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Twinscroll turbo setup on 2005 subaru wrx
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Old 05 May 2012, 11:00 PM   #1 (permalink)
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Exclamation Twinscroll turbo setup on 2005 subaru wrx

Ive just bought a 2005 subaru wrx (blobeye) and i'm going to have the engine rebuilded which consists of a front mount intercooler, K&N panel filter, oil filter, 2x Cosworth head gaskets 1.1/1.2, 550cc injectors, fuel filter and turbo.

I was thinking of upgrading the turbo to a vf37 sti twinscroll turbo from litchfield,
here's the link
VF37 Twinscroll Turbo [LIE011] | Litchfield Motors.

Will I need any other things with this turbo or can it just go straight into the engine to replace the old TD04 one???

Please reply ASAP

Thanks,
scoobyworks

Last edited by scoobyworks; 06 May 2012 at 09:51 PM.
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Old 06 May 2012, 11:22 AM   #2 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

direct bolt on!!
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Old 06 May 2012, 11:39 AM   #3 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

You'll need sump and uppipe
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Old 06 May 2012, 09:54 PM   #4 (permalink)
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Exclamation Re: Twinscroll turbo setup on 2005 subaru wrx

Cheers for the advice...

The sump washer and up-pipe will be done, but is the vf37 twinscroll turbo a good fast setup on the wrx??? Cos' i know its very fast on the standard jdm sti but will the same performance be carried out with this one??

The original turbo is the TD04 dont know if there is any difference.

Thanks,
ScoobyWorks

Last edited by scoobyworks; 06 May 2012 at 10:17 PM.
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Old 07 May 2012, 03:47 AM   #5 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

it will fit OK but am sure the turbo has bigger blades you would need a bigger inlet pipe where the fans are on the hosing and the pipe runs under the inlet manifold just double check and ask them to check the size of the hosing you dont want to strip the inlet manifold off after would again to get the pipe in.

don't forget the vf37 starts to spools up at 3600rpm you wnt get a full spool till 4000rpm you will get may be a better top end rather then take off.

but it all depends on how good the tune up on the engine is and you will need to upgrade the fuel pump.

its a said truth but 2.0 wrx stock internals are not capable of handling more then around 280hp safely.

if your looking for sharp power i would get a simple decat intercooler and a good remap.

you will get more fun out of the td04 in my opinion with quick spool.



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Old 07 May 2012, 07:39 AM   #6 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

Thought the idea of twin scroll was that it made boost earlier than a single scroll, it does in a mates car here. I was also under the impression that the wrx can handle up to 340.

And it's not a sump washer its an actual sump you'll need to allow clearance for the twins scroll up pipe
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Old 07 May 2012, 01:54 PM   #7 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

Is this what you mean by sump:

Subaru Sump Pan and Bolt Kit - £86.12 : Scooby Projects - Shop

Why would I need another genuine subaru sump when i think the car is already supplied with one???

Last edited by scoobyworks; 07 May 2012 at 02:28 PM.
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Old 08 May 2012, 12:35 AM   #8 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

If you are interested in your engine lasting 100K don't go over 280 hp. That's at the crank lads not the wheels.

WRX engine has cast pistons instead of forged and softer valve materials that is why it's not good. The engine will only last 15-20k before a major re-build again.

You can get more power like 340- 350 hp safely in the WRX, but you have to strengthen the internals with stronger pistons and valves.
Even at stock power levels transmissions will break, and then suspension and braking problems

VF37 turbo is good for 400HP the ej207 jdm spools at 2800rpm and its 20psi at 3600rpm thats with the avcs different ecu mapping and shorter jdm gear ratios.

most 2003 onward sti models jdm runs at 18 psi on vf37 400 hp.

On a wrx with around 350 horse power you need at at least 1.6 bar of boost thats 23 psi for the turbo to spool at 3200rpm.

I don’t think the stock internals will last long. Even at stock power levels transmissions will break, and then suspension and braking problems.

