Rear end build up advice...

nmcgrawj

Advanced Member
Sep 28, 2003
3,651
4
68
Indianapolis, IN
Whats up guys, im throwing around ideas in my head on what to do for traction/60ft times. I was thinking coil overs...then i thought control arms and subframes....and then i thought "well i gotta get new gears put in so why not go ahead and get some axles and a new differential put in"

So who all is running a f150 posi and 31 spline axles? That will be able to take a lot of abuse right? how do the f150's compare to auburns or another company like that?

Best and cheapest would be to get the posi from a junkyard, rebuild it, and get some axles and throw them in right?

Can someone explain how or why putting extra clutch packs in benefits you?

Thanks
 
nmcgrawj said:
ok so more clutch packs make more friction which puts more power to the ground....gotcha :nice:

Actually, let me modify my equation...

Extra clutch disks = increased surface area = increased friction = more tq required to overcome the friction.

It's a simple step I dropped in there, but an important one none the less.
 
baglock1 said:
Actually, let me modify my equation...

Extra clutch disks = increased surface area = increased friction = more tq required to overcome the friction.

It's a simple step I dropped in there, but an important one none the less.


So that "more torque required to overcome the friction" is then put into the ground for better performance right? When i first read it, it seemed like it soaked up torque kinda like an automatic transmission does HP.
 
nmcgrawj said:
So that "more torque required to overcome the friction" is then put into the ground for better performance right?

Yup. Push your index fingers together as hard as you can and turn them in opposite directions. You can easily overcome the friction between your finger tips, right?

Now push against you palms together as hard as you can and try to twist the hands apart. It's much harder to do. (note: any hair on the palms may give a false friction coefficient ;)). The same amount of force is being used, but by adding surface area to the friction surfaces, they can hold more force before breaking loose.

Now by adding clutch disks, you're creating more surface area and so thay can hold more tq before breaking loose. What this means is both wheels will get an equal amount of force instead of one getting all the tq and going up in a cloud of smoke (the "one wheel peel" as it's called). This gets you down the track faster.
 
Nate - from what I understand, you're going to be doing a 351 build, right? If so, that will grenade the rear end if you launch on a stick tire. I just ordered a set of Moser axles. Why Moser? Well, I'm not really sure. I've heard and seen too much bad about Strange. FMS axles just cost too damn much. Superior is an option (and a good one I might add), I just felt that Moser had a better reputation.

Joe
 
baglock1 said:
After reading (and responding) to your other post, I'm not sure you should bother upgrading right now. How much power are you putting to the ground now, what are your planned power levels, and what's your budget?


Nah Joe, cant afford the 351 in college right now. Im just going to be doing a h/c/i 302 rebuild on the stock shortblock. I plan on having in the normal area of 300rwhp like every other h/c/i 302. Its definantly NOT for the mods i have done right now. Its gonna be a project for this winter.
 
nmcgrawj said:
Nah Joe, cant afford the 351 in college right now. Im just going to be doing a h/c/i 302 rebuild on the stock shortblock. I plan on having in the normal area of 300rwhp like every other h/c/i 302. Its definantly NOT for the mods i have done right now. Its gonna be a project for this winter.
From personal experience...

You will need to upgrade the rear end. Axles, posi, everything. It will blow up - it's just a matter of time. After a smokey 2nd gear burnout with a line lock and slicks, I rolled through the beams at 3500 RPM and grenaded everything. Posi, axles, bearings, trans, driveshaft - everything.

Joe