Did not state that in absolute terms. Just that if you do not fly in the teens, a super charger or a turbo generally do not pencil out for most cases.
A super charger works in many use cases; e.g. Wayne but not in all cases, e.g. you.
Tim
Moderators: Rick, Lance Murray
Did not state that in absolute terms. Just that if you do not fly in the teens, a super charger or a turbo generally do not pencil out for most cases.
The detail overlooked here is that extra MAP boost is not free. It robs engine power to compress (and heat) the incoming air, and the compression system is not going to be 100% efficient (nothing is). That's why SL performance is not going to be improved and might easily be degraded. The improvement comes at the point where the parasitic HP draw (and other factors) is less than the gains obtained by the increased MAP.Antoine wrote: ↑Wed Jun 03, 2020 11:38 pm Thanks Wayne
Performance of SC planes should be massively better even at low altitudes because no DA40 can make 30 inches of MP after take-off.
The price to pay is higher SFC, a big increase in FF and maybe wear, but if an engine overheats, something is wrong.
The FAA would have denied the STC if this issue were not under control.
With all due respect for Chris' efforts and disappointment, I am leaning (pun!) towards issue(s) specific to N171CB - mag timing, baffling, fuel flow - Brock's thread is full of stories about such issues and fixes.
Hi Antoine -
Why would this not be apparent - at all - in the comparison with Wayne's aircraft in the initial post?
The 2x improvement in CHT spread (32 => 17) suggests that the pre-supercharged configuration would have been up to 15F cooler with the baffle improvements FAT implemented during Wayne's installation.waynemcc999 wrote: ↑Wed Jun 03, 2020 10:08 pm per my PIREP (pg 4) over 116 flights these are the data recorded changes from pre-supercharged to supercharged:
-- Max CHT in Flight up 7 degF (385 to 392)
-- Max CHT in Cruise unchanged at 374
Hm, is there a post on this? I don't recall. I wouldn't mind checking this out.
Hi Rich -
Link doesn't work. Is it incomplete or something?Chris B wrote: ↑Thu Jun 04, 2020 1:34 amHi Rich -
Check Wayne's PIREP ( bit.ly/wam-sc-pirep ) that he references in his post at the bottom of page 1.
Chris
Thanks. Unfortunately there aren't any references to the specifics of baffle changes. Something I could use in light of my observed Surefly behavior, if there are some changes that would help. Wayne, could you chime in, here?