Info needed.......

[THOR]

Hello Ladies and Gents,

Well to start with, a brief intro of my baby. BE-5 model Single turbo(STi-5 Type Ra Limited) converted B4 with Omega ceramic pistons, HKS manifolding with down-piping and Priest exhaust. STi coils and Bilstein shocks. I'm running 1.1 bar boost and +330 bHp. I think it's time I went ahead and changed the intercooler and fuel system so I'm looking for some advice :smt026 .

1. I'm thinking of sticking with a top-mount inter-cooler. Is it advisable? If so, what would be the best inter-cooler to go for?

2. Would an STi inter-cooler be made to fit with a few mods so I can have the added advantage of an IC spray?

3. Regarding the fuel system. I'm on stock at the moment. Any suggestions for an upgrade for the pump? Would a new fuel rail be required? I might put in a 5th injector. Is it advisable?

4. Stock ECU. Any recommended, affordable ECU upgrades?

5. Strut bars (front & rear) for the B4?

Thanks in advance to any of your replies guys...Would really appreciate it if you guys could get me any info regarding the above queries including prices and any web contacts.

Thanks again :smt023 ,

Thor.

[rougeben83]

what intercooler are you using now? The problem with the BE turbos is that there is less space between the throttlebody and the firewall, so you cannot use some of the big top mounts for the WRX. An STi top mount may be able to fit but it's not much bigger than the regular wrx tmic.

Fuel pump, Walbro 255lhp is the gold standard for fuel pumps. Plenty of headroom for future upgrades to the rest of the fuel system. No fuel rail is required, but depending on your power goals you may need to change your fuel rail routing from serial to parallel (basically to even out fuel distribution). Don't go with a 5th injector, just get larger injectors. There are plenty of options, I'm not sure if you have top feed (WRX) or side feed (n/a and STi) but there are many 550cc+ injectors you can chose from including from other subarus (popular options are the "pinks" 550cc STi injectors and the 565cc dark blue 06-07 US WRX injectors, to 650cc Deathwerks modified stock injectors, etc).

ECU depends on how you plan to tune your car. Here in the US the turbo ECU's programming have been cracked and can be changed directly via OpenSource. Many people opt to get the ECU tuning done on a dyno to get a custom tune specific to their setup. Popular options are also Cobb's Accessport, TurboXS UTEC in the US for piggybacks to the ECU and standalone EM like Hydra, Motec, Autronic, Megasquirt etc.

[Reuben]

I'll try answer these as best i can. Remember this is the interwebs though:P

"1. I'm thinking of sticking with a top-mount inter-cooler. Is it advisable? If so, what would be the best inter-cooler to go for?"

The TMIC is an option for this kind of power, sure - but you gotta worry about heatsoak, and the small legacy bonnet scoop being limiting factors. What turbo did you use for the single conversion? A V7 STi intercooler though would be a good bet, and will fit with some modification. The problem is it will conflict with the clutch master cylinder i think, but it's been done before and is possible with some modifications.

"2. Would an STi inter-cooler be made to fit with a few mods so I can have the added advantage of an IC spray?"

Ummm... The sprayer and the intercool aren't the same things. You'd need to get a custom water tank, and sprayer motor put in the legacy, and the nozzle goes on the underside of the bonnet. It's entirely seperate from the intercooler, the car either has a sprayer or not. This means though you can add it to the car now, and you'll always have it no matter what intercooler.

"3. Regarding the fuel system. I'm on stock at the moment. Any suggestions for an upgrade for the pump? Would a new fuel rail be required? I might put in a 5th injector. Is it advisable?"

It would be a VERY good idea to upgrade your injectors. You will have to tune the ECU to take the injectors. Go to your local tuning shop and ask them what is required to put larger injectors in your engine. A bigger fuel pump is a good buy too, no supporting mods needed for a fuel pump upgrade. I'll echo what rouge said, Walbro fuel pumps are the ones to go for, and a split fuel rail mod might be handy. FYI your injectors are side feed.

