40 rwhp gain after locking 3200 stall. This can't be good.
01-17-2005, 08:36 AM
#1
11 Second Club
Thread Starter
40 rwhp gain after locking 3200 stall. This can't be good. My converter was originally a vig. I say "originally", because I had it rebuilt locally after finding out that the vig came apart and destroyed my tranny. It was originally a 2800 stall but I had it upgraded to a 3200 by the local guy. The problem is that now my car seems to have lost almost 2 mph on the top end, even with a larger cam.
A recent trip to the dyno showed that I did pick up 20 rwhp with the larger cam but only after converter lockup. I have a 94 Z28, and for whatever reason, the converter locks up at WOT in 3rd gear. I know this doesn't happen with ls1s. Anyways, on the dyno, before lockup, my horsepower plateaus around 320 from around 4900 rpms up to 5600 rpms which is where the converter goes into lockup. At that point it shoots up to 363 for the next 200 rpms until coming off the gas. My original 2800 stall and smaller cam netted me 345 rwhp which got me 113.78 mph. With that converter/cam setup, the graph showed a more steady climb until lockup. I think that 700 rpm band where the power isn't climbing may be costing me at least a couple mph. I was thinking about going back to a 2800 stall but am wondering if maybe this 3200 converter can just be made more efficient. Afterall, even though I did lose mph, I picked up .07 in 60' alone.
What do you guys think and what would you suggest?
A recent trip to the dyno showed that I did pick up 20 rwhp with the larger cam but only after converter lockup. I have a 94 Z28, and for whatever reason, the converter locks up at WOT in 3rd gear. I know this doesn't happen with ls1s. Anyways, on the dyno, before lockup, my horsepower plateaus around 320 from around 4900 rpms up to 5600 rpms which is where the converter goes into lockup. At that point it shoots up to 363 for the next 200 rpms until coming off the gas. My original 2800 stall and smaller cam netted me 345 rwhp which got me 113.78 mph. With that converter/cam setup, the graph showed a more steady climb until lockup. I think that 700 rpm band where the power isn't climbing may be costing me at least a couple mph. I was thinking about going back to a 2800 stall but am wondering if maybe this 3200 converter can just be made more efficient. Afterall, even though I did lose mph, I picked up .07 in 60' alone.
What do you guys think and what would you suggest?
01-17-2005, 12:13 PM
#2
with as much trouble as you have had with tranny problems in the 94z, I'd leave it alone if it is working. 
A .07 gain in 60' is a good gain and probably is worth more than the MPH. If the rebuild included a strong clutch, i'd program your lock-up rpm in 3rd down to around 5200 rpm. Doesn't help in 1st or 2nd gear, but it may get you some help on the top end.
A .07 gain in 60' is a good gain and probably is worth more than the MPH. If the rebuild included a strong clutch, i'd program your lock-up rpm in 3rd down to around 5200 rpm. Doesn't help in 1st or 2nd gear, but it may get you some help on the top end.
