diff gears for vn

[seabs]

mmm 1750rpm @ 100kph... that must be auto..

my manual sits at slightly under 2000rpm @ 100kmh in 5th gear

and a manual with 4.11's in it would sit closer to 3000rpm.

i remember when i asked a diff place they said if i went 3.73's i would sit at about 2400rpm in 5th doing 100km/h... thats what im going off

 

[383 hatch]

Well there you go! I would have thought the revs between the auto & manual would be near the same, as the ratios are almost the same, auto 0.7:1 manual 0.72:1 in top gear. Yes you are right my auto used to do 1750 at 100 and now sits dead on 2000 at 100 with 3.45 gears. Learn something every day.

 

[premmy186]

4.1 doing 2350 at 100? doesnt sound right. my mates torana sits on 4 grand on the high way in top gear... doing 80 hahaha. chews a hole tank going to the coast. its set up for the quater lol, fuk that i said and convinced her to blow the diff n put a normal one in. dunno wat the raito is, n it's only a 4 speed.

 

[premmy186]

4.1 doing 2350 at 100? doesnt sound right. my mates torana sits on 4 grand on the high way in top gear... doing 80 hahaha. chews a hole tank going to the coast. its set up for the quater lol, fuk that i said and convinced her to blow the diff n put a normal one in. dunno wat the raito is, n it's only a 4 speed.

 

[383 hatch]

You have to realise that with a 4 speed manual the ratio in top gear is 1.00:1 (engine speed the same as tailshaft speed) and in a 4 speed auto the ratio is 0.72:1 (engine speed slower that tailshaft speed), hence the lower engine speed.

 

[premmy186]

yeh my premier shits all over it in top speed, but i've got nuthing off the line

 

[383 hatch]

Exactly, obviously with a lower diff ratio you will get better take off, but if you go too low the engine will run out of top end revs too quick. So thats where you have to get a good comprimise of good take while still maintaining good top end. Generally 3.45 or 3.55 is a good comprimise for a street car but it all depends what you are using your car for. With late model cars with 4 speed auto or 5 speed manual you can get away with 3.7 and still maintain that good comprimise.

 

[vn_ss_hsv]

so can anyone recommend a diff place that does a good job in melbourne? :|