Spool w/V8 & 88" wheelbase - will I regret this?

Would I regret running a spool or Lincoln Locker in an 88" wheelbase rwd car with V8? Say, early Pontiac Firefly (Chevy Sprint)?

Would a spool be wiser than a lunchbox locker?

You might not, but your tires surely will.

If I were building such a critter as you describe, it would have a spool in it. Bad handling, but awesome traction...

Im pretty sure it will suck big time. I had a lockrite in my jeep and it wasnt bad once you learned how to navigate turns. You have to coast through the turn. So stop a little bit back at the stop sign, goose it, then let off the gas as you turn. That lets it unlock. What is the intended use of the vehicle?

First of all, if you want this car to grip corners decently, don't put a locker or spool in it. These kinds of diffs are useful only for going fast in a straight line, getting traction off road, and drifting.

Next, if you drive on the street with a spool or locker, tire wear on the affected axle will be greatly accelerated.

An exception might be a manual locker. It can act like an open diff or a spool depending on the position of a switch. They're madly expensive though and most require you to add a compressed air system to the vehicle for actuation.

Get a clutch limited slip and call it a day. You will hate a spool on the street.

Spool + really soft rear springs + really stiff rear sway = lift inside rear tire to navigate turns with ease.

Good 'Ol Fashion Posi unit will do both drag and corners as it sounds like the car will be lite, A Spool IS ONLY good in a straight line and heavy duty Lockers are for heavier or racing cars, not needed for what it sounds like you are After.

Ever wonder why you see so many drag cars run into the wall? mostly it's due to spools and non-articulating rear suspensions.

My street car runs mid 5's in the 1/8th with a TruTrac diff and a torque arm. It's easy to push in the lanes all by myself, and it can coast thru a u-turn on a two lane road. The savings in tire costs for a street/strip car will pay for the diff pretty quickly.

Triumph TR8 race car. 85"wheelbase. V8 power. I was faster with an open diff than a locked diff except for climbing the off camber turn into the hill at New Hampshire. Fastest of all was with either a Quaife in a stock rear end, or my personal preference, a Ford 8.8 with limited slip. If you were just running a 1 mile oval, then you'd be fine. Any tracks with tight turns or street driving, forget about it.

Appleseed wrote: Get a clutch limited slip and call it a day. You will hate a spool on the street.

This. You'll still be able to step the rear out at will but it'll be more controllable an you'll get better launch off tight corners.

I was told what a nightmare a spool would be to drive every day on the street. I had a spool in my only vehicle for a long time.

Those guys couldn't have been more wrong. Snowy roads were amazingly easy and pleasant to navigate, dry roads barely made any difference save for some chirping under power around sharper turns.

Can't say without a micrometer if there was increased tire wear or not.

This was in an XJ Cherokee with a Dana 44 if that matters.

I always wondered if the guys that warned me over and over had ever driven anything with a spool or were they just repeating what they heard from some imaginary person.

I can vouch for Detroits on Jeeps too. Daily driven (as in, their only vehicle) was hardly noticed.

In reply to ebonyandivory:

Keep in mind, stickier tires will multiply all of the bad effects of a spool. Typical Jeep tires will make it a lot more liveable than sticky performance tires. And the shorter the wheelbase is relative to track width, the worse it'll be as well.

In reply to rslifkin:

Sure, I acknowledge those points. The footprint of a large all-terrain tire on a 79.9" wheelbase Samurai must magnify a spools effects but I know of dozens of guys with Lincoln-locked rears without issues. Certainly none that made them regret it.

drove a 430whp chevy nova with a spool (and crappy no-season tires) at an autocross.

The rear end didnt take a set like other cars. You will always be mid corner with some degree of drift happening. That said, very controllable drifting...

