I suppose the question should be asked, what do you want the stack to do? If it is to maximize flow, the shape is different than one that is longer for flow reversal purposes. Also, maybe a cowl specific 90 degree version?

How long can you make them, and what color options? For my Carden, I just needed to get the intake outside of the cowl. The TBM one worked perfectly once I stripped the anodizing off.

Basically, whatever length and color you want. Why did you strip the anodizing?

Originally Posted by jack01

How long can you make them, and what color options? For my Carden, I just needed to get the intake outside of the cowl. The TBM one worked perfectly once I stripped the anodizing off.

Yo!...that's the Velocity Stack that I want....can you take it off and ship it to me overnight!...


two questions.....what did stripping the anodize off do?
and, tell me the purpose of connecting the tubing from the carb breather to the VS?




Thanks
R

Originally Posted by ghoffman

Basically, whatever length and color you want. Why did you strip the anodizing?

The bare aluminum looked better against the spinner/cowl than the bright red did....

Originally Posted by RICHMATH

Yo!...that's the Velocity Stack that I want....can you take it off and ship it to me overnight!...


two questions.....what did stripping the anodize off do?
and, tell me the purpose of connecting the tubing from the carb breather to the VS?




Thanks
R

I just thought it looked better on my plane. The tubing makes sure that the carb throat and then diaphragm 'see' the same pressure. The 3W snorkel ones do the same thing.

If you have a printer, here is the DA-170 model. I did a flow simulation, with 100 ft/sec input air velocity, and the carb opening at 1 atmosphere.

170vel (0 min 10 sec)

Originally Posted by jack01

How long can you make them, and what color options? For my Carden, I just needed to get the intake outside of the cowl. The TBM one worked perfectly once I stripped the anodizing off.

that must run like crap with all the turbulence over the opening NG
the stack needs to be in calm air or forced to work , never noticed a big gain or loss with one the 3W's come with a weird stack too

Originally Posted by airboss/oc

that must run like crap with all the turbulence over the opening NG
the stack needs to be in calm air or forced to work , never noticed a big gain or loss with one the 3W's come with a weird stack too

Dead opposite. It runs really well now.

Originally Posted by ghoffman

If you have a printer, here is the DA-170 model. I did a flow simulation, with 100 ft/sec input air velocity, and the carb opening at 1 atmosphere.

170vel on Vimeo

Nice flow simulation!!

I have been looking to get a 3D printer.

I may need to redesign one for DA-120?



Joe

Originally Posted by ghoffman

If you have a printer, here is the DA-170 model. I did a flow simulation, with 100 ft/sec input air velocity, and the carb opening at 1 atmosphere.

170vel on Vimeo

I meant to ask earlier, how much $$ for a stack and how does the abs seem to hold up over time? I saw where you soaked it in gasoline, but I'm curious about sun exposure, vibration, and all.

Originally Posted by sJK13

Nice flow simulation!!

I have been looking to get a 3D printer.

I may need to redesign one for DA-120?


Joe

I have a DA-120 version already printed

Originally Posted by ghoffman

I have a DA-120 version already printed

Could I buy one from you?



Joe

I'll be happy to give the stl file for free.

I have the same question. The earlier ram charging chart assumes air is coming straight into the stack. When the airflow is 90 degrees to the opening, how does the shape of the trumpet affect the pressures within the stack.

I have seen and heard Jack01 's motor run and fly with that dangling velocity stack. That motor runs like a Swiss watch at any speed or attitude. I would not have believed it unless I had not personally witnessed it in flight myself .