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Here's mine... 996.1, 92k miles. Only thing that could affect power is a factory muffler delete, 7" race mufflers in their place.
Originally Posted by zagamuffin
My Hartech 3.9 complete oversize conversion Hartech 3.9 torque build
Thanks for sharing ! On the Hartech sheet, it's referencing BHP so not going to include it in the list but I appreciate it being shared for another data point.
Thanks for sharing ! On the Hartech sheet, it's referencing BHP so not going to include it in the list but I appreciate it being shared for another data point.
Not to be confused with imperial brake horsepower (bhp), which, although also used to measure a vehicle’s power output and often a similar figure, is a different type of unit (1bhp = 0.9863hp).
Brake horsepower is a measurement of the engine’s power taken at the flywheel or crankshaft without the engine losing power due to drivetrain and gearbox resistance
Brake horsepower is a measurement of the engine’s power taken at the flywheel or crankshaft without the engine losing power due to drivetrain and gearbox resistance
I'd like @zagamuffin to weigh in. Were those numbers obtained on a wheel dyno or an engine dyno? The numbers don't make sense for a 3.9L hot rod motor unless they're at the wheel, which is why I'd like clarification.
I'd like @zagamuffin to weigh in. Were those numbers obtained on a wheel dyno or an engine dyno? The numbers don't make sense for a 3.9L hot rod motor unless they're at the wheel, which is why I'd like clarification.
Fun fact: For the term ‘brake horsepower’, thank Gaspard de Prony, inventor of the Prony brake (circa 1820’s). The Prony method (bhp) measures engine torque at the flywheel. Sounds familiar. The geriatric bhp method was commonly used to measure pulling capabilities of tractor engines in the early 1900’s.
When I look at the dyno sheet from Chipwizards, I can’t tell if the whp was measured and bhp was calculated, or vice versa. Bhp and net standard SAE dyno results are super close, both being crank-derived measurements without down line power loss being factored. Bottom line: No matter where measured, if you know the density of the air, the torque at any given rpm, the resistance from outside systems (driveline) as precisely as possible, you can calculate whp within 1.5% from bhp or hp. So within + or - 5 whp seems good enough for me. *For Discussion Purposes Only* of course!
That said, does anyone have the gouge on no-bull driveline loss numbers for our cars? C2/C4/C4S?
Wayne Schofield at Chipwizards has always shown Dyno Horsepower at the flywheel ( BHP ) from his rolling road..
It is common practice for the dyno to make measurements then corrections and calculations from actual Torque to whatever "hp" figures they want...
Custom Map by Wayne Schofield at Chipwizards in Rochdale, 487.7bhp @ flywheel, 546ft/lb @ 3500rpm. The front propshaft has been removed for the 2wd mapping process. Totally standard 996 Turbo (K16's).
I'll buy this, as it says 48x hp @ flywheel. That's where std K16's are maxed out.
Anyway, post me your mass airflow log (=MAF) and I'll say how much hp the engine gives out. Or you can calculate it yourself...if the MAF just is new(ish):
I'll buy this, as it says 48x hp @ flywheel. That's where std K16's are maxed out.
Anyway, post me your mass airflow log (=MAF) and I'll say how much hp the engine gives out. Or you can calculate it yourself...if the MAF just is new(ish):
If you log MAF vs RPM at 2k 3k 4k 5k 6k using Durametric or PIWIS, you can get horsepower numbers all up the RPM range and use that to evaluate your new exhaust, ot heads, cams, big bore ect......
You can't use MAF/housing to evaluate another intake/air box though without a redundant MAF/housing as seen in the thread.....the Fabspeed intake was over-reporting as we concluded..
Mods:
Dry Sump
Carrillo Rods
Motec M130 ECU
Chinese Ebay headers which are too small
2.5 inch tailpipes, no mufflers
Open intake prior to throttle
Thanks for putting it up - I think good to go since it's a 996 motor in a boxster... Won't be the only dry sump motor on the list for long, although willing to bet it will maintain being the only dry sump M96 for a long, long time.
2003 C2. Stock 3.6 motor, stock exhaust, stock intake. This motor suffered an IMSB failure prior to my ownership and was rebuilt by the dealer 5 or 6 years ago with a new short block. 61k total miles and ~15k miles on the rebuild.
Rainy 42 degree day at ~200 feet above sea level. RPM was calculated by speed and gearing. Variocam Plus action is easily identified. I think these are solid baseline numbers and I should be happy. The shop owner said they see a lot of BMW there and the numbers are close to what they usually see on a stock E46 M3.
2003 C2. Stock 3.6 motor, stock exhaust, stock intake. This motor suffered an IMSB failure prior to my ownership and was rebuilt by the dealer 5 or 6 years ago with a new short block. 61k total miles and ~15k miles on the rebuild.
Keen eyes might notice TQ and HP do not cross at 5252rpm. This is due to different scales on the left and right sides of the graph. RPM was calculated by speed and gearing. Variocam Plus action is also easily identified. I think these are solid baseline numbers and I should be happy. The shop owner said they see a lot of BMW there and the numbers are close to what they usually see on a stock E46 M3.
Thanks for sharing ! You are right at what I thought mine was making. Would you mind sharing the shop for a fellow MA guy ?
Thanks for sharing ! You are right at what I thought mine was making. Would you mind sharing the shop for a fellow MA guy ?
Aponte Rios Racing in Newton NH. They don't appear to advertise much so I'll PM you more contact info.
This was done at a dyno day through COM intended for motor swaps or elective dyno based classing. Doesn't really apply to me now but maybe in the future. $100 for some baseline data was a good deal.
03-15-2023, 08:01 AM
