no they won't. the rings are fine, good for 400hp all stock. heavier valve springs my ***! no need for valvesprings unless you're putting a set of high lift cams in the head. do you even know what valvesprings do?
there is no correlation between valve springs and larger turbos.
300 whp is an easy cheap goal on these cars if you know what you're doing.
on a 2g its' a bit harder as the T25 just won't flow the air to make 300 hp.
so basically on a 2G this is the order to buy and install parts.
1. boost gauge and datalogger, so you know what the hell your ecu is doing. $100 if you know how to find deals.
2. fuel pump, without more fuel, you'll blow it up. $79 for a 255 lph. do the fuel pump rewire with a relay and run 15psi.
3. 3" downpipe and exhaust, no cats. $300
4. hi flwo air filter $40
5. manual boost controller $50
6. upgraded turbo, at least an evo3 16G. they can be had used for about $350. new they're about $500. keep it at 15psi or less until the new injectors are in.
7. front mount intercooler $250 off
ebay, yeah they're chinese but they do the job.
8. safc, to control the fueldelivery, used about $150
9. injectors, about $200.
10. tune it at about 19-20psi and you'll easily be over 300whp.
anything else anyone says is bullshit.
http://www.dsmtuners.com
http://www.dsmtalk.com
http://www.vfaq.com