Here is a list of what the difference on the jdm to wrx

Twin-scroll Header
Twin-scroll Uppipe
VF37 Turbo
VF37 specific flange Downpipe
Braces going from turbo and uppipe to block
Oil pan
Oil pickup
Cover that goes over the crank and under the oil pickup
Uppipe to turbo metal gasket
Turbo to downpipe metal gasket

hope this helps



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Last edited by ccsworks; 08 May 2012 at 12:38 AM.
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Old 08 May 2012, 06:49 AM   #9 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

engine will last longer then gearbox, and 350 isnt going to kill a wrx engine whatever anyone else may say if its mapped correctly.
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Old 09 May 2012, 04:05 AM   #10 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

The? we need to ask is how long will 340bhp last and how many times we are in and out the garage or down the mappers.

Well you can put as many horses and as much boost out the wheels the bigger the bhp the bigger the wallet bill. It wonít last 15 to 20k depending how itís used. It will only be good till it lasts.

Common thing is differential wheel bearings will go before anything then depending on use the oil will fry piston rings lands or you will hear the rods knocking the ratios in diff and transmission are totally different on that kind of bhp

the stock bits will only last up to the wrx ppp bhp or a little over which is the safe upgrade for the wrx which consist along with the shot shifter decat exhaust filter and a remap.

The mappers wonít guaranty anything as at the end of the day itís the driver he is the one who tells the car how and when to use the engine. And it has to be a trusted mapper that is recommended by other who used him.

Am pulling an engine out right now that last the poor chap 7 month running 330hp on the roller print out bottom end knocking number 3 again on a new age wrx.

uneven fuelling, which is apparently a common fault in these engine (and am willing to be corrected on this of course) that if you asked anyone who had blown their engine due to inadequate fuelling which cylinder went they would say number 3.

and if internals are not appropriate why bother with 550cc injectors the stock 440cc ones are good for 352bhp on wrx why use sti ones here is a ruff work out below.

20bhp per 100cc of injectors works out at 352bhp 20 x 4.4 x 4 = 352bhp

And if you are going over 352 bhp and are changing the injectors a lot of the time people change the injectors but it would be a good idea changing the Fuel rails as well so thereís no lost of presser and you have less chances of number 3 going.

Forged pistons would also be good if you intended to use the car aggressively.

Ask any good mechanic who rebuild engines he will tell you lads that itís all about getting the technical data right for the engine life to last. Not over ridding the engine to kill the torque will only last you short terms.

This is my personal opinion from daily experience not a debate or to impress people just sharing knowledge.



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Old 09 May 2012, 05:28 AM   #11 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

If in doubt ask a expert, api or aj will give you proper advice based in what they have done,
As a mapper I see more engines killed thru poor servicing and cheap fuel then too much boost, but what would I know lol
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Old 09 May 2012, 09:58 PM   #12 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

I thought the standard injectors were 380cc???

350 will be good for me its just after that I might start to add some other upgrades to about 380 maybe 400 but only if I feel that I need it. From what i've heard 350hp is better than you think it will kill m3's keep up with porsches and will give ferrari's a run for there money. I've got a standard 2001 wrx with sti kit only mods are bigger oil pump, NGK spark plugs, cat back exhaust. Even standard i'm impressed how it accelerates to 120+, it's just that it won't beat a porsche, ferrari, etc so this is what this car will be made for.

Is upgrading the stock internals, pistons and valves expensive??? What do you mean by how the car's treated because it will be serviced by a subaru specialist and maybe ONCE I might go on a track to see what it can do, but I wouldn't try drive the car at it's max as I don't want to damage the car. It will always run on shell v-power. Occasionaly I might floor it up the motorway and 'rally'(don't mean actual term) just acceleraing through the corners etc.
This can't be too bad for the car can it??

Will I need to upgrade the fuel pump, and if so what will happen if I didn't upgrade the fuel pump.

