RWD conversion

[Guest]

Hey guys,

Have searched on here for how to rear wheel drive my BC Legacy sedan but I have a few of my own questions that I'd like to ask. I have a spare fresh gearbox in the shed for my car and have been pondering over whether to get the centre diff welded up or not. How much should/would this cost me?

Also, my rear cv joints fcuk out bad enough as it is without giving them even more death, and I've heard that I could put in an r180 diff and axles and it'd handle for a heck of a lot longer? Is this true? Also what subby's did the r180 rear diff come out in? Also what do I do with the front axles once it's rwd?

Can people with rwd's please give me some feed back on how their car handles day to day driving with the car set up rwd?

If you're gonna say "why would you do this, keep it awd" please save it for someone else...

Thanks,

-Sam

[driftrex]

hey dude, i DO have a rwd and this is my advice.

-welding centre diff, should cost you around $50 thats all marshall transmissions charged me.

-180 diff, yes these can be fitted, requires r180 diff/axles/hubs to convert, easy if you can get the parts all together but not a cheap conversion either expect between $500-1000 for these. personally i havent bothered, i have been rwd for a while now and i wouldnt say im nice to my car, never broken an axle or cv and i do like to play alot lol, i have however worn one front bearing out in the rear diff, just replaced with another r160 and its fine. im not sure exactly which models the r180 were in apart from sti's.

-fornt axles, completely remove them, pull apart the outter cv joint so your just left the the bare cup/spline that holds the hubs together and your done. or do what i did, dismanlte your gearbox and remove the front diff altogether (alot of weight in these) and get some brass frost plugs to fill the hole left in the gearbox casing.

-handling, hmmmm well its not gonna be the same, you WILL have to learn how to drive your car again lol but i wouldnt say its any slower, i think aftermarket rollbars and the like would help a rwd conversion alot. im goin back to 4wd soon simply because i will have alot more horsepower and i want the traction/handling for track racing.

but yea definatley a fun mod to do and something i think more people should do. i have a v2 wrx btw so the same running gear as you.

hope this helps.

[nt_a_foz]

Just fyi R180s arent in your normal STIs only in RAs and Type R stis the models with DCCD as far as im aware..

THis is in the gc8 models.

GDB Models mostly have R180 i think if not all?

[zarnah]

R180 diff etc is a good upgrade on the R160 but I wouldnt (and havnt) bother doing it unless you got heaps of coin to spend, I spent my money getting bigger rear halfshafts made as they were the only thing I managed to break in my old setup and havnt had a problem since, and yea its pretty easy to weld up the centre diff (can be done with box still in the car as the centre diff is accessed from the rear of the box) so any mechanic/engineer should be able to do it for a decent price for you, the other option (and I dont know if it makes much, if any difference) is to have the centre diff filled with lead to lock it all up, one of my rwd box's is welded and the other is lead-filled and they both seem the same to drive to me (although the lead filled one, in my rs, has a shitload more grunt in front of it than the one in my wagon)

And yeah essentially the legacy chassis/suspension/brakes etc were not made from the factory as a rwd platform, so suspension/braking mods are a must if you ever want it to be anything more than a 'done some skids at my mates bbq the other day' car.

Give it a go, if you dont like it- chuck a normal centre diff, and you're front halfshafts back in and you will be 4wd again.

Like driftrex, I also am going back to 4wd for traction reasons, and also because I think a subaru is all about that boxer rumble and that 4wd grip in the twisties!

Was definately fun while it lasted though

[Guest]

Thanks for your help guys..

Also what ratio are the r180 diffs, and will that matter for me if I'm running a gearbox out of a twin turbo legacy? Heard that running the wrong diff/box combo kills diffs pretty darn quick? Isn't r180 the same diff code as what are on some of the turbo rwd nissans?

[Guest boostin]

When you go RWD it doesn't matter what diff ratio you have. It only affects your speedo accuracy.

[driftrex]

 tedebare said:

Thanks for your help guys..

Also what ratio are the r180 diffs, and will that matter for me if I'm running a gearbox out of a twin turbo legacy? Heard that running the wrong diff/box combo kills diffs pretty darn quick? Isn't r180 the same diff code as what are on some of the turbo rwd nissans?

turbo nissans have r200's, they have been made to fit before but quite a bit of work.

[Guest boostin]

I have heard rumours that Possum Bourne Motorsport do a custom subframe to accept a Nissan diff. Unconfirmed though...

