ebrow21
forum member
I've fought some issues with my car for the past month or two and I would like to ask some advice from the forum here.
Some Backstory: 06 convertible auto. The car went [email protected] with JLT 110mm , CMDP, O/R X, 4.10's, Brenspeed tune, GTB mufflers. Ran pretty consistent 1.90 60 foot times. Added a HSW 75 shot and HT0's, still ran well, but no track times. I also have an AEM wideband hardwired to datalog.
I then added: PTC 3000 restalled/upgraded stock converter and BBR STG1 NSR cams. I specified I would be spraying the car, so PTC provided a nitrous converter.
Car went [email protected] with an e-mail base tune in similar weather. 60' now 2.1, no matter how I launched it. I chalked the 60' up to the converter being more set up for nitrous. I was more concerned about the MPH. Contacted e-mail tuner, they strongly suggested the car was out of time and I need to have that checked before they can do anything.
I was not inclined to believe them, and the I had the opportunity to work with a local tuner, which I took. Datalogged the car, the cam angle was the same, both banks. Compression within 2psi across all cyls. E-mailed back and forth with the local shop and worked on the tune.
I wanted to be sure the tune was going in the right direction, so I brought the car to a friend's dyno, where it made within 1hp of what it did prior to the gear, cams, and converter, and HTO's (same dyno). As they generally lose power after a gear install (and the tune was not finalized), I can only assume the cams worked as intended.
I also dyno'd the car on nitrous, where it acted a bit weird. The loop is normally indicatave of tire spin or a slipping trans, as I understand it. I have provided the dyno graphs to illustrate. Two runs were a 100shot, the last was a 125. AFR/Plugs looked good. This particular dyno reads pretty low in general, but dyno numbers aren't the point of this thread.
I know that was a bit long, but I felt like I needed to provide all the details up to this point.
Current Issue
Ran the car on the 125 shot on the street. Ran great 1st-3rd, the car shifted into fourth and had a small fuel backfire soon thereafter. No damage beyond the filter bulging some. The plugs also looked undamaged. I did not think to datalog the car.
I needed to investigate the problem further, so I brought the car to the track on some taller tires I purchased for nitrous and the stall speed being too low for the cams. The car went [email protected] straight from the road. I then warmed the bottle and ran the car. I sprayed 30 feet out, it ran 12.1@116mph with a 2.1 60 foot. The car loaded up on fuel badly in fourth (Pegged gauge at 10.0), but did not backfire. The datalog was interrupted, so I don't have it.
I ran the car again, sprayed from the launch. 1.71 60', the car did the same thing in fourth again, but this time it did backfire. The car did a 7.48 1/8th, and it backfired right before the marker.
The datalog showed the car sat at whatever rpm it shifted to for progressively longer periods in each gear. The TCC ACT SLIP portion of the datalog jumps at each shift. As the shift to fourth happens, the value spikes, and the car sits at 4500rpm or so for an extended period of time (about 1 full sec). As the value drops, it loads up on fuel and the AFR dropped rapidly until it backfired.
I wanted to try to let off through the 3-4 shift (200rpm before/300rpm after) and see what it did. 1.74 60' 7.55 1/8 and 11.81@115 1/4. The torque converter slip value again jumped when it shifted into fourth gear. However, I hit the nitrous after the spike, and the car did not sit at an rpm in fourth gear. The afr remained in a relatively stable 11.0 area in fourth gear.
I'm thinking the issue I'm having is primarily with the converter. PTC has been more than willing to accomodate me with whatever I would like to do. However I want to diagnose this fully before taking any major steps.
I know this is an absurdly long post, but I tried to provide all the information I could to get an educated response. Any suggestions are very much appreciated.
Some Backstory: 06 convertible auto. The car went [email protected] with JLT 110mm , CMDP, O/R X, 4.10's, Brenspeed tune, GTB mufflers. Ran pretty consistent 1.90 60 foot times. Added a HSW 75 shot and HT0's, still ran well, but no track times. I also have an AEM wideband hardwired to datalog.
I then added: PTC 3000 restalled/upgraded stock converter and BBR STG1 NSR cams. I specified I would be spraying the car, so PTC provided a nitrous converter.
Car went [email protected] with an e-mail base tune in similar weather. 60' now 2.1, no matter how I launched it. I chalked the 60' up to the converter being more set up for nitrous. I was more concerned about the MPH. Contacted e-mail tuner, they strongly suggested the car was out of time and I need to have that checked before they can do anything.
I was not inclined to believe them, and the I had the opportunity to work with a local tuner, which I took. Datalogged the car, the cam angle was the same, both banks. Compression within 2psi across all cyls. E-mailed back and forth with the local shop and worked on the tune.
I wanted to be sure the tune was going in the right direction, so I brought the car to a friend's dyno, where it made within 1hp of what it did prior to the gear, cams, and converter, and HTO's (same dyno). As they generally lose power after a gear install (and the tune was not finalized), I can only assume the cams worked as intended.
I also dyno'd the car on nitrous, where it acted a bit weird. The loop is normally indicatave of tire spin or a slipping trans, as I understand it. I have provided the dyno graphs to illustrate. Two runs were a 100shot, the last was a 125. AFR/Plugs looked good. This particular dyno reads pretty low in general, but dyno numbers aren't the point of this thread.
I know that was a bit long, but I felt like I needed to provide all the details up to this point.
Current Issue
Ran the car on the 125 shot on the street. Ran great 1st-3rd, the car shifted into fourth and had a small fuel backfire soon thereafter. No damage beyond the filter bulging some. The plugs also looked undamaged. I did not think to datalog the car.
I needed to investigate the problem further, so I brought the car to the track on some taller tires I purchased for nitrous and the stall speed being too low for the cams. The car went [email protected] straight from the road. I then warmed the bottle and ran the car. I sprayed 30 feet out, it ran 12.1@116mph with a 2.1 60 foot. The car loaded up on fuel badly in fourth (Pegged gauge at 10.0), but did not backfire. The datalog was interrupted, so I don't have it.
I ran the car again, sprayed from the launch. 1.71 60', the car did the same thing in fourth again, but this time it did backfire. The car did a 7.48 1/8th, and it backfired right before the marker.
The datalog showed the car sat at whatever rpm it shifted to for progressively longer periods in each gear. The TCC ACT SLIP portion of the datalog jumps at each shift. As the shift to fourth happens, the value spikes, and the car sits at 4500rpm or so for an extended period of time (about 1 full sec). As the value drops, it loads up on fuel and the AFR dropped rapidly until it backfired.
I wanted to try to let off through the 3-4 shift (200rpm before/300rpm after) and see what it did. 1.74 60' 7.55 1/8 and 11.81@115 1/4. The torque converter slip value again jumped when it shifted into fourth gear. However, I hit the nitrous after the spike, and the car did not sit at an rpm in fourth gear. The afr remained in a relatively stable 11.0 area in fourth gear.
I'm thinking the issue I'm having is primarily with the converter. PTC has been more than willing to accomodate me with whatever I would like to do. However I want to diagnose this fully before taking any major steps.
I know this is an absurdly long post, but I tried to provide all the information I could to get an educated response. Any suggestions are very much appreciated.
