Vlad's rides thread

[vlad01]

So Im looking at the idea of buying a 068 gearset which is the following but using the original input shaft.

1st gear Tremec #1352-080-030

2nd gear Tremec #1352-080-152

3rd gear Tremec #1352-080-151

input Tremec #1352-085-025

cluster Tremec #1352-077-068


This will yield the following ratios from 1-4

3.35
1.99
1.33
1
xx

Stock V6 ratios are similar and based on the 052 cluster.

052 set has the following ratios

3.35
1.93
1.29
1
xx

Holden V6 is.

3.25
1.99
1.29
1
xx

But since we can't get the V6 gear set new Im opting to use the 068 as its got a better 3rd gear ratio as the V6 one is crap, a big jump from 2-3 so the 068 will close the gap a little.
The 068 has also a shorter 1st, only becasue the odd aussie box has an unusual 3.25 1st where the rest of the world only uses 3.35. Not sure how that will fair but should be fine.

According to this T5 history page the 068 was rated a bit stronger,probably the same as the V6 box given its in the same era.


http://www.pro-forceperformance.com/t-5_history.htm

[vlad01]

Here is a gear chart I ran with stock ratios bottom pic and 068 set top pic.

You can see the stock ratios seem to be like 2 separate close ratio boxes. Close for the low speed half and close for the high speed half. You can see that 2-3 gap I was talking about.

We disregard the 5th as thats over drive and not used for accelerating the car normally.

If you notice the 068 set the ratio spread progressively closes up as the gears go higher, so getting closer ratio the higher you go. This will result in overall better acceleration across the operating range of the car.

The car simulation shows that with my built V6, 068 and 3.45 diff it all works out very optimal.

Changing just on the high end of peak power the next gear lands on peak torque band.

[immortality]

1st gear will start getting really short if using a 3.35 ratio and anything other than the standard 3.08 diff ratio.

If your building a strong engine than you don't really need the short 1st gear, even a stock standard manual V6 will bake the tyres in 1st gear, it's really a waste of the low rpm torque.

Personally, I'd be going for a longer 1st gear and bring the other gears closer together and then fit a decent diff ratio, mY old VN had 3.45 gears and really tight LSD with decent tyres and it was severely traction limited in 1st gear.

[Dylan]

Just for reference my VZ 6 speed LS1 has some pretty close ratios. Think the diff is 3.7 being manual. First seems bit tall then 2 3 4 5 feels like a kenworth at times.

[HQ355]

Who dosnt accelerate in 5th ? I do, and 6th if the roads is long enough

[immortality]

Just for reference my VZ 6 speed LS1 has some pretty close ratios. Think the diff is 3.7 being manual. First seems bit tall then 2 3 4 5 feels like a kenworth at times.

That sounds right, 1st in the T56 is 2.66 followed by 1.78, 1.3, 1.0, 0.74, 0.5

A T56 with 3.9 gears has almost identical final ratio (in 1st gear) as a V6/T6 with 3.08 gears..........

T56 with 4.11 gears is just full of WIN.

[vlad01]

Just for reference my VZ 6 speed LS1 has some pretty close ratios. Think the diff is 3.7 being manual. First seems bit tall then 2 3 4 5 feels like a kenworth at times.

I agree, stock v6 ratios all round i can do over 70km/h in 1st so its pretty tall by any car's standard these days. Stock is undrivable in traffic, just to fast even below idle.

with 3.08 on 6k rpm 3.35 vs 3.25 is only 3-4km/h less or 200rpm more if viewed the other way.

if you look at the charts thats on 3.45 and 1st still will do the same speed with this engine's slightly higher rpm range and slightly shorter gearing.

so....


I can use a 3.23 or stock 3.08 but this engine makes best torque higher up and broad. little bit less than stock at the very low end. Cuts even at 1500.

[HQ355]

T56 and 4:11's is full of WIN ! I'm sure Vlad will back me up on that !

[vlad01]

T56 and 4:11's is full of WIN ! I'm sure Vlad will back me up on that !

Yes great combo!

[VK_3800]

I agree with immortality, if your engine warrants the gear upgrade then go closer ratio rather than wider and select a diff ratio to suit. You want it to be fun to drive, not like an old truck.