My 220K mile 98 z28 drag thread
#63
TECH Apprentice
Thread Starter
Think the 4L60E failed
I rented a U-Haul trailer, which is a pretty good trailer by the way, and towed the car. Glad I did. Also installed HP tuners and went out just to do some N/A logging to email to my tuner.
I let the car idle for five minutes or so and took a couple laps around the pits to warm it up. First run was a 13 flat at 105. Nothing big but normal considering the higher D/A. Let it cool down for 20 minutes than set the computer to log the second pass.
On the 2 - 3 shift right at the stripe I heard a bang from underneath me so I let off, then then a whirring sound and the engine free revved. Coasted to the turn around and tried first gear but nothing. No smoke, dripping fluid or anything else. Engine seems to run fine but still get the whirring sound from the transmission.
Loaded up and cam home. With the car strapped to the trailer, I put the car in gear and give a little gas and the driveshaft didn't turn. Time to find a new transmission.
I let the car idle for five minutes or so and took a couple laps around the pits to warm it up. First run was a 13 flat at 105. Nothing big but normal considering the higher D/A. Let it cool down for 20 minutes than set the computer to log the second pass.
On the 2 - 3 shift right at the stripe I heard a bang from underneath me so I let off, then then a whirring sound and the engine free revved. Coasted to the turn around and tried first gear but nothing. No smoke, dripping fluid or anything else. Engine seems to run fine but still get the whirring sound from the transmission.
Loaded up and cam home. With the car strapped to the trailer, I put the car in gear and give a little gas and the driveshaft didn't turn. Time to find a new transmission.
#64
TECH Apprentice
Thread Starter
New trans & stall
New trans is in. Performabuilt Level 2 with an FTI 4k hard hit converter. Also added a bigger cooler, all new lines, new rear main seal, new SFI flexplate, poly trans and torque arm mounts and temp gauge. The old converter was in fact a Circle D that could be stalled 2600 - 3000. Trans failure looks to be a broken drum.
The car sure pulls much much harder. It really gets up and goes. It spun hard on the street so I had to adjust the shocks. Never had much trouble hooking before. LCA angles look good but I had the shocks set very loose. I called Kevin at MWC and he was very helpful with shock settings. I stiffened up both front (9c/12r) and back (10c/8r) according to his suggested starting points and the car hooks much better.
It drives much better than I expected. Have to give it a little more gas but otherwise drives like stock. This is a very streetable 4k converter. Can't wait to get it to the track Friday night. Still waiting for the tune.
The car sure pulls much much harder. It really gets up and goes. It spun hard on the street so I had to adjust the shocks. Never had much trouble hooking before. LCA angles look good but I had the shocks set very loose. I called Kevin at MWC and he was very helpful with shock settings. I stiffened up both front (9c/12r) and back (10c/8r) according to his suggested starting points and the car hooks much better.
It drives much better than I expected. Have to give it a little more gas but otherwise drives like stock. This is a very streetable 4k converter. Can't wait to get it to the track Friday night. Still waiting for the tune.
#67
TECH Apprentice
Thread Starter
Three N/A passes last night. First pass right off the trailer was a 12.705 @ 106.48 on a 1.727 60' and D/A of 2,600. Hooked great and on average the car picked up about 4 tenths with the new trans and converter. That's about what I was hoping for. I was expecting 60's to drop a solid couple of tenths but they only dropped about 1.5 tenths on average. The more noticeable drop was in the 330'. It dropped another 1.5 tenths from the 60' to 330' and then another tenth from 330' to 1/8 mile.
Two other n/a passes of 12.833 @ 104.2 on a 1.774 60' and 2,500 D/A; and 12.720 @ 104.71 on a 1.739 60' and 2,300 D/A.
Then three passes on 75 shot (41 jet). First 11.969 @ 111.57 on a 1.717 60' and 2,300 D/A. My HP Tuners log showed AFR in the low - mid 11's so I jetted the fuel from .18 to .17. I lost the second time slip but it was another 11.9x and AFR log moved very little. Jetted fuel down to .16 and ran an 11.864 @ 112.31 on a 1.714 60' and 2,000 D/A.
No spinning on any of the runs. (Thanks to Kevin from MWC for advice.) Hit the limiter on the 2-3 shift on nitrous. Think it cost 1 - 2 mph and a tenth or two. Received base tune from Pat G yesterday. Can't wait to get the tune right.
Two other n/a passes of 12.833 @ 104.2 on a 1.774 60' and 2,500 D/A; and 12.720 @ 104.71 on a 1.739 60' and 2,300 D/A.
Then three passes on 75 shot (41 jet). First 11.969 @ 111.57 on a 1.717 60' and 2,300 D/A. My HP Tuners log showed AFR in the low - mid 11's so I jetted the fuel from .18 to .17. I lost the second time slip but it was another 11.9x and AFR log moved very little. Jetted fuel down to .16 and ran an 11.864 @ 112.31 on a 1.714 60' and 2,000 D/A.
