"T" vs. "Y" fitting

Is anyone seeing a possible flow restriction when using a "T" fitting compared to a "Y" fitting? Every single 12v dual feed kit you see uses a "T" fitting for the simplicity of the install. Are we possibly sacrificing flow because of that 90* turn or because of how close it is to the pump is it even an issue? Would like to hear people's thoughts on this.

I think if you are feeding it with 40 psi, the negative aspects are quite small.

WUnderwood said:

I think if you are feeding it with 40 psi, the negative aspects are quite small.

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In our application, I would think things like this can be overlooked until you are trying to squeeze every .01hp out of the truck. I think not eating lunch that day would give better results.

To keep the flow uniform to both pump inlets, a Y or T will suffice provided the T is fed through the middle section. However, the Y will provide less restriction and therefore less pressure drop.

In the instance the OP described, I believe the feed is actually through one of the branches, and the center is an outlet. In this scenario, the fluid will not want to turn 90 degrees and is likely the worst option from a flow restriction standpoint.

I doubt anyone has taken the time to do any testing to see what the resulting ramifications are. Simple fluid calculations will provide insight to what the fluid is doing, and it is possible that this may not affect overall engine performance unless you are already pushing the limits of your supply pump. Beyond the calculations and testing, all that really can be offered is speculation.

Af far as piping restrictions go, a bullheaded tee is the worst option possible. ( bullheaded means feeding through the center inlet ) A wye is far superior to any tee, and contrary to most people's thinking the tee actually becomes worse at higher pressures due to cavitation and turbulence in the downstream piping. Gassers have known this for decades as indicated by the abundance of wye shaped fuel blocks. Fuel rails are the exception due to the volume providing a buffering effect.

Being a pipefitter as a living.
A 90* turn will add 10x the resistance of flow in a piping system.
So a 45* elbow only adds 5x the resistance of flow in a piping system.

You guys do the math, but there really isnt much to think about.

either way a dual feed with a bullheaded tee had got to be better than a single banjo bolt fed Pump...

I looked into running a Y when I did mine, but the tee's are so plentiful and cheap I went for it.

But I do agree that a y will flow much better, but will it actually make a difference on our applications, I doubt it...

tony597fitter said:

Being a pipefitter as a living.
A 90* turn will add 10x the resistance of flow in a piping system.
So a 45* elbow only adds 5x the resistance of flow in a piping system.

You guys do the math, but there really isnt much to think about.

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That might be a good rule of thumb in the business but that isnt quite true. Laminar vs turbulent flow, fluid density, wall roughness, and bend radius all play big rolls. I havent had to do those calculations in a long time, but I'll do some skimming in my old notes and see if I can't find some more info (if it takes me more than 10min I might give up on looking ;-) ).

I still think, however, that this is negligible in this application.

I was thinking about running one of these to dual feed my pump.

JEGS Performance Products 15165 JEGS One-Piece AN to AN Y-Fittings

Earl Y-Fittings

Sniper Motorsports 26008063 Sniper Motorsports AN Adapters

Anyone ever run sniper motorsports fittings? Not to bad of a price.

It's basically just a cheaper version of Aeromotive that will work just as well. I would run at least a -8, 1/2" setup though.

I've decided to scrap both the T and Y dual feed setup and revert back to my original plan of feeding each port with its own pump. No fitting restriction to account for!