T350 Diff change,what model??

[astonman]

Hi,I want to change my diff, currently 3.46 Hydratrac for a 3.91Quaife.Its a May 2005 T350.
I'd like to use all new parts.
Spoke to Topcats,but they couldn't source the new diff.
So,what diff am I looking for?
BTR M78 or M80 diff?

[ridgey]

Try John Reid at Grantura Engineering , he does all the TVR racers diffs and boxes , supplied me with a 3:77 , better around town and not too loud on motorways ( same car 05 T350 3.6 )

[anonymous-user]

ridgey said:

Try John Reid at Grantura Engineering , he does all the TVR racers diffs and boxes , supplied me with a 3:77 , better around town and not too loud on motorways ( same car 05 T350 3.6 )

Another reccomendation for John, he's built four or five diffs for me now and a few gearboxes. Always first class.

[MonkeyJez]

Another recommendation for Grantura Engineering. They converted my Sag's 3.46 diff to 3.71 and were about 70% of the cost TopCats quoted to undertake the same work including the shipping.

[astonman]

Thanks guys excellent recommendations.
Do you guys know what diff I'm looking for?
Cheers
Simon.

[anonymous-user]

astonman said:

Thanks guys excellent recommendations.
Do you guys know what diff I'm looking for?
Cheers
Simon.

If you have a 3.6 and a CR box I would be happy with a 3.9
If you have a 4.0 and a CR box, I would opt for a 3.7
If you have a 4.3 and a CR box, I would stay with 3.7

Always had the quaife down as a compromise, is it for a car that will be doing a lot of track work?

[astonman]

The cars 3.6, I want a CR box ( I hate the gap between 2nd and third in the standard box) and the 3.9 diff makes sense .
I want the ultimate fast road / trackable machine ( still using the 3.6).
I like the spring / damper set up I've evolved,which is Nitrons with 500lbs/inch front and 450lbs/inch rear,for the road.
I want a drive train to compliment this.last time I took the car out,we were late,and I noticed a significant issue with one black line and not two, with the Hydratrac.I don't think it's really up to very determined driving?
I have experience of ZF style locking diffs, is the quaife too tame?

[ridgey]

3.9 good for sprint , short circuits , but you need to keep the 3.6 engine spinning .
My race diff is 3.22 but have LS3 500+ lbs and only 6k red line
Ideal track diff is plate type but won't work well on the road
450lb rear is a bit stiff with the later T350 28mm anti roll bar . I run 400 lb no arb and nitron 3 way , rebound set to less than half way and still planning on going softer to get better traction , car sub 900kg
No diff will be ideal for all tracks and road use .
3:45 too tall
3:9 could be too short
3:7 possible compromise

[anonymous-user]

astonman said:

The cars 3.6, I want a CR box ( I hate the gap between 2nd and third in the standard box) and the 3.9 diff makes sense .
I want the ultimate fast road / trackable machine ( still using the 3.6).
I like the spring / damper set up I've evolved,which is Nitrons with 500lbs/inch front and 450lbs/inch rear,for the road.
I want a drive train to compliment this.last time I took the car out,we were late,and I noticed a significant issue with one black line and not two, with the Hydratrac.I don't think it's really up to very determined driving?
I have experience of ZF style locking diffs, is the quaife too tame?

I tracked, hillclimbed and sprinted my first Sagaris for 5 years, never had an issue with the hydratrack, in fact the only issue I had was fuel starvation on some circuits.

Quaife gets good reports, but compared to a plate diff, it's a compromise for track use. I would stick with the Hydratrack to be honest.

What brakes are you using?

[spitfire4v8]

Am I the only person wanting to make my diff taller ratio? I find the 3.7 in the 4 litre too low geared, and i have the close ratio box with taller first 3 ratios too.
I don't think a 6speed box is an easy or cheap install, I'd love better (less frantic/buzzy) cruising so I'm seriously considering going for a taller final drive. I'm not sure if there's anything between a 3.08 and 3.45 in the btr range though is there ? 3.08 might be a bit tall with the CR gearbox for setting off/traffic, and 3.45 not enough of a change (got that in the cerbera and that's ridiculously low geared too!)

I don't find crawling in traffic an issue at the moment, and wheelspin is easy in first and second, so a taller final drive will dull the wheelspin slightly, give me more relaxed cruising, and better fuel economy (important when you do long journeys).

[ridgey]

Hi Joolz , got the 3:22 for the s3rbera from JR direct swap for 3:44 plate
Found the 3.44 in the t350 too tall at setting off speed so went 3.77
The cerbera is 4.5 and find the standard 3.44 diff ok
I've still got the t350 3.44 diff if you want to try it

[astonman]

Which diff case do I already have? M80 or M78. May 2005 T350.