Hi guys. Got the VL out to the strip. Still running a very safe 14psi tune. 35/40, 4spd auto 3000 stall and the usual plenum, ecu etc. Best I could manage was a 13.2 @ 106mph 2.17 60ft (foot brake). Was on 235/60 15 ET streets. I had the shift light set to 5600 and never once came on up the top end in 3rd. A few people up here are saying go to 3.9 diff gears. Just after peoples oppinions on sticking with the 3:45 or go the 3.7-3.9? Will be going down in 2 weeks with a full tune also. So hopefully a bit more power. On the last run something let go in the diff on launch pretty sure it is the pin the goes through the centre at this stage. Will know more when i get the centre out. Cheers Ian

You'll need to rev it a bit harder than 5600 for 3.9s, but 3.7s with a jatco are pretty friendly

Quote: Originally Posted by qldvl5spd [View Post] Hi guys. Got the VL out to the strip. Still running a very safe 14psi tune. 35/40, 4spd auto 3000 stall and the usual plenum, ecu etc. Best I could manage was a 13.2 @ 106mph 2.17 60ft (foot brake). Was on 235/60 15 ET streets. I had the shift light set to 5600 and never once came on up the top end in 3rd. A few people up here are saying go to 3.9 diff gears. Just after peoples oppinions on sticking with the 3:45 or go the 3.7-3.9? Will be going down in 2 weeks with a full tune also. So hopefully a bit more power. On the last run something let go in the diff on launch pretty sure it is the pin the goes through the centre at this stage. Will know more when i get the centre out. Cheers Ian run it with more power first and then decide and check rpm over the finish line, depends what you want to do.. if you want to use race fuel later you might want to keep 3.45's , but it depends on power/converter/camshaft where the motor makes peak power etc ..among other things. cheers darren

I wouldn't rush out to change gearing - at 106mph your issue is power not gearing!

Yeah cheers guys. I got the car tuned, was running 290hp- 16psi. We ended up with 388hp on 19-20psi. Ran a best time of 12.001@ 114mph (1.796 60ft). and a best mph of 117. Was hitting 5900-6000 at the line in 3rd. So pretty glad i stayed with the 3:45s now. Going to go back in 2 weeks to hopefully get an 11.**