TD04 to VF34/35 something else?
 

Looking for the next step up in performance for my Hawk WRX. It's rebuilt / forged, with a 255 fuel pump.

What are people's experiences upgrading their TD04s? I don't want to break the bank - looking at gradually acquiring the parts I need then getting it all set up.

From some researching I've heard VF-something turbo, possibly an STI tmic? STI/uprated injectors. I'm targeting the mid 300s if possible.

Ta!

I'd say since you don't want to break the bank go for a hawk or hatch STI turbo, I think it's a VF48 but don't quote me, good for 360 ish and a bit more with bags of torque.

like ditchy said, go for a turbo from a 2.5.

I think the vf34/35 are more suited to a 2.0 engine

thanks guys :D

I have the VF43 on my WRX hatch making 350bhp and 385 torque spools up ok too. its coming off in 4 weeks as I am heading for 400bhp.

We can sort you a Billet TD04 hybrid for not a lot of money.
It'll make good power with exceptional spool and beats everything else we'very tried for driveability in that 300-330hp range.

i would say a hybrid TD04 might be worth looking into if you can get it for a decent price - all the quick spool of a TD04 but with a little more top end so you can reach the BHP figure you want.

But if you can get a VF from an STI for the same money then you might as well go down that route though you will lose out lower in the rev range.

I have a VF28 on my hawk WRX. made 316bhp and 350ft/lb on stock cat and stock TMIC. I prefer the power delivery over the td04. pulls well in high revs and hardly any lag.

If not already done I would spend money on supporting mods first. Exhaust, 2nd cat removed, silicone Y pipe and air filter. that should see the TD04 doing 270-280bhp with an appropriate map.

oh and the STi injectors are same as WRX on hawk, 550cc so no point changing them.

Sc36 or sc42

Which way to go
 

Lot's of good advice above, but as you have a forged engine unit already:

I'd be inclined to put the money into a good turbo, a MD321H would be fantastic , as are the larger / later VF's The VF35 is about the same as a TD05 18G any of these will get you to 380bhp the TD05 20G will be too laggy even if it can make 400 bhp Id say for most driving daily keep away from that.
The SC 42 would be a better solution against the lag and easy 380bhp.

Just don't do what I did trying to push a smaller turbo too hard. Trying to get it maxed out , with a TD05 16G on a cheapy jammed MBC which caused a boost spike and knocked out my WRX bottom end. Sure it was cheap alternative but its always going to be struggling hard to breath/create over 320 bhp , if you over boost things it becomes hard for a small turbo/ and for that matter the engine to live with the consequences.

Im now just about to put my rebuilt engine back in this time with Sti Rod/Pistons ACL shells and an uprated oil pump. That little exercise costs 1500 pounds even if you do a lot yourself. If I had known what I do now I would have plumbed for either a good used VF unit or saved for The MD321H and tuned it nicely down to 350bhp at say 1.2-1.0 bar. To stay in the most efficient area of the Turbo's performance. ( look at and compare flow graphs before you buy one ) then smile because your turbo runs cooler and while you also save fuel. Best Regs Linksfahrer

So if I found myself a VF43 what else would I need as supporting stuff - Would my stock TMIC be ok or is it worth grabbing an STI version? Injectors seem fine as fuxzzbom mentioned, I have a ninja II exhaust - where are the cats in a Hawk? up pipe and somewhere else?

Ta!

there are 2 cats in the downpipe - remove the 2nd one and keep the 1st one or replace it with a sport cat which might be cheaper.

Stock TMIC should be ok, the STi one is only a little bigger I believe. only worth doing if you intend to do track days etc.
Cats on the hawk. main one is in the down pipe. the 2nd one is after that.
Up pipe on the hawk does not have a cat in it.

http://www.scoobyworld.co.uk/catalog...oducts_id=1116

or as Bludgod says replace with a sports cat.

if not already done the centre pipe is worth changing
http://www.scoobyworld.co.uk/catalog...roducts_id=448

Cheers, so those two products are enough to decat my WRX? Then it's just finding a turbo and getting a remap?

I have a vf48 and hatch sti top mount for sale in the subaru parts section!

Interested in the turbo - full working order etc?

no. they will keep the downpipe cat in place. this will keep it MOT friendly.

those pipes will remove the 2nd cat and the centre pipe (you may not need the centre pipe as your Ninja II might have this already in place?)
You can get a sports cat to improve flow but it should still make good power with the stock cat.

I would fit an uprated fuel pump, air filter and intercooler Y pipe personally before looking at a bigger turbo.
without doing that lot you will not get the full benefit of the bigger turbo.

the TD04 can be a lot of fun with supporting mods and make loads of power from low in the revs.

Yes mate, no problems whatsoever no smoke, boosts fine.

I was going to keep it and have a billet wheel upgrade to hit 400bhp. But decided i wanted 450 lol. With the right mods you should see 360-380 with ease.

Heres the for sale thread

https://www.scoobynet.com/subaru-parts-451/1019157-vf48-turbo-550cc-injectors-sti-intercooler.html

Hope this helps

Jamie

TMIC Sti or similar for dependable power
 

Personally I think just changing the turbo will leave you short. The Sti TMIC will allow you to keep the air charge temperature down and ultimately this makes for more reliable power in warm weather and what's more important it keeps your MAP timing where it should be , otherwise as things warm up you will feel the car will seem to feel / and is slower. All this depends on how your engine mapper plays safe . If you are on the Rolling road with a TD04 Intercooler you will see good power produced for the first 3 or 4 power runs , thereafter and despite the mappers best attempt to improve , the power curves will just fall away. This is also why the homologated cars got the water spray option to keep the intercooler cool.

The answer for you is to put the Sti intercooler on or think about one like I have attached in pic below for the 300-400 bhp range , maybe also think about adding water spray for the upper levels , after this band you should consider a FMIC.

You should try to bear in mind that a TD04 was never designed to flow large amounts of air needed to run toward 300 bhp , so its charge temperatures are always critical for efficiency. The higher the speeds you ask this turbo to spin (higher boost pressure ) the worse the effect on your power/ fuel comsumption will be. The TD04 will run fairly efficiently till 1.0 bar after that its efficiency falls off rapidly. Im not saying the std intercooler won't work but you will not get the best out of the other modifications if you dont change it.

I bought mine from CX racing USA and it only take 10 mins to bolt it on. The Y pipe kit is included and is effectively flows like the PPP mod. The sti ones are available on here SH for reasonable money from people going to FMIC so its not hard to get one , Then of course do go and get it mapped. ;)

Cheers for that, will consider the STI cooler then!