About to get some diff gears but just wondering what you guys are running or recommend? Specs: VH Commodore Supra 5 Speed 308 with a 5770 Crow Cam (2100-5000) Running straight LPG I don't do much driving really at the moment (highway would be limited to 40kms every 2 weeks). But in future might have to start doing more. I was thinking 3.7's but they seem hard to find at the moment. 3.45? 3.9?? Most other posts with V8's they are running auto so I guess manual having a shorter first gear would mean different diff ratios? Cheers

Quote: Originally Posted by deviot [View Post] About to get some diff gears but just wondering what you guys are running or recommend? Specs: VH Commodore Supra 5 Speed 308 with a 5770 Crow Cam (2100-5000) Running straight LPG I don't do much driving really at the moment (highway would be limited to 40kms every 2 weeks). But in future might have to start doing more. I was thinking 3.7's but they seem hard to find at the moment. 3.45? 3.9?? Most other posts with V8's they are running auto so I guess manual having a shorter first gear would mean different diff ratios? Cheers I've got 4.11's in my walkinshaw but if your going to do highway driving go for the 3.9's it will be nicer to drive without revving off the clock.

I guess the walkinshaw is running the T5, how do you find taking of? 1st gear not too short? What RPM are you roughly sitting on at 100? Thanks for your advise so far. ---------- Post added 25-05-11 at 17:37 ---------- Rang around and can't seem to find anyone at all with 3.7s So 3.45 vs 3.9 hrmmm?

3.9s

Already on order Some original photos have not been recovered yet.

to give you an idea, my VH with 308 and supra 5 spd ran around 3800-4000rpm at 100k's with 411's due to the supra gearboxs already having short gears. there coming out soon and getting replaced with 345's, i wouldnt go any higher than that. 3.9 or 4.11 you wont even use first gear, its a bit pointless.

3.45's definitely the way to go

Hrmm I have the chance to swap them for 3.45 but need to make my mine up soon. I worked out that with 205/65/15 Tyres (Think thats what I got) 0.861 5th gearbox ratio(Worst case scenario) 3.9 Diff gears 100km/h would be at roughly 2750RPM Never have driven a V8 is 2750 bad on the highway? What about even at 3000??

2750 isnt too bad considering the diff gearing of 3.9s but as above 3.45s would be more practicle

Fine, i'll be sensible and get the 3.45s :P Fitting the gears, Use the shims that come with the gears (if they do come with them..?) use the shims in my housing or not wroth the risk and get a diff joint to fit them? (recommend anyone in the western suburbs please)

I've got 3.9's in my vr clubby and wouldve rather have preferred 3.45's. Don't like the fact that 1st gear revs out too quick. Goes through a bit more fuel too. Got 3.45's in my355 stroker and had it in my Walky too, felt like a nicer drive too

Quote: Originally Posted by deviot [View Post] I guess the walkinshaw is running the T5, how do you find taking of? 1st gear not too short? What RPM are you roughly sitting on at 100? Thanks for your advise so far. ---------- Post added 25-05-11 at 17:37 ---------- Rang around and can't seem to find anyone at all with 3.7s So 3.45 vs 3.9 hrmmm? I'm actually running a Tremek TKO 600. 1st gear is not too bad it does rev out reasonably quick. At 100 it revs at about 2700 only because I've got the 0.82 fifth gear which is not an overdrive gear but a race gear. ---------- Post added 01-06-11 at 11:28 ---------- Quote: Originally Posted by deviot [View Post] Hrmm I have the chance to swap them for 3.45 but need to make my mine up soon. I worked out that with 205/65/15 Tyres (Think thats what I got) 0.861 5th gearbox ratio(Worst case scenario) 3.9 Diff gears 100km/h would be at roughly 2750RPM Never have driven a V8 is 2750 bad on the highway? What about even at 3000?? Now that I see the Supra box has 0.86 fifth gear I would recomend you go lower ratio. My Walkie at around 2700rpm at 100kl/h is not bad but my rev limiter is set at 7200rpm and my cam doesn't start working until 3500rpm. If your cam is already working from 2000rpm at 2700rpm it will be starting to make power and become very anoying not to mention the fuel consumption. It will sound like I'ts revving of the clock while your cruising down the highway.

Thanks for this thread. Its helped me to decide on 3.45 on my VL with T5 and Twin throttle Walkinshaw setup. On 20 inch rims it is a Dog in third and fourth gears. Seeing I use Walkinshaw 16 inch rims as well I wasnt sure which ratio to go with.