Torque converter diameter is very important to consider. A 12 inch converter with the stall raised as high as possible (2,500 RPM) will have much more slippage at the shift point than a 10 inch converter built to the same stall speed. The 10 inch converter will allow for a lower gear ratio. 10 inch converters in their stock applications stall around 1,800 RPM, they are a lot more enjoyable for street usage and better on the track. Well worth the price.
Hi. The calculator I used was at wallaceracing.com/calculators. The specific one I used was "RPM drop from shift calc". It gives rpm assuming zero slippage. To find torque converter slippage would require chassis dyno of your car to prove exactly. You could get an estimate from the manufacturer of your torque converter. The premise of the video is to choose a stall speed at or below the theoretical RPM of the 1-2 shift in order to limit slippage. Most off the shelf torque converters are rated at an assumed 350 ft pounds of engine torque. If you make more than that, it will stall higher. Usually only a couple hundred RPM if you arent severely above on torque.If you are, then the next tighter converter may be appropriate.A 3000 stall converter can stall at 3300 or even a bit higher with a lot of torque. If you have more than 450 ft pounds, it may be necessary to get one with a balloon plate. This will get you close if you're buying an off the shelf converter. Enjoy!
What about my cam say I need a 2800 plus stall I am not racing can I use a 2500 instead of 2800 plus stall my motor is 350 bore 60 700r4 trans 99 block 99 vortec heads and I’m getting 411 gears 2door 84 caprice 30inch wheels
I have a twin turbo ls 416 foxbody with a powerglide transmission 3800 converter trick performance stage 3 cam and 273 gears, and my transmission is overheating car weight 3500 with me in it will changing the gear fix the heating issue and what gear you recommended I was thinking 331 for 1/4 mile or I'll be in the same boat with slippage
More gear will reduce the load on the torque converter at part throttle cruising for sure. The correct gear for your turbo motor I don't know. Turbo motors are tough, because the torque curve can be changed a lot with tuning. 2.73 is pretty tall, though. 3.31 would be an improvement, though I expect a bit more gear would be appropriate, like about 3.73 maybe. I would add an oil cooler with a dedicated fan if you don't already have it.
For mostly street with occasional drag duty i would recommend that. If it's mostly drag and occasional street, it could work ok with more stall. I would keep an eye on trans temp if I did that though.
Torque converter diameter is very important to consider. A 12 inch converter with the stall raised as high as possible (2,500 RPM) will have much more slippage at the shift point than a 10 inch converter built to the same stall speed. The 10 inch converter will allow for a lower gear ratio. 10 inch converters in their stock applications stall around 1,800 RPM, they are a lot more enjoyable for street usage and better on the track. Well worth the price.
Before changing gears I’ll play with tire size
Very nice informative video. Did you say there is a calculator that would help with converter options?
Hi. The calculator I used was at wallaceracing.com/calculators. The specific one I used was "RPM drop from shift calc". It gives rpm assuming zero slippage. To find torque converter slippage would require chassis dyno of your car to prove exactly. You could get an estimate from the manufacturer of your torque converter.
The premise of the video is to choose a stall speed at or below the theoretical RPM of the 1-2 shift in order to limit slippage.
Most off the shelf torque converters are rated at an assumed 350 ft pounds of engine torque. If you make more than that, it will stall higher. Usually only a couple hundred RPM if you arent severely above on torque.If you are, then the next tighter converter may be appropriate.A 3000 stall converter can stall at 3300 or even a bit higher with a lot of torque. If you have more than 450 ft pounds, it may be necessary to get one with a balloon plate. This will get you close if you're buying an off the shelf converter. Enjoy!
What about my cam say I need a 2800 plus stall I am not racing can I use a 2500 instead of 2800 plus stall my motor is 350 bore 60 700r4 trans 99 block 99 vortec heads and I’m getting 411 gears 2door 84 caprice 30inch wheels
Sorry, but mending from a stroke. i can't tend to my channel right now.
I have a twin turbo ls 416 foxbody with a powerglide transmission 3800 converter trick performance stage 3 cam and 273 gears, and my transmission is overheating car weight 3500 with me in it will changing the gear fix the heating issue and what gear you recommended I was thinking 331 for 1/4 mile or I'll be in the same boat with slippage
More gear will reduce the load on the torque converter at part throttle cruising for sure. The correct gear for your turbo motor I don't know. Turbo motors are tough, because the torque curve can be changed a lot with tuning. 2.73 is pretty tall, though. 3.31 would be an improvement, though I expect a bit more gear would be appropriate, like about 3.73 maybe. I would add an oil cooler with a dedicated fan if you don't already have it.
So I have a 99 Vic 8.8 I’m gunna run 3.73s I can only get 2800 or 3200?
For mostly street with occasional drag duty i would recommend that. If it's mostly drag and occasional street, it could work ok with more stall. I would keep an eye on trans temp if I did that though.
Is there's a way to calculate my rpm recovery using some formula??
Yeah I know where Wallace is but not what I asked for thanks