g/box strength

[Pappu1]

how mucg better is a v4sti gbox than a v2wrx non-sti box?

i know ratios etc may differ etc but just in terms of is there any difference in the "abilities" of the 2 boxes.

also, what diff did the v4sti run - r160?

what about the v2 sti-ra - r160?

[Drunkenmonkey]

the v4 sti had the 206 kw where as the v2 wrx i think was 160kw so i would at a guess say the v4 would be a fair bit stronger..

as for ratios

v4 is 4.44

v2 i think is 4.11

[Pappu1]

yea bro tru that..

\just that some ppl seem think that there is really no "strength" difference between the wrx/sti box

only the ra box had the better gear set..

im not sure if that is correct hence wanting to confirm with the team here

(its for a wrx auto-manual and just checking what wud wud be better for the dude as both are availble but price difference

[kamineko]

to be honest you've only got peoples assumptions relating to gearbox strength.

afaik theres little hard data, apart from there being NA gearboxes, and Turbo ones.

some syncros are improved throughout the versions, and some RA gearboxes get a 3rd/4th steel selector fork.

[Pappu1]

na these ones are non RA bro

either

v2 wrx non sti box

or

v4 sti box

i mean obviously treat either like a dog and it wil die but i guess which will take more punishment (to a point obviously)

[Drunkenmonkey]

well if the v2 is the same as the gen1 legacys get the v4! got a trans code?

[Ninja8)]

 pappu said:

na these ones are non RA bro

either

v2 wrx non sti box

or

v4 sti box

i mean obviously treat either like a dog and it wil die but i guess which will take more punishment (to a point obviously)

now i wouldnt b an expert in all this....but wouldn a sti box b a tad stronger than a non sti?? hence the fact that a STI produces more power when compared to a non-sti..

so by thinkin that...wouldnt a sti box be strongr (can take more sh!t) than a non sti?

[NotAWhiteGTB]

As far as i was aware, the only difference in the turbo gearboxes that changed as time went on is small things like changed syncros, final drive ratios and centre and front diff's etc, like Kami pointed out. But all of the 5 speed gear sets are essentially identical strength wise with the respect to the different ratios as the gears are all helical and the same length.

If you want stronger gears get a 6 speed as the gears are way longer and take a f*ck load more to shear teeth off

If you want somethign that is less likely to crunch as time goes on, get a later box with better syncro design, or dont slam through gears and be nice to it.

The only other thing worth mentioning is there are two generation of 5 speeds, ones that are pre (and including) version 4 gboxs, which have the gearbox code start TY752, which are the 4 point mounted boxes.

Everything after this is 8 point mounted, which means if you want to fit this onto a 4 point block/motor, minor modifications will have to be done

[Koom]

edit: damn captain vice pres beat me to it :'( haha

The early STI (Pre v3) boxes have the same code as the plain WRX ones.

They all share the same casing and there's only so much that can change inside the box. I think early RA's had wider gears than standard and syncro's got changed around but I'd say that in reality, the gears between most Impreza boxes are pretty much the same. The actual ratio and the tooth profile might change strength marginally, but not much only material could make a major difference.

Even my MY05 5-speed has pretty much the same gearset as the early boxes as it is also in essentially the same housing.

[NotAWhiteGTB]

I think you should leave it auto.

What you need to do is get it rebuilt and revalved so if shifts at break neck speed, put an automatic shift kit onto it. Then remove the torque converter and replace it with a clutch. You will have one sweet gearbox then, and you can flatshift gears the whole time and not worry about destroying syncros! F*&K YEA!!!

[Pappu1]

ahh so basically there is not much of a difference between the stiv4 box and the v2wrx... :

as for the mounting etc - 4 or 8, is it like the older boxes have 4 and the newer ones have 8? which wud mean older motors are 4 point and newer 8 point?

sorry but not too clued up on g/box etc..

and in saying that, if the 6 speed is 8 mount then how does it have a chance to fit an older block? or m i missing something

[NotAWhiteGTB]

 Koom said:

edit: damn captain vice pres beat me to it :'( haha

I know, im too quick sometimes... just need to find a way to speed up my girlfriend now...

[Pappu1]

 NotAWhiteGTB said:

I think you should leave it auto.

What you need to do is get it rebuilt and revalved so if shifts at break neck speed, put an automatic shift kit onto it. Then remove the torque converter and replace it with a clutch. You will have one sweet gearbox then, and you can flatshift gears the whole time and not worry about destroying syncros! F*&K YEA!!!

its not my car bro, its a mate who got an auto wrx and wants to manual now...just helping with some answers

ok what did u mean in the post above abt the flat shift and auto and all that? sounds like a good thing?? ;D

[NotAWhiteGTB]

 pappu said:

ahh so basically there is not much of a difference between the stiv4 box and the v2wrx... :

as for the mounting etc - 4 or 8, is it like the older boxes have 4 and the newer ones have 8? which wud mean older motors are 4 point and newer 8 point?

sorry but not too clued up on g/box etc..

and in saying that, if the 6 speed is 8 mount then how does it have a chance to fit an older block? or m i missing something

Yes you are right, old boxes have 4 point mounts, new ones have 8.

But that isnt a major as you can easily modify a gearbox that has an 8 point to fit an older motor. Im sure koom can elaborate on this if need be because i know he has done it before.

[Koom]

With the 8-bolt ones, you use one of the extra holes for starter and leave the others empty when fitting to old 4-bolt blocks.

[Pappu1]

if one was to treat a 5 speed box good-ish

as in no hard launch , no flat shifting and kinda smooth in the gear changes,

how much power they can handle?

i know that some 5 speeds have had issues with over 230kw (funkytown- did ur hac=ve an issue?)

my old v1 rex had 230kw@w and eventually it started having issues getting in reverse and issues in 5th

the guy who rebuilt it (amac automotive) said that the torque was causing the shafts to "flex" and that was just cos the 5 speeds were not made to handle too much output

[funkytown]

i cant say.. i recon'd the box on 200kw.. but that was due to 160,xxx kms of abuse i can only imagine.

It got about 5000kms of 235 and then swapped out for the 6MT. It was fine for the 5000kms

Any box raping it with launches and flat shifts isnt going to end well. I would imagine the 5MT wudnt have lasted for ever in mine.. but i was planning to give it a good raping on the track and different events.

In a straight road / daily car there is no reason it cant last ok.

[Pappu1]

wats the story when there is a fair of extra torqe flowing thru it say whne heavy acceleration

running something like 280kw@w type power

[Koom]

Depends, is that 2.5L torquey 280kw or 2.0L peaky 280kw?

Some people get away with it, some people break them with standard power/torque outputs.

[Pappu1]

2lt top end type...

[sultan]

i destroyed my original 1st and 3rd gear on a 120km v2 non-sti gearbox with std clutch, after 2 years of 200kw. it started to get worse and worse after the first year.

my v4 sti gearbox with 100km has been handling 240kw with HD clutch for 2 years now no problem

[marc]

my gearbox lasted about 30 mins after my dyno on 280 odd wkw. stripped 3rd gear. I was smart (well thought I was) because I never shocked the box or nada. put it in 3rd on way home and brought it up to about 4000rpm than pushed my foot down and BANG it went! was using a 8 bolt TY753VB1AA forester box at the time. was only a short term replacement to tune the car and then move to 6 spd but expected abit more then 30mins without launces/banging gears.

[rockr]

did the sti boxs and /or the ra close ratio boxes not have shot peaned gearsets to destress them also??, have always had this done to gearsets that i have rebuilt to give them a bit more life. also polished any sharp edges of the gears to remove machineing marks and dags from factory machining.