Hi Guys,

Currently in the processes of thinking about getting enginetuner ( Alan ) to build me a 2.1 Stroker engine.
Now before I commit to anything as its a lot of £££££ I need to ask some questions on things I'm unsure about.

Now I will be happy with a reliable 400bhp, any more then that's a bonus!!
My car at the moment is a 2003 WRX.

Can I use my current WRX Inlet manifold & throttle body @ 400bhp??

Have a STi Top Mount, Do I need to look at a FMIC now? Also can I retain the Std Dumpvalve or need to go after market at that power??

Also I know the SC turbos have been talked about a lot, but what other Turbo out on the market could I look at for the 400bhp Fig??

Injectors - I dont want to run at 100% so what would be the best to go for?
I already have a set of Hawk Eye 560cc, Guess they are not enough?

Fuel pump, I did read that the Walbro 255 max's out at 390bhp?? Or is that rubbish?


Headers and Up-pipe???

And the gear box, I'm guessing the WRX 5 speed won't last long??

Cheers Guys.

Sorry for all the questions, I need to be 110% sure.

 

at 400 front mount for def. sc42 for that power figure, 03 wrx box wont last long at all at 400.

best bet speak to ET if there gonna be building it for you, if theres a specific power figure you have in mind tell them, they can advise best route to get to where you want to go.

 

Someone will be along in a bit to say "Buy an STi" 400hp on WRX is going to cost loads.

 

Yea you just done it for them but just incase "you should have bought an Sti"

Best advice would be to have a good chat to the guys at ET with all your questions as they will hold all the answers, there is not alot that many of the tuners on here have not come across odds on

 

Hi mate,

Thanks for bringing this up, I just want to lay all options down before I make a choice!

What is the max power a Sti engine can handle then??

 

How long is a piece of string? newage sti (excluding the 2.5 hawk) Some are up over 500 on standard internals, mine is 450, so quite varied but they are said to be the strongest motor produced, but your wrx bottom end should be more reliable than a newage 2.0 Sti motor once complete and be able to take more abuse depends on what your wanting and heading for as an end goal, if you just want 400hp then maybe just go with a newage Sti bottom end but no doubt the forged motor would be the better of the 2

 

Just after a nice solid 400bhp, fast road car, do some track days 2-3 a year, but just need to make sure I take the right route about doing it.

 

By the time you've bought a 6 speed and had the engine built you'd of spent enough to buy a blob STI.
Then theres brakes to think about, minimum £500 if you can find a cheap set of brembos.

People go mad when they see someone saying "sell the wrx and buy an sti", but in reality its the wisest thing you can do.
A good, average mileage, cared for car can be had for well under 7K now. Already has the £2000 gearbox that you'll need, decent brakes and an engine that will take 400bhp all day long.

 

As above.SJ.

 

Already have 8 pot Brakes on the car, but I see what you are saying, by time I have got all the parts and fitted I may as well get an Sti

 

It can be done with a wrx but your going to have to spend.a sti is a good start but if you have a wrx you'll just have to spend a bit more.SJ.

 

so if I had a std Sti, what parts need to be changed in order to get this power fig

Decatted Exhaust
Injectors?
Fuel Pump?
Maybe a FMIC
What turbos do they use as std?

I already have my WRX and know its a solid car, flew through an MOT 4 weekago, but then it will cost more to go 2.1 for this fig.. Its done 103,000 not sure it will go for loads, Maybe get 4k?? for it, Sti is say 8k so an extra 4K is better than 7 or 8 k on a engine, gearbox and then need a turbo..

 

I think the main thing that makes it expensive is when your 5 speed box ***** Itself and you have to upgrade to 6 speed,but that is, just speculation as I know of 5 speed boxes pushing more then 400 bhp but they are carefully driven and never launched.what ever your going to do it's going to cost for example bigger injectors say 650cc a better turbo say a SC42,fuel pump maybe FPR,parralel fuel rails,induction kit 3 inch exhaust.you said you have 8 pot calipers so that's one less thing that would need doing so you'll save on money there.a standard turbo in a sti is a VF35.SJ.

 

Will the 5 speed last if not doing hard launches, because tbh I don't thrash it 1st!

 

buy an sti............

 

Iv got a 2003 WRX with a engine tuner 2.1 and is running well over 400bhp but the cost to get it there and safe was a lot more than it would of cost doing it to a sti,, my advice is get the best starting point you can if your after over 400bhp as it gets very expensive otherwise

 

the thing is an sti will get to 400 bhp safely without a rebuild and will just need a turbo,injectors and a few other things but it also has the six speed box.

whats the point of 400 bhp if your scared to drive it hard incase the 5 speed breaks??

 

There's been a at least 2 blob STI's sold on here in the last 6 weeks for around 5k just to keep things in perspective I don't think you would have to budget anywhere near 8k fella.

