subster

Why with a subaru is it like trying to get blood from a stone (bhp) when other cars like the skyline or cosworth gains come easy

Nezz10

I disagre, well sort of. Yes you can get big gains from cosworths and skylines but still at a cost ££. The other things with skylines is that they are made to be so restriced its unbeliveable. The japanese government will not allow production cars to have over 270BHP so a hugely restictive exhaust, air filter, turbo setup and so on are put on as standard, its simply taking away these restictions that allow such big power gains.

example: Skyline rated at 270 bhp, actual is about 290 on the rollers. With an induction kit and an exhaust you would be seeing close to 350 straight away!!

As for cosworths you are taking about an engine that is especially designed for race use but made to be run on the road. Its like getting an engine from a WRC and putting certain road going parts in to make it pass EC regualtions and to make it more drivable. All you have to do is start replacing the road parts for the racing ones and you will start to get huge power gains because thats what is started with.

Big power gains CAN be made from scooby engines but you need to start with a high spec engine in the first place. Tuning a 95UK spec will be lots harder than tuning a 99 WRX STi RA. That is the good thing about Subarus, they have a high performance engine to start with and if you want the big power (which many ordinary poeple don't) then you have the option of going for the big beast to begin with.

Neil.

subster

I have a 96 sti which with an fujitsubo exhaust gave 280 bhp, unichip fitted I have been told to expect about another 14bhp, I have an hybrid turbo coming next week will have to see what I get but you seem to struggle to get a scooby over 340bhp, the quoted power gain figures on products just don't seem to work on subaru's

Nezz10

I see what you are saying but Scoobys with 400bhp have been known. Don't forget it isn't all about BHP. You could have 500BHP but only 100 ft/lbs of torque so it is a mix of the two that gives the best driving experince.

To get your scooby going over 340 you will need a front mounted intercooler, your hybrid turbo, larger injectors (probably 550cc will do) water injection, equal length headers and a better ECU such as the link, Motec or GEMS as well as a really good mapper. The unichip is really a low end ECU that doesnt have the mapability of the other ECUs. You will have to end up paying a lot for all these bits though as i am sure you know.

At the end of the day if you want REALLY big power then sell the scooby and get either a TT supra of an TT R34, but I love my scoobys to much to let them go.

subster

I've got to admit I am a torque man myself I love the surge of acceleration an sti gives
thanks for your input, is replacing the injectors a big job

Nezz10

Yes it is a bog job. Definately a porfeesional thing unless you really know what you are doing.

You will not need to uprate the injector unless you intend to run a lot of boost, say 1.5bar+. I think Rich wild runs his very high on the standard injectors and had no problems that I know of so far but he must be running right on the max out limit which could cause serious problems if boost spikes start occuring.

A hybrid turbo is a good way to go cause it would kill the standard turbo to run constantly over 1.3bar of boost. The engine is easily capable of taking high boost to a certain extent but watch out for any detting (really bad).

Consider getting an uprated fuel pump as well. No performance gain but could save you an engine rebiuld if the standard one is not up to the job.