stock Subaru 2.5 STI shortblocks are stronger than many people think. It's not power that's killing most of them, but poor or aggressive tuning, poor build quality, lack of/poor maintenance, and a slew of other issues. After multiple lapping days last fall and a race weekend with NARRA at Watkins Glen, this 2.5 shortblock was far from new, but it got the job done.

Unfortunately we've seen our share of customers come in with blown ringlands on stock cars too. There are some defects and some cars with stock tunes that I feel are causing the problem.

Then there are some cars with aftermarket tunes that are more aggressive than I suggest and may be the cause of failures on almost stock cars.

Then there are cars making 300-400 wheel HP that last a while and some that don't depending on tune, supporting mods, maintenance, driver behavior etc.

Above that how the car is cared for is really important, but I agree it's also somewhat of a crapshoot. Some stock shortblocks are so tight it's just a matter of time before someone builds enough heat make clearances disappear.

I'm ripping this car around a road course so I'm doing long high speed pulls which build a lot of heat, but I'm mindful of that when I tune my car. It's always warm up before I go on track, fluid temps are always totally under control, I change my oil for each track day, etc. so I do what I can.

I mean if you consider that I'm at full boost for around 1 minute per lap on the road course at Watkins Glen, that's like 6 ish drag passes which is more than I would do at a whole track night. Then think of how many on ramp pulls you'd have to do to be at full boost for 1 minute. Then think about me turning lap after lap at a road course. The time at full boost adds up rather quickly this way compared to how the average STI owner drives on the street.