Well...

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balduccibros
Posts: 25
Joined: Wed Jun 05, 2013 10:33 am
Bronco Info: '75 Bronco 4600 class legal. Built for east coast racing.
Location: Cumberland, MD

Re: Well...

Post by balduccibros »

Very cool bronco! I'm curious what the advantage of the jounce shocks is compared to other shocks(I've never heard of them before). Also why would you choose a nwf black box/atlas over just a 4 spd. Atlas?

The 2002 looks like it will be badass when its all done!
yellowbronco
Posts: 19
Joined: Wed Jun 05, 2013 1:18 pm
Bronco Info: '69 with a 426 inch windsor, air suspension, full width axles, yadda yadda yadda

Re: Well...

Post by yellowbronco »

balduccibros wrote:Very cool bronco! I'm curious what the advantage of the jounce shocks is compared to other shocks(I've never heard of them before). Also why would you choose a nwf black box/atlas over just a 4 spd. Atlas?

The 2002 looks like it will be badass when its all done!
Here's why the jounce shocks are better than just a standard rubber bump stop - First of all, they're not connected to the axle like a regular shock. They're mounted to the frame just like a rubber bump stop. Next, let's say you hit a really big bump at speed and you've got regular rubber bump stops. The rubber will compress and keep the axle from hitting the frame but it will then rebound shoving the axle back downward causing a large rebound in the suspension and the vehicle will be likely to bounce up into the air from this rebound. The jounce shocks are charged with nitrogen which acts as a big spring to protect from the axle hitting the frame (just like the rubber bump stop). However, the jounce shocks also have hydraulic shock oil and a compression/rebound valve stack just like a shock absorber and they can be tuned so that they return to their extended state more slowly and don't shove the axle back downward. The feeling when driving is that the vehicle "sticks" to the ground when landing from a jump or hitting a large bump. The less time you spend in the air, the more time your tires are on the ground maintaining control.

Now for my choice of gearing. I currently have a NP435 truck 4 speed. It's got a 6.68:1 first, a 3.34:1 second, a 1.66:1 third and a 1:1 fourth. That first is great for my crawl ratio but I've found that I like to have more gearing options that I can shift rapidly between as well as an overdrive, especially for faster off-road driving. Enter the T56 six speed. The ratios are 2.97:1 first, 2.07:1 second, 1.43:1 third, 1:1 fourth, .84:1 fifth, and .63:1 sixth. This gives me several gear options for any situation I may find myself in plus the two overdrives will be nice on the highway. The only problem is that the crawl ratio sucks with that first gear. Even with a 5:1 Atlas my crawl ratio would only be about 70:1. My current crawl is 80:1 and I'd like to have at least that number in the new set of gearboxes. That's why I like the NWF Black Box. It'll get me about 150:1 with an Atlas 5:1 as well as an intermediate low range of about 2.7:1 for situations where I need a little more wheel speed. Plus, it's only 4" long when bolted to the Atlas and will affect my driveline angles minimally. So, adding them up, I'll have 24 forward speeds and 4 in reverse and the ratios will range between 150:1 and .63:1. My current setup has 8 forward speeds and two in reverse and the ratios range between 80:1 and 1:1. That's just not enough options for how I like to drive.
User avatar
PaulW
Posts: 1589
Joined: Wed Dec 09, 2009 8:56 am
Bronco Info: Modified and Linked 1972 Bronco

Re: Well...

Post by PaulW »

Gearing.
Consider an auto like most all crawlers or street setups. With a torque converter stall ranging from 1.5 to 2:1 The CR gets above 100 pretty quick. So if it is gearing you want consider a manually controlled auto with a manual lock up converter and reverse valve body.
Example Crawl Ratios:
For an EB; diff 4.88, Atlas 4.3, 700r4 3.06 = 64.2CR x TC = 128CR
diff 4.88, Atlas 5.0, 700r4 3.06 = 74.7CR x TC = 149CR – Not great, but nice and you will love the quick shifts up or down. And the overdrive is another feature. The length of the Atlas/700r4 vs D20/C4 is very close.
Maybe it’s too late to suggest an Auto trans with your big torque motor? However looking at the 700r4:
A stock 700r4 is designed for 350 ft lbs according to GM. Built built ones are good for up to 600-700 ft lbs, depending on your budget. 400 to 500 are pretty common.
PW
balduccibros
Posts: 25
Joined: Wed Jun 05, 2013 10:33 am
Bronco Info: '75 Bronco 4600 class legal. Built for east coast racing.
Location: Cumberland, MD

Re: Well...

Post by balduccibros »

yellowbronco wrote:
balduccibros wrote:Very cool bronco! I'm curious what the advantage of the jounce shocks is compared to other shocks(I've never heard of them before). Also why would you choose a nwf black box/atlas over just a 4 spd. Atlas?

