Alfa Romeo Owners Club of Australia Forum

Technical => 932 Series (156, GTV, Spider, 147, GT, and 166) => Topic started by: Colin Byrne on May 18, 2021, 08:54:41 AM

Title: Plate Type LSD
Post by: Colin Byrne on May 18, 2021, 08:54:41 AM
Hi guys
just wondering if anyone has any experience with Plate type LSD's for the 6 speed boxes.
As we're running the engine/drivetrain as a RWD in the Stratos not sure the standard Q2 diff is going to be all the suitable

AHM lists one that looks pretty good, but exchange rate and shipping is going to be pretty bad

Kaaz diff's list one that fits, I contacted the local dealer, but have had nothing back

Anyone got any other ideas or experience?

Cheers
Title: Re: Plate Type LSD
Post by: Cowie on May 28, 2021, 07:48:31 PM
G'day Colin, I have a plate diff in my 147 Gta gravel rally car.
AHM stock them, but it is actually built by Gripper Differentials in the UK. I have used Gripper diffs in a few of our rally cars now, can highly recommend them. They will set it up to your preference of preload and ramp angles.
They also custom build diffs, they've just done one for us, and a mate of ours helped sort out Mal Keoghs centre diff for the Quattro, which is also a gripper.
As for plate type diffs vs torsen (Q2, Quaife etc), don't waste your time or money. Torsen diffs don't work anywhere except at the traffic light GP. That's why anybody that knows, or anybody that wants to be competitive, uses a plated diff, so you're right about the Q2 not being suitable 👍
Title: Re: Plate Type LSD
Post by: Evan Bottcher on May 30, 2021, 09:51:25 PM
Our 156 GTA race car had a plate type fitted when it was first built back in 2003, the diff was built in the UK.  The Q2 was not available at that time.  In 2019 a clutch failure led to destruction of the bell housing and transaxle housing, so we swapped in a spare transaxle that I had on the shelf, with a Q2 diff centre.

Because of a global pandemic, we didn't get that much track time in until this year - Phil and I are both really surprised at how much worse the Q2 performs compared to the plate type diff.  Night and day.  The plate diff will go back in to the car at first opportunity.  Don't waste your time with the Q2 is my opinion.  I expect the difference would be even more severe in tarmac rally.
Title: Re: Plate Type LSD
Post by: alfagtv58 on May 30, 2021, 10:13:43 PM
Nothing to add that hasn't been said Col, other than to confirm what the other folks have said....night and day difference.
Title: Re: Plate Type LSD
Post by: Colin Byrne on May 31, 2021, 05:11:48 PM
Awesome guys, the info that is, not what it's going to do to my wallet...

I'll fire off an email to Gripper and see what i get, AHM have got some nice stuff but they charge a heap for shipping and when i got the ITB had to pay via International bank transfer it all added up pretty fast

Evan, very interested to know what the clutch failure was, was it a pressure plate failure by any chance? did the centre of the pressure plate come loose? any photo's?

thanks again guys

Title: Re: Plate Type LSD
Post by: alfagtv58 on June 01, 2021, 09:39:51 PM
It happened in the 12 Hour.  All the consequential damage added up...
Title: Re: Plate Type LSD
Post by: Colin Byrne on June 02, 2021, 07:20:56 AM
Thanks Phil!
OK so i was completely wrong, full failure of the clutch disc, haven't seen that before, but I've never run that type of clutch plate.

Yea clutch failures can do some damage, can't they!
Title: Re: Plate Type LSD
Post by: Evan Bottcher on June 06, 2021, 08:12:40 PM
I've bought some things from AHM via credit card, no international bank transfer - I guess CC comes with it's own charges.  A few years ago I bought a LSD centre for the Sud from AHM, got it delivered to our London office and then picked it up myself when I was over there.  I brought it back in my hand luggage!

I bought the torsen style for the Sud, and one day when that car gets resurrected I think I'll try to source a plate type.  The diff in the Sud and the Q2 feel quite similar - much better than a standard diff, but no good out of the tighter stuff.
Title: Re: Plate Type LSD
Post by: Sheldon McIntosh on September 10, 2021, 09:21:51 PM
After reading this thread, and then doing some research, Gran Turismo on the Playstation 25 years ago makes so much more sense now. 
Title: Re: Plate Type LSD
Post by: Alfatango on September 10, 2021, 10:18:01 PM
Quote from: Sheldon McIntosh on September 10, 2021, 09:21:51 PM
After reading this thread, and then doing some research, Gran Turismo on the Playstation 25 years ago makes so much more sense now.

Except slicks don't cost $40,000 while an s13 J Silvia does ;D