"4. Stock ECU. Any recommended, affordable ECU upgrades?"

As above, you need to tune the ECU for bigger injectors, so it would be an idea to upgrade both the ECU and injectors at the same time, and have it dyno tuned.

"5. Strut bars (front & rear) for the B4?"

Pleanty around, CUSCO, ZeroSports etc all do them, A very good upgrade. Note; you can use STi front strut bars. The rear strut bars you will need to buy specially for your car.


I recommend you do ALLOT more research on subaru's before going any further with modding your car, it's easy at this stage to get something wrong which can be a very expensive mistake. I suggest you head over to NASIOC and have a read through the FAQ's forum, and the technical forums, there's ALLOT of great knowledge over there. Some other sites that may help out too like this one: http://www.scoobytuner.com/tuning/

[THOR]

Thanks a lot for the invaluable advice guys...Please, by all means, keep it coming.

Few of the problems I'm facing are the fact that I'm in Sri Lanka and over here we don't have an AWD-dyno so getting a custom tuned ECU is an issue. The other major problem is we are lacking a major tuning outfit. There are a few guys who do the Scoobies and Evos here but I prefer the agents. So I'm sticking with them. So far all these mods have been done my them and I'm happy with the reliability and performance of the car.

The turbo is a twin ball bearing turbo taken from an STi-7 RA. A correction on what I stated earlier.

Regarding the front strut bar.....I did try an STi one but it doesn't seem to fit. Are you sure it's a direct fit or do I need to make a few mods? If so, won't that make it less rigid?

[Huffer]

Legacies have less underhood clearance than Imprezas - so you need to find a strut brace with low-profile mounting brackets. The STI carbon fibre one should fit. I wouldn't spend a lot of money on the brace though, the firewall is pretty close to the struts. This isn't like a Honda where the struts are 10" from the firewall.

[Reuben]

Hmm, re the strut bar, i think huffer is right. I've seen pleanty of stock GC8 Carbon strut bars in legacy's before, but not sure about aftermarket ones. Getting a set of front and rear bars from CUSCO can set you back only $300 or so here in New Zealand. I'm not sure about Sri Lanka.

Maybe if you get something like a Cobb access port, or equivelent to suit the V5 STi ECU, you can tune on the road. No dyno needed, just a competent passenger :D I don't know ANYTHING on that subject though. Did you head over to NASIOC? http://forums.nasioc.com/forums/index.php Always good to get a second opinion.

[THOR]

Now that you have mentioned it Reuben I wonder if the V5,6 or 7 ECU would be a direct plug in....should get that checked out. As for the strut bars, it's a little difficult if not impossible to obtain a GC8 carbon fibre strut bar here but I will look it up. Worst case scenario I shall have to order one made for the B4 from tuningspec :-(

Thanks for the link Reuben, I'll look up some further info...

[Reuben]

So.. Just what has been done to the car? Did you do the single conversion? What parts did you use to convert it i? It's not still running on the stock ECU is it?

If you bought the car already converted, you will likely already be running a V5/6 STi ECU, or an aftermarket ECU already.

Would be great to know where the car stands at the moment mod wize you see.

[THOR]

Well as I said earlier, she has a STi V7 RA turbo (twin ball bearing), Omega forged piston, STi con-rods and shaft, HKS manifolding with down-piping and 3" Priest exhaust. I have done the resonator chamber mod and she has a K&N high-flow filter (the only suitable one for the dusty local conditions). Suspension is on STi coils and Bilstein shocks. That's off the top of my head....

At the moment I'm running around 1.0-1.2 bar boost given the OAT and time of day and with some dry ice on the intercooler. Average around 1.1 bar.