No spinning on any of the runs. (Thanks to Kevin from MWC for advice.) Hit the limiter on the 2-3 shift on nitrous. Think it cost 1 - 2 mph and a tenth or two. Received base tune from Pat G yesterday. Can't wait to get the tune right.
#68
TECH Apprentice
iTrader: (1)
Car looks like my cars twin! I too have a 98nbm z28 with awesome paint!
Mine also came with a rebuilt trans with a shift kit, and had a borla adjustable catback as well.
I did a bit of weight reduction, but not as crazy as yours. I have rear seats taken out, ac out, egr delete, air delete, longtubes, x pipe dumps, spohn lower a arms, founders lca relocators and lcas.
Nice job, and keep up the good work!
Mine also came with a rebuilt trans with a shift kit, and had a borla adjustable catback as well.
I did a bit of weight reduction, but not as crazy as yours. I have rear seats taken out, ac out, egr delete, air delete, longtubes, x pipe dumps, spohn lower a arms, founders lca relocators and lcas.
Nice job, and keep up the good work!
#70
TECH Apprentice
Thread Starter
Car looks like my cars twin! I too have a 98nbm z28 with awesome paint!
Mine also came with a rebuilt trans with a shift kit, and had a borla adjustable catback as well.
I did a bit of weight reduction, but not as crazy as yours. I have rear seats taken out, ac out, egr delete, air delete, longtubes, x pipe dumps, spohn lower a arms, founders lca relocators and lcas.
Nice job, and keep up the good work!
Mine also came with a rebuilt trans with a shift kit, and had a borla adjustable catback as well.
I did a bit of weight reduction, but not as crazy as yours. I have rear seats taken out, ac out, egr delete, air delete, longtubes, x pipe dumps, spohn lower a arms, founders lca relocators and lcas.
Nice job, and keep up the good work!
#75
TECH Apprentice
Thread Starter
#76
TECH Apprentice
Thread Starter
Lol. Yes, this whole trans project wasn't cheap. The trans alone cost as much as the car, but so did the nitrous set up. It is fun though and I don't have to worry about trashing a nice car.
#77
TECH Apprentice
Thread Starter
I received my base tune from PatG and I loaded it and did some street logging but no wot pulls through third gear. I sent him the log and he sent me an updated tune. I loaded it but didn't get a chance to street log.
The front driver's side bumper is already damaged and it caught on the trailer and I almost ripped it off. We had to cut out part of the plastic inner fender and the air dam underneath the bumper. Now I have to check out the aftermath and see what needs to be done to ramshackle that together.
Only three n/a passes just to datalog and to adjust the shocks. 12.841 @ 103.28 on a 1.753 60' and 1780 D/A; then stiffened the rear shocks to 12c/10r -- 12.786 @ 103.22 on a 1.731 60' and 1750 D/A; and stiffened the front shocks to 11c/14r -- 12.743 @ 104.45 on a 1.728 60' and 1700 D/A.
I was hoping to pick up maybe a tenth or so with the tune but it didn't pick up anything and the D/A was lower than previous outing. Trap speed is down. It's hitting the limiter on the 2-3 shift so that's not helping. Hopefully an updated tune based on these logs will help. Please note that I don't mean to imply the tuner did anything wrong or I am upset about the tune. Going back and forth is part of the tuning process I expect. If the car doesn't pick up anything with the tune I won't be upset. I just want a good reasonable tune for the trans and engine so I can tune separately for nitrous.
The front driver's side bumper is already damaged and it caught on the trailer and I almost ripped it off. We had to cut out part of the plastic inner fender and the air dam underneath the bumper. Now I have to check out the aftermath and see what needs to be done to ramshackle that together.
Only three n/a passes just to datalog and to adjust the shocks. 12.841 @ 103.28 on a 1.753 60' and 1780 D/A; then stiffened the rear shocks to 12c/10r -- 12.786 @ 103.22 on a 1.731 60' and 1750 D/A; and stiffened the front shocks to 11c/14r -- 12.743 @ 104.45 on a 1.728 60' and 1700 D/A.
I was hoping to pick up maybe a tenth or so with the tune but it didn't pick up anything and the D/A was lower than previous outing. Trap speed is down. It's hitting the limiter on the 2-3 shift so that's not helping. Hopefully an updated tune based on these logs will help. Please note that I don't mean to imply the tuner did anything wrong or I am upset about the tune. Going back and forth is part of the tuning process I expect. If the car doesn't pick up anything with the tune I won't be upset. I just want a good reasonable tune for the trans and engine so I can tune separately for nitrous.
Last edited by gesto; 08-07-2017 at 03:47 PM. Reason: clarification about tuning
#79
Staging Lane
It's really cool for me to read this thread, I had a 99 z28 m6 with 231k on it. Took it to the track at 229 or 230 don't recall. I pulled off a best of 13.7 with a 2.2 60'. I missed third twice on that pass, it dead hooked and bogged a little causing my garage door opener to fall into my shift boot. Never got a good pass in the car before black ice took it's life. Keep pushing I'm curious how far it'll go!