The 2002 looks like it will be badass when its all done!
Here's why the jounce shocks are better than just a standard rubber bump stop - First of all, they're not connected to the axle like a regular shock. They're mounted to the frame just like a rubber bump stop. Next, let's say you hit a really big bump at speed and you've got regular rubber bump stops. The rubber will compress and keep the axle from hitting the frame but it will then rebound shoving the axle back downward causing a large rebound in the suspension and the vehicle will be likely to bounce up into the air from this rebound. The jounce shocks are charged with nitrogen which acts as a big spring to protect from the axle hitting the frame (just like the rubber bump stop). However, the jounce shocks also have hydraulic shock oil and a compression/rebound valve stack just like a shock absorber and they can be tuned so that they return to their extended state more slowly and don't shove the axle back downward. The feeling when driving is that the vehicle "sticks" to the ground when landing from a jump or hitting a large bump. The less time you spend in the air, the more time your tires are on the ground maintaining control.

Now for my choice of gearing. I currently have a NP435 truck 4 speed. It's got a 6.68:1 first, a 3.34:1 second, a 1.66:1 third and a 1:1 fourth. That first is great for my crawl ratio but I've found that I like to have more gearing options that I can shift rapidly between as well as an overdrive, especially for faster off-road driving. Enter the T56 six speed. The ratios are 2.97:1 first, 2.07:1 second, 1.43:1 third, 1:1 fourth, .84:1 fifth, and .63:1 sixth. This gives me several gear options for any situation I may find myself in plus the two overdrives will be nice on the highway. The only problem is that the crawl ratio sucks with that first gear. Even with a 5:1 Atlas my crawl ratio would only be about 70:1. My current crawl is 80:1 and I'd like to have at least that number in the new set of gearboxes. That's why I like the NWF Black Box. It'll get me about 150:1 with an Atlas 5:1 as well as an intermediate low range of about 2.7:1 for situations where I need a little more wheel speed. Plus, it's only 4" long when bolted to the Atlas and will affect my driveline angles minimally. So, adding them up, I'll have 24 forward speeds and 4 in reverse and the ratios will range between 150:1 and .63:1. My current setup has 8 forward speeds and two in reverse and the ratios range between 80:1 and 1:1. That's just not enough options for how I like to drive.
I should have looked up the jounce shocks...sounds like its pretty much standard air bump.

On the black box, are you familiar with the 4 spd. Atlas? It is basically an atlas 2 tcase with a black box already bolted to it. They're a great setup and I think it would be a good bit less expensive than buying a black box and atlas separate.
balduccibros
Posts: 25
Joined: Wed Jun 05, 2013 10:33 am
Bronco Info: '75 Bronco 4600 class legal. Built for east coast racing.
Location: Cumberland, MD

Re: Well...

Post by balduccibros »

Rmc
El Jefe
Posts: 6026
Joined: Tue Oct 09, 2012 10:22 pm
Bronco Info: 94 bronco xlt prerunner
Location: IE SoCal
Contact:

Re: Well...

Post by Rmc »

The jounce shocks are air or nitrogen bumps. Light racing calls there product by that name, "jounce shocks"
yellowbronco
Posts: 19
Joined: Wed Jun 05, 2013 1:18 pm
Bronco Info: '69 with a 426 inch windsor, air suspension, full width axles, yadda yadda yadda

Re: Well...

Post by yellowbronco »

PaulW wrote:Gearing.
Consider an auto like most all crawlers or street setups. With a torque converter stall ranging from 1.5 to 2:1 The CR gets above 100 pretty quick. So if it is gearing you want consider a manually controlled auto with a manual lock up converter and reverse valve body.
Example Crawl Ratios:
For an EB; diff 4.88, Atlas 4.3, 700r4 3.06 = 64.2CR x TC = 128CR
diff 4.88, Atlas 5.0, 700r4 3.06 = 74.7CR x TC = 149CR – Not great, but nice and you will love the quick shifts up or down. And the overdrive is another feature. The length of the Atlas/700r4 vs D20/C4 is very close.
Maybe it’s too late to suggest an Auto trans with your big torque motor? However looking at the 700r4:
A stock 700r4 is designed for 350 ft lbs according to GM. Built built ones are good for up to 600-700 ft lbs, depending on your budget. 400 to 500 are pretty common.
PW
I actually have a 4R70W bolted to the 302 going in the BMW and I've considered putting it in the Bronco instead. It can easily be beefed up enough for that engine. So that option is definitely on the table, especially since the torque converter can absorb driveline shock that might break the manual when bombing down a fast trail. Definitely a cheaper alternative, too.
yellowbronco
Posts: 19
Joined: Wed Jun 05, 2013 1:18 pm
Bronco Info: '69 with a 426 inch windsor, air suspension, full width axles, yadda yadda yadda

Re: Well...

Post by yellowbronco »

balduccibros wrote:Here is a link to the 4 spd atlas
http://www.advanceadapters.com/products ... sfer-case/
Yeah, I looked at the 4 speed Atlas...and the old model would be fine because it's the same length as an Atlas 2 speed with the integrated Black Box. However, Advanced Adapters went and redesigned the 4 speed and it grew an inch. That doesn't sound like much but I want to keep my rear suspension geometry as close to current as possible and that 1" means the difference between just moving some stuff and major surgery on the rear suspension.

