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funny how wide the curve is with it peaking around the middle on the two lower boost dyno graphs, which is in the mid-upper 5000 rpm range if the 2x rpm factor is correct, lower than I’d have expected.
which if it mirrored a similar result at the highest boost setting, that would potentially put wtq not far off from the whp listing at the slightly lower 5250 rpm point (10.5k on the graph).
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Sorry if this is a dumb question but how would I get the rpm to read correctly? I’m not sure if it’s in the dynojet settings. I also revved the car out to 9k on the dyno.
Dynojet has a couple of ways to get rpm signal from vehicle.
Diesel guys use optical pick-up and a piece of tape on the crank pulley because no spark plugs.
Gas guys can use the inductive spark plug clamp and configure the dyno software for how many sparks per revolution.
Rotary can attach to rotor 1 trailing plug wire and set software to "4 cylinder".
If you cant get a clean rpm signal off the inductive clamp-
I have heard of people using a paperclip on the ground clamp for the inductive clamp and putting it somewhere there is signal pulsed by rpm.
Trailing coil bullet connector (tach hookup) is easy one for rotary. I guess people have resorted to injector connectors.
If none of this works you can run roadspeed and maths it out later by tire height and gearing.
Looks like you were getting 2x rpm if you revved to just over 7,000rpm on that 19psi 429hp pull.
You said you revved to 9,000rpm though. Or was that just on some pulls?
that was my bad then, thinking you were only revving to the more usual upper 7k range, but I did say if the 2x factor was correct in a later post.
but at a 9k cut that’s a 1.67x factor rather than 2x I had previously stated
so the lower boost graphs are still peaking at ~7100 rpm, but I recognize now that it only appears so wide due to that factor scaling
and also then seems to possibly indicate that 551 lb-ft is the correct WTQ value at -6.2k or so for the high boost setting? Higher than I was expecting so maybe not.
all sideline theory aside, it must feel great dropping the throttle and once the turbo spools up. With better fuel I’d expect that the low end spool could be improved quite a bit.
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I just checked the datalogs and for the 325hp pull I revved it out to 8500, the 429hp pull I revved out to 8750, then the final 550hp pull was up to 9000
Since the dyno runs we're already completed; as Blue TII suggests just calculate the rpm using the speeds displayed on the graph along with your tire size and rear end ratio.
so I corrected the factor a bit based on your log rpm limits post (1.67x)
but back calculating WTQ based on rpm and WHP is easy enough once you apply the xfactor to correct the graph rpms, except you apparently don’t have the high boost graph. They should have been able to email you the data file though.
With WinPeP, you'll be able to change the scale and each axis for each run. If you select speed then you can calculate the rpm from the speed indicated.
The drf files are very small usually less than 10kb, so he should be able to send them to you fairly easy.
07-11-23, 11:12 PM
545HP/330TQ @30PSI BWS366SX 93 Octane
