Twin-charged Ae71 Finer-details...

[Victim]

Hello hello all...

 

If i had a RollaRides thread, i'd point you in it's direction. But i don't, so i shall just explain my intentions haha.

Picked up an AE71 off eBay for the grand total of $325.

Have the intention to learn as i go, have some fun, do it on the cheap etc etc, common story.

The car itself has a great interior, clunky as hell automatic trans, couple of deep rust parts that have now ben repaired... overall not as much damage as expected, mostly consisted of surface rust + a bit of a dented front which is to be cured with my newly acquired apron bar.

 

Furthur down the track (once i get it back registered and with a year to kill) i have been offered a 4A-GZE engine in good nick for a cheap-as-chips mate hookup, that comes with an SC12.

 

My future plans are, in a nutshell, to install the 4A-GZE, replace the crap automatic to convert it to a manual transmission, upgrade the SC12 to the SC14 for a bit more low-end kick, twin charge by adding a medium-sized turbo (nothing stupidly sized and there shall be no BOV's around here psssssht flutter flutter) and upgrade the rear diff for a disc diff to get rid of the drum brakes for some increased stopping power (as well as obvious things like suspension, big brakes upgrade etc etc).

 

But my original plans for getting hold of a T50 gearbox and possibly a sprinter disc diff and just bunging those in were cut short when a man more knowledgable than me said the T50 wouldn't be able to handle that much power from a twin-charged engine for anywhere near long enough, and the current diff / a sprinter diff would probably shit themselves as well. He then suggested the S / W (i cannot remember) series of Supra gearboxes & diff's, but a new Supra diff alone nudges a thousand bucks...

 

So my question stands in two parts as thus:

 

1. If anyone knows, what would be the best kind of diff and manual transmission to withstand the power of a twin-charged 4A-GZE in an AE71?

2. If the answer is a Supra, would the diff + tranns from an 1984 2.8 Supra Celica be up to the challenge?

 

Thank you all for your help, i'm constantly impressed with this site's community atmosphere. :yes:

 

- Aleks, aka Victim.

[machg]

W series (celica/supra) gearbox will be strong enough. Supra ass end is IRS, so can't use diff unless you spend $$$$$$$$$$ doing an IRS conversion. A Hilux diff would be a good option.

[Instigator]

Twincharging is a good idea in theory but rarely works in practise. Will be alot of headaches and $$$ to get the same result as a decent turbo setup but good luck to you. Definately not the way to go if you're after cheap.

 

W* series Supra box for anything above 150rwkw. F series tarago, Hilux, or R31 Skyline diff. Hilux would be the strongest and heaviest but you are somewhat limited in ratios/lsds. Skyline not as strong but more options in that regard.

[Victim]

W series (celica/supra) gearbox will be strong enough. Supra ass end is IRS, so can't use diff unless you spend $$$$$$$$$$ doing an IRS conversion. A Hilux diff would be a good option.

 

Yeah, i have seen many people go the Hilux option of diff's, i presume just for their rugged toughness. So in saying that, is the Hilux diff going to stand up to such power and be a reliable option? I'd rather not go with a band-aid solution and have to keep replacing them, rather do it right the first time and then forget about it.

 

On another note, when you say IRS conversion, what exactly is needed to complete it? What is needed to change, and how big of a job is it?

 

Twincharging is a good idea in theory but rarely works in practise. Will be alot of headaches and $$$ to get the same result as a decent turbo setup but good luck to you. Definately not the way to go if you're after cheap.

 

W* series Supra box for anything above 150rwkw. F series tarago, Hilux, or R31 Skyline diff. Hilux would be the strongest and heaviest but you are somewhat limited in ratios/lsds. Skyline not as strong but more options in that regard.

 

Yeah, so i've heard haha. But it seems a waste of a good SC and it'll be something a bit different. If all else fails i'm going to set up the system for the overall power of the upgraded SC14 and the turbo initially, so if it's still an option later down the track there'll be minimal work required to bung the turbo on top, if not, no harm no foul. Haha yeah, that's what i'm getting the impression of. Kiss my cheap project goodbye haha, although i've been blessed with finding much of the crap i've needed so far for good deals, and i'm patient if it means doing it right.

 

You mention it's not the option to go down if you're after the cheap, would the cost be offset somewhat by already having the SC12 and using the deal on the diff i've been offered below? Or where would the majority of the money be going even after said options already being in my posession? Just looking at my options and where i'm going to need to focus.

 

I've been offered a W series Supra diff for $100 from the same guy as mentioned above, although it's in pieces. So i'd have to take it to a diff shop and get them to reasemble it, then presumably take my existing diff and get them to fabricate some mounting points using the original one as a template.

