scoobyboy1

iTrader: (16)

Having some mods put on my car to beef up the performance and was just wondering what bhp i would be looking at.

The car is a MY00 with the following performance mods:
Full decat
Dump Valve

The car is having the following fitted in the next month or so:
VF23 Turbo
APS TMIC
550cc Injectors
Uprated Fuel Pump
Tek3 Remap

So what are peoples predictions on the following mods anyone please.

Neilo

not sure what the capabilities of the turbo are but id guess around 320bhp 300lbft? with ease probably, that looks like a nice safe set up to me, watch the gearbox tho

scoobyboy1

iTrader: (16)

Thats the kind of power id like to have, i know the turbo would be at its limits with 320bhp but i dont really want loads of power, like you say the gearbox would be my only worry for the time being, so id better start saving for a Type RA gearbox.

TonyBurns

iTrader: (3)

You wont find any 5 speed gearbox that subaru make that will safely take that sort of power unless its been rebuilt, and that includes the type RA boxes.
The only sure way of knowing your gearbox is going to last is to have it rebuilt with stronger internals, not the cheapest way but probably better than buying a new one every 6 months

Tony

Tone Loc

iTrader: (1)

Are you taking the **** Tony... many many standard gearboxes are taking 300lb/ft quite easily without spending £2k on a gearset (plus fitting). And have been doing for 1000s of miles.

Plus it's torque not power that kills the box.

Tony.

yhe chod

what about the sti 8 6 speed -any tougher??

john banks

Tony, Bob and Harvey did OK with STi 5 speed boxes, with 400+ lbft.

I was toying with an RA gearkit with long UK Legacy diffs for a 350-400 lbft 2.5.

scoobyboy1

iTrader: (16)

I think i would rather wait for the standard gearbox to go bang before investing in a new stronger gearbox, Why change my standard gearbox when my MY00 standard gearbox might be allright with that sort of torque. Touch wood and fingers crossed and all that.

Probably jinxed myself now, and ill be on here in a couple of months asking where to get a new gearbox from.

TonyBurns

iTrader: (3)

If you read my post, i stated that you wont find any subaru 5 speed box that will saftely take that power (see above my thread, 320bhp/300lbs of torque), and its true, at 300lbs of torque you start to see the failures, and there are alot more gearboxes that go with 300lbs through them than those that dont, damn, even standard cars have problems with these gearboxes sometimes (215bhp/218lbs of torque!), they are the weakest link in the chain, along with the clutch, and for reliability you will need a rebuild.
You have to remember Tony that not everyone drives like a granny

Tony

TonyBurns

iTrader: (3)

Didnt Harveys WRX's gearbox go with 290lbs of torque though it?

Tony

john banks

What has that got to do with the price of fish when we are talking about STi boxes?

There are clear examples of Subaru 5 speed boxes that have taken massive torque - ie Bob and Harvey.

TonyBurns

iTrader: (3)

John,
The car in question is an MY00, i take that to be a uk car, "most" of these running over 300lbs of torque suffer on the standard gearsets, even the STi gears are not much stronger (afaik only the 22B had a hardened gearset).
The only gearbox that was designed to take 300lbs of torque in its stride is the new 6 speed box, not an enhancement of the 5 speed box but a completely new design! (a very rare occurance btw!!).
Even changing the gearbox to a RA box will still eventually bring about the inevitable, just that you will be 25mph (or there abouts) lower geared (and then you need the diff to go with it).
Wasnt there a gearbox thread earlier this year? about whos gearbox had expired?
The power etc that was going though them?
But IMHO, you have a gearbox that wasnt designed to take 300+lbs of torque on a daily basis, then your looking at reliability in the short term, and gearbox failure in the longterm, even though, it shall be said, you have pointed out correctly that there are cars out there running more than 300lbs quite happily (possably down to the driver/gearchanges/abuse etc).

Tony

Tone Loc

iTrader: (1)

So by your last post saying that gearboxes on standard cars let go that you'd recommend a standard car also has a 2K plus gearbox rebuild . Your advice here is way way of track Tony. Yes gearboxes have failed at low torque..... but why? You don't know the full facts or how they have been driven. You seem to imply that a car driven hard will destroy it's gearbox, that's just not the case. A tuned car can be driven hard but still with a bit of mechanical sympathy.

I'd say put the mods on the car, drive it as you want to and see if the box holds. If not spend the money but if it holds (ala Bob's, Harvey's) then the guy has saved over 2k by not taking some bull**** advice..... I.E NO subaru box will take 300lb/ft for over 6 months. Absolute crap!!!!!!

Tony.

TonyBurns

iTrader: (3)

Actually i said this in my last post.

