HP, how much can a LIL 2.5L take? How do they Blow?

[efahl]

Originally Posted by pk2

250whp is certainly nothing to sneeze at, and that’s all stock? Tempting. I thought I’d seen “crank” numbers which didn’t seem terribly impressive.

I have forced induction. With a modest boost (a 10% pulley change) (and retuning) I figure I can hit or exceed 300 hp, (an arbitrary goal I set). I’d really like to do it though without blowing it up, to much fun to drive.

At 300hp would you still bother with new pistons? Would that be to lower the compression? Who sells pistons and