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Post by racket on Jul 10, 2021 23:09:18 GMT -5
Hi Cullen
One other consideration ...................how are you going to sit on it ??
Finding space for the test pilot is often the hardest job to get right , with so many hot surfaces it can be difficult :-(
Cheers John
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Post by turbojet atv on Jul 11, 2021 3:04:33 GMT -5
Hi John,
Where I’ll sit is one thing I’ve thought about. Well at least room between my legs & the engines. I already have leather riding gear from my 4 cylinder bike. Leather gear is required for bikes like mine that exceed 100mph in the 1/8. I’ll be putting some carbon fiber between my legs and the engines as an added protection.
I don’t have a pic of my sitting on the bike but it’s similar to a crouch rocket (Suzuki, Yamaha, Kawasaki, etc). You sit behind the engine & your legs are kinda folded up like a jockey on a race horse. There’s a subframe that’s bolted to the main frame section that would hold the seat.
-Cullen
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Post by turbojet atv on Jul 11, 2021 3:16:51 GMT -5
hey John, Right here is a pic of the subframe I mentioned I use a carbon fiber seat so there’s not much of a seat on this thing. Also, there’s a carbon fiber back rest on the end of the sub frame to make sure I stay positioned on the bike and seat. the seats not comfortable but when run time is short in drag racing I can afford to deal with it for only a minute or two. Plus i save over 3lbs with this seat. A good power to weight ratio will make this thing a beast on the track. -Cullen
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Post by turbojet atv on Jul 12, 2021 23:00:24 GMT -5
Hi guys,
So, silly stupid question of the day. Has anyone tried to use a intercooler to bring P2 charge temps down and increase the engines power? Intercoolers are a tricky thing in the piston world; wether they help the performance or not, but turbines are completely different. Clearly noted in my mind.
I know in my piston engine, my intercooler drops my charge air temps 40° at idle & 10° at 6000rpm. All those temps are below atmospheric temps (ei, 85° would become 45° at idle). Just a rough example, I haven’t studied that data when I’m ever at the track.
Now; insert stupid ideas, what if you could incorporate a small intercooler in a turbine engine and make an additional 20% or more hp because the cold air from the cooler is picking up more fuel and creating more power in the process. Because hot air is thin and moves fuel but not as much fuel as compared to dense cold air.
Surely flametube design would have to accommodate for the increase in dense air but what if? I just added so much complexity to a very simple engine haha. Complexity that shouldn’t be done on something simple. Surely I’m crazy for thinking complex ideas haha.
These are just the thoughts I make up as I’m working on my engines in my shop.
-Cullen
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Post by racket on Jul 13, 2021 1:03:54 GMT -5
NO NO NO , why heat it up in the comp just to cool it down so that you need to burn more fuel to heat it back up again , you'll lose power if you add one because of the pressure drop across the HX
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Post by turbojet atv on Jul 13, 2021 7:58:42 GMT -5
Thanks John for that info 🙏
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Post by turbojet atv on Jul 27, 2021 18:54:48 GMT -5
Hey guys,
It’s been a little bit but I’ve gotten a lot accomplished. I finished both oil tanks. Those were fun to make as I had to weld stainless to aluminum. Those welds turned out ugly but they ended holding up leak free! I finished engine ones construction, I just need to attach a place for the spark plug, fuel injector and the main header. I need to also put a spot for the sensors and a fuel drain in the combustion chamber (since I’m using kero)
This question right here is an ECU question (since i know what fuel System I’m using). Do y’all use a certain ecu or do y’all make it “stupid simple” and wire up switches and gauges to monitor the engine?
I can easy wire my engines as simple as possible or I can use a “fancy” ecu to control and monitor the whole engine thoroughly. The cost effective option is just switches & gauges but the fancy option is a fancy ecu w/ a built in dash.
-Cullen
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Post by racket on Jul 27, 2021 19:24:57 GMT -5
Hi Cullen "KISS" , always best for initial build , can get sophisticated latter on
Cheers John
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Post by turbojet atv on Jul 27, 2021 23:44:11 GMT -5
Hi John,
So for just at this point in time. I can use simple gauges and switches and then later on upgrade a smarter system? Sounds easy, very easy, I can do that.
The ecu I want to use after I get the engines running and all the kinks/wrinkles ironed out is a fancy ecu with a built in dash. The dash shows (in a regular car): rpm, oil, fuel, voltage, tps & boost. The dash is configurable so I could arrange it to show everything I need and take away stuff I don’t need to see. It has all the ins/outs I’d need to monitor/control the whole bike/engine combo.
-Cullen.
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ausjet
Veteran Member
Joined: May 2013
Posts: 133
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Post by ausjet on Jul 28, 2021 2:33:55 GMT -5
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Post by turbojet atv on Jul 28, 2021 10:26:31 GMT -5
Hi ausjet,
Both of those ECU setups are nicely done. I like how they both made & wired them up. I’ve got the skills to wire up a basic setup or a complex setup. I’ve got a base layout already drawn up for the fuse & relay placement. So I can go either route.
With a high end ecu, it comes with a “blank” wiring harness for you to make it how you want for custom projects. Now, I’d probably need 2 ECUs for each engine. Just so I can accurately read how each engine is running. I don’t want a single unit to misread any information between the two engines.
A basic switch/gauge set up I’ll have to do the same so it’s no big deal to make a complex wiring harness. My 4 cylinder has a more complex wiring harness than this thing will have. My 4cyl has injector & spark drivers/exciters and a ton of sensors. So wiring is not a big hard deal for me to take on.
-Cullen.
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Post by wannabebuilderuk on Jul 28, 2021 18:15:24 GMT -5
Those were fun to make as I had to weld stainless to aluminum. Those welds turned out ugly but they ended holding up leak free! What exactly do you mean by this as it is not possible to weld ali to ss unless you use a special transition piece of other special methods?
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Post by turbojet atv on Jul 29, 2021 4:37:36 GMT -5
Those were fun to make as I had to weld stainless to aluminum. Those welds turned out ugly but they ended holding up leak free! What exactly do you mean by this as it is not possible to weld ali to ss unless you use a special transition piece of other special methods? That was an accident on my part. I had no idea it was aluminum until I laid down my first few tack welds. I was confused why it welded so poorly so I checked my cfm on my regular then put another tack down. That when I realized it was aluminum. I was using 75/25 argon/co2 with my mig welder with I welded up my engine. This is one of my oil tanks. The fill cap on the left was the aluminum part, the bung on the right is regular SS. I pretty much just “burst pulled” the trigger to get it to “look” decent on the fill cap. I need to clean it up with a grinder but it didn’t leak when I tested it out so I’m not sure how I did it. -Cullen
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Post by wannabebuilderuk on Jul 29, 2021 13:46:08 GMT -5
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Post by turbojet atv on Jul 29, 2021 15:03:59 GMT -5
I can’t remember what wire I used off the top of my head. I did test out the welds with a hammer and screw driver. I threaded the cap on, put the rubber end of the screw driver on the fill cap and hit it with a hammer. I hit it pretty hard and it didn’t budge or crack.
I just remembered, I welded both side of it so I might’ve just made a good strong lip for it. It might not be a good strong bond but so far it survived a hammer test. I’ll look into those options you sent Incase this cap fails.
-Cullen
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