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disappointed dyno numbers.....

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Old 02-19-2006, 08:57 AM
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gimpster621
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Default disappointed dyno numbers.....

268 hps/257 torque. i lost 3 hps since my plenum and intake but i gained 14 torque (270.5/243.4). a/f was 16.5 is that the culprit? i did a reflash when i installed pulley, hfc, and y pipe. since then i took off the y pipe and got hks exhaust. if i reflash the ecu again and run 13:1 ratio would i gain about 20 hps that i should with the mods?
Old 02-19-2006, 09:29 AM
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Zivman
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Originally Posted by gimpster621
268 hps/257 torque. i lost 3 hps since my plenum and intake but i gained 14 torque (270.5/243.4). a/f was 16.5 is that the culprit? i did a reflash when i installed pulley, hfc, and y pipe. since then i took off the y pipe and got hks exhaust. if i reflash the ecu again and run 13:1 ratio would i gain about 20 hps that i should with the mods?
if your car ran a 16.5 AFR, your internals would be toast. You are seeing the max AFR that is seen at the very begining of the pull. You should be concerned with the AFR curve not the peak.

Did you do a dyno pull for AFRs and determine if an ecu flash was needed before you sent yours in?

There are many other factoring in on your dynos:
Correction factor
humidity
temp
etc.

A 3 hp loss could just be variances in the dyno itself and not indicating a true loss. I would be happy with the tq gains you are seeing. Personally, I think your numbers are high for the parts you are running so be happy with that.
Old 02-19-2006, 03:35 PM
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Sharif@Forged
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Was your AF really 16.5:1 at WOT? If so..you engine is not going to last very long.

I assume that is a typo. The numbers are excellent for your mods, and the fact you gained 14ft/lbs is impressive. Oftentimes NA mods and tuning will generate more meaningiful improvements in the midrange, and smaller gains up top.

What kind of dyno was this? Can you post your dyno chart?
Old 02-19-2006, 05:41 PM
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Mr_pharmD
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ya, a/r is really lean if thats at wot. Also, u got to rememeber tq wins the race.
Old 02-19-2006, 05:54 PM
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Alberto
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What was the old and new correction? Dyno type? I ran my car as lean as 15.3:1 a/f(at worst) avg 14:1 and leaner for months before biting the bullet and doing a flash. Gained 9whp/12 ft/lbs with it and midrange. BTW Id take all that TQ and lose 2whp peak anyday....
Old 02-19-2006, 05:59 PM
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davidv
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A dyno chart would be helpful.
Old 02-19-2006, 06:02 PM
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steela2110
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screw the high flow cats and go with test pipes... also look into utec or unichip rather than having to reflash again
Old 02-19-2006, 08:24 PM
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Armitage
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Originally Posted by davidv
A dyno chart would be helpful.
+1. I'd like to see the entire curve.
Old 02-19-2006, 11:12 PM
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gimpster621
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no scanner
i'll try to take a clear pic
the a/f ratio reading of 16.5 is from like 2k rpms. then it dips down to like a 13 and climbs back up to 15.6ish. im going to reflash the ecu again this week and do a dynojet dyno. reason numbers are high is because they were on a dynopak

Last edited by gimpster621; 02-19-2006 at 11:15 PM.
Old 02-19-2006, 11:41 PM
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Fairlady_z33
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Get an e-manage ultimate and tune that sucker

Last edited by Fairlady_z33; 02-19-2006 at 11:44 PM.
Old 02-21-2006, 04:32 AM
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PoWeRtRiP
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was the a/f taken at the tailpipe? or in the exhaust stream?
Old 02-21-2006, 07:00 AM
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fahrenheit350
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A/F measured at the tailpipe. I think Church's run no correction, someone correct me if I am wrong. Still a noob when it comes to dynos.
Old 02-21-2006, 07:08 AM
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PoWeRtRiP
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if the sensor was at the tail pipe then its not an accurate a/f ratio. im not sure how much it could be off, but it may not be as bad as you think.

i would encourage you to get it tuned and have the a/f read in the actual exhaust stream via one of your o2 sensor bungs.
Old 02-21-2006, 07:12 AM
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Originally Posted by PoWeRtRiP
if the sensor was at the tail pipe then its not an accurate a/f ratio. im not sure how much it could be off, but it may not be as bad as you think.

i would encourage you to get it tuned and have the a/f read in the actual exhaust stream via one of your o2 sensor bungs.
is it better to put the sensor in the test pipe region? probably. Because the sensor was in the tailpipe does not mean it is not accurate. I would trust the numbers
Old 02-21-2006, 07:21 AM
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fahrenheit350
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I think since the A/F was measured at the tailpipe, realistically the A/F is not that high. I think it was DaveZ that told me that it would come out higher at that end, something like a point higher.
Old 02-21-2006, 09:27 AM
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EM-EFER
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Dyno charts are useful
Old 02-22-2006, 02:03 PM
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gimpster621
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just got back from technosquare. i had a slight pinging and fixed it. af is now 13:1 and car pulls hard all the way til 7k. redynoing it this sunday. i'll figure out a way to scan it =D
Old 02-22-2006, 02:14 PM
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Robert_K
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I be happy with a a 3 hp lost and 14 tq gain. Remember that the tq is what gets your moving.
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