I would prefer not to upgrade the turbo because of costs, but ive reasearched and found out that the TD04 turbo starts losing power after 5000rpm, is this true??

Is this worth it:
http://www.japperformanceparts.co.uk...ils.asp?ID=109
£1,100 is the real price.
The majority of the stuff needed are only found second-hand cos the up-pipe, down pipe, etc for a twinscroll is very expensive =(. The only reason why I prefer the twinscroll turbo to others is because the performance you get is the best acceleration and top end speeds are exhiliarating.

Thanks,
ScoobyWorks

Last edited by scoobyworks; 10 May 2012 at 08:29 PM.
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Old 11 May 2012, 03:11 AM   #13 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

As I mentioned before this is my personal opinion from daily experience with details of what can happen not a debate.

mappers will map your car according to your upgrades and no mapper will tell you your ok going around corners at 350bhp with stock suspensions, breaks, differential and so on and nether would they recommend or guaranty that you run high boost on regular bases with a second hand engine internals which already has had good enough use out of it and doesn’t hold the same compression.

As bob mentioned i think you should ask a good engine rebuilder and a mapper that you want to take the engine to 350bhp and what i have mentioned in my posts if it makes sense.

You mentioned Porsche’s and other cars if you planning on having a shot at them on the track one off that’s fine but if you planning on doing this at the lights you won’t have your licence for long with cameras and bumps on every corner.

Stock internal might not be expensive but if you’re doing a rebuild and got the engine opened up why not use forge internal and if you are planning on taking the bhp high later your main jobs don on the engine why pay again for everything. And it will put a hole in your pocket.

The tdo4 turbo just spools faster but as i said before it’s no good for 350 horses i don’t think they can take more than around 280bhp anything over that you might be changing it every now and then
.
Why not go for a vf34 ball bearing type similar to the vf30 but comes in 500rpm earlier then the vf30 or better still the vf35 which is a really good spool and will hold near enough that king of bhp.

The vf37 is really good but you will get the best out of it at 400bhp.

stock injectors 380cc injectors are good to run 276 to 299bhp

550cc injectors are good to run 400bhp to 432php depending on fuel presser.
Here is a lay out below on how you can work your bhp.

Injector Size>> BHP AT 3bar fuel press>>BHP at 3.5bar fuel press
380cc>>>>>>>276>>>>>>>>>>>>>>>299
440cc>>>>>>>320>>>>>>>>>>>>>>>346
550cc>>>>>>>400>>>>>>>>>>>>>>>432
650cc>>>>>>>473>>>>>>>>>>>>>>>511
740cc>>>>>>>538>>>>>>>>>>>>>>>581
800cc>>>>>>>582>>>>>>>>>>>>>>>628
850cc>>>>>>>618>>>>>>>>>>>>>>>668
880cc>>>>>>>640>>>>>>>>>>>>>>>691
960cc>>>>>>>698>>>>>>>>>>>>>>>754
1000cc>>>>>>727>>>>>>>>>>>>>>>786
1200cc>>>>>>873>>>>>>>>>>>>>>>943
1600cc>>>>>>1164>>>>>>>>>>>>>>1257

hope this helps



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Last edited by ccsworks; 11 May 2012 at 03:23 AM.
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Old 11 May 2012, 06:27 AM   #14 (permalink)
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Exclamation Re: Twinscroll turbo setup on 2005 subaru wrx

Thanks ccsworks,

it will be upgraded 2 400bhp but should I use 650cc injectors just 2 be on the safe side cos I don't want to end up replacing the 550's in the future.

Thanks,
ScoobyWorks
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Old 11 May 2012, 02:33 PM   #15 (permalink)
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Re: Twinscroll turbo setup on 2005 subaru wrx

why not just buy a Sti and know everything will take what you want, gearbox WILL take the power your after, the internals will also, brakes are sorted and you get dccd to play with,
the extra you will pay for a highly modded wrx has to be considered.
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