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I drive a 997.1S with the normal mods I am courious how far off I am from a stock 997.2. My last dyno run was 310hp & 284tq. I’ve had better hp results however this was just my last run. I’m trying to get on Steve Ashworth’s dyno tomorrow if they have time for me. I looked before posting this, just having a hard time finding the answer.
No way to compare your Dyno to anybody else's anyways. Each and every single Dyno can vary significantly even if it is the exact same model of dynamometer.
I’m only courious how far off I am. I get that results can vary. My best hp on a dyno is 327.
Hi Bailey,
Using absolute numbers is fraught with peril because there's a ton of variability between different dynos (including the same models). There was a classic article back in 2003 when Turbo Magazine took a 350Z around to 6 different dyno shops in their area on the same day and got the following RWHP results:
A'PEXi Integration - Dynapack 5500 249.4 HP
XS Engineering - Dynamic Test Systems (DTS) 257.6 HP
XS Engineering - Dynojet 248 235.8 HP
Dynamic Autosports - Dynojet 248 243.7 HP
Area 51 - Clayton VTT 265.7 HP
Skunk2 - Super Flow SF-1853 228.9 HP
As you can see, there was an almost 37 rwhp variation in the result. A 350Z (back in the day) made about 287 bhp (which is ~244 rwhp assuming rule-of-thumb 15% drivetrain loss).
So 37 rwhp variation on a car that makes a theoretical ~244 rwhp is a 15% measurement variation.
Let's apply that to you situation... let's say someone else measures 352 hp (25 hp more than what you list). What would that tell you?
Honestly, nothing because they might in reality be making 10 hp less than you, and you'd never know it from the dyno results. The accuracy simply isn't there...
All you can really do is compare cars on the same dyno on the same day, with the same fluid temperatures (e.g. transmission oil temps), tire pressures, alignment, etc.
Dang Karl this is informative. Thank you. My car feels so strong & I remember 4 yrs back when I bought it how fast a 997.2S felt. Only courious. Thanks for all the replies everyone.
While dynos cannot be reliably compared acceleration data definitely can. All you need is a reliable source of collecting acceleration data and then you can compare it to a 997.2 s taking onto account slope, wind and density altitude and there you go.
Only way to Truly test and trust WHP is to go to a drag strip. Get on the scales and weigh the car with you in it. Launch it best you can and get a few 1/4 mile trap speeds (get an average). Then plug those numbers into a HP calculator.
Weight and Trap Speed will tell ya everything you need to know.
Screen shot from my last big HP toy in my sig. The Dyno Jet 248 said it made 1053 WHP, so that makes Garmons Diesel Dyno pretty dang accurate.
While dynos cannot be reliably compared acceleration data definitely can. All you need is a reliable source of collecting acceleration data and then you can compare it to a 997.2 s taking onto account slope, wind and density altitude and there you go.
mike
Yup, agree. Back when I had the 135i, I did a baseline run and then repeated the runs as I added various changes while trying to keep the environmental conditions the same (i.e. early morning runs in cool weather).
My technique was to first add a gauge that displayed speed (this P3 gauge scanned the speed from the OBD port, our 997 gauge is quite laggy by comparison):
Then point a GoPro at it (the frame-to-frame time base accuracy was good enough for me):
Perform a number of runs with each mod, extracted the time-to-speed data using various video timestamps, throw all the data into a spreadsheet, apply some basic high school level physics (i.e. the simple set of equations of motion), and I got:
It gave (what I believe was a) reasonably good real world comparison of the gains with the various mods.
Karl.
PS: There's a bunch of BWM specific acronyms in the above (like saying PSM, PSE, etc), they're just various turbo engine related stuff, not important for this conversation...
Yup, agree. Back when I had the 135i, I did a baseline run and then repeated the runs as I added various changes while trying to keep the environmental conditions the same (i.e. early morning runs in cool weather).
My technique was to first add a gauge that displayed speed (this P3 gauge scanned the speed from the OBD port, our 997 gauge is quite laggy by comparison):
Then point a GoPro at it (the frame-to-frame time base accuracy was good enough for me):
Perform a number of runs with each mod, extracted the time-to-speed data using various video timestamps, throw all the data into a spreadsheet, apply some basic high school level physics (i.e. the simple set of equations of motion), and I got:
It gave (what I believe was a) reasonably good real world comparison of the gains with the various mods.
Karl.
PS: There's a bunch of BWM specific acronyms in the above (like saying PSM, PSE, etc), they're just various turbo engine related stuff, not important for this conversation...
right on Karl! I love my p3 Guage in the s5. I have the track pack so it gives acceleration data....
Karl, I have a 135i w/ that P3 gague. I have a 0-60 of 3.66.
Come on Rennlist Family someone humor me & share or lead me to my answer of what a stock 997.2s puts down on a dyno. Or just forget about my original post someone share with us what a dyno sheet looks like.
Karl, I have a 135i w/ that P3 gague. I have a 0-60 of 3.66.
Come on Rennlist Family someone humor me & share or lead me to my answer of what a stock 997.2s puts down on a dyno. Or just forget about my original post someone share with us what a dyno sheet looks like.
Thanks,
bailey
Not sure it really helps but I dyno'd my stock GTS a couple years go for the hell of it and it made 347whp @ ~7200rpm on an AWD dynojet (didn't like being run in RWD mode) and that was with STD correction (not SAE, which would produce a lower number).
Karl, I have a 135i w/ that P3 gague. I have a 0-60 of 3.66.
Come on Rennlist Family someone humor me & share or lead me to my answer of what a stock 997.2s puts down on a dyno. Or just forget about my original post someone share with us what a dyno sheet looks like.
Thanks,
bailey
We can post dynos all day long but theyll be meaningless. Here's a stock 997.1S making 317whp...
some good data here all. Never did dyno the GTS when it was stock as I couldn't abide by the weak exhaust sound and did the bypass ASAP after purchase. I am planning to do same day same dyno back to back comparison for mods I do in the future.
Random dynosheet I found for 997.2 S
02-21-2018, 09:06 PM
997.2S stock dyno results