Driving a welded diff in the 95" wheelbase RX-7 was just fine. Drove just like the limited slip. Heavy understeer unless you're on the throttle, and then the nose dove into the corner when on-throttle. (This is kind of the opposite of "the back end slides out" - it would feel like something was pulling the front bumper to the inside of the corner)

Just don't back up and turn.

ebonyandivory wrote: I always wondered if the guys that warned me over and over had ever driven anything with a spool or were they just repeating what they heard from some imaginary person. I can vouch for Detroits on Jeeps too. Daily driven (as in, their only vehicle) was hardly noticed.

I DD a Samurai with an automatic locker in the rear axle...it doesn't unlock much, so it mostly acts like a spool. I'm going to try different springs & pins to fix that.

Anyway, even on a light vehicle the wear on the rear tires is definitely accelerated. On clean pavement, it leaves skidmarks on every turn like a tank or a Bobcat. In turns you can feel the locker resisting rotation, more strongly the lower the speed. Sometimes in slick mud the effect is so severe that it doesn't rotate at all on power and whips sharply into turns off power. I don't think it has much effect on peak cornering but it's definitely not good for handling and agility.

There's plenty of chirping and chuffing on any low speed turn, that could be annoying.

Seems like you could mimic Kart geometry to make it handle.

ebonyandivory wrote: I was told what a nightmare a spool would be to drive every day on the street. I had a spool in my only vehicle for a long time. Those guys couldn't have been more wrong. Snowy roads were amazingly easy and pleasant to navigate, dry roads barely made any difference save for some chirping under power around sharper turns. Can't say without a micrometer if there was increased tire wear or not. This was in an XJ Cherokee with a Dana 44 if that matters. I always wondered if the guys that warned me over and over had ever driven anything with a spool or were they just repeating what they heard from some imaginary person. I can vouch for Detroits on Jeeps too. Daily driven (as in, their only vehicle) was hardly noticed.

I think this is a little different application than what we're assuming the OP is going to use his car for.

I had a spool in my Samurai for about 500 miles. The tire wear was significant to say the least.

Rears with spool.

Fronts.

It also drove like a broken wagon. I hated it.

For a track only car, I could probably stand it, otherwise no way.

https://www.youtube.com/embed/H4c1V637XNo?ecver=1

Nothing useful to add so here's some wheelstand carnage.

Recent info on one of the British Car forums in the Motorsports section. Tested in an MGB, the welded rear end came out ahead of the Quaife and spool in nearly all conditions. Lost a bit on short up hill turns, gained some on long lazy lefts, but over-all the welded rear won the day.

If I can find a spool for the Mustang II rear end I'll grab it right up, otherwise it'll be welded; going into an extremely light MGA with a real front end weight bias.

^That's odd, there should be zero difference between a welded diff and a spool. They both force both rear wheels to turn at the exact same speed at all times.

I run a mini-spool in both of my Nova's (cause they're cheap) which are both street driven and autocrossed; one 500hp with 255 tires and the other 400hp with 315s. Outside of slow/sharp corners you would never know.

They do make for very predictable and gradual rear slip-angle and the straight line traction is amazing.

The fastest autocross cars I know run lockers with soft release springs.

This is good discussion, and good points.

The intent of the car is first and foremost: street driven.

I want to do autocross, hillclimb, and drag racing, albeit not really seriously.

A spool is cheap (challenge friendly), a Lincoln Locker is even cheaper (challenge friendlier), and any type of proper limited slip is approximately $500 regardless of what type.

I'd say run the spool. The only downside over a differential is that spools are slower at the dragstrip, although this might be able to be mitigated by paying close attention to tire diameters. (Only reason I can think of why installing a spool will reliably make you a tenth or two slower)

Again, I hardly noticed any difference in the RX-7, and I drove it just about everywhere. On the other hand, I had been running limited slips shimmed so tight that they never broke loose except in tight, low-speed turns, and only if the road was dry. Then it made all sorts of barking/cracking noises. I know the breakaway torque was well over 250 ft-lb.

(Also, one of my customers sunny-day commutes with a vehicle with a spool. And 165R15 front tires and 31x18.5x15 DOT-legal slicks. No problems for something like a decade now)