"yet to be named" build

[SMKYTXN]

I am building an oddball of a rig. We'll see if my need to do things differently works out in the end. Here's the pile of parts so far....

• Bentfab AZ Pinata chassis
• 2006 Jetta TDI BRM 1.9L Diesel
• 4L60E (shorty)
• 10.3:1 Atlas
• 16" 2.0 King air shocks
• PRP high back seats
• TG 8" front and FJ80 rear, both steering
  • TG 9's w/JHF portals

Here's the current state of the build. I'll go into more detail soon.

 

[SMKYTXN]

Engine: 2006 VW Jetta TDI (1.9L BRM)

I pulled the motor from a still running wreck of a car. Pulling up to the office with this on the trailer turned a few heads.

There are a few companies that make adapters to turn these transverse mounted diesels longitudinal, but none that adapt this year to the 4L60E, so I took it upon myself to design an adapter. Using verified engine dimensions and models found online I designed the adapter using Inventor.

I utilized two 1/2" thick steel plates for the main adapter plates to allow me to use sendcutsend's laser cutting services. The crank and starter adapter where both machined out of 4140 by pcbway. By far, pcbway is the cheapest rapid prototyping service around.

3D printing the adapters allowed me to check my design and tolerances.

Here's the laser cut and machined parts all bolted up. I did hit a snag with the location of the starter. The starter centerline was 0.9mm too close to the centerline of the crank. That resulted in the bendix hitting the back of the flexplate, so a quick redesign was in order and a new set of plates.

New plates in hand and everything lines up.

 

[SMKYTXN]

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[SMKYTXN]

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[SMKYTXN]

JHF TG 9's

Here's the current dilemma. I've been collecting parts for a few years now, so they're kind of a hodgepodge. The toy axles have 4.10's in them and the motor puts out 124hp/227tq. So the 10.3:1 atlas I had on the shelf made sense. Now that I've made the expensive decision to switch to portals I run the risk of having more gear than I need or never using the crawlbox. I do have options though.

Portal x R&P x 1st gear x tcase

4L60E first gear
1.92 x 2.5 x 3.06 x 10.3 = 151.29

4L60E second gear
1.92 x 2.5 x 1.625 x 10.3 = 80.34

So if I keep the 4speed and go with a high ring and pinion ratio I will have gearing options that put me in the normal final crawl ratio window. Is running second gear for the majority of climbs an issue and then using first gear if there's something dumb? I'm coming from a manual trans rig with 235:1 low, lol.

So far the consensus is to put a lower gear in the R&P and sell off the 4spd, but I like options. What do you guys think?

 

[Blase]

I guess I need more info.
What's the ratio of the crawl box and the atlas? meaning 2.62:1 for the crawl box and 3.8:1 for the atlas? as stated combined they are 10.3:1 but you don't have to run both in low.

 

[SMKYTXN]

I guess I need more info.
What's the ratio of the crawl box and the atlas? meaning 2.62:1 for the crawl box and 3.8:1 for the atlas? as stated combined they are 10.3:1 but you don't have to run both in low.

You're correct, 2.62:1 for the crawl box and 3.8:1 for the atlas. I contacted Advanced Adapters to see if it was possible to just pull the crawl box off, but the cases are different, so that's a no go.

So, yes I can run just the 3.8 and put something like 4.11's in the axles and achieve a final crawl ratio of 91:1 in first. I'll just have extra weight from the 4spd that won't be used.