the best differential ratio

[1 TUF AC]

[quote=1 TUF AC;1324507]

Originally Posted by Krait

3.9 with a T56 & LS2 2nd gear starts are fairly easy. Sits comfortably in 6th on the highway.

Wish I had it here in Dubai, no hills and 140k speed limit [/QU

mine takes off in second pretty easy too. Especially when I'm just cruising around town are normally take off in second. I've tried doing some hard launches in second and I think it gives me a better 0 to 100km time but you have to ride the clutch a fair bit more to take off cleanly. I'm pretty sure the ratios I posted are right because on my engineer certificate it says I have a t 56 out of a VX ss Commodore and a R 32 GTR differential which came out from factory with 4.11 unless someone has changed that ratio on me. But tomorrow I might go for a drive and make sure the ratios and speeds are correct. I know my speedo is not out I checked that with the GPS the other day. But according to the calculator it says I do 101km in in second gear but when I drive it to speedo is a bit slow to react so it's hard to tell if I have got 100km out of second because by the time that happens I am bouncing on the limiter and I need to change to third. if sixth gear was a 0.68 ratio 3.7 would be perfect. I am still very happy with the car performance especially when you're driving through the mountain areas it's so much fun. But always thinking of different ways to improve the car even further.

.

I went for a dirive today and I think found out why I couldn't get 100km out of second gear. It looks to me that my tacto is out buy at least 500rpm. Because the calculator say I should be reving 2000rpm @ 60kph in 4th gear but I am reving 2500rpm. normally I don't rev over 6000rpm but today i rev it to 7000rpm but the tuner sad he set the limiter to 6300rpm. And the gps says i did 100km out second so I'm pretty sure my tacto is out or my limiter is off and I have 4.3 diff gears. It definitely went a lot better when rev it That little bit more. i have a vdo tacto maybe it needs to be reclabraded or something. I might go past the tuners and get them to plug the laptop in to see if the revs Maching up with the tacto. At idle my car sits at 1100prm but it doesn't sound like it idling that fast. I am 90% sure my tacto is out but it could be something else.

[Mrs flatchat]

Oh boy ! "Cyber bench technicians"
T56 -- 5th - 6th are over drive -- they don't like to be loaded too much -- just a tip

[Tenrocca]

[quote=1 TUF AC;1324593]

Originally Posted by 1 TUF AC

.

I went for a dirive today and I think found out why I couldn't get 100km out of second gear. It looks to me that my tacto is out buy at least 500rpm. Because the calculator say I should be reving 2000rpm @ 60kph in 4th gear but I am reving 2500rpm. normally I don't rev over 6000rpm but today i rev it to 7000rpm but the tuner sad he set the limiter to 6300rpm. And the gps says i did 100km out second so I'm pretty sure my tacto is out or my limiter is off and I have 4.3 diff gears. It definitely went a lot better when rev it That little bit more. i have a vdo tacto maybe it needs to be reclabraded or something. I might go past the tuners and get them to plug the laptop in to see if the revs Maching up with the tacto. At idle my car sits at 1100prm but it doesn't sound like it idling that fast. I am 90% sure my tacto is out but it could be something else.

You or your tuner should be able to plug into the obd2 port and get a RPM straight off the CPU to compare to the gauge.

[1 TUF AC]

when I was looking to buy a cobra I noticed a lot of people are running a open differential instead of a limited slip differential. they were saying that LSD differentials in cobras create two much understeer when accelerating through a corner because of the short wheelbase. Has anyone out there experienced that? because if I decide to change the differential ratio I might as well put a good 1 way, 1.5 way or even a 2 way LSD centre as well.

[Mother]

I chose to use 3.5 finals with an Auburn Ratchet Spool. The Tires are Nitto 555 with 315 / 35 / 17's for rear tires. The motor is an extensively modified 460. Plenty of torque. Lots of horsepower, But pilled at 5200, because I am using a re-worked 650 holley. The carb is somewhere north of a 770. I need the spool to get the power down to both wheels when pulling off a corner.