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guy posted nb1 head flow bench results within the last year.
....somewhere on this forum
bust your your search skillz. I bet 2.25 would likely handle most if not all that anyone ever needs on a Miata. assuming the bends are not terrible and core flows okayish
guy posted nb1 head flow bench results within the last year.
....somewhere on this forum
bust your your search skillz. I bet 2.25 would likely handle most if not all that anyone ever needs on a Miata. assuming the bends are not terrible and core flows okayish
Core is a precision 550 (600? dunno). I have 2" piping from another project. And I have a pile of 2.5" piping I got for cheap. So its going to either be 2" or 2.5". Just need to do math. Oh well.
I will probably make 2' and 2.5". Swap out on the dyno and see if i get gainz.
On mine I feel like we did 2" between the turbo and intercooler and 2.5" between the intercooler and the throttle body, but stepped up to 2.75" in the vertical stretch after the sway bar to accommodate a 2.75" bend into the Skunk2 throttle body. My logic was velocity with hot air coming out of the turbo, and minimal restriction after the intercooler.
Some guys tend to be concerned with "too much volume" in the system causing lag, but I think some guys may not be members of the glorious EFR master race
If you find a nicer tight radius 2.75" silicone 90° for the throttle transition, please let me know. I've never liked mine as its still too long, and I had to butcher it to make it fit. I hid my sins under the t-bolt clamps.
Ok math. Instead of calculating what the engine can flow I'm going to go with what the turbo can flow. It won't give me an exact value. But it will give me a max flow at a boost level.
Soviet did 400whp at ~25psi of boost.
Pressure Ratio:
(25 + 14.7)/14.7 = 2.7
Looking at the 6758 compressor map at a pressure ratio of 1.7 the compressor can flow anywhere between .017kg/s and .40kg/s.
That is 22.4 lb/min and 53 lb/minn. So at 25psi I will be somewhere in that range.
General rule of thumb is like ~10lb/min to hp. So around 25psi, 400hp it should be in the ~40 lb/min range.
So 2" piping should be reasonable at least up to 25psi and 400hpish.
Worst (best?) case (compressor flowing the most for that pressure ratio) 2" will top out at 26.5psi. I doubt I will be flowing that much.
2" it is. It might choke up trying to hit 400. But I think it will be fine for 350whp. Which is what I'm probably going to try and hit the first time out.
The question is not if I can get away with it, but can I find it and the needed couplers for a reasonable price. Snaking the piping from the super past the PS/AC is gonna be the fun part and I may end up with 1.5 anyway....
The question is not if I can get away with it, but can I find it and the needed couplers for a reasonable price. Snaking the piping from the super past the PS/AC is gonna be the fun part and I may end up with 1.5 anyway....
Silicone intakes sells 1.5" couplers, I don't see 1.5" aluminum pipe on their site though.
Ok math. Instead of calculating what the engine can flow I'm going to go with what the turbo can flow. It won't give me an exact value. But it will give me a max flow at a boost level.
Soviet did 400whp at ~25psi of boost.
Pressure Ratio:
(25 + 14.7)/14.7 = 2.7
Looking at the 6758 compressor map at a pressure ratio of 1.7 the compressor can flow anywhere between .017kg/s and .40kg/s.
That is 22.4 lb/min and 53 lb/minn. So at 25psi I will be somewhere in that range.
General rule of thumb is like ~10lb/min to hp. So around 25psi, 400hp it should be in the ~40 lb/min range.
So 2" piping should be reasonable at least up to 25psi and 400hpish.
Worst (best?) case (compressor flowing the most for that pressure ratio) 2" will top out at 26.5psi. I doubt I will be flowing that much.
2" it is. It might choke up trying to hit 400. But I think it will be fine for 350whp. Which is what I'm probably going to try and hit the first time out.
01-19-2017, 11:52 AM
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