[nzkaosnz]

confirmed - POA only

[Guest]

GF8M8 said a bunch of crap about this in a form, Shezzy as hell could not understand but got the point but not really and yea what was I saying???? F8ck that screwed me up,

anyhow Subaru’s are designed to be awd, iv personally have done 3 and dyno have lost 23.8 (yes that accurate) 23.8% drive train loss but f8ucking fun as hell for drifting (driftrex) would know with a name like that ya know aye burning up tires instead of trannies...

any who most my crap like that last 6months before blowing motors and trannies, and local plod not being to amused with the idea that my drive way ,( seriously long and black stuff with two really good bends) not to mention the old school run road that no one uses) for drifting yea they not happy, but in saying that, got one local plod to buy my 1997 sti, man we had fun, (no names Andrew) lol oh man that’s sweet, sorry personal joke there

[Joker]

How to:

http://www.clubwrx.net/forums/powertrain/27532-converting-awd-2wd-rwd-w-pics.html

we don't recommend it but many have with varying degree's of success

[driftrex]

 JoKer said:

How to:

http://www.clubwrx.net/forums/powertrain/27532-converting-awd-2wd-rwd-w-pics.html

we don't recommend it but many have with varying degree's of success

just to clarify that how-to is for the later type gearbox/centre diffs and does not apply to the earlier ones like you're rs, you wont need to dismantle like in those pics, just weld the spider gears together through the gaps in the housing and your done.

joker might not recommend it but im guessing he hasnt done it before

[Guest]

suppose you could say, Not everyone recommends it

-smurff

[Joker]

i thinking about doing it.....

[funkytown]

 JoKer said:

i thinking about doing it.....

insert tui here

[Joker]

hah thinkiong and doing is two different things

[Guest]

hahaha, your on trade me now aye, buying up all the parts you need

-smurff

[Guest keltik]

I considered it. Would be fun for 5 mins but too much like hard work for me to actually do it. I seem to smoke up tires easy enough as it is. Plus with the right technique and enough torque you can slide an AWD legacy around almost as easy as a RWD setup

Ive got a couple broken half shafts sitting in my magical shed in case i get bored one day

[nzkaosnz]

have a welded centre diff sitting here - kinda tempting - but the dccd sti type R was scary enough in the wet with diff open. (80% rwd)

Possibly on the legacy.

[Guest]

I have done this for the use of dynoing on a rwd dyno.

Just get a spare center diff, pull it apart, cut the spline off that drives the front wheels, put it back together, weld it up, clean it well, put it in and there's no need to pull the front shafts as they arn't being driven by the box anymore. It's easy to put in and out.

I don't know what EGOREX is on about but i cant understand whats he's saying to start with, the drivetrain loss will not go up.

[driftrex]

 RAC said:

I have done this for the use of dynoing on a rwd dyno.

Just get a spare center diff, pull it apart, cut the spline off that drives the front wheels, put it back together, weld it up, clean it well, put it in and there's no need to pull the front shafts as they arn't being driven by the box anymore. It's easy to put in and out.

I don't know what EGOREX is on about but i cant understand whats he's saying to start with, the drivetrain loss will not go up.

yea my drivetrain loss didnt go up, if it had my dyno would of been alot lower.

[Guest]

Was basically a typo guys, I wasn’t saying that I lost that % I was saying after the dyno was only that amount of drivtrain loss, I thort it would of been less, the typo was when I said “LOST” should of been “a loss” considering awd car’s have a 30odd % loss compared to rwd’s 20odd % so down to 23% I was expecting more of a drop is all, hope this time I make sense, my fault I find it hard to relay from my head to txt sometimes

[Guest boostin]

 EGOREX said:

Was basically a typo guys, I wasn’t saying that I lost that % I was saying after the dyno was only that amount of drivtrain loss, I thort it would of been less, the typo was when I said “LOST” should of been “a loss” considering awd car’s have a 30odd % loss compared to rwd’s 20odd % so down to 23% I was expecting more of a drop is all, hope this time I make sense, my fault I find it hard to relay from my head to txt sometimes

Bollocks. Drivetrain loss is measurable. Go talk to Gary Capper. Subaru AWD has a loss of 10-12kW. There's no way its a percentage figure.

[Guest]

 boostin']

[quote name='EGOREX said:

Was basically a typo guys, I wasn’t saying that I lost that % I was saying after the dyno was only that amount of drivtrain loss, I thort it would of been less, the typo was when I said “LOST” should of been “a loss” considering awd car’s have a 30odd % loss compared to rwd’s 20odd % so down to 23% I was expecting more of a drop is all, hope this time I make sense, my fault I find it hard to relay from my head to txt sometimes

/quote]

Bollocks. Drivetrain loss is measurable. Go talk to Gary Capper. Subaru AWD has a loss of 10-12kW. There's no way its a percentage figure.

sorry boostin your wrong and Right as well, as I was told and you will soon see the only way to fully measure the loss is with the engine out and at the flywheel and using some fundamental physics and equations, and yes Gary still in Pukekohe is he? I have his email anyway will email him tomorrow. Below is the link good read

http://www.pumaracing.co.uk/trans.htm

David Baker is the guy i delt with have a read of this Tech doc from the uk from him and others on there to all good reading

[Guest keltik]

Where is he wrong? Its NOT a percentage figure and can be measured... And you can get a rough idea of it with the engine in the car.