Frankly, if I could find an old Atlas 6:1, which Advanced has discontinued, that would be fine too because it would give me a slightly better crawl ratio than what I've currently got and the driveline would be just over 2" longer than my current setup (vs just over 6" longer than the NWF Black Box/Atlas and just over 7" longer for the Atlas 4 speed). Plus, there would be no duplication of ratios - all of the ratios would be sequential from 1st low range all the way to 6th hi range (with 6th low range being just a bit lower than 1st hi range). So, if anyone knows of a driver's drop Atlas 6.0 with a 32 spline input for sale, I'm definitely interested as it would save me the entire cost of the Black Box.
yellowbronco
Posts: 19
Joined: Wed Jun 05, 2013 1:18 pm
Bronco Info: '69 with a 426 inch windsor, air suspension, full width axles, yadda yadda yadda

Re: Well...

Post by yellowbronco »

So it's been three years with almost no progress. Didn't help that I lost my job in February of 2014 and I had to sell the BMW project. Then I was working remotely (a 5 hour drive from home and family) for about a year so the Bronco just sat. Then we sold the house and moved into a condo where I have no garage to work in. Needless to say, I had to reevaluate my plans for the Bronco. At least I got a few things done during my "time off"/job search.
Light Racing air bump mocked up

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Tacked

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Burned in

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All better now

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Here's a shot of the white delrin (plastic) straight rate piston I made to replace the bell shaped air bag piston. Now I don't hit a super high spring rate in the bag at the same time the air bump is doing it's thing.

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I didn't like choking the air bumps up so much but there just wasn't enough space available to mount them in front of the airbags. We'll see how they work long term as far as durability. The performance is great. I can now bomb down trails where, previously, I'd have to watch carefully for the big hits and slam on the brakes to keep from getting out of control. After a recent trip, I was doing a post-ride inspection and noticed a 1" dent in the right front rim. Further proof that the air bumps are working because I don't recall the hit that caused the dent!
yellowbronco
Posts: 19
Joined: Wed Jun 05, 2013 1:18 pm
Bronco Info: '69 with a 426 inch windsor, air suspension, full width axles, yadda yadda yadda

Re: Well...

Post by yellowbronco »

In chasing the scary steering, I made a few changes that helped considerably.

Before

Image

You can see drag link steering box end is 4 to 5 inches below the track bar pivot. Well, the chassis pivots around that point and this 4 to 5 inch distance becomes a lever arm that amplifies steering input.

Moved the drag link to the top of the pitman arm.

Image

You can also see the sway bar I added. It's from a '94 to '01 Dodge Ram 1500 so it's a bit stiff which is fine for the street but makes for a lot of head toss offroad. Thus the disconnects.

I also fabbed up a little setup that keeps the tie rod from rotating. You can't see in the picture below but there's a little link that connects the arm welded to the tie rod to the forward flat top stud on the driver's knuckle. Works awesome at alleviating the "dead center" steering vagueness from tie rod rotation.

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Here I am all ready to head out for a weekend...

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yellowbronco
Posts: 19
Joined: Wed Jun 05, 2013 1:18 pm
Bronco Info: '69 with a 426 inch windsor, air suspension, full width axles, yadda yadda yadda

Re: Well...

Post by yellowbronco »

PaulW will be happy to know that I listened. Ditched the 6 speed idea in favor of an auto...

4r70w auto background, T56 foreground

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The auto gets the nod. Now the plan is to use a reverse pattern manual valve body from Silver Fox Transmission, rebuild the auto and, while it's apart, swap to the 4x4 output shaft and adapter housing. Then mount it up to an Atlas 2.

My only concern with the auto is, with 4th gear and torque converter lock both controlled by switches, either a 4-2 shift (because I forgot to switch off 4th gear when downshifting with the lever) or a shift with the torque converter locked (because I forgot to switch off the converter). After a lot of searching, I settled on the Art Carr/Winters shifter as a starting point.

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The barrier keeping the lever from moving to second gear is an optical illusion in the photo. That's a reflection off of the mechanism under the gate plate. Anyway, you can see where I cut a lateral gate in next to first gear. Obviously, with the reverse pattern, this will be where the lever will reside in third gear. Well, I installed a switch inside the shifter that will activate when the lever is moved over into this extra lateral gate. Here's the switch.

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Switch mounted

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Now, to control the torque converter lock, I'm adding a thumb-activated lever to the shifter lever. This lever will actuate another switch similar to the 4th gear switch while simultaneously blocking the shifter's ability to change gears. I have no photos here because it's just in concept stage. I'll post up a Solidworks model of the thumb lever once it's ready to send to a machine shop. We'll see if I have some time to work on the model this weekend. No promises, though because, as you can see, my projects move slow.
User avatar
BDKW1
Posts: 1517
Joined: Mon Jun 14, 2010 1:19 pm
Bronco Info: It's the new and inproved Party Barge!
Location: Not Socal

Re: Well...

Post by BDKW1 »

Very nice!

I love airbags, they ride so nice.........
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