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Just interested in what people have done or heard of being done to Forester GTs (2001 model ej20 Turbo) motors to improve their performance. The main use of the car is a daily driver and to tour about on holidays towing the camper.

I have heard of things like turbo swaps, ecu chips, exhausts and boost controlers etc etc.

I am interested in cheapish, bolt on performance mods that wont increase my fuel consumption too much... i know with performance mods usually the more fuel you use but i thought i would see what ideas people had.

Dave

you probably already have but if not check out gtrydas.com.au

Probably the first thing I'd do is get some good equal length headers to allow for exhaust gas flow more freely to your up pipe and thus to your turbo. Lots of people cry at the thought of EL headers because you lose some of that classic boxer rumble...but you can make up for that with mufflers and ****. Most of the real performance boosts you get are with engine internals and fine tuning, engine management etc etc. There's no easy bolt ons you can do that'll improve performance all that much.

You can always upgrade your turbo and run at higher levels of boost but you have to consider the pressure you'd be putting the internal engine components under.

No offence but i have had equal length headers before in the past and i wont go there again. When it comes to the very very slight performance improvement it made and compare that with the dirt bike sound the car made... i choose the boxer rumble.

Thanks for that Matt... i have been there before but i forgot all about it.

Been doing some more research and i think the factory boost level is about 6psi and using a manual boost controler i can apparently safely get up to 10psi out of the existing Turbo and everything. This information was off a variety of different sites so i expect some people to disagree but to hear from people that have done it would be nice.

Also considering what i use the car for and the fact i use it for touring and towing the camper it's seaming more like changing the turbo will gain me power but not really where i need it.

Dave

So you're saying you need lots of low end torque?

I don't need lots of anything but i need more of something.
But yeah i guess the times it seams to lack the most is coming off the line with the camper on the back.

Dave

The problem with taking off with the camper I guess is related to having turbo lag and a low compression engine. Best thing for that I suppose is a small turbo but you already have the stock one which is probably about the most suited you can get. Anything bigger will probably just increase the lag (unless maybe if you go for some kind of high tech twin scroll turbo but these are very expensive). I think the boost idea is good, should get you more power all round for hardly any cost
.
Thinking outside the box, I think you might not need more power but rather just change the delivery of the power and how it's used. One crazy idea might be to look into the automatic transmission. I'm really not sure on your specific model but lots of later model Subaru auto's are fully electronically controlled. It is possible in some models to actually program/control the TCU to change the various oil pressures which gives you control over how it shifts and delivers the power and torque. OverSteer is very knowledgable on this and I beleive has majorly customised his auto TCU in his Liberty for drag racing applications (obviously the mod you might need would be incredibly smaller!) - might be worth contacting him as he will be a better bet for talking custom than your average auto transmission workshop. Try posting on some other Subaru forums with more members with later model performance Subarus too (rslibertyclub.org) - probably lots of people doing similar things. From memory Oversteer mentioned the early WRX automatic TCU might be the one to use.
Another thing that can be done with autos is to change the stall rate which I think has to do with the torque converter. This allows the motor to rev up to a higher rpm before actually engaging the torque converter and making the car drive. This means you'd take off from a standstill with the engine revving higher and much closer to where it has power, rather than when it is still waiting for the boost to come on. Often referred to as a "high stall" mod.

Some things to research anyways, I am in no way an expert on autos!

Just cop out and buy a diesel Land Rover






*ducks*

im really really starting to wonder what hatchies motor would be like in a forester. Hatchie has the power delivery i like for my needs but lacks the comfort and traction.

Dave

Probably similar to a non-turbo Forester - they have n/a EJ20's which I'd imagine behave exactly like hatchie's EJ22 but slightly less power due to 200cc less capacity.
I'm assuming you mean Hatchie's lack of traction is referring to his lack of AWD for on-road. Offroad surely he has more traction than a Forry with the locked centre

***Edit - *slap*. I completely forgot about hatchie's supercharger! Yeah that would change the dynamics of the Forester a fair bit I'm guessing. Maybe you should trade the Forry in for an n/a model and then supercharge it

add a supercharger to the gt motor
it would be the first twincharged gt forrie ive seen

theres a rex out there thats been done

Belive me... i have thought of it and it might be what i end up doing in a few years. I think the Motor in the hatch is going to outlive it's body so i will have a spare motor in a while.

Dave

SuBaRiNo wrote:I don't need lots of anything but i need more of something

You're very specific dave!

I'd like to see the supercharger/turbo combo happening, I'm sure you'll work something out... And why wait???

Cheers

Bennie

I believe Dave's disappointment comes from the off-boost performance of a lower compression motor.

Jordan.

I'd suggest an electronic boost controller - That way the boost reaches maximum faster by leaving the wastegate completely closed. I'm not sure if the newer ECUs do this already but it made a noticeable difference on my '93 EJ20G.

Peejay... will only the electric ones do this?? not the mechanical ones?? Seams to be a big price difference between the electric and manual ones.

Dave

I'm not sure actually. I think the mechanical ones work by using a spring diaphragm which I'm guessing would slightly open as the boost increases. If you goto a Jaycar Electronics store and have a look in a magazine called "Performance electronics for Cars" they have a boost controller article in there and they explain it better than I could.

Yeah most manual boost controllers, bleed valves and such, will let the wastegate gradually open. Electronic boost controller, because they are operated by an electronic solenoid can keep the wastegate completely shut until the desired boost level is reached. Which should let you have full boost a little bit earlier.

Well actually buying this car off Subarino a few years ago, selling it and now buying it back with 400k km on the ODO. What I have done is what he should of done.
I removed the 3 cats. The one in the up pipe, down pipe and mid section. This improved the turbos spool by 500rpm. The car now reaches full boost 0.9Bar(Max for the little TF035) @ 2500RPM. For the 4 speed auto this is great as the torque converter gets the car into boost fairly quickly and allows you to power on. I swapped out the stuffed intercooler for a better condition 01-02 Forester GT one(Same as 99-00 GC8 STI) with a GC8 STI Y pipe behind it for better flow. I Removed the old MBC Bleed Valve and got the ECU Remapped and peaking at 0.9 Bar (13.2PSI). The remap was a stage 1 tune plus I've removed the flow restrictions from factory. I don't see any added benefit in fitting a 3" turbo back when its still only running a tiny turbo. The turbo starts running outta puff around 4800rpm but how often are you above there anyway.

This remap as refined the auto gearbox shifts, improved fuel economy and made the vehicle quick'ish. On average it's around 9-12l per 100km. Speaking to the tuner the vehicle would be putting out around 165-170kw and 320nm at the crank which is respectable.

If the original motor didn't have 400k km I would of swapped on a VF29 which is great for mid range power and well suited to the 4EAT gearbox in my opinion. It is used on Rally spec subarus due to its ball bearing spool characteristics.