Would you say that 275whp on a STOCK and I mean STOCK longblock (rebuilt with arp headstuds) would be reliable?
I've built a several boosted b18's but I always did forged internals. I'm wondering if I can just turbo it and not have to worry about the sleeves/rods/pistons failing. I will obviously do the injecters, Walbro, Hondata, GM 3bar etc...
If I do this and want more power then I will spend the $$ on internals and maybe a block guard. Its going in a Del Sol so anything over 300-350whp is waisted on the street (IMHO).

(yes I searched, didn't find what I was looking for)

 

275 will be fine on stock B20 internals with quality parts and a professional tune. By professional tune I mean one done on a dyno by a reputable tuner, not your buddy's friend Jimmy down the road who has a laptop and a chip burner.

Trying to build the engine far beyond that without sleeving is an exercise in futility as the stock sleeves will be far, far weaker than anything else in the engine.

 

I would imagine you would have to keep a close eye on torque. Torque is what is going to break stuff. It would be possible with a smaller turbo to make 300ftlbs in the middle and then fall off to 275hp at the end.

300ftlbs is going to be more like 600hp on something that makes all the beans right at the top of the rev range.

 

Yes it can be done but the bigger the turbo the better. If you try it on a 350 hp turbo youll break your engine. Also it depends on the condition of the engine. Huge factor. These engines are 20 years old.
Get a 3076 equivalent or a gtw3476 sized turbo with a ramhorn and it will last many miles. Do it with a gt2860 and a cast manifold and youll have a lot more stress on the engine cause youll need to push everything harder to hit your powertarget.