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Old 10-06-2008, 06:44 PM   #1
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Default E4 Transmission Ratio

I would like to lower the E4 tranny ratio to 1.8 from the standard 2.0588 if I use the 34 tooth diff gears for frt and rear what would I have then ? anything I'm missing let me know (like the formula of the math here would be sweet like how they got the 2.0588 ratio)wanna change it over to vintage racer totally lost on this
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Old 10-06-2008, 08:18 PM   #2
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The math is pretty simple. Divide the number of teeth in the diff gear )or pulley for a belt car) by the number of teeth in the bevel gear (or driving pulley) to get the car's transmission ratio.

For the Losi type R, we run a 42 tooth diff pulley and a 23 tooth layshaft pulley for a tranny ratio of 1.826 (or 1.83 rounded off)

Just count the teeth of the bevel gear that drives your diff gear, and then divide 34 by that number to find out what the ratio will be with the 34 tooth diff gears in place.

I'm going to guess that your car has 35 tooth diff gears driven by 17 tooth bevel gears, that works out to 2.0588. If you were to run the 34 tooth gears, your ratio would be 34/17 or 2.0

I don't know if the gears are available to get you to 1.8... A 31 tooth diff gear with the 17 bevel gear would be 1.823, or the 35 tooth diff gear with a 19 tooth bevel gear would be 1.842. The 34 diff gear with a 19 bevel would go 1.789. You'd have to see if gears like that are available or not...
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Old 10-06-2008, 11:14 PM   #3
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Originally Posted by Enzok View Post
I would like to lower the E4 tranny ratio to 1.8 from the standard 2.0588 if I use the 34 tooth diff gears for frt and rear what would I have then ? anything I'm missing let me know (like the formula of the math here would be sweet like how they got the 2.0588 ratio)wanna change it over to vintage racer totally lost on this
to get the internal ratio of 1.88 you will need the 34t pulleys for the diffs and the 18t lay shaft pulley for the front and rear layshaft.

look here for the parts
http://www.wolfhobbies.com/E4_Parts-...ar_Pulley.html

http://www.wolfhobbies.com/E4_Parts-...er_Pulley.html
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Old 10-13-2008, 03:37 PM   #4
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Default E4 Transmission Ratio

I have it started but have some other ? to ask like what about the frt inner gear which is attached to a shaft that is 17t does it also get chged to an 18t gear, and what about the 2 outer gears that are also 17t, is this possible and what about a frt 34t spool or oneway. Emailed wolfhobbies waiting for their reply.
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Old 10-13-2008, 03:48 PM   #5
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Originally Posted by Enzok View Post
I have it started but have some other ? to ask like what about the frt inner gear which is attached to a shaft that is 17t does it also get chged to an 18t gear, and what about the 2 outer gears that are also 17t, is this possible and what about a frt 34t spool or oneway. Emailed wolfhobbies waiting for their reply.
Yes...the INNER pulley, you have to change to the 18T 503222, front and rear...and leave the outer small pulleys (side belts, both pulleys) to 17T 503197. Then your front and rear diff pulley, need to be 1T bigger = 34T 503201

To sum it up, you have to change 2 small inner pulleys (+1) and change 2 diff pulley (-1).

And the above is for changing from the stock 2.0 final drive to 1.8 final drive just like the FOAM spec...
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Old 10-13-2008, 03:54 PM   #6
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Hi:

This seems like the best place to answer this question. The original E4, the E4RS, E4JS and the E4JR all have a 2:1 internal ratio. This is accomplished with the center small pulleys and the diff pulleys. They are 17 tooth and 35 tooth respectively. All cars use the 17 tooth side pulleys. On the E4FS they changed the internal ratio to 1.88 by changing the center pulleys to 18 teeth and the diffs to 34 teeth. When I asked TM why they did this they said "It improves the feel of the car". When I mentioned that they made the car incompatible with the spool and 1 way they said that they would have a 34 tooth option for the spool and 1 way soon. That email was in February so I would not hold by breath. We recommend to everyone with an E4FS that they change their center pulley and diff pulleys to the 17 / 35 tooth "standard" so that they can easily swap front diff systems. For a while we were giving these away to anyone who asked for them. They are still available to anyone who purchases a new FS. If you are never going to use anything but a front diff on your car then this is a moot point and you are best to stay with what came on the car. Please let us know if this does not fully answer the question.
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