Engine vs chassis dyno numbers
11-09-2018, 09:16 AM
#1
Race Director
Thread Starter
Engine vs chassis dyno numbers
Has anyone had comparable figures between an engine dyno and a chassis dyno for the same engine? Just curious how much is lost from the drivetrain ? I’ve heard 12 to 18% and wondering if there may be some real world figures out there?
11-09-2018, 10:01 AM
#2
Race Director
Member Since: Mar 2011
Location: SW Florida
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2021 C6 of the Year Finalist - Modified
12-13% for the manual transmission
15% for the automatic
15% for the automatic
11-09-2018, 10:04 AM
#3
Burning Brakes
Some things to consider:
- STP vs. SAE
- measured vs. unmeasured losses
- correction factors
- unlocked vs. locked converters
- requested and real AFR
- requested and real timing
- etc. etc.
Logs from the dyno runs are essential be be able to compare any dyno runs.
Without those provided, comparing is pretty useless.
Just my 3 cents.
- STP vs. SAE
- measured vs. unmeasured losses
- correction factors
- unlocked vs. locked converters
- requested and real AFR
- requested and real timing
- etc. etc.
Logs from the dyno runs are essential be be able to compare any dyno runs.
Without those provided, comparing is pretty useless.
Just my 3 cents.
11-09-2018, 10:10 AM
#4
Burning Brakes
11-14-2018, 12:51 PM
#5
Melting Slicks
Blue line locked Red unlocked
Last edited by algZO6; 11-14-2018 at 12:52 PM.
11-16-2018, 07:38 AM
#7
Team Owner
It isn't a set percent. It is a percent+fixed number, depending on drivetrain.
Kind of a pointless thing to chase down anyways. Seen a rock crawler do 900hp on engine dyno, then 600rwhp on a dyno.
Seen a c6z lose 25rwhp just swapping wheels/tires. Plus dyno to dyno variation, dyno type, etc etc
Figure anywhere from 10-40% or set number to spin certain parts + percent for friction/pumping/etc losses.
Kind of a pointless thing to chase down anyways. Seen a rock crawler do 900hp on engine dyno, then 600rwhp on a dyno.
Seen a c6z lose 25rwhp just swapping wheels/tires. Plus dyno to dyno variation, dyno type, etc etc
Figure anywhere from 10-40% or set number to spin certain parts + percent for friction/pumping/etc losses.
Last edited by Unreal; 11-16-2018 at 07:39 AM.
11-16-2018, 09:34 AM
#8
Melting Slicks
It isn't a set percent. It is a percent+fixed number, depending on drivetrain.
Kind of a pointless thing to chase down anyways. Seen a rock crawler do 900hp on engine dyno, then 600rwhp on a dyno.
Seen a c6z lose 25rwhp just swapping wheels/tires. Plus dyno to dyno variation, dyno type, etc etc
Figure anywhere from 10-40% or set number to spin certain parts + percent for friction/pumping/etc losses.
Kind of a pointless thing to chase down anyways. Seen a rock crawler do 900hp on engine dyno, then 600rwhp on a dyno.
Seen a c6z lose 25rwhp just swapping wheels/tires. Plus dyno to dyno variation, dyno type, etc etc
Figure anywhere from 10-40% or set number to spin certain parts + percent for friction/pumping/etc losses.
11-17-2018, 06:59 PM
#9
Melting Slicks
Very pointless exercise.