Jeep transfer case swap - preliminary fe data

[AdrianD]

it would be possible but I don't know if there would be benefit from the side plates being too far inward from the edge of the D-pillar:

[cRiPpLe_rOoStEr]

Originally Posted by AdrianD

I don't know if there would be benefit from the side plates being too far inward from the edge of the D-pillar

Maybe, even if the side plates get closer to the edge of the D-pillar, you could still make some attachment which would allow the entire spoiler to lift up with the rear hatch. How to get it supported by the rear glass might not seem easy, but I'm sure it's not rocket-science.

[AdrianD]

The front left wheel looked like it pointed way out compared to the right when the steering wheel was straight. So I rigged up a toe-measuring tool and it turns out there was a massive amount of toe-out, enough that I had to thread in the left side tie-rod 5/32".
Normal specs call for 1/16" toe-in on each side and by my measurements, toe-out was 5/16".

I've been driving like that for all the tests after the transfer case swap since almost at the same time I replaced the left side tie-rod.

Now I'm curious to see what effect that has on the fuel consumption reported by the trip computer.

[AdrianD]

I took the car for a professional alignment after my diy alignment:
0.005" of toe-out on the left side
0.04" of toe-out on the right side.
The guy at the shop said it's green on the machine and did not want to touch it any further. I'll build a couple of steel plates and then I can dial it in to a little bit of toe-in.

And we were lucky and managed to go on the summer vacation, which means fuel economy data.
I've had some sections identical to last year.

Section 1 (293 miles, 40 miles of highway, similar traffic):
25.59 mpg in 2019
27.22 mpg in 2020 - this is very close to what I noticed testing earlier

Section 2 (232 miles, 70 miles of highway, worse traffic in 2020):
28.51 mpg in 2019
27.47 mpg in 2020

Total average fuel consumption over the entire trip:
2051 miles / 25.34 mpg in 2019
1608 miles / 27.57 mpg in 2020 - this includes 2 hours of driving in torrential rain, and even more with very serious wind and 400 less highway miles.

This is a sample of national roads. Every time I'm driving under 40mph, the torque converter unlocks, so that's wasted fuel.


Driving in the torrential rain I must've hit a puddle fast enough to break the airdam away from one mounting bolt, so I will rebuild it out of sheet metal and I will have the option of adding a shelf on the bottom if that could reduce drag.

Total average fuel consumption over 11.250 miles: 23.9 MPG.

[skyking]

I take it that this did not give you a low range like the truck transfer cases?

[cRiPpLe_rOoStEr]

Originally Posted by skyking

I take it that this did not give you a low range like the truck transfer cases?

IIRC they still had a low range as standard.

[AdrianD]

It's still the same 2.72 low range as the old transfer case.

[AdrianD]

Not much happened in the past year car-wise, as having a baby that doesn't love sleeping in the car means all trips were under 90 minutes


However, in the idea of improving the rear aero, I have found the factory spoiler, which is said to reduce the dirt build-up on the rear glass. On rainy days the build-up is very severe.

[cRiPpLe_rOoStEr]

I remember similar spoilers used to be a quite common accessory for economy cars in my country, even though people got them mostly for the look than for the actual function.

[Piotrsko]

Odd side statement: way late into our travels, we found that my son was extremely sensitive to travel and got car/motion sick about 1/2 hour into trips unless he was sleeping.