how mush difference will one tooth make?

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hyper 78

hyper 78

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Was just wandering how much difference it would make to my top end if i changed gear ratio from 46/18 to 44/20,. ultimately i would like to go to 42/22 and replace from stock to a red spring to try and slightly eliminate the inevitable bog on the acceleration.i have seen 40mph with 46/18 gearing!could i expect a noticable top speed with 42/22
? i KNOW I WILL LOSE BOTTOM END.
 
Do a search through the FG marder section. There is a chart somewhere that gives all the different speeds for different gear ratios for both marder and MT but I cant remember what the thread is called! 22/42 should see 50mph with the std 16t layshaft gear.
 
Here you go mate - found it on my C: drive :D

picture.php
 
providing your 48/16 on your diff/layshaft then

46/18 is 7.67:1
44/20 is 6.6:1
42/22 is 5.72

its quite a sizable jump in gear ratio. in my touring car going from 42/24 to 40/26 (5.25 to 4.61) was a huge change.

now making that change should make a noticeable change in top speed providing your motor has enough power to pull that gearing. if you gear it too steep the motor wont get right up in the powerband and you will go slower.
 
sharky, yes 46/18 on diff/lay , I got the chart and with 44/20 i should get 44.5mph(there abouts) 42/22 should see 51mph, like i said ,its 29cc with jetpro 2 which i think is a topend pipie, what u think, enough power to pull that much of a tall gear? Now i don't know what to do, im just bashing so bottom end isnt as important for me!I know i can go somewhere inbetween but don't want to chande diff or layshaft gears, more cash!
 
while we are on this subject, does anybody have any views on upgrading to steel gears , pros n cons, obviously they will be stronger but should i have a weak point in there with maybe one plastic(clutch gear) so i don't damage any part of the drive chain inc diff, cups ect if anything was to put stress on them or get a stone or other foreighn object in it?
 
hiya mate :)

i ran steel pinion & alloy carrier with stock plastic spur, did me ok but i was using a gear cover too so this would have helped, in the 5 years i had this setup it was only last year i had to replace the spur as the teeth stripped, i then decided to go all out & replace with steel all round including alloy carrier, touch wood so far no probs at all.

I know what ya sayin though as its always good to have a weak spot somewhere in the drive train otherwise any potential damage can be pushed internally. It's catch 22 really. i noticed my upper alloy arm have a small nick in it, this was prob cuz i landed badly on a jump & my steel spur hit it, if this was a stock spur i know it would defo have stripped it & ruined my days bashing!.
 
cheers mate, nice one, what you think about the 42/22 ratio, will i be able to pull it?
 
yeah i'm the same as tizdaz, i've always ran a plastic spur and steel everything else and alloy gear carrier, never had any problem! even with the plastic carrier things were top notch. the only thing to bear in mind is the meshing of the two gears, not too tight and not too slack either! i'm gonna try n upload this excel file onto this page, see if it works again...
 
22/42 is appoaching touring car gearing for small tires. don't be stressing things on low revs much like climbing hills or you'll be smelling clutch
 
I ran 22/42 on a leopard once as an experiment and it took a while to get up in the revs, and the clutch didn't really appreciate that move.. Top end was nuts though. On an offroad track it's a waste of time, couldn't even get up to a speed whereby then there'd be a bend to slow u down again. On a wide open flat area it's great, get a speed gun :-)
 
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