to change 5th gear ratio???? possible??

[badguy]

my car which engine is mitsubishi 4G91
at 90km/h the RPM already 3K
which i think is quite high

is it possible to change my 5th gear to make 3K rpm at 100-110km/h???
because i travel quite alot at high way therefore can help me to save some fuel also

where got forman can do it??

roughly how much will it be??

 

[simon]

my car which engine is mitsubishi 4G91
at 90km/h the RPM already 3K
which i think is quite high

is it possible to change my 5th gear to make 3K rpm at 100-110km/h???
because i travel quite alot at high way therefore can help me to save some fuel also

where got forman can do it??

roughly how much will it be??

i dont know abt yr engine....but my 4g15 is 3k at 100kph....normally if the clutch has worn off to a certain extend or about to finish then the rpm reading would be quite high than usual so better check that first......i have never heard of changing gear ratio to get lower rpm at top gear.....if there is such a thing then i would also like to do it so i can save more petrol as i also use highway daily.

 

[Yong_5290]

i also got think b4 of changing the 5th gear 2 1.8 gear...
i blif it can be done as my fren 4g91 auto is using all diff gear from 1.5-1.8 gear

i also dunno y 4g91 3k rpm will be 90kmh
while the 4g13-15 3k rpm will 100kmh
even tho its same ratio gearbox wit the same code....

 

[badguy]

yah loh!
so Yong you got ask any forman about this or not??
maybe we can go to the gear box specialist to ask ask leh!
donnot how much they will charge??
if below 400 maybe i will consider it

the old gear box used in the 1.3 engine 3K already 100KM/h
but when used it in 4G91 story different

 

[sam1741]

hi all
i also thinking of doing it for a long time liao....
to obtain higher top speed
but not affect 1 to 4th gear...
(but offcourse have to rev kao kao only shift to 5th, if not no power lo)

but dono if it is possible or not..

can the gears be taken out seperately and be replaced one?
cause saw the gearbox photo before really.. complecated... (many many gears.. not just 5 sets)

 

[Zeroed]

If you can find a set of 5th gear synchro and the other gear connected to it (dont know the technical terms) then theoretically its possible... havent heard of such a thing though.

Best way is to change the final gear la, all ratios will be longer but you got to sacrifice some things if you dont want to spend big money... matspeed has something like that it I think.
Or you could use a Wira 1.8 gearbox if it fits, slightly longer gear ratio than SGTi/Putra gearboxes. If Im not mistaken I recorded about 2800rpm at 100km/h on 5th gear, it was about 2900 on my SGTi gearbox (speed meter a bit off, it should be 3000rpm at 100kmh for GTi gearbox).

Advertising: May have the 1.8 Wira gearbox for sale soon.... thinking of switching back to GTi gearbox. :p

 

[wirafly]

my car which engine is mitsubishi 4G91
at 90km/h the RPM already 3K
which i think is quite high

is it possible to change my 5th gear to make 3K rpm at 100-110km/h???
because i travel quite alot at high way therefore can help me to save some fuel also

where got forman can do it??

roughly how much will it be??

If speedo show inaccurate speed is not an issue, why not consider update tyre diameter(bigger tyre), e.g. from 195-50-15 to 195-55-15 or 195-60-15

e.g.
when you speedo show 70mph on meter

in
195-50-15 actually travel 70mph
195-55-15 actually travel 72.37mph
195-60-15 actually travel 74.74mph

1mph === 1.60934kmh

 

[sam1741]

If you can find a set of 5th gear synchro and the other gear connected to it (dont know the technical terms) then theoretically its possible... havent heard of such a thing though.

Best way is to change the final gear la, all ratios will be longer but you got to sacrifice some things if you dont want to spend big money... matspeed has something like that it I think.
Or you could use a Wira 1.8 gearbox if it fits, slightly longer gear ratio than SGTi/Putra gearboxes. If Im not mistaken I recorded about 2800rpm at 100km/h on 5th gear, it was about 2900 on my SGTi gearbox (speed meter a bit off, it should be 3000rpm at 100kmh for GTi gearbox).

Advertising: May have the 1.8 Wira gearbox for sale soon.... thinking of switching back to GTi gearbox. :p

change final drive then all gear will have to be sacrifice mar..
if we can mod gearbox to change only one gear, only that gear will be affected.. :)

 

[badguy]

if change whole gear box will cost a boom
my gear box also not the pump type (it is used cable to pull the clutch)

so if i change to 1.6 gear box will need to buy also the clutch pump set
i think easily go up to RM1000+++

 

[sam1741]

ya.. whole gearbox really cost a bomb
for a second hand car the gearbox alone might cost more than that car.. :D

 

[speedking]

If speedo show inaccurate speed is not an issue, why not consider update tyre diameter(bigger tyre), e.g. from 195-50-15 to 195-55-15 or 195-60-15

e.g.
when you speedo show 70mph on meter

in
195-50-15 actually travel 70mph
195-55-15 actually travel 72.37mph
195-60-15 actually travel 74.74mph

1mph === 1.60934kmh

he might be right....may be u all can go check in Japan lancer/mirage 4G91 running on wat tyre size....
may be just tyre size is wrong

 

[Zeroed]

change final drive then all gear will have to be sacrifice mar..
if we can mod gearbox to change only one gear, only that gear will be affected.. :)

Thats what I said la. :D I dont think anyone makes a conversion kit for only the 5th gear though.




True that if you change gearbox you will have to change many other things as well... final drive is the most practical change I guess.

 

[rorytate]

guys
sorry for the late bump

yes i have done it before....and for 100km/h on 5th gear only 2700rpm...

was using old saga gearbox 5th gear....eventually the gearbox letup also...

 

[badguy]

wah now got one ppl done it liao!!!
so where u do it????
me also want to do
how much??