 

I'm giving it some serious thought, as it will work out nowhere near as expensive as a working Supra diff to begin with.

 

So, assuming i'm going to run with the R31 diff (to keep my options open), when you say it's not as strong, would it be strong enough to perform reliably for an extended period? Keeping in mind this is going to be my daily, so i'm not going to be punting it around the track. Maybe the occasional bit of drift as i'd like to get into the sport, but it'll be a daily first and foremost. As mentioned above i'd rather go for an option that provides me a long-term solution, rather than have to keep replacing the things which'll end up a costly headache and be time consuming (and time's money homie!)

 

And lastly, is the W series Supra box my only real feasible gearbox option?

 

Ah thanks guys, you're both legends. I would have no clue if it wasn't for you two. Much respect and e-love.

 

- Aleks.

[tas_ae71]

IRS=independent rear suspension.

 

ae71, r31, hilux, tarago are all live axle (your traditional style diff)

 

a conversion is a fairly big job that requires a descent bit of fab work, its also usually works out heavier. not really worth it IMO.

 

 

a w-series box is strong, awesome bang for buck, you wont break one with any 4a. its a tried and tested box and conversion. there are parts to make this bolt straight to the motor such as bellhousings, clutch set-ups etc so minimal custom work is needed.

 

a R31 borgwaner should be plenty strong enough. also if you have an LSD instead of a locker it will last much longer and be quite a bit more street friendly. they are fairly common so getting replacement axles if you do happen to ever break one is easy. they also have the factory disk brakes which the hilux doesnt. they are a descent bit wider i believe. doesnt necessary mean it needs shortening. running +offset wheels or having flares will help.

 

i wouldn't think that it would be a great daily driver though. usually with a daily you want something a bit less inconspicuous, comfortable, fuel efficient, quiet and easier to drive. no PS, bitey clutch make it a bit more difficult in town.

Edited June 15, 2009 by tas_ae71

[Victim]

IRS=independent rear suspension.

 

ae71, r31, hilux, tarago are all live axle (your traditional style diff)

 

a conversion is a fairly big job that requires a descent bit of fab work, its also usually works out heavier. not really worth it IMO.

 

 

a w-series box is strong, awesome bang for buck, you wont break one with any 4a. its a tried and tested box and conversion. there are parts to make this bolt straight to the motor such as bellhousings, clutch set-ups etc so minimal custom work is needed.

 

a R31 borgwaner should be plenty strong enough. also if you have an LSD instead of a locker it will last much longer and be quite a bit more street friendly. they are fairly common so getting replacement axles if you do happen to ever break one is easy. they also have the factory disk brakes which the hilux doesnt. they are a descent bit wider i believe. doesnt necessary mean it needs shortening. running +offset wheels or having flares will help.

 

i wouldn't think that it would be a great daily driver though. usually with a daily you want something a bit less inconspicuous, comfortable, fuel efficient, quiet and easier to drive. no PS, bitey clutch make it a bit more difficult in town.

 

Ah, fair enough... So, even with my dirt-cheap $100 supra diff, it still won't work out in my favour, taking into account the fabrication needed?

 

Yeah, looks like the Supra W box is a winner. Would you happen to know a rough price figure i'd be looking at? And who, if anybody, sells these custom parts to make it bolt-in?

 

Lovely, disc rear's is definately a plus. One of the boxes i wanted to check in the upgrade. Hahaha... yeah... maybe you're right. But even so, i'd like to do it. Call me crazy... I have a few reasons for wanting this as inconspicuious as possible, are we talking about the R31 diff and it's length making it more conspicuious so that it's poking out the sides? Or the overall engine? And i want to keep the stock AE71 rims which are pretty positive offset as changing the wheels screams 'modified car', something i want to avoid at all costs, but some slight flaring we can do. Bolt on SL/R 5000 looks ftw!

[Instigator]

I probably wouldn't bother with an unassembled Supra diff. You have no idea of the condition of it or if any bits are missing so it's worth nothing really.

 

Depends what you can find a box for second hand, usually around $400 or so I think? The bellhousing can be sourced from a few different places. AE86DC forum has vendors that sell them. I can't remember which is the preffered brand to get.

 

R31 diff is two wide so if you run 0 or - offset rims you'll be poking tyre out the sides which is a quick way to get noticed by the boys in blue. You can get them shortened but there's more $$$

 

Throw the stock wheels in the bin ASAP. How can you say you want to modify a car to this level and keep stock rims? They'll hear your motor before they'll see your rims. If you want to avoid attention make your car look as neat as possible and not derro spec like a lot of them. I've been pulled over once in mine in almost a year and that was because I was sideways round two corners in the wet and an undercover saw me.

