I was told that a high torque 455 should have a 10" converter vs a smaller one. I see a lot of fast Buicks on here with 8 or 9" converters. What rationale is used to make the decision? If an 8,9 and 10" all had a 3500 stall why would one be chosen over the other? Mike
The smaller the diameter of a converter, the easier it is to get higher stall speeds. The downside to higher stall speeds is that they can slip more at lower speeds. That will make a car feel lazy for normal street driving. There is no such thing as a converter that will stall the same in any application. Stall speed depends on engine torque, car weight, and even gearing. If you buy an off the shelf converter, it is a hit or miss kind of thing. The best thing to do is have a converter built for YOUR combination by someone with experience in doing that. The ideal result is a converter that feels nearly stock with great efficiency, but stalls where you need it when you stomp on the gas. With the current state of converter technology, you can have your cake and eat it too. It costs a bit more, but you get what you pay for, and converter choice plays a big part in how your car actually drives. I have one of Jim Weise's 9.5" converters in my car. IMO, it is a no brainer, https://v8buick.com/index.php?threads/tsp-9-5-street-strip-converters-lifetime-warrantee.147066/ https://v8buick.com/index.php?threads/updated-torque-converter-program.278923/
That can be a complex question to answer, but safe to say that about 90% of the Street/strip Buicks out there will like the 9.5" diameter. Some call this a 10".. The other 10% are actually race cars with lisc plates, and as such, benefit from a good 8" unit. JW
If you do that, you must have a dyno sheet.. from an engine dyno.. most are not familiar with Buick engines. Getting the right pump/stator combo is all about torque at rpm, vs vehicle weight and gearing. If they have the info, they typically can nail it.. I just lubed up and got an ATI 8" (ouch.. 12 hundred bucks) for a customer here last winter. Was just a touch faster than my race 9.5.. about 3 hundredths in 60', still working on the combo on that one to evaluate mph. Low 8 second car.. JW
6800. Through the top end of the quarter mile about 7000. 4.30 gears are for 1/8 mile but a tick too much in the quarter. New trans is going to be setup with reverse pattern and airshifter instead of forward and column. The 4.30 were put in so I had a little bit of time after going into 3rd to judge the finish line
