ski_dwn_it
Member
- Joined
- May 3, 2005
Ok a little background for you.
The car is a vette with a 434ci motor, n/a, 11.5:1 compression and runs 10.0X@135MPH. The 60' times are always in the low 1.3X when it trips the 60' beams with the front tires. And the car leaves rediculously hard, very violent but straight as an arrow.
Yesterday (2nd time out this season) the car started off running great. The 60' times were 1.33X and the car ran a 10.24 which was expected for the 3k DA weather. Right where I expected it to land.
On the third run the car on the launch left like a snail. It barely pulled the front about 4" and 60'ed in the 1.42 range. To me it felt like as mentioned a snail leaving compared to how it normally feels; which usually it feels like you got rearended by a semi at 40mph when you mat it. I ran the car about 4 more time and the end MPH was exactly where it should have been, but the 60' all felt like I had No Gearing in the car or the way it would feel if you raised the rear gearing.....no snap.
Couple of questions and scenerios I want to ask about.
First thing that came to mind problem wise was the fact that lately I have been getting an open pump error on my LM1 that is tied into my DFI system. This has been happening more and more. Plus to me it seems that it takes a long time to heat the O2. Do you think the problem is a lazy or bad o2?
I did not have my laptop with me - DUH. So I did not have a good way to diagnose it there. This morning first thing I probably have some mad neighbors because I was out there at 7am with the car on the trailer idling it and pulling numbers. No codes were set, but I am not sure if the 02 is a code in DFI that will clear itself?
Also something else that I noticed with my tune is the Acceleration modifier changes gradually with temperature and flattens out at about 200F. I am thinking for consistency purposes I would want to flatline this between about 120+ since I usually try to keep the car around 130-150 when staging. If that is different throughout the temp range I might get varying results - RIGHT? ( I don't think this is the problem though with the soft launches, but something I wanted to make sure I was thinking correctly about).
Lastly, on the launches I have noticed in the past that the AFR overshoots the desired fuel I have set pretty much. But I just left it go because the car is like a rocket off the line - is this modifier where I would dial that in?
Sorry for all the questions. The main this I guess I am asking is there is any way to tell if the 02 is flaking out causing my problem. My fear is the converter might have broke and not be giving out any multiplication.....
Any assistance you can give would be appreciated.
Here is a video of the car leaving normally....
Video of Run1 - Photobucket - Video and Image Hosting
Video of 10.08Run - Photobucket - Video and Image Hosting
The car is a vette with a 434ci motor, n/a, 11.5:1 compression and runs 10.0X@135MPH. The 60' times are always in the low 1.3X when it trips the 60' beams with the front tires. And the car leaves rediculously hard, very violent but straight as an arrow.
Yesterday (2nd time out this season) the car started off running great. The 60' times were 1.33X and the car ran a 10.24 which was expected for the 3k DA weather. Right where I expected it to land.
On the third run the car on the launch left like a snail. It barely pulled the front about 4" and 60'ed in the 1.42 range. To me it felt like as mentioned a snail leaving compared to how it normally feels; which usually it feels like you got rearended by a semi at 40mph when you mat it. I ran the car about 4 more time and the end MPH was exactly where it should have been, but the 60' all felt like I had No Gearing in the car or the way it would feel if you raised the rear gearing.....no snap.
Couple of questions and scenerios I want to ask about.
First thing that came to mind problem wise was the fact that lately I have been getting an open pump error on my LM1 that is tied into my DFI system. This has been happening more and more. Plus to me it seems that it takes a long time to heat the O2. Do you think the problem is a lazy or bad o2?
I did not have my laptop with me - DUH. So I did not have a good way to diagnose it there. This morning first thing I probably have some mad neighbors because I was out there at 7am with the car on the trailer idling it and pulling numbers. No codes were set, but I am not sure if the 02 is a code in DFI that will clear itself?
Also something else that I noticed with my tune is the Acceleration modifier changes gradually with temperature and flattens out at about 200F. I am thinking for consistency purposes I would want to flatline this between about 120+ since I usually try to keep the car around 130-150 when staging. If that is different throughout the temp range I might get varying results - RIGHT? ( I don't think this is the problem though with the soft launches, but something I wanted to make sure I was thinking correctly about).
Lastly, on the launches I have noticed in the past that the AFR overshoots the desired fuel I have set pretty much. But I just left it go because the car is like a rocket off the line - is this modifier where I would dial that in?
Sorry for all the questions. The main this I guess I am asking is there is any way to tell if the 02 is flaking out causing my problem. My fear is the converter might have broke and not be giving out any multiplication.....
Any assistance you can give would be appreciated.
Here is a video of the car leaving normally....
Video of Run1 - Photobucket - Video and Image Hosting
Video of 10.08Run - Photobucket - Video and Image Hosting