Hi guys,

I have a Series 2 EL XR8 Auto. Its in really good condition with only 132,000ks.

So far mods are limited to just air filter/maf pipe (next week) and extractors/exhaust.

I am not chasing big power or 1/4 times with this car. Truth be told it will never see a dyno competition or 1/4 run. I am just looking to make it a fun street car.

So based on that I have been recommended to get a set of diff gears and a new stall for better acceleration.

I wont do alot of highway driving so I was thinking maybe a set of 3.9s? What are peoples thoughts on this and assuming my LSD is in ok condition what should I expect to pay for the change?

Also everyone who gets stall convertors seems to love them and love the extra performance they give? So I know I want a lock up type but what stall would be appropriate, 2500ish? What should I expect to pay for this work?

The car will eventually see a set of AU heads/throttle body/MAF and a tune if this helps but that is probably as far as I will go in the shorter term.

If anyone can recommend good workshops is SA I would be happy to hear from you.

Thanks!

For what it's worth and in the context of giving an insight into the change with diff ratios, I went from 3.08 to 3.45 diff in my Automatic ED and noticed nothing in off the line performance and not enough change to cruising revs to have made it worth while - ie. not sure how the 8 stacks up (especially an XR) but a 3.08 (Gli / Futura) 6 has you having to manually select third below 80kph for comfortable driving and below 60 then it's down to 2nd. Going to 3.45 made it a tiny bit more flexible but not much - manually selecting lower gears in the auto was still necessary all over the place - and off the line was NO different. I always felt I should have gone to 3.7 or 3.9 at least.

I realise you're probably looking at different ratio situation of course (already 3.45? ), but I'm getting at the qualitative change with the order of magnitude of ratio change - ie. anything similar in scale as 3.08 up to 3.45 IMO will be a total waste of money and effort - if you're running 3.45 now then it needs to go to at least 4.11.

Alternatively:

I've now got a roughly 2500/3000 stall converter in my 3.08 diff EF 6 (it's Gli but with engine mods makes more power than std XR6) and overall it's STREETS ahead of when I went from 3.08 to 3.45 diff - off the line is easily as good as manual with 3.45 diff and traffic tractability is great - don't need to bother with manual downshifting any more and when you poke the pedal it responds real nice. This car now goes better and is nicer to drive than the ED did with 3.45 diff and manual conversion.

If I were you I'd definitely start with a torque converter upgrade and THEN look at the diff. Pretty sure doing the torque converter will be cheaper anyway - and I might be wrong, but I'd tip that within a week of having a higher stall converter you'll stop even thinking about the diff