drive
09-20-18, 02:22 PM
#1
Racing Rotary Since 1983
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drive
2018 has been a fun year so far as i have been doing road tuning on various turbos and it sort of lines up with the drift of this thread.
i worked w my SXE 62 using both the .91 and 1.0. once finished, i swapped in my EFR9180 external (is there anything else?) wastegated 1.05.
let's do a bit of comparison w post one:
if i properly transposed newton meters and the removed 15% considering it is crank power, O P's motor made approx 480 at 6700 and 366 at 7675 at 23 psi.
the key on the data is higher RPM significant power fall off. this was recognized by the OP as it is the title of the thread.
i made about 120 more hp at the same rpm so there is a significant problem at higher RPM. 488 rwhp at 7649 rpm using the same SXE 62 .91, 20.5 psi, 93 pump and 1000 CC of meth as AI.
OP's problem is so large that it is flow related.
my bet is the turbo manifold.
while nicely crafted, physics rules.
the 13BREW exhaust port is 3.04 sq inches and the I D of the primary runner is 2.07 sq inches! a brick wall as RPM increases. i can only imagine how high the EGTs and back pressure is with 32% less runner area.
after switching to the 1.0 hotside my EGTs dropped 40 degrees and i made 510 at 20.8 psi. this was right on the money as to my expectations. there is 550 available at 25 psi. the next SXE 62 test will be w the 80 mm turbine wheel.
i then switched to the EFR9180 1.05. EGTs dropped approx 70 F and backpressure about 20 points. 570 at 24.9/7722 RPM AFRs in mid nines. this was my first pull in the 25 area and i wanted to start out rich, i will no doubt tune about one point leaner.
should you have an interest in manifold/system design i invite you to read pages 85-139 of my 200 page FD comments located on Google Drive...
https://docs.google.com/document/d/1...dpatiR-rk/edit
https://docs.google.com/document/d/1...dpatiR-rk/edit
i worked w my SXE 62 using both the .91 and 1.0. once finished, i swapped in my EFR9180 external (is there anything else?) wastegated 1.05.
let's do a bit of comparison w post one:
if i properly transposed newton meters and the removed 15% considering it is crank power, O P's motor made approx 480 at 6700 and 366 at 7675 at 23 psi.
the key on the data is higher RPM significant power fall off. this was recognized by the OP as it is the title of the thread.
i made about 120 more hp at the same rpm so there is a significant problem at higher RPM. 488 rwhp at 7649 rpm using the same SXE 62 .91, 20.5 psi, 93 pump and 1000 CC of meth as AI.
OP's problem is so large that it is flow related.
my bet is the turbo manifold.
while nicely crafted, physics rules.
the 13BREW exhaust port is 3.04 sq inches and the I D of the primary runner is 2.07 sq inches! a brick wall as RPM increases. i can only imagine how high the EGTs and back pressure is with 32% less runner area.
after switching to the 1.0 hotside my EGTs dropped 40 degrees and i made 510 at 20.8 psi. this was right on the money as to my expectations. there is 550 available at 25 psi. the next SXE 62 test will be w the 80 mm turbine wheel.
i then switched to the EFR9180 1.05. EGTs dropped approx 70 F and backpressure about 20 points. 570 at 24.9/7722 RPM AFRs in mid nines. this was my first pull in the 25 area and i wanted to start out rich, i will no doubt tune about one point leaner.
should you have an interest in manifold/system design i invite you to read pages 85-139 of my 200 page FD comments located on Google Drive...
https://docs.google.com/document/d/1...dpatiR-rk/edit
https://docs.google.com/document/d/1...dpatiR-rk/edit
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