mjharper

iTrader: (1)

I have a Hawk forged and rebuilt by the excellent API. It has been mentioned putting too much power through it may pop the 5 speed box - I was wondering what people are managing to get out of the standard boxes?

I'm currently on about 290 after a remap. I'm in the process of (saving for!) upgrading the brakes and suspension.

I'm starting a new job next week so will only be doing 2 miles to the train station and back and some weekend fun drives - do you think I could drop a larger turbo in then save up for the 6 speed, or will it pop instantly?

Cheers

yabbadoo4

iTrader: (8)

they say around 350 bhp for a 5 speed but some have run more through them. i think its about driving style and mechanical sympathy as to how they last. if your launching your car hard and driving hard then it will be on borrowed time. its the torque that kills boxes. also depends what power your aiming for and what turbo your considering.

mjharper

iTrader: (1)

Thanks for that, aiming for 400 - 450 so it might be wise to sort the box first

yabbadoo4

iTrader: (8)

Def need the 6 speed then bud yeah.

BoozyDave

iTrader: (8)

I know a couple of people running 380bhp on the std hawk wrx 5 speed, but they have mechanical sympathy.

wouldn't fancy trying any more than 380 through it, buy the 6 speed and sell the 5 speed while it's working

scooby87

iTrader: (5)

I run 385 on mine and I'm not exactly gentle, I heard the later 5 speed like yours can take a bit more.

I've also read people running over 400, but its one of those things.

I broke my Mondeo gearbox (stock diesel) so who knows.

thenewgalaxy

drop the engine into an STI

henrysmith

iTrader: (5)

Running 462BHP/490lbft in my GB270 with an 'Enginetuner' forged build. Brakes/suspension and such all sorted. Still has the 5 speed and is still fine. Been running this for almost 2 years now and have done 20 000 miles since build. Did 15 000 miles at 360 BHP/320lbft before this. I don't EVER launch it and am well past traffic light GP's. Mostly a road car but does get 'used' regularly and with mechanical sympathy! It's great with the 5 speed which I love. Run it until it breaks (if it breaks) and then either a 5 speed upgraded gear set or a 6 speed setup, don't think a secondhand 5 speed is worth that much nowadays?. This is what I AM doing for what it's worth

neil-h

Any chance of some more details? I've reached the point now with my GB270 where i'm happy with the chassis, so i'm looking at increasing the power a bit and it would be good to see how someone else has done it.

henrysmith

iTrader: (5)

First engine mods were STI TMIC, Undertray and Bellows (that's what Subaru officially call them), a Full Milltek 3 inch exhaust with sports CAT, K&N panel filter and a SC42 Billet (version 1 - TD05 20g) and mapped at Powerstation - made 363BHP and 321 lbft - boost was a max of 1.2 bar and was worked back down to this figure to save engine.

Generally a good exhaust, panel filter, STI TMIC, VF43/VF48 and a remap will get you a nice healthy return in the mid 300's for BHP/lbft. Fuel pump would be good as well on a 6 year old or so car.

Talk to respective/respected mappers and builders and ALWAYS be aware of the 2.5 weaknesses.

Car now as link below

https://www.scoobynet.com/projects-4...n-project.html

BrownPantsRacing

iTrader: (6)

I've always heard that the later Hawk 5 speed boxes are much stronger than the older 5 speeds. Someone on here also took one apart and compared the cogs etc.

Been running 334/381 aggressively on mine for years with no issues at all.

The only issue I now find is that 1st gear is WAY too short. If your not careful the rev limiter can be hit in 1st.

neil-h

Nice, how long did Alan spend on the engine build?

henrysmith

iTrader: (5)

Think it was about 5-6 weeks total build time drive in drive out and then another 3 or 4 days when finally mapped/tweaked/toucan and Syvecs fitted.

boosted

Hawk wrx box running 460bhp

No point in having 4wd if your not able to use all that power and grip to launch hard and pull through 1st and 2nd, IMO, but then I like a bit of drag racing.

mjharper

iTrader: (1)

Good to know the Hawk 5 speeds can take some extra beans! which turbo would I need to get her to the 380 mark? Cheers

Tidgy

i ran 390bhp and 420ftlb for 14 months no issues on the box

mjharper

iTrader: (1)

Ace! which turbo?

Tidgy

sc46+, it wasnt even trying hahaha spool was epic as well, slight correction 410ftlb

mjharper

iTrader: (1)

Great stats! would this be a direct fit? my engine is forged, sti gaskets, up-rated fuel pump etc - cheers

Tidgy

yep direct fit, had a few supporting mods like wing mounted induction kit, perin inlet pipe etc

mjharper

iTrader: (1)

Good stuff, I shall investigate coilovers first tho!

boosted

Playing it nice and safe at 11:1