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Old 06-29-2017, 01:02 PM   #101
steved0x
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Join Date: Dec 2012
Location: FL
Posts: 4,144
I tell you what would be cool, if you can tap into the k-line and get info like RPM and Throttle position, is some code that would receive requests in CAN OBDII protocol, send the request to the K-line, and return it back in CAN OBDII format.

I have one a RaceCapture/Track data capture device, and one of its features is that it can take CAN OBDII requests and translate then into various pre-CAN OBDII protocols. This lets me get things like RPM and Throttle position. However, the refresh rate on this is pretty slow, I get around 2 RPM readings per second, and 2 Throttle position readings per second.

Edit: forgot to include the links

Here is the adapter that translates the CAN OBDII requests into older OBDII formats:
https://www.autosportlabs.com/product/obdii-legacy-adapter/

Here is the device I have that uses this adapter:
https://www.autosportlabs.com/product/racecapture/

Here is a short clip, the first column is time in seconds, 2nd column is RPM, and 3rd column is Throttle Position (range 1-100)

Code:
Time	RPM	TPS
359.409	4666	31
359.611	4709	31
359.809	4709	31
360.007	4709	35
360.21	4789	35
360.61	4789	53
360.789	4852	53
360.809	4852	53
360.989	4852	100
361.009	4852	100
361.19	4852	100
361.21	4852	100
361.61	4975	100
361.788	4975	100
361.808	4975	100
362.007	5060	100
362.208	5060	100
362.611	5175	100
362.811	5175	100
363.012	5175	100
363.611	5278	100
363.812	5391	100
363.988	5391	100
364.008	5391	100
364.21	5391	100
364.59	5500	100
364.61	5500	100
364.81	5592	100
365.011	5592	100
365.209	5592	100
365.41	5656	100
365.61	5656	100
365.81	5656	100
366.011	5774	100
366.211	5774	100
366.39	5774	100
366.41	5774	100
366.611	5886	100
366.811	5886	100
367.011	5886	100
367.211	5974	100
367.61	5974	100
367.811	6077	100
368.011	6077	100
368.191	6077	16
368.211	6077	16
368.59	5904	16
368.61	5904	16
368.81	5904	11
369.009	5423	11
369.19	5423	10
369.21	5423	10
369.592	4912	10
369.612	4912	10
Each RPM reading lasts for 5 or 6 updates and the TPS seems to be a little faster, maybe every 4 updates.

From capturing logs with my Durametric, I know I can get about 10 discrete pieces of data per second, like this (this is a pull in 2nd gear)

Code:
Time                    RPM  Speed in MPH
14:07:08.1607752	2805	25.5
14:07:08.3697872	2838	26.1
14:07:08.5797992	2959	28.0
14:07:08.8008118	3101	29.2
14:07:09.0218245	3264	30.5
14:07:09.2408370	3422	32.3
14:07:09.4498489	3571	33.6
14:07:09.6608610	3721	35.4
14:07:09.8708730	3880	36.7
14:07:10.0808850	4028	37.9
14:07:10.2998976	4183	39.8
14:07:10.5099096	4328	41.0
14:07:10.7199216	4490	42.3
14:07:10.9299336	4652	44.1
14:07:11.1399456	4821	46.0
14:07:11.3499576	4993	47.2
14:07:11.5529692	5137	48.5
14:07:11.7599811	5301	50.3
14:07:11.9709931	5470	51.6
14:07:12.1860054	5626	53.4
14:07:12.4050180	5811	55.3
14:07:12.6300308	5975	56.6
14:07:12.8470433	6147	58.4
I would *love* to be able to get that type of update rate from the car in a way that I could send it to me data logger.

From what I understand, CAN is more of watching a stream of data rather than query/response like older OBDII protocols?

Wish 1 - an OBDII dongle that could query the k-line and give the fast refresh rate that I know the car is capable of. You could probably sell a decent amount of these All 986, 996, and maybe even early 9x7, could use this.

Wish 2 - a port somewhere that would simulate tapping into the CAN line on the newer cars and stream selected performance data, even if it was *only* RPM and TPS, since the other stuff you can get from OBDII like intake air temp etc... doesn't require a fast rate.

Since you are in there anyway...

Since you have access to all that,

Last edited by steved0x; 06-29-2017 at 01:06 PM.
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