astraboy

"A friend of mine" has an Impreza (Old shape, not sure of the year).
He would like to know if it is possible to modify the engine to produce more power, but in a way that it looks standard, sounds standard and can only be discovered if the engine is dissasembled.
Is this possible?
astraboy.

Markus

I know you can get a BMP stroker kit, which enlarges the bore to 2.2l instead of 2.0, thus this could give more power, not sure. guess that by getting different cams you could also gain more power, and maybe porting and polishing the heads will help. Also, unless you really know your beans then uprating the turbo should be fairly 'stealthy'

I'm not technical, so not sure if what I'm saying is tosh or not.

Of course if the car is UK spec, or low end jap then you could always drop in an STi engine pref a 22b's 2.2 (yeah right!), but the red bits might give the game away

john banks

Is he trying to avoid telling the insurers? If so don't bother tell them all or it could all end in tears.

It depends on how hard people will look and it depends on the reason for secrecy. For example an altered ECU could be easily found, as could a bleed valve or a boost controller, or a panel filter. I suppose if the head was gas flowed that might release more power, but the biggest improvements are had on Scoobys cheaply by changing the induction and downpipe, then the backbox/centre and then doing the ECU.

A car with a DP, panel filter and a ECU remap could look and "almost" sound standard if you kept the centre and backbox as std. Potentially this could release up to 20% extra power.

Mine is quite stealthy - PPP with DP & K&N - the only visible difference is the tailpipe, and it only sounds a little beefier than standard unless you rag it.

Adam M

Markus,

by definition, the stroker kit sincreases the stroke of the engine. The bore would be the same unless it needs sorting for new pistons.

The power of the turbo charged car is pretty much defined by how much boost it can run. This is defined by the map. I.e. more boost (invisible) = more power.

The standard engein doesnt like too much boost, so you can strengthen the things which fail (con rods and pistons) and tehse are all inside the engine so are v stealthy.

Hope this helps.