I was talking to Dederich’s Motorsports about getting a speed sensor and reverse switch light to replace damaged sensors on my T56 Magnum. When I told him that I had the TUET 11102 (wide ratio), he told me that this was a bad choice because my cruising RPMs would be too low, particularly with the 3.54:1 Q45 final drive I intend to use. He said that ‘lugging’ the engine like this is going to be bad for the gears in the transmission and not too good for the motor, either. He went so far as to recommend I stick with the stock 4.08:1 S13 final drive instead.

According to my calculations, freeway cruising RPMs would be around 1900RPM at 80MPH, 1650RPM at 70MPH, and 1550RPM at 65MPH. I didn’t think this would be a problem on a small, light, and aerodynamic car like the S13. I figured it would even get me some pretty good highway fuel economy as well as a quiet and comfortable ride. Plus, the LS1 F-bodies have the same .50:1 sixth with an even TALLER 3.42:1 rear end. And in a heavier car to boo. But to the best of my knowledge, this isn’t a problem. Is there REALLY a problem with this setup?

 

That sounds perfect lol. That's the whole point of 6th to cruise below 2k at highway speeds.

 

If your engine runs smooth at lower rpm, it won't hurt a damn thing to run it and the transmission there. My 3200 rig has a 3.42 rear with a .50 o/d ratio. 26.7" rear tire. It runs fine at 55mph with the engine turning less than 1100 rpm. If you're towing a heavy load, it's different. Not so much with a light load.

 

Low rpm = MPG's

as long as it's smooth I'd run it!

 

I would imagine it comes to the size of the cam and some to the heads. Crappie lazy ports with a biggish cam may not like to drive under 2k. Like people say, it’s all in the combination of parts. It least the I would think