Turbo manifold styles- Absurdflow lowmount vs ramhorn, which for maximum power?
What runner length are you aiming for with the designs?
What I'd be looking for is equal length above all else, and the longest runners that can package.
Edit: And... looking for AC compatability. No PS though. Hard mode!
What I'd be looking for is equal length above all else, and the longest runners that can package.
Edit: And... looking for AC compatability. No PS though. Hard mode!

If the last tubes had a nice U in them and the turbo was sitting lower and futher back, I could see a longer tube header working fine with AC. Certainly not in the low mount spot of the Absurdflow setup, but doable.
It's a greddy, and obviously not perfect, but just as an idea. Moved a bit further down and further forward, actually... lots forward without PS would be possible.
Fluid dynamics favors a design with the fewest bends from a drag and loss of impulse energy standpoint. You want very few 90s and no 180s if you want to maximize the effect of energy pulses on the turbine and not slamming into a corner and being dissipated as heat or rebounding. I don't have access to the fluid dynamics programs that some of you were using for intake manifold design, but many of the same principles are applicable. I recall that each 90 creates as much drag as 20 feet of straight pipe of the same diameter. If you must bend, use wide sweeping arcs.
Fluid dynamics favors a design with the fewest bends from a drag and loss of impulse energy standpoint. You want very few 90s and no 180s if you want to maximize the effect of energy pulses on the turbine and not slamming into a corner and being dissipated as heat or rebounding. I don't have access to the fluid dynamics programs that some of you were using for intake manifold design, but many of the same principles are applicable. I recall that each 90 creates as much drag as 20 feet of straight pipe of the same diameter. If you must bend, use wide sweeping arcs.


true. Or in front of the engine sideways like some drag cars do. Anything's possible.
Here is whats on my car.
1-1/4” schedule 40 pipe from head flange to turbo flange the equal lenght runners are 16.6” long
Note the Dyno-plot. Heavy on low and mid rage torque spools a GT3071R quickly not a top end only shape at all.
Definately not AC/PS compatable.
Bob
1-1/4” schedule 40 pipe from head flange to turbo flange the equal lenght runners are 16.6” long
Note the Dyno-plot. Heavy on low and mid rage torque spools a GT3071R quickly not a top end only shape at all.
Definately not AC/PS compatable.
Bob
Last edited by bbundy; Feb 1, 2011 at 01:48 PM.
Things to note the turbo is shifted forward and is mounted very low. If it was centered between the 4 runners the outlet of the compressor would be pointing right at the steering shaft U-joint and wouldnt fit well.
Bob
What size A/R on the 3017 bbundy and who made the manifold?
Also Tim could you possibly replicate that thing. That low end torque is godly. Beat my t2554 by a metric shitton.
Also Tim could you possibly replicate that thing. That low end torque is godly. Beat my t2554 by a metric shitton.
Last edited by shuiend; Feb 1, 2011 at 03:07 PM.
-Wheel: 56.5mm w/ 84 trim
-Housing: 0.64 a/r
Compressor
-Wheel: 71mm w/ 56 trim
-Housing: .50 a/r
Internally wastegated.
I made the manifold myself. It’s lasted almost a year without messing with it now that I switched to Inconel studs. I made it before there were V-bands available.
Bob











