Converter Slippage by gear?
John
John
John
I recently bought a TH350 and paid extra for the 2.75 first gear. Well, I was worried I accidentally got the 2.52 first gear because at 6800 RPM in 1st gear I was going 47 mph. That seemed awfully high to me. I have 4.10 rear gears and 27" slicks. I found a gear/mph calculator that does not take into account slippage. If I enter 2.75 it says I should be going 48.5 mph @ 6800 RPM but if I enter 2.52 it says I should be going 51 mph.
47/48.5= .9691 (About 3% slippage) if 2.75 first gear
47/51.0= .9216 (About 8% slippage) if 2.52 first gear
According to my converter's manufacturer, my converter should have about 5% slippage. So as you can see, I was stuck in the middle and didn't know which 1st gear ratio my TH350 has.
I do know my second and third gear ratios. At 6500 rpm in 2nd gear I was going 79 mph but the calculator said I should be going 85. At 6400 rpm in 3rd gear I was going 118 mph but the calculator said I should be going 128.
79/85 = .9294 (About 7% slippage) for 2nd gear
118/128 = .9219 (About 8% slippage) for 3rd gear
So it looks like 3rd gear has 8% slippage, 2nd gear has 7% slippage and 1st gear has 3% slippage. Does this sound right? If not, maybe I did get a 2.52 first gear by mistake.
Trending Topics
The Best V8 Stories One Small Block at Time

