Gear Ratios??

[GotBoost4Yall]

What is the stock gear ratio on an Open diff. vs LSD ,is there? Is there any other applications with better gearing

[Trigger]

same gears if im not mistaking

Tim

[NeedCAforS13]

pretty much all the same... turbo 300z has taller gears, so you could get some top speed, but your acceleration would suck balls...

the CA silvia Diff (maybe only the non-turbo) uses a pretty sweet shorter gear ratio, but they are extremely difficult to find.

Sean

[cbryant]

Stock diff (open or VLSD) is 4.08.

The "shorter" gear ratio he is refering to is 4.36 from a JDM, CA18 equipped S13. I finally found and purchased one, though I may wait to install it, as I drive 120 miles/day during my commute.

I once did a gear calc to determine engine rpm at 80mph (typical commute speed) - 3900/4000rpm at 80 assuming no change in the 5 forward gear ratios and proper tire diameter. Great for turbo response, bad for fuel economy.

Chris

[float_6969]

Has anyone contemplated swapping in the 5th gear from a KA transmission? I'm seriously considering it. I've got the transmission out and I'm going to have to rebuild it because of a bad syncro and input bearing, so I was thinking of picking up a spare KA transmission and swapping the 5th gears. I thought the KA had the tallest of the 3 (SR,KA,CA).

[NeedCAforS13]

ryan, read the other thread... someone checked and they're all the same. even 5th:)

Sean

[USDM_OneVia]

If they are the same then why does my fastback (KA) turn 3200 at 70 mph and my coupe (CA) turn almost 3800 at 70 mph?

Joe

[NeedCAforS13]

I haven't noticed a difference between my two motors (CA and KA), but you could be right Joe. I didn't have anything to compare them back to back with (like 2 cars in your case)...

some tables with gear ratios... IIRC the SR transmission is the same as the KA transmission right?http://www.nissansilvia.co.nz/...e.htm

Sean

[float_6969]

Sean, I know the CA and KA aren't the same. As Joe said, my KA reved a lot lower in 5th @ 60 than my CA does. And that table that you linked to shows that the SR is geared lower than the CA (SR in 5th = 0.759, CA in 5th = 0.838), so even if the KA and SR are the same, it will still be an improvement. The only time I use 5th is on the highway and that is the only time I'm really concerned about mileage. Plus it will increase my top speed by a bit

[knightrider]

yep, open dif is 4.08, 6 bolt vlsd 4.085 bolt vlsd 4.36 or 4.08 if it was from CA its 4.36, if from early SR 4.08

[r34 gtr]

is there any car with a signifcantly lower 5th gear that i could swap into my transmission? or does anyone make one? (think nismo does iirc). i just want to keep my car from shatting on itself as much as possible as it made oil disappear muuch faster at higher rpm.

- tim

[knightrider]

i would recommend fixing the oil consumption problem, rather than regear the transmission.