Mick

 

As above, blob sti (good ones) can be had for a remarkable price now.
Tuning a wrx to a safe 400 just doesn't make sense anymore.

 

As i said before it would be easier for you to get a sti but if YOU want to keep your car and go the 2.1 route that is a choice your going to have to make and budget for,if I could do things again I would of taken my Subaru to the maximum and if it blew up then rebuild it but I would budget for it.It all depends if you are looking that kind of power straight away or can you make do with what you have now until you have enough money to do it properly.the Market for buying and selling cars is bad at the mo depending on who is selling and who is buying,just take your time and make a decision for yourself and go with it.SJ.

 

Hi there

From personal experience 2.1L is great choice with right turbo will be awesome to drive.

Yours Inlet manifold should be OK,just get removed TGV delete(or try source STi TGV deletes,they're cost around £50) and yours throttle body will be OK too

STI TMIC should be OK at this level,for more track would go with FMIC,we are run Japspeed FMIC without the problem

From personal experience would go with MDX321T,SC42(never tried,but seen few of them with great results on 2.1L)on yours,should be awesome to drive

Injectors would suggest source 650cc with those you will have some headroom,FPR I would add too

Fuel pump not sure,we are run HRC 340LPH without the problem,headers and up pipe 3 bolt headers from WMS and Harvey Up pipe from Alyn@AS Performance

Gearbox will be main concern for you,if you are looking to run track days and drag runs,6 speed or PPG is only option,maybe later 5 speed(TY754) should last longer like yours(TY752)

Good luck there



Jura

 

I love my forged 2.1 from EngineTuner. I had the 5 speed 'box rebuilt at the same time and when the car came back the whole drivetrain felt smooth, tight, free from slack and better than new.

Only thing is, as noted above the 'box can't take the increased torque even on a relatively lowly 300 lbs.ft and after 8,000 miles the 'box started to bite back (weak 3rd gear synchro, I believe). Using slicker gear oil and slightly slower shifts smoothed it out a lot and now 20,000 miles on it's very slightly notchy 3rd/4th but fine overall.

I'm planning to target 360bhp in the near future but I've no plans to swap or upgrade the 'box now that I've slight altered my shifting style.

And "why not buy an STi?". Because:
- Subaru didn't make a Newage STi wagon
- its been fun making my own
- and not all of us want/need a great big spoiler!

 

Theres a few newage STi wagons out there

https://www.scoobynet.com/members-ga...n-finally.html

 

or maybe a 2.5?

 

i got a 2.1 built by ET
i ran 445bhp on v power with walbro 255
800cc inj
FMIC
3 bar map sensor
up to you what turbo, but good ones are SC42, MD321H or T
im running original throttle body, but had tumbler valves deleted
also you might need an upgraded ECU
ran my 5 speed with no probs at this power

wiley

 

You have some good information here,im glad wiley has posted as he has done it with a wrx so he really is the man to send a pm to for his hands on advice.SJ.

 

I'm forever telling people to go sell their car and buy another one when they ask me tuning questions! Usually it's because they want to fit a bigger engine in their Peugeot or something. Not that I'm against car modifying, but there has to be a reasonably viable cost/benefit ratio applied.
Of course I appreciate the WRX/STi choice, and there are plenty of good reasons to go for the latter if you haven't bought one yet. Once you have a car however, the choices aren't so simple. Your WRX may be in really good condition as against that dog eared STi. Or vice versa!
The most common issue brought up is the gearbox. Yes, the six speed is a stronger box, no question. It's also clunkier, and doesn't have the feel of the five speed. Basically, you get more missed gears! They may also be strong, but that doesn't mean they are all in perfect condition after ten years or so. The five speed box is reasonably cheap to fix, certainly compared to the cost of a six speed conversion.
If you aren't drag racing or rallying, you may find they last longer than you think.
Being old fashioned, I'd suggest that waiting until the box breaks is a reasonable betting man's choice. You then have the options of fitting another five speed or shelling out for a six.
As you can see, it isn't at all clear cut.

OP's questions..

Inlet/throttle is fine, we'd pull the TGV's.
STi top mount is fine, bearing in mind we're interested in charge temp and nothing else. Assuming it's road use only, and assuming you aren't inclined to go mad when the Moon is full, it's adequate.
SC40/42 is where it's at right now, we can't see anything else out there as we speak.
There are a number of new pumps out there we could choose from.
Headers and up pipe, we only supply RCM.

 

Nice reply straight from the men that deal with these things everyday.SJ.

 

bang on alan, the 5 speed i had was fine, only upgraded to 6 speed as my plans was to run over 500bhp and i had a good deal also.
techdw - you can use your existing block and build the 2.1, the WRX block will be good for what you need. alternatively, a semi or closed deck will be a bonus if you want to have that peace of mind and go for more power in the future

wiley

 

Cheers Alan!

Wiley - I thought the WRX block was Semi?