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dropstep
dropstep Dork
4/21/17 7:55 p.m.

My friends s10 ran a mini spool on the street for 2 years. Other then parking spaces it was alright. 275 rear tires and the occasional dragstrip pass.

BrokenYugo
BrokenYugo MegaDork
4/21/17 8:07 p.m.

That's a 7.5 10 bolt right? Lincoln locker it for now and wait for a deal on a used factory posi carrier out of a F/G body?

SkinnyG
SkinnyG SuperDork
4/22/17 12:09 a.m.

It's a 7.5" F-body 10-bolt, yes. Currently sporting 2.73 gears, but with 22.6" tires that's still over 2500rpm on the highway with a 3-speed.

Where is the carrier split for a factory posi on these?

I think Summit lists LSD for 3.23+. I have an open carrier with 3.42 gears, but then I'd be cruising at 3200, and could probably use an overdrive. And definitely some kind of traction aid.

Knurled
Knurled MegaDork
4/22/17 7:20 p.m.

This is the point where the older guys I work with would scoff, and talk about the days when they drove big block Chevelles with 4.56 gears on the highway, and they ain't no overdrive in an M21.

The carrier break is somewhere around 3.23. It wouldn't be possible to put tall gears on a 3-series carrier, the ring gear mounting surface is too far over to the right. What you want is a 2-series carrier. I could have sworn that Chevy made 7.5" rears with a 2.73 and Posi.

Is taller tires an option? I stuff 205/70-15 tires on the back of the RX-7 to cut the highway revs down. Just a little bit more circumference than a 185/70-13.

jarrettp
jarrettp New Reader
4/23/17 8:48 p.m.
Robbie wrote: Spool + really soft rear springs + really stiff rear sway = lift inside rear tire to navigate turns with ease.

When I was in uni I was in baja SAE and all of our cars were mid engine, rear wheel drive, and spooled, as are a good 90% of the cars in that competition. Usually ranging from 50/50 to 40/60 weight distribution. Rates were soft be necessity, and the cars had a tendency to understeer until you put a lot of rear roll stiffness in. Our best handling car was a swingarm design sort of like the back of a quad, and on pavement it would lift the inside rear 6" off the ground. Was highly maneuverable and definitely a blast to drive. Picture of a nearly identical design from another school below, it behaves like a solid axle with a massive swaybar. You won't get any push from a spool if your rear weight transfer is at 100%.

http://imgur.com/a/XNMaD

BrokenYugo
BrokenYugo MegaDork
4/23/17 9:09 p.m.
Wall-e
Wall-e MegaDork
4/24/17 7:26 a.m.

It seems if you want to drive on the street with a locked rear your need soft thick sidewalls like drag or off road times. My dad had a welded rear in his Monte Carlo with low profile tires when we were kids and my mother hated driving us to school in it. Eventually he put a freewheeling tow hub on one side until they could get a second car.

Sky_Render
Sky_Render SuperDork
4/24/17 8:14 a.m.

Personally, I wouldn't run a spool on anything that isn't a drag-race-only car.

I think an Eaton TrueTrac is much better for street use.

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