Went to the dyno yesterday.
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Went to the dyno yesterday.
Here is a sheet from the dyno.
It shows speed instead of rpm due to the fact we were mapping shift points on the other runs. I do have sheets with all the info in data form instead of graphs.
The A/F was almost constant, only changing from a low of 11.1 to a high of 11.4.
The torque curve is like all 4 . 9s in that it starts high and goes down from there. The hp curve is flat from the start of the run till near the end.
The first 3rd gear pull, it had 160.7hp @4800 and 216trq @3800
For the last pull I moved the timing from a base setting of 12 to 16 degrees with the timing control bypassed.
This gave me the days best of 169.6hp@4800 and 218trq @3800.
All the runs ended at 4800rpm in high gear which is 102mph. The factory speed limiter is 118mph. With the change from 2.73 to 3.06 final drive and 24" tires, the computer thinks I am going 118 at an actual 102.
I wish it could have pulled higher because in both cases it made a big hp jump from 4400 to 4800.
It was 7hp in the first pull and 10hp in the last with the advanced timing.
I am now going to send all the data I have to Rocksrawl and get a new chip. I will dyno it when I get it back to see the changes.
Gene
It shows speed instead of rpm due to the fact we were mapping shift points on the other runs. I do have sheets with all the info in data form instead of graphs.
The A/F was almost constant, only changing from a low of 11.1 to a high of 11.4.
The torque curve is like all 4 . 9s in that it starts high and goes down from there. The hp curve is flat from the start of the run till near the end.
The first 3rd gear pull, it had 160.7hp @4800 and 216trq @3800
For the last pull I moved the timing from a base setting of 12 to 16 degrees with the timing control bypassed.
This gave me the days best of 169.6hp@4800 and 218trq @3800.
All the runs ended at 4800rpm in high gear which is 102mph. The factory speed limiter is 118mph. With the change from 2.73 to 3.06 final drive and 24" tires, the computer thinks I am going 118 at an actual 102.
I wish it could have pulled higher because in both cases it made a big hp jump from 4400 to 4800.
It was 7hp in the first pull and 10hp in the last with the advanced timing.
I am now going to send all the data I have to Rocksrawl and get a new chip. I will dyno it when I get it back to see the changes.
Gene
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This is the data from the best run which was a 3rd gear pull
This sheet is from one of the runs where we started in 1st and let it shift till the speed limiter cut in at ~101mph. What is confusing to me is the numbers shown in first gear and notice how the a/f ratio is nearer to normal, then drops off. after the shift to second.
Gene
This sheet is from one of the runs where we started in 1st and let it shift till the speed limiter cut in at ~101mph. What is confusing to me is the numbers shown in first gear and notice how the a/f ratio is nearer to normal, then drops off. after the shift to second.
Gene
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The ECM may be seeing a decrease in load during the shift, but it seems unlikely that the it could sense the load change, shorten injector pulse, and have the O2 sensor show the effect of it within one or two tenths of a second, but I suppose it's possible. A log of the MAP sensor could be the answer. More likely the ECM has a torque limiting routine that it uses to protect the transmission during shifts. Since the ECM controls the shift points, it can anticipate the shift and start taking action before the shift even starts.
Could be, but the 3.4l DOHC hits an a:f right at 13:1, from start to finish. But it does have a knock sensor. As enignes become more efficient, DOHC hemi head design with excellent squish areas, with good ECU controlling, it enables manufactorers to move a:f's leaner and leaner, which uses less gas, without the traditional harmful effects of running lean.rockcrawl wrote:11.1:1 WOT AFR is pretty normal for a stock chip. I have a dyno chart showing 10.7:1 on a stock Peice of shit at WOT. I guess they were thinking better safe than sorry, afterall there's no knock sensor on these babies.
88GT 3.4 DOHC Turbo
Gooch wrote:Way to go douche. You are like a one-man, fiero-destroying machine.
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Re: Went to the dyno yesterday.
Isn't that a little light on torque? I thought that 4point9's usually put down about 230-240 TQ...scrabblegod wrote:Here is a sheet from the dyno.
The A/F was almost constant, only changing from a low of 11.1 to a high of 11.4.
The torque curve is like all 4 . 9s in that it starts high and goes down from there. The hp curve is flat from the start of the run till near the end.
The first 3rd gear pull, it had 160.7hp @4800 and 216trq @3800
For the last pull I moved the timing from a base setting of 12 to 16 degrees with the timing control bypassed.
This gave me the days best of 169.6hp@4800 and 218trq @3800.
Gene
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Re: Went to the dyno yesterday.
The torque peak for the 4point9 is at 3000 rpm, so this graph starts almost 1000 rpm past peak.The Dark Side of Will wrote:scrabblegod wrote:Here is a sheet from the dyno.
Isn't that a little light on torque? I thought that 4point9's usually put down about 230-240 TQ...
Gene
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