differential

[hound dog]

I have purchased the Windsor motor for rebuilding this winter. So I'm pretty well set on what I'm going to do in the "go" department. Question is what am I going to do in the "anchor" department. I'll probably go with the Jag rear end but what is best for running the road courses, standard differential or "posi-traction" differential. I know that a locked rear end is best for drag racing and street racing (although I never do any of that), but what goes better on the road course?
Thanks,
H dog

[wadesdad]

A locked rear end is just that. Both wheels fixed or tied together for better or for worse, in sickness..... It is a set-up I've used in racing, but not good for the street. (the rear wheels fight eachother in turns. Both wheels are turining at the same rate, but on different radius circles in a turn. It typically makes them "chirp" or bind. (A 4x4 in low range will give you the same sensation as you turn).

A "posi-traction (GM?)" or "torque-lock" (Ford) is a limited slip rear-end. With as much power as you intend, you definately need a limited slip rear-end. As one wheel begins to slip, the other joins the traction party. I'm using a torque-lock 9" Ford 3.50:1

Good-luck. I'm in the same winter-build phase as you are.

[hound dog]

Wadesdad,
That's kind of what I thought, but I wasn't sure if the posi-traction rear ends would cause any binding in tight corners. What are you putting in your 351? I'm intending to go with a stroker kit from Speedway Motors, Ford N351 heads, and Crane roller cam. I've ordered the Dyno 2000 program to run the numbers on this combination to see if it's what I want before I buy all the stuff and put it together. Seemed as though it was $50 well invested.
H Dog

[wadesdad]

Hound Dog,

Not yet decided on cam. I'd be interested to see how the program works. I was leaning toward something I came across in a 351M/400 build-up article, but it's a custom order now.
Comp CAms X-Treme Energy P/N 32-000-5

Other similar cams exist, I'm just sifting through all the data.
Advertised
IN 268
EX 268
Actual @0.050"
IN 224
EX 230


What is the "Stroker Kit" you referred to. I didn't see it on the web site.

Dual Plane Edelbrock intake most likely.
Finally, receiving conflicting carb info. 650 or 750?
With 400 plus cubes I'm not sure
(not known how much overbore required to straighten things up)

[2fast]

So what type of kit are you planning to put the differential into?

[hound dog]

wadesdad;
The stroker kit is listed on their website speedwaymotors.com. Look in the race parts catalog under the Ford parts and you'll find a stroker kit on page two that includes a Scat cast steel crank, H-beam rods, Keith Black pistons, and rod and main bearings for $1149.00 I think. The crank is the 3.85 in. stroker. They also have the Jack Roush cast iron heads for under $1,000.00, which look the same to me as the N351 Ford heads. I'll have to call to check on that one. But, they seem to have some pretty good deals on speed parts. Check 'em out.

2Fast;
If I was buying today, I think I would be going with the Unique deluxe pallet kit. It comes with the Jag rear end and the frame already powder coated. I reckon I need to be at VIR this weekend checking things out! Unfortunately too many things to do here right now! What kits do you prefer?
H Dog

[2fast]

Hound Dog

I just don't like the Jag rear end. Personal preference, I guess. And I don't like the inboard brakes. I like the Tbird based IRS used on the Superformance and FFR. I also like the Corvette based IRS used on the Hunters. Either way, you want a limited slip differential. Until you get the kit settled on, I would recommend that you concentrate on the engine and transmission type choices that are pretty much useable with any kit.

[hound dog]

2fast;
Yep, that's the way I'm heading.
Thanks,
H Dog

[wilf leek]

Hound dog - my car currently has a non-lsd jag diff, and for road use, it is a sweeter, better handling car than when it had a lsd. On the track it's a totally different matter - it just spins the power away through the unloaded "inside" wheel.

Since my use of the car is 99% road, 1% track, I'm gonna keep the non powerlock diff in it for now.

If your kit is designed for jag diff, and you want track time primarily, then go for the powerlock item. I can't comment on the various US LSD differentials 'cos you can't easily get 'em in the UK anyway! We all use jag diffs, or some kits now using Cosworth items.

HTH

Wilf

[Campy]

I also run a 351W up front with a solid Ford 9" in the rear.
In an effort to facilitate getting my car completed, I simply had the stock (non-limited slip) third member rebuilt by a local shop.
I purchased the rebuild set and new gears from Summit Racing.
I decided on a 3.50 gear set. I have a 5 speed T5 Tremec.

The results:
Off the line I can smoke em almost forever. The car stays relatively straight with very little deviation. If I intentionally leave a short strip of rubber, they are equal in length. This tells me, that as long as my car is pointed straight ahead, a limited slip would do me little benefit. However, if I were racing and expecting to translate as much horsepower to the road whilst in a turn, I'm confident a limited slip differential would be well suited.

My only regret, in retrospect, given my engine and tranny combo, I should have used a 3.73 or possibly a 3.90 gear set.

That's OK, it gives me something to do next summer.

[Campy]

Deleted,
Inadvertent double post, sorry.

[Zderf]

You don't want a locker for the street... period. The latest technology for limited slip is the Detroit Tru-Trac. No clutches, all gears, so forget the special lube stuff.

Check out their offerings:

http://www.tractech.com/Products.htm#true

I can't say enough!!


Zderf