Unchewable, the D170

[Tincup]

Welcome to the "Red-Headed Step Child" of truck building, Nobody makes anything for Dodges. Looks like you found yourself an real nice foundation to start with.

[kingcrunch]

Well, Chevrolet has nice trailing arms that can be adapted.
I look at myself as a pioneer, establishing a bridgehead into uncharted territory



This is the second one but trust me, the first was no different.
It took two hours to straighten and split the first one.



Drilling out the spot welds went down very easy though, center punch, drill a pilot, drill out with a 10mm drill.



The arms are held together by ten spot welds with 6 at the axle end and the other four spaced over the whole arm.
They are pretty solid, there's only one spot that has rust damage...

I don't know how i want to fix it because there is two ways i could do that (the arms are 4mm thick steel aswell):
No. 1:
- cut two 4mm plates to fit and replace the rust damaged area on each arm individually

No. 2:
- cut one 8mm plate to fit in that rust damaged area, the plate would connect both arms solid in that area.


I absolutely had to do a little mock up to see what i am working with.
This is an empty D60 housing, flipped upside down (don't pay attention to that, i did it so the spring pads sit flat on the trailing arms, no other intention).
The "crossmember" is just a piece of aluminum stock we have in the shop.

[kingcrunch]

I played a little with some random picture editing software because i had no schematic of a 115" frame.



For a while now i wanted to visualize where the crossmember will have to be located and how the coil springs would have to be mounted to the D150s frame.
Which is why i made an overlay of both:



CardboardAidedDesign will be applied ;D

I figure, with that much room on top of the axle (compared to the Chevy frame) i could aswell move the coils on the axle housing.

[brawls43]

Loving the look of this project! Truck looks great!

[kingcrunch]

Sh... now this wheel bearing load topic Mike mentioned freaks me out.
I guess you are correct Mike, the same bearing arrangement is used in Grand Caravans and they eat wheel bearings while weighing about the same as my truck.
So that might be a regular item to change... the spindle itself looks beefy enough to me.

[kingcrunch]

I played with LibreCad to visualize the bolt pattern dilemma. I like the Viper spindle but the Viper bolt pattern is a p.i.t.a.





The Viper has a 6 x 4.5" bolt pattern. It's odd, there is a limited amount of wheels available (at least for the European, thoroughly regulated market) and all sell for obscene four-digit-per-wheel-prices.
The Viper wheels themselves do not look that great, carry a Viper price tag and do not fit under the truck.

For a 5 x 4.5" bolt pattern, the variety of actually affordable wheels is much broader.
In fact this bolt pattern is the only one that could be machined into a Viper brake rotor without really intersecting the existing bolt holes.
All other common bolt patterns, like 5 x 5 or metric, like 5 x 120, 5 x 112, etc. breach into one or more holes of the Viper bolt pattern.

It also happens to be the bolt pattern used on the only wheel bearing that could be used to convert a Viper to a 5-bolt pattern. Looks like it has to go that way...

Mopar Part Number is 4641517AD, MOOG 513123, SKF BR930

All info obtained at Viperalley.com.

[kingcrunch]

Tin-hammering friday:







This is prep-work for taking a mould of the bumper to re-create it in carbon fiber.
The company i hire for that job asked me if i could close all the holes and larger openings. I also wanted a place to mount a splitter/aid dam to, so i had to elongate the lower flange of the bumper.

[kingcrunch]

Spent half of the day measuring for a coil spring crossmember and landing pads for the coils and in the end it turns out i based my measurements on a misconception. Bummer.
Good thing i noticed my mistake before i have a crossmember made...

[kingcrunch]

Chewing metal. Second attempt on designing a rear coil spring crossmember and coil spring landing pad.
I think i have it now...

This was attempt no. 1 and is a bad design. It will interfere with the axle housing (testing with my spare full floater D60, because i wanted an axle housing with a large pumpkin).
What you see is the profile (which would sit inside the framerails), the spring landing pad is the strip of metal underneath the frame.



When i noticed that (big DOH! moment), i looked at the Chevy frames again and basically adapted that to the Dodge frame.


Attempt no. 2:



C-profile crossmember, the landing pad is bolted to it.

That got transferred to CAD. I sent the drawings to a company i occasionally hire to do laser cutting, they have a cnc-press brake aswell.

[kingcrunch]

You have to look at the little sketch on that piece of paper, to see the whole idea for the spring landing pad. It's not just that strip of metal, but basically a box that engulfs a part of the frame.
I don't want to put the load into the lower flange alone.

I'll post screenshots of the dxf-files when i am awake again. Right now typing happens on auto-pilot...