Stock ECU so that is a major problem as I'm unable to harnass her full potential. I have further plans of upgrading to a bigger turbo and the bhp goal is 700......someday. The main issue is the fact that it's really hard to come by the required hardware here. Most of the time it has to be imported. Then after paying import duty and taxes you have basically ended up paying almost double the cost of purchase! :-(

Here are a few pictures of my baby...

http://img10.imageshack.us/img10/6721/dsc00100iv4.jpg (http://img10.imageshack.us/my.php?image=dsc00100iv4.jpg)
http://img9.imageshack.us/img9/9945/dsc00099xf0.jpg (http://img9.imageshack.us/my.php?image=dsc00099xf0.jpg)
http://img11.imageshack.us/img11/8259/dsc00102er7.jpg (http://img11.imageshack.us/my.php?image=dsc00102er7.jpg)

[THOR]

Ah there we go! Thanks Jey

[rougeben83]

So you basically have a vf37 or 36 twin scroll IHI turbo.

stock ecu is your biggest limiting factor. You can tune that turbo to around 18-21psi (1.3-1.5bar) with the fuel modifications I listed and have terrific engine response and a significant power boost. 1.0-1.2 is also a pretty significant boost fluctuation. What are you running in terms of boost control? When are you getting a .2 bar difference in psi?

Even on a built subaru engine, a spike of 2-3psi (which is what you're getting) can mean the difference between reliable power and a blown engine. It again boils down to your tune. I cannot emphasize this enough for anyone planning to make significantly more than stock HP on a subaru - the aluminum block and construction has a smaller threshold for knock vs. some of the iron block inline 4's like 4g63...

700hp...to be frank, is not possible with your current engine, let alone your turbo, fuel, and intercooler. Some of the fully built 2.5L racing engines used in STi's can eek out barely over 500+whp on a good day. Not to mention that you often have to sacrifice a lot of drivability, engine response, and power delivery to shoot for such lofty numbers.

I don't want to sound negative but I just don't want people to have overinflated expectations that may lead to costly mistakes down the line.

[THOR]

Well I have run her on 1.7 bar for quite some time and have never had any issues. Decided to tone it down a little due to the horrendous amounts of fuel she was gulping down at the time. :lol:

I have noticed I get a .2 bar increase on a cool night running with some ice on the inter-cooler. I know 700 bHp is not realistic with the present config obviously, which is why I have plans for upgrades on the turbo, other engine internals and ofcourse suspension to put the power down onto the tarmac. I'm not looking at racing her but just as a pet project to while away my time when I'm home after a flight with some time to kill...Especially on those 12 hr long standby times we are rostered on....

For now ofcourse I need to harnass her full potential as she is...So I'm looking for the stuff I mentioned earlier on in the thread. The grade and quality of fuel available here is also a bit of a problem so we petrol-heads in Sri Lanka have found the answer in Toluene. However, for the day to day driving, standard Octane-Booster is what I run on.

I'm using a manual boost controller with a boost gauge at the moment till I can get my hands on an AVCR.

Trust me mate I'm paranoid when it comes to my car :smile: ! The agents have called me an "over-perfectionist" as I have a habit of running to them at the slightest hint of trouble or unusual sound. But I suppose it happens to all Scooby owners. Figures why women hate us eh?!!

[Reuben]

Ok, first things first, ditch that old ECU. You should not be running a single turbo car on a twin turbo ECU!! I can get you a stock ECU no worries, consider about $150NZ for the ECU, and $30NZ for shipping. But that's a stock ECU, you will need to get one that can be tuned for larger injectors... Boost wise, once fueling is sorted, i imagigne the block will handle around 20 to 25psi, depending on the build quality. I would not go over 20 psi if i were you, otherwise it will end in tears... On stock fuel, you can get 18psi easy, i run that daily on my VF39 powered 2L with stock V3 STi ECU and injectors (440cc yellows) (That's on 98 RON octane gas though!!!).

[THOR]

How much do you figure an ECU that could be tuned for larger injectors be? Bear in mind we don't have an AWD dyno here so basically it would have to be tuned on the run.

[THOR]

Is there a company website based in NZ that I could go to to check out the prices? I have a strange feeling stuff over there is extremely cheap going by your price quote for the ECU. If I am to put it into perspective...the same type of ECU you might be refering to, would set me back by about 740 NZD over here and that's off a car that was raced and met a horrible ending..... :neutral: