Transmission of the Lizard Rodeo

[Dudejo]

Hi again.

Have you considered converting the Lizard Rodeo into a manual transmission truck? When in 1st person view, the truck has 3 center pedals and the gear lever has a round rubber base typical of manual shifters.

Trucks of the Rodeo's apparent generation with automatic transmissions would have a steering column-mounted selector on the right-hand side. However, the Rodeo only has the left-side selector for operating flashers, wipers, etc.

[Mogli12]

Hi,

You can switch from automatic mode to manual mode. But the torque converter will stay.

Regards, Stefan

[Dudejo]

I know I can do that.

It's just that the truck ISN'T an automatic...

It's not supposed to be equipped with an automatic.

[Mogli12]

Hi,

Ok, I thought that the lizard rodeo is somehow similar to an Ford F-series 5th gen. So I tried to emulate an 3-speed automatic (C4) and a 4 speed manual (T18) transmission. The ratios between the gears should be realistic. But I did not have good information about the final ratio.

Please try 3.1 build 66.

Regards, Stefan

[Dudejo]

I found this Ford sales brochure which provides the appropriate axle ratios for a 5th generation Ford truck.

http://paintref.com/graphics/brochure/1970fordtruck_pickup_12.jpg

Assuming this is a light duty 4x4 truck with LSD, the axle ratios would be 3.50 or 4.09. The tire size for the Lizard Rodeo, if it matters, is 280/55R16.

Also, according to the following link, the gear ratios for the T18 are off.

http://www.novak-adapt.com/knowledge/transmissions/manual/t18-t19

In your mod, the First gear has a rated speed of 35 km/h. This is only possible with the Chrysler Jeep model or the heavier duty Ford T19. The Ford T18 uses a much lower gear that would result in a rated speed of 22 km/h.

Edit : Also, I have found discussion citing that the stall ratio for the C4 automatic is 2.14 https://www.7173mustangs.com/thread-torque-converters?page=2

Btw, since this is a fictional vehicle, would it be possible to implement this third-party gear splitter? It was designed specifically for classic transmissions. https://www.gearvendors.com/f2wd3s.html

[Mogli12]

I adjusted the gear ratios of the manual transmission.

[Dudejo]

I noticed the automatic has a shorter gear ratio. Is this to help the torque converter stay locked?

Also, if it helps, I made a template using the inverse ratio tags as used in the larger Trucks

        <transmission name="T18" speedLimiter="false" maxRpmThrottle="0.5" fuelPerDistanceMinSpeed="10" minTargetRpm="1000">
            <blowOffVentilSound volume="0"/>

            <!-- 280/55R16 with 3.5 axle => 153 km/h ratios 6.32 3.09 1.69 1 R7.44 -->
            <gears axleSpeed="3.5" tireWidth="280" tireRatio="55" rimDiameter="16" defaultGear="1" startInSmallest="true">
                <gear name="R" reverseOnly="true" inverseRatio="7.44"/>
                <gear name="1"  forwardOnly="true" inverseRatio="6.32"/>
                <gear name="2"  forwardOnly="true" inverseRatio="3.09"/>
                <gear name="3"  forwardOnly="true" inverseRatio="1.69"/>
                <gear name="4" forwardOnly="true" inverseRatio="1.0"/>
            </gears>
        </transmission>
        <transmission name="C4" torqueConverterProfile="oldCar" speedLimiter="false" maxRpmThrottle="0.5" fuelPerDistanceMinSpeed="10" minTargetRpm="1000" torqueConverter="true" clutchCloseRpm="1700" torqueConverterMaxFactor="2.14">
            <blowOffVentilSound volume="0"/>

            <!-- 280/55R16 with 4.11 axle => 130 km/h -->
            <gears automatic="true" axleSpeed="4.11" tireWidth="280" tireRatio="55" rimDiameter="16" defaultGear="1" shiftTimeMs="0" shiftEffect="false" clutchRatio="0" manualClutch="false" startInSmallest="true">
                <gear name="1"  forwardOnly="true" inverseRatio="2.46"/>
                <gear name="R" reverseOnly="true" inverseRatio="2.18"/>
                <gear name="2"  forwardOnly="true" inverseRatio="1.46"/>
                <gear name="3"  forwardOnly="true" inverseRatio="1.00"/>
            </gears>
        </transmission>

[Mogli12]

Good idea. Maybe we can have different axle speed ratios with and w/o splitter. Let' see.

[Dudejo]

wait, nevermind about the gear splitter.

having failed to read the fine print, I just noticed that the device cannot work while 4WD is active. There is simply no space to install the unit between the transmission and transfer case so they only install it on the rear axle side.

This may also explain why no 4WD truck from that era use overdrive transmissions...

EDIT : On the other hand, 4WD trucks DID have Lo-Hi transfer cases. The most common one at that time was the NP-203 or NP-205 iirc

There are also doubler transfer cases, such as NP205/NP203 combinations, with two separate 2:1 ranges. For lighter duty, a manufacturer called Advance Adapters makes the Atlas II, allowing for extreme gear reductions as low as 10:1.

[Dudejo]

It would roughly look like this with an Atlas II.

While building this, I also realized that the inverseRatio flag does not work when used in a secondary Range flag. The inverseRatio flag only works with the main gears or the primary range.

        <transmission name="C4/Atlas II" torqueConverterProfile="oldCar" speedLimiter="false" maxRpmThrottle="0.5" fuelPerDistanceMinSpeed="10" minTargetRpm="1000" torqueConverter="true" clutchCloseRpm="1700" torqueConverterMaxFactor="2.14">
            <blowOffVentilSound volume="0"/>

            <!-- 280/55R16 with 4.11 axle => 130 km/h -->
            <gears automatic="true" axleSpeed="4.11" tireWidth="280" tireRatio="55" rimDiameter="16" defaultGear="1" shiftTimeMs="0" shiftEffect="false" clutchRatio="0" manualClutch="false" startInSmallest="true">
                <gear name="1"  forwardOnly="true" inverseRatio="2.46"/>
                <gear name="R" reverseOnly="true" inverseRatio="2.18"/>
                <gear name="2"  forwardOnly="true" inverseRatio="1.46"/>
                <gear name="3"  forwardOnly="true" inverseRatio="1.00"/>
            </gears>

        <ranges defaultRange="2" reverseReset="false" shiftTimeMs="3000" shiftNoThrottle="true">
            <range inverseRatio="3.80" name="Lo" />
            <range inverseRatio="1.00" name="Hi" />
        </ranges>

        <ranges defaultRange="2" reverseReset="false" onlyStopped="true">
        <!-- inverseRatio does NOT work with this range box -->
            <range ratio="0.36765" name="L" />
            <range ratio="1.00" name="H" />
        </ranges>
        </transmission>

[Mogli12]

Hi,

I think I want to keep the engines as they are to have them as close as possible to the vanilla configurations.

Regards, Stefan

[Dudejo]

do you mean the engine torque templates that I sent you by e-mail?

I tuned them to match the in-game power ratings (NOT the engine names) so they should match pretty well.

the only potential concern is the low RPM limit of the 300 I6 I made. It needs a tall differential ratio to reach the rated top speed of 120 km/h

[Mogli12]

Ok, what do you think of v3.1 build 70?

[Dudejo]

assuming you wish to stay close to the stock 5th generation model, I would recommend simulating a Dana 24 transfer case, which has a 1.86:1 low gear ratio. That transfer case was the most common in the 60's and 70's for that model.

The 2.72 low gear ratio used in your mod will not appear until the late 1980s.

EDIT : Also, I notice you use the 4.11 axle gear ratio. This was only a choice for open differentials, which the Rodeo does not have. The correct ratio would be 4.09 according to that brochure I posted earlier.