I then also stated this>>

So, having given the advice i do stand by it, 300lbs of torque is pushing your luck, your gearbox may last 1 year, it may last 1 month, but it will wear alot quicker, and reliability will be compromised.
I would have thought someone like yourself Tony, would be there to say you get to a point in tuning when you have to look at whats going to go wrong, where reliability is going to be compromised for performance, we all know that you can only go so far before you have to put your hand in your pocket to get reliability, ok this guy may run this gearbox until it goes, but is then the excuse of "ill buy another uk box" going to hold? I personally dont think it will, but ive given the option of reliability, and though i have stated that its not cheap, it will be reliable (as long as its done by someone reputable).

Tony

john banks

Tony (Burns), you said there was no Subaru 5 speed box that will safely take the power, then you change tack and say they weren't designed to take that power.... there are several examples of cars that have taken far more power and torque without falling apart, and have done so for tens of thousands of miles, to the point where if someone had a 5 speed STi box I wouldn't see any point in changing it or rebuilding it until it breaks.

In fact at only 320 BHP and 300 lbft it is entirely reasonable to see how you go on a UK 5MT, and replace as necessary, and can work out quite cheap in the long run as a 5MT is about 1/4 the price of a 6MT. Agreed it is pushing it a bit, but an STi 5 speed gear set is a totally different animal - there are some who have got through a few UK boxes and then had no trouble with the STi for far longer.

My UK 5MT did considerably over 300 lbft for about 18000 miles on the original clutch before 3rd gear let go. For some people that would take them a long time to do.

Tone Loc

iTrader: (1)

As John has just stated.... you are now changing tack Tony. Your first point was NO Subaru box will take 300 lb/ft. I still say this is horse ****. That is the only point i'm trying to make in this thread. We all know that increasing power/torque will reduce the life of the box, same goes for engine etc. but that does not mean that you should recommend to somebody spending 2K plus of their hard earned money when in all likely hood the gearbox will last in excess of 20K miles at that torque level.

Stick with the box you have, learn to change gear properly and replace it only if (and it's a big if) it fails would be my advice.

Tony.

TonyBurns

iTrader: (3)

Tony,

I acutally said You wont find any 5 speed gearbox that subaru make that will safely take that sort of power unless its been rebuilt were my actual words, note the word safely, ie it wont be reliable and you can expect a good chance of failure.
The point im making on this is that 300lbs of torque will eventually kill the gearbox unless its rebuilt, the fact is, is that you dont know what that gearbox has already been through, and my answer for reliability is a rebuild, ok let the first gearbox go, but then you dont want to shove another box in there really unless its going to take the power, your just throwing money away, rather you do the job properly or you dont do it at all.
My final point on this, is that STi put a hardened gearset in the 22B, with just 267lbs of torque, and AFAIK, this is the only hardened gearset that STI did on a classic scoob, the likes of the type RA's didnt need a hardened gearset, they were meant to rally in grp N races as they were, and if you see the cost of a grp A gearbox you would be a bit surprised! (quite a bit more than 2k!)
My last post on this, is that if you want reliabilty, it comes at a cost, and if that cost is a rebuild then thats the way to go, its up to the owner if they want to run the car until it lets go, but changing to another standard gearbox is just plain silly IMHO.

Tony

Neilo

i just wish that subaru would over engineer things like toyota do....the GT4 and supra gearboxes can take 500lb + so ive been reliably informed......i can dream.....

john banks

Tony, you do talk some twaddle. The STi gears have in some cases steel shift forks, cryogenic stress relieving treatment, increased gear width and gear tooth root thickness. They do seem to stand up to far more torque than would break a UK 5 speed, why otherwise would several have found them a viable high torque standard or upgrade gearbox? Maybe they are just imagining it, in which case I'll happily take their poor gearboxes off them for the price of a UK/non-STi gearbox

john banks

I need not remind you I've had the pleasure and displeasure of three five speeds and one six speed, and a £2500 rebuilt setup was the least reliable of the lot. Number 1 5MT lasted for 30000 miles and by the end had quite hilarious performance, number 2 5MT took 370 lbft for a while and lived and is now a spare, number three was the rebuilt 5MT with what was considered the dog's wotsits of a gearkit at the time and broke with 400 lbft in 3000 miles. Number 4 is the six speed which has taken 400 lbft+ with some use at up to 450-460 lbft and is now over 15000 miles.

I've seen Alan Garrod have incredible reliability with an STi 5 speed box and he has had it stripped (without failure) and the gearset is fine after extended use.

How many Subaru gearboxes have you broken or taken apart Tony?

Pavlo

Touché