kb1

iTrader: (1)

my question is how strong is the hawkeye 2.5l wrx gearbox
i`m looking to up the power on my 07 wrx and all i here is you will brake the gearbox, but after searching the forums on here i can`t find any hard facts.
plenty of older cars having problems,

even looking at andy forrests tunning stage for the 06/07 wrx
he recomends uprated clutch but not a mention on the gearbox.

he does mention the need on 03/05 wrx

any help guys i need facts not speculation.

dynamix

iTrader: (3)

In truth I don't think that many have done it so that is why it is a grey area. It depends on how far over 400 you are looking. Seen a few make low 400's and keep the gearbox in tact but the clutch does get hammered because of the torque of the 2.5.

It is a stronger box than the previous 5 speed though but a lot does depend on the useage and how gentle you are with the box.

APIDavid

iTrader: (4)

The 5 speed box is at it's limit at 400 hp. And on a 2.5 the torque will kill it. I usually advise to expect it to break and run it 'til it does. It isn't worth a lot as a used box to sell and you never know it might just last out.

We've just completed a P1 2.5 steel rods forged pistons upgrade, that is still running the original turbo for the owner's financial reasons. That made 340 odd horsepower, but 406 ft lbs of torque...... on somebodys rollers yesterday.

I expect a call for a new box any minute now.........

Hang on!, gotta go, the phones ringing.

David APi

Watch out for our new rolling road coming on stream soon


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kb1

iTrader: (1)

just what i was thinking duncan, a grey area.

david still no hard facts only assumptions. but good for trade.

dynamix

iTrader: (3)

Are you looking to up your power then kb1 ?

I would say that the std pistons are more of a concern at that power level than the gearbox.

kb1

iTrader: (1)

400/400 duncan

dynamix

iTrader: (3)

How? You will probably find that you will get more torque than bhp. You will be looking at something like a 20g at that level. Geordie stews cars was that level with gearbox intact. Clutch went eventually though.

Makes for a perfect road car.

APIDavid

iTrader: (4)

Hard proven facts where gearbox strength is concened are impossible.

We have one customer with circa 400 hp on a TY 752 series, hillckimbing and so on. Never broke it in three years of competition in a winning car.

We have another customer in a road car with 330 maybe - has broken 3 TY 754's this year on the road.

We had a customer break a straight cut PPG 2nd gear on his way to lunch with his lady at barely 350 hp.....

I don't need to exaggerate gearbox facts to keep my workshop full.

David

addison

What can you replace the box with if/when it breaks
i would want to keep 5 speeds

PS thanks to David API for my clutch it handles 400ft/lbs and feel so good

kb1

iTrader: (1)

my quote was not intended david i`m just trying to get true facts on the wrx strenth and i do think its a lot better than earlier models
now your saying how do we know gear box strenths are impossible to put limits on. this is my question. i`m not trying anything on david just fact finding

APIDavid

iTrader: (4)

PPG is the only upgrade that will bring a benefit that can be measured Just fitting another standard box will ultimately bring the same result.

KB1, no offence taken - gearbox strength is truly a " how long is a bit of string question."

David APi

dazdavies

iTrader: (22)

I have one of these boxes in perfectly good condition that I can't sell for anything that i'd call a fair price.

I'm wanting a six speed to cope with the power i intend to run (550+).

As this box is worth **** all I may as well put it to the test and see at what level it breaks when it breaks not if.

dynamix

iTrader: (3)

It really depends on whether you let Steve drive the car Daz

APIDavid

iTrader: (4)

That's what I like to hear; " constructive destruction " regardless of MR Darley's attempts.

Bez300

iTrader: (2)

I'm running 300BHP 370 lbs, I do a few track days, my hawkeye box went bang. now got it rebuilt dog box some straight gears some heli gears, with platted front and rear diff as I broke the std ones. Car is ace now

so the answer I think is it will break

PS I did not use PPG

Bez

scooby1929

iTrader: (1)

Where did you get your gearbox done!! What did it cost to rebuild?

dunx

iTrader: (3)

Bez is busy getting it fixed....

I know two people who have killed hawkeye WRX gearboxes with around 350 bhp / 390 ft.lbs.

A six speed really is a no brainer unless you are headed ( Like Bez ) into motorsport seriously.

IMHO.

dunx

P.S. Yes I am going to be selling one in a few weeks....

scooby1929

iTrader: (1)

Is it a combination of bhp and torque that kills them or just the torque??

You say its a no brainer but at about 3 grand its alot of money for a six speeder. (Even then it will be a used one and you prob wont know mileage, history of it etc)

dunx

iTrader: (3)

An early STI non-dccd box and diff will be around £1800, with all the bits, someone on here will explain which driveshafts are required.

A full new-ish DCCD box will cost around £3K.

IMHO.

dunx

scooby1929

iTrader: (1)

Hope mine does not break with 350 lbs/ft torque!! Its a lot of money to fork out!!

dunx

iTrader: (3)

Mostly torque kills gearboxes, mine has the typical early six speed lazy synchro on top gear, so it's coming out, but I have a DCCD box from a Hawkeye to put in, as I fancy a RWD style power split...

dunx

P.S. A proper PPG or similar gearbox is eye wateringly expensive. Me likee a sequential one please Santa....

71/200

iTrader: (2)

Chris, 2 places to get a box built over here PPG Or OE

Ali Burrows or Ian Bishop look no further!

tempop1

Or scooby clinics new gearkit.

dunx

iTrader: (3)

BEZ would argue that may not be the best choice, but I will admit that WHO does the build is as important as what they use...

dunx