CAMCMD spikes to 45 degrees

chunky · Post by **chunky** » Sat Jun 18, 2005 3:00 pm

Have any of you noticed this occuring? In the process of tuning my custom k20a3 cams, I have observed this disturbing anomaly under the following conditions.

1) below 3000rpm, but above 2000rpm
2) 0 tps
3) no more than 3 min after startup
4) duration of CAMCMD spike is less than 1/2 second

The cam angle maps in this region are set to 0 or 5 degrees advance. I think this is some sort of startup check coded into the ecu, or some kind of software glitch.

I really need to find a way to disable this spike in the CAMCMD as I have datalogged it spiking the actual cam values to 50+ degrees. Right now I am running these cams with VTC disabled, which is a temporary solution for preventing the cam angle spike.

HELP! and thanks in advance.

here is a screen shot from k-manager, I purposely took out the cam angle maps as I do not want them leaked until the official introduction of the cams. You can still cearly see that the CAMCMD should be interoplated between 0 and 5 degrees, yet the CAMCMD sent by the ECU is 45 degrees!

engine model: civic si - k20a3 + custom cams + intake + header + exhaust + 6spd tranny

ecu model: PRB, hondata #649

k-manager 1.2.0.0, now upgraded to 1.2.0.2

Post by **Hondata** » Sun Jun 19, 2005 1:10 pm

Can you send a datalog with calibration to us?

chunky · Post by **chunky** » Sun Jun 19, 2005 5:01 pm

Hondata wrote:Can you send a datalog with calibration to us?

the only email address i could find on your website is sales@hondata.com.

do you have a specific email you want me to correspond to? if you'd rather not post it, email me @ mr.chunky@gmail.com.

thanks!

Post by **Hondata** » Mon Jun 20, 2005 1:25 pm

sales@hondata.com will work

chunky · Post by **chunky** » Mon Jun 20, 2005 3:34 pm

thanks, email sent.

Post by **Hondata** » Tue Jun 21, 2005 10:10 am

Thanks for the calibration. The calibration looks OK and I can see the spike in cam angle.

You can try the beta version to see if that eliminates the spike; otherwise we will try to repoduce the problem here (this may take a little while).

chunky · Post by **chunky** » Tue Jun 21, 2005 12:14 pm

I'll give the beta version a shot.

In order to catch the spike on datalogs, I had to start datalogging from when I started the car. then just start driving normally staying out of vtec in the 2000-3000rpm range. The sound didn't seem to occur if I immediately started full throttle driving.

I had no idea of what I was looking for as I only knew there was a strange sound coming from the engine occasionally at low RPM. It finally occured to me it might be something to do with the cam angle, so I made a graph template overlaying camcmd & cam, and it happened every time I started the car. Since I've turned off VTC, the cam angle stays fixed at zero, and I don't hear the noise that I heard before.

I don't have any previous datalogs taken that soon after startup so I couldn't verify if the ECU has been doing this all along. I'm going to try to find a local k-pro user to see if I can log the same thing on their car.

Thanks for helping me out with this issue.

chunky · Post by **chunky** » Wed Jun 22, 2005 10:27 am

Just thought i'd post the untuned dyno here to show the difference the VTC makes.

i'd love to be able to have VTC running all the time w/o fear of the cam angle spike!

Gearhead Geek · Post by **Gearhead Geek** » Thu Jun 23, 2005 11:54 pm

I've verified this happening on my car as well. My setup is as follows:
PRB K-Pro #306 using the second release of K-Manager 1.2.0.3 beta, K20A3 (EP3) with A2 head, 310cc OEM injectors, 6 speed, i/h/tp/e
I have two datalogs (both that I'm more then happy to supply along with my calibration), one with closed loop disabled (aproximately 6 minutes long) and one with it enabled (aproximately 21 minutes long), both showing the same spike at aproximately the same time under the same conditions. The following picture shows the spike happening shortly after uploading a calibration with the car running, with closed loop disabled:

[/img]

chunky · Post by **chunky** » Mon Jun 27, 2005 4:41 pm

Any updates on this?

Jpax · Post by **Jpax** » Sat Jul 02, 2005 1:29 pm

Mine is showing spikes too. I am running a PNF ecu, on a K20A3. mods

CAI, Race header, and DC sport exhaust.

Any ideas mate?

mdoyle · Post by **mdoyle** » Fri Jul 08, 2005 12:43 pm

Mine is doing it also.

PNF ECU with K20A running a modified version of the K20A2 ITR Cams JRRH 310cc kal

Post by **Hondata** » Tue Aug 16, 2005 2:22 pm

I've fixed a problem with the cam angle tables in the Civic ECU. It should fix the problem which you were seeing.

Download here

(This is a beta version).

CAMCMD spikes to 45 degrees

CAMCMD spikes to 45 degrees

Civic cam angle