u r a bus

can you please tell me the difference between an sti engine and a wrx engine, what internals are different???

not bothered about suspension etc, just need engine differences.

thanks

u r a bus

ttt

KenG

If you are referring to the new model, then this is taken from Subaru UK's web site:

Tuned by Subaru Tecnica International Inc
Larger air to air intercooler with water spray
Sodium-filled exhaust valves
Hollow intake valves
Reinforced engine block and connecting rods
Forged pistons
Shimless valve lifters
Active Valve Control System (variable valve timing)
265 PS and 253 lb ft of torque
Up to 80 per cent of the STi’s all-alloy engine is new compared to the standard turbocharged 2.0 litre four-cam ‘boxer’ unit as fitted to the regular Impreza WRX.

In order to meet the stringent Euro3 exhaust emission levels, the catalyst is uprated, the air-fuel ratio sensor modified and special multi-hole fuel-injectors fitted.

Engine strength and rigidity are boosted by using semi-closed-deck cylinder blocks, reshaping the piston head, fitting screw-in type connecting rods and using forged
pistons and shimless valve lifters. Also aimed at high-rev durability are sodium-filled exhaust valves and hollow intake valves.

A larger intercooler and air intake provide better cooling and a special intercooler water spray is fitted, operated by the driver with the water tank fitted in the boot.

Also specially fitted to the STi is Subaru’s Active Valve Control System – variable valve timing – which ensures maximum engine response over a wide rev-range.

The result is a maximum power output of 265 PS (261.5 bhp/195 kW) at an accessible 6,000 rpm and 253 lb ft (343 Nm) torque at an equally usable 4,000 rpm.

This compares with the standard WRX figures of 218 PS at 5,600 rpm and 215.4 lb ft of torque at 3,600 rpm – significant increases of 47 PS and 37.6 lb ft.

As with the normal WRX, the horizontally-opposed four-cam, 16-valve ‘boxer’ engine has a bore and stroke of 92x75 mm for a capacity of 1,994 cc and runs on an 8.0:1 compression ratio.


Hope this helps.

Ken