Help me out with dyno, A/F, and ATAP data.
06-11-2002, 03:16 PM
#1
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Help me out with dyno, A/F, and ATAP data. I just dynoed this past Friday w/ home ported heads.
Below is a summary of the data I have.
Dyno 379 rwhp, 372 rwtq (SAE corr.)
(Pulled 386/375 on third pull but I don't have Atap data for it)
A/F ratio measured with probe in tailpipe (is that the correct way?)
Maintained about 13-13.2 then dropped to about 12.7 above 6k rpm.
ATAP,
32 deg timing at throttle tip in and 23.5 by 6k rpm, 0 KR
O2's B1 .989-.980 B2 .1019-.1002
Coolant temp 196-198F
Unfortunatly that's all the Atap data I have, we were having connection problems.
Can someone tell me how this looks?
It appears to me the A/R ratio data contradicts the O2 readings.
Below is a summary of the data I have.
Dyno 379 rwhp, 372 rwtq (SAE corr.)
(Pulled 386/375 on third pull but I don't have Atap data for it)
A/F ratio measured with probe in tailpipe (is that the correct way?)
Maintained about 13-13.2 then dropped to about 12.7 above 6k rpm.
ATAP,
32 deg timing at throttle tip in and 23.5 by 6k rpm, 0 KR
O2's B1 .989-.980 B2 .1019-.1002
Coolant temp 196-198F
Unfortunatly that's all the Atap data I have, we were having connection problems.
Can someone tell me how this looks?
It appears to me the A/R ratio data contradicts the O2 readings.
06-11-2002, 04:44 PM
#2
Re: Help me out with dyno, A/F, and ATAP data. The wideband sensor is typically connected to a pre-cat O2 bung. If you have cat's they will alter your readings if you place the wideband sensor after the cat. It's my understanding you want the probe as close to the engine as possible to minimize other factors. If the compression changed as a result of your ported heads, it might like a little more spark advance in the PCM.
Timing seems a little low in the upper RPM's. Don't make any correlation between O2 readings and AFR readings. You may find a correlation between the two on your vehicle, but you shouldn't tune the car using your O2's.
Timing seems a little low in the upper RPM's. Don't make any correlation between O2 readings and AFR readings. You may find a correlation between the two on your vehicle, but you shouldn't tune the car using your O2's.
06-11-2002, 05:20 PM
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Re: Help me out with dyno, A/F, and ATAP data. The car doesn't have cats and C/R is about 10.6:1.
Would measuring at the tailpipe sway the results toward rich or lean?
Would measuring at the tailpipe sway the results toward rich or lean?
06-11-2002, 11:35 PM
#4
Re: Help me out with dyno, A/F, and ATAP data. Cats & Wideband: Here's a good thread https://ls1tech.com/ubb/cgi-bin/ulti...=000474#000002
Timing: If your ported heads were milled for more compression the PCM will "like" more spark advance than with stock compression. What year is your car? I've heard the '02 (and possibly the '01s) have less timing at WOT than the earlier years.
Timing: If your ported heads were milled for more compression the PCM will "like" more spark advance than with stock compression. What year is your car? I've heard the '02 (and possibly the '01s) have less timing at WOT than the earlier years.