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Datsun LSD VS Welded Diff

Posted: Sun Sep 29, 2013 5:34 am
by Steve49841
Does anyone have experience running a Datsun LSD in a race car. I'm currently using a welded Diff which is okay on a road course but I don't like it for AutoX.

Re: Datsun LSD VS Welded Diff

Posted: Mon Sep 30, 2013 9:22 am
by Mike Unger
Yes, I've used all types. What is your question?

Mike

Re: Datsun LSD VS Welded Diff

Posted: Mon Sep 30, 2013 6:39 pm
by Steve49841
Good point, I should have asked a question. Is a Datsun LSD up to the job of handling the loads put on it by a race car or is something else better.

Re: Datsun LSD VS Welded Diff

Posted: Mon Sep 30, 2013 7:28 pm
by Mike Unger
Very much up to it. The H190 LSDs have been used in a wide variety of Nissan race cars (roadsters, 200SX, HL510, 1200 GTL etc.) for many years. They require shimming of the clutches to get the desired break away depending on the car set up and application. I use one in my roadster road race car.

Re: Datsun LSD VS Welded Diff

Posted: Tue Oct 01, 2013 5:24 am
by Steve49841
Hey Mike, thanks for the info... I have a few more questions. One, Is there anything different about an LSD install VS a non LSD. Two, where would I get the shims you mentioned. And third, do you know where I might track down an LSD unit. Thanks....Steve

Re: Datsun LSD VS Welded Diff

Posted: Tue Oct 01, 2013 7:33 am
by Mike Unger
They occasionally show up for sale here. You can post a wanted ad. The pumpkin itself is the same and it installs the same in the rear housing. The ring gear carrier is the LSD part. The unit needs to be assembled by someone that knows what they are doing as the pinion height and gear backlash are critical for it to last and must be set up correctly if you are installing the LSD unit in a different rear or changing ratios. They made two sizes of LSD carriers for differing thicknesses of ring gears. I think 4.38, 4.62 and 5.125 were the 4mm wider gear carriers. You can use the thinner ones with a 4mm spacer to install one of those ratios but obviously not visa versa. Make sure you get one that will fit your desired application. A LSD made for the 4.62 won't go into a 3.89 for instance. The clutch shims can be made by cutting them out of sheet shim stock. They look like big flat washers the size of the friction discs. They go on top of the clutch stack before assembly. They set the preload to the clutch.

Re: Datsun LSD VS Welded Diff

Posted: Wed Oct 02, 2013 5:57 am
by Steve49841
I've located a unit with the ratio I want so changing the ring gear will not be an issue. Setting the preload and actual installation will have to be dealt with however. From reading your reply I need to pay attention to what I'm doing, thanks.

Re: Datsun LSD VS Welded Diff vs. Ford 8"

Posted: Mon Feb 03, 2014 11:45 pm
by TexasStig
On another thread, Steve Heimsoth mentioned swapping in a 8" Ford read axle. I didn't find this swap mentioned anywhere else, so was wondering if anyone else did that as well and what all was involved.

Re: Datsun LSD VS Welded Diff vs. Ford 8"

Posted: Tue Feb 04, 2014 1:00 am
by Alvin
TexasStig wrote:On another thread, Steve Heimsoth mentioned swapping in a 8" Ford read axle. I didn't find this swap mentioned anywhere else, so was wondering if anyone else did that as well and what all was involved.
go here, scroll down:
http://311s.org/phpBB3/viewtopic.php?f= ... e&start=45" onclick="window.open(this.href);return false;

Image

Re: Datsun LSD VS Welded Diff vs. Ford 8"

Posted: Tue Feb 04, 2014 9:19 am
by spl310
Alvin wrote:
TexasStig wrote:On another thread, Steve Heimsoth mentioned swapping in a 8" Ford read axle. I didn't find this swap mentioned anywhere else, so was wondering if anyone else did that as well and what all was involved.
go here, scroll down:
http://311s.org/phpBB3/viewtopic.php?f= ... e&start=45" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Image
Mmmm... Sexy...

Re: Datsun LSD VS Welded Diff

Posted: Tue Feb 04, 2014 12:03 pm
by Gregs672000
What a sexy beast that car is in the referring thread. Truly incredible and highly professional work!

Re: Datsun LSD VS Welded Diff vs. Ford 8"

Posted: Tue Feb 04, 2014 3:16 pm
by SLOroadster
spl310 wrote:
Alvin wrote:
TexasStig wrote:On another thread, Steve Heimsoth mentioned swapping in a 8" Ford read axle. I didn't find this swap mentioned anywhere else, so was wondering if anyone else did that as well and what all was involved.
go here, scroll down:
http://311s.org/phpBB3/viewtopic.php?f= ... e&start=45" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;

Image
Mmmm... Sexy...
Mmmmm HEAVY! My friend Tim had a Ford 8" rear end on one of his race cars, it was far heavier than the stock one. Sure diff internals are easy to source, but the axles are still custom, and yeah its way heavy.

Will

Re: Datsun LSD VS Welded Diff

Posted: Tue Feb 04, 2014 3:48 pm
by spl310
Yes, it is heavier than stock, but that is not going behind a 100hp engine either. I doubt that the driver will EVER destroy that rear end. And it is not as big and stout as the legendary 9"!

Re: Datsun LSD VS Welded Diff

Posted: Wed Feb 12, 2014 3:53 pm
by RC240z
It IS heavy, but if you have the HP to back it up, okay...

Not vintage, and heavy from a racer perspective. Takes the broken axle problem off the table...full floating Toyota units with rear disc brakes are an option too. Bullet proof, rugged and not as heavy....But I digress....

R

Re: Datsun LSD VS Welded Diff

Posted: Thu Feb 13, 2014 1:44 am
by fj20spl311
For a race car...if the rules allow....I would get a Speedway Quick change
Either a hot rod version:

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Or a full floater Mini Stock:

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