By the way..... I've done this.... Actually done it... Lined up side by side with another bb Hard to believe I know WTF I'm talking about, but deal with it. Sig www.pless.com.au/mechanics.htm
Totally, way back when my brother and I had our Toranas I was running 3.9 diff ratios, which worked beautifully with the Celica 5 speed. It was (back then) a quick car running easy 13 second quarters. On our annual pilgrimage to NQ we always fitted 2.78 gears for the mostly highway driving. The cars instantly became slugs, no where near the pick up of the low diff ratio. It would've been a good couple of seconds slower down the quarter mile!!
No, because drag increases with the square of speed. Once you get to 100mph (3rd gear in a normal 365) you're pushing a huge amount of air. With the too-tall diff you'd be hitting the higher drag at the wrong part of your horsepower and torque curves. That's why 5 speed cars are always setup with the biggest ratio gap between 2nd and 3rd, because at that speed the drag impact is much less. Road or track doesn't matter. The more gears (i.e. closer ratios) you have, the less effect the diff ratio has, apart from off the line and top speed.
For serious!! You just can't get off the line with tall gears, and it doesn't rev as freely. Its literally like having a traffic light race where your competitor takes off in first and you take off in second!! They're gone!!
I predict this car with that diff set up will give Simon the sheets more than the other did for being UK delivered. Sounds the car was misrepresented, I would be thinking of getting the ombudsman involved and heading towards a refund…
Just NFI, you need to have raced to understand the difference diff and gear ratios make to a car from track to track .