[kingcrunch]

I aquired a copy of Suspension Analyzer FV. Let the measuring odysee begin!
I will take the trucks front suspension apart for that task, mainly because all bushings need replacing (and a tour to the media blaster) and second it's easier to take frame measurements this way.

[kingcrunch]

More money spent:
- nobody would want to answer my questions about the dimensions of Viper front UCAs, so i bought one to figure out myself
- i also aquired the passenger side Viper spindle

Another 600 bucks out the door.

[Dr G]

More money spent:
- nobody would want to answer my questions about the dimensions of Viper front UCAs, so i bought one to figure out myself
- i also aquired the passenger side Viper spindle

Another 600 bucks out the door.

It's hard to beat having the part right in front of you in terms of getting the right measurements. Not cheap, but worth in my opinion. Gustave

[kingcrunch]

I tend to agree but knowing a part has dimensions close to the target before shelling out money beats having it on the table to play with it in my book.
But when i learn a part fits i can't wait to get it in my hands... each coin has two sides i guess

[kingcrunch]

Interesting fact:

The LRE (little red express) needed only 225hp to run 118mph (with a 727).


For itself, that's no news.
But it allowed me to back-guesstimate the drag coefficient, because everything else is known.
It looks to me like 2wd Dodge trucks have a drag coefficient of 0.55 and a (guesstimated) frontal area of 33sq ft.

That's the guesstimated value for a - excuse the choice of words - pig on stilts.
I think a lowered truck with a few aero enhancements might actually do better than this.

It still needs 650hp to run 170 though... but it should run 150 with the stock 6.4 crate motor it will give a home to. Yay!

[kingcrunch]

Bronze is the new hype, isn't it?
They also make wiiiiide wheels with lots of backspacing (5" +), WITH road legal certificates!



Everything is still very much experimental and undocumented at this moment, i will have to measure and do the math to find the backspacing needed for a nice scrub radius (not dead zero but juuuust a little positive radius for more steering feel).

[2ndroundko]

Those wheels are sick. loving the build. Interested to see how the truck arms work out but also curious why use factory trailing arms when there are so many other options; used nascar, custom, tubular... Either way good look looks like you have a good handle on it.

[kingcrunch]

The fabricated I-beam of the factory arms is in fact the most flexible arm around. With a setup like this you absolutely need flex to avoid binding or premature bushing wear.
This is why i shied away from fabricated tubular or Nascar arms. Too rigid. This is why i will stick with factory rubber bushings instead of poly.

Also too problematic to get these fabricated arms through the road tech inspection, staying road legal is key to this project.

Sooo, rebuilt factory arms it is. I plan to reinforce them like the factory did: They put a plate on the underside of the arm, about 1/2 of the arm in length.
The factory arms also give me a good datum to build from. All of the Nascar arms i looked at had a different length, pretty confusing.

I received the passenger side spindle i bought off Ebay. That's what you get for 480$:




I am also digging through the Rockauto database for a suitable front brake rotor. Using the Viper rotor gives me headaches, because of the bolt pattern.
Drilling a 5x4.5" bolt pattern next to a 6x4.5" bolt pattern without interference is next to impossible. There is no "nice way" to close the interference bolt holes.

The closest candidate i could find is the front rotor of a 2015 Mustang GT:

13.85" in diameter - Viper is 18.97" (no problem, machine 1/2 of the difference in diameter off the mounting pads on the spindle, done)
1.26" thickness - Viper is identical
1.18" discard thickness - Viper is identical
5x4.5" bolt pattern - as needed

I am having a hard time to find more info about the rotor, especially the height. It has to be larger than 2.334", which is the height of the Viper rotor.
Larger can be spaced out, smaller would interfere with the caliper.

Bodge measuring using a random image manipulation program leads me to the conclusion that the Mustang rotor has a height of 2.48" ... but i have been mislead by that method before.
Anybody happen to own a '15 Mustang GT 5.0 and willing to remove a rotor for taking measurements?


The next best candidate is the rotor of a 09-13 Mercedes CL550 but that would require modification in form of drilling the desired bolt pattern, which would not be a big problem at all but i like a better solution if possible.
I would really like to be able to order a bone stock wear part and use it without modification. Modification is time and in this case lost time.

[kingcrunch]

Because race truck:

[kingcrunch]

Viperrrrr parrrrrts. Yay. I received the passenger side front upper control arm for mockup!
It is 10mm smaller on the inside (from the face of the bushing to the face of the opposed bushing) compared to the trucks UCA.
Everything else, like the position of the ball joint, looks to be in the ballpark. Obviously i will have to mock it up to get more accurate measurements.

In case i need some variation, i can swap drivers and passenger side UCAs.


I am waiting for that guy to pick up the last large parts of my former '76 truck to free up the shop space for the D170. Can't wait!