Performance diff info thread.

For non EFI mechanical discussion
brindo
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Location: Western Queensland

Re: Performance diff info thread.

Post by brindo »

The first one I bought was from Supa F Spares and the second one from Mace. But both would be the same version which is what Mace currently sell. Both were around double the price of the one in your link so it’s unlikely they are the same item – potentially nothing wrong with them though.
Buy it and let us know how it goes :thumbup:
vp304
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Joined: Wed May 19, 2010 2:21 pm

Re: Performance diff info thread.

Post by vp304 »

Thanks for the info mate
Will see how i go another project to add to the list lol
VK_3800
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Re: Performance diff info thread.

Post by VK_3800 »

immortality wrote: Mon Jan 15, 2024 9:23 am I have a Harrop that I want to use in my Senator but I've not found a solution yet :( except stripping the diff and taking it to a machine shot so they can cut the required groove.
Would be worth asking to see if anyone is interested in doing that. Same old story with it being too small a job to be worth the hassle, but has to be fairly simple to do. I'd be tempted to set up a small cutting disc on a die grinder and feed it in somehow.
immortality
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Re: Performance diff info thread.

Post by immortality »

If I had a lathe I'd probably attempt it myself (good excuse to by a little die grinder).
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vlad01
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Re: Performance diff info thread.

Post by vlad01 »

VK_3800 wrote: Mon Jan 15, 2024 3:56 am I have a Harrop-cased Eaton Truetrac; note these never actually lock, just transfer torque around provided there is some amount of traction. But good for street driving and laying down power out of corners for that very reason, it's quite cool getting forward drive while one wheel is spinning.

Regarding the cheaper version I definitely would have tried this if they were available at the time as the Harrop option you basically pay full price, twice! No idea on longevity but I would think if it works initially then there's no reason why that would change over time as the gear design doesn't wear like a traditional LSD.
That's ideally what I want to move to on future projects where LSDs will be necessary. The KAAZ is a handful when putting a lot of power down on take off or out of bends, bends are something you can control easily once you get used to it. On straight launches it often wants to do a 180 lol, you have to counter steer heaps on straight launch. Open diff not so much and I would imagine the Truetrac would be similar, probably better.

The issue I have with open diff is only on wet greasy roads where the wheel spin swaps back and forth in a oscillation type of mode, this is highly unstable and hard to control but having good tyres reduces the severity of it.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
vp304
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Re: Performance diff info thread.

Post by vp304 »

Vlad01 maybe you can try the $380 chinese tru trac tell us what its like hehe
immortality
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Re: Performance diff info thread.

Post by immortality »

With the Truetrac I find it will kick the back out initially but then tend to come back inline. Quite predictable once you get used to it. The worst thing I find is that traction control than kicks in and you end up going no-where.

At the bottom of our street is a nasty little T intersection heading uphill with very short sight lines and if there is even a hint of moisture as soon as the rear wheels hit those double lines it'll spin because you need to give it a decent amount to take a gap. With the Truetrac I find it will spin, but the diff quickly does it's thing and will start to push the car straight so then you need to correct the turn as it's now pushing across the road. It's kind of counter intuitive as mostly you'd expect the back of the car to over-rotate so you need to counter steer and get in opposite lock to correct a slide with a normal factory type LSD which it will still do if you decide to give a boot full and purposefully step the back of the car out.
VK_3800
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Re: Performance diff info thread.

Post by VK_3800 »

vlad01 wrote: Mon Jan 15, 2024 8:33 pm The KAAZ is a handful when putting a lot of power down on take off or out of bends, bends are something you can control easily once you get used to it. On straight launches it often wants to do a 180 lol, you have to counter steer heaps on straight launch. Open diff not so much and I would imagine the Truetrac would be similar, probably better.
Yeah I had a Lokka before and it would completely lock axles as soon as one wheel starts spinning, giving the 180 result all too easily. Especially with a short wheelbase like the Torana.

Exiting corners with the Truetrac you can power on early; the unloaded tyre lays rubber but with limited over-speed, the harder it turns the more it transfers torque to the loaded tyre which stays stuck to the road and offers a lot of forward drive. No counter-steering at all, but it doesn't just light up the spinning tyre and go nowhere like an open diff would. Of course after a certain amount of throttle both tyres still let go regardless :-)
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