[Victim]

I probably wouldn't bother with an unassembled Supra diff. You have no idea of the condition of it or if any bits are missing so it's worth nothing really.

 

Good point, although i know the bloke flogging it so it's not a random trying to flog shonky parts, and i'd take his word for it that all it needs is to be reassembled to be put back to good working order. Hence my interest in using it, considering the $100 price tag, even with the price for reassembly + mounting point fabrication would work out cheaper than buying one complete. But that was before i heard about this large-scale IRS conversion...

 

So my two options are basically thus: buy disassembled Supra diff, pay to have reassembled + mounting points fabricated. Then pay for this IRS conversion & fabrication, which has been mentioned to be hella large ammounts of the $$$. Anybody got a rough figure or an idea on what that would set me back?

Or, door two: R31 diff... possible shortening (although i doubt i'd go to that extent, to be honest) which entails positive offset wheels then flared guards.

 

Depends what you can find a box for second hand, usually around $400 or so I think? The bellhousing can be sourced from a few different places. AE86DC forum has vendors that sell them. I can't remember which is the preffered brand to get.

 

Ah, for sure. Cheers for that, i wasn't aware they were there. I shall keep my eyes out for threads over there for some knowledge + vendors flogging such parts. You (or anybody) wouldn't happen to know what types of Supra's have the required W-series boxes? I found an '84 Celica Supra for wrecking on the heaps cheap, and it would be good if those parts were compatible / that model had the correct gearbox... I'm not too sure where to check these things.

 

R31 diff is two wide so if you run 0 or - offset rims you'll be poking tyre out the sides which is a quick way to get noticed by the boys in blue. You can get them shortened but there's more $$$

 

Throw the stock wheels in the bin ASAP. How can you say you want to modify a car to this level and keep stock rims? They'll hear your motor before they'll see your rims. If you want to avoid attention make your car look as neat as possible and not derro spec like a lot of them. I've been pulled over once in mine in almost a year and that was because I was sideways round two corners in the wet and an undercover saw me.

 

Yeah... more $$$ sucks, in short. So to be honest, i doubt i'd go to the effort of shortening an R31 diff. Which leaves me with the alternative of really positive offset wheels, and then flared guards...?

In that case, by how much does the R31 diff extend length-wise over the stock diff? Is it a large ammount, or just enough to be noticible, or only a slight ammount? If it's not that noticible, would it be feasible to get away without shortening it?

And following once again on the R31 diff front, how easy is it to install? A matter of a bolt-in job, or is it going to be a real prick?

 

Hahahaha... ahh, you've got no idea the ammount of people that say that. To be honest, i want to keep it as stock looking as humanly possible. As little attention as this car initially gets from a glance is what i want to achieve (especially from the 5-0). Plus i like the stock rims for some reason. They've got old-school gang bangin' corolla cred, and i also can't justify spending money on things that look nice over hardXcore engine bits. I've never put much chop in showy cars, i like the sleeper look. And any money i save from bits like wheels and the like goes into usefull things like what i'm trying to do here, which i feel is a better use of it, but i see your point.

 

Ah, derro spec. Hahaha, great call. Currently though it does look a little 'derro spec', primer spots all over the shop. That'll change once all the surface rust has been removed and primed + painted over, but i can't really be shagged to find the proper colour paint so i'm eye-balling paint matching (and getting it hopelessly wrong might i add... Bunnings has very few paints that match faded silver).

 

Cheers for the continued help guys, very very much appreciated. E-beers on me.

 

- Aleks.

[Victim]

p.s. sorry for the essay post, but i wanted to get cracking on this as soon as possible. It's hard to just look at the old girl sitting in my carport in an undrivable state!

[Boost+k]

W box for sure... you want w55-w57 not a w50, bellhousing kits arn't cheap tho, there a guy over here in nz that makes them if you can't find anyone local

 

hilux diff (G series) is what i run because i got sick of breaking axels and diffs, and also if you get the right model then its only 10mm wider per side so no shortening, BUT there lsd's are useless, not a proper lsd for tarmac, i run a locker now, lsd is in junk pile

 

F series diff is only slighlty smaller and can handle a fair wack of power and there is lots of aftermarket lsd options and stuff around so id look into that

 

also mk3 supras run G series diff heads in IRS, so you can use them for ratios by putting crown wheel and pinion into a solid axel head

 

as for wheels, how about getting the corolla centers put into some 7" bands so you can run some decent tyres and still look stockish