best performance.  For oil cooling I removed the stock oil cooler from it's location and added a Derale 15840 Hyper Dual-Cool Remote Cooler on the right side.  Living in south Texas, I also added a secondary oil cooler in the belly with a scoop for forward flight as well as a fan.  For water cooling, there is also a secondary water radiator under the copilot's seat with a fan ejecting down.  Plus, the turbo has a radiator for the intercooler up on the aft portion of the mast above the water reservoir with it's own fan.    Lot of stuff that I think if I went with your airflow modifications, It would be better.

I will be helping 2 RX buyers, who paid for all the kits but only received groups 1 & 2,with my cooling and fuel systems, so I am seriously thinking about making some more moulds to make the parts easily, if there is interest please let me know. I already have had machined the 51 tooth cog drive set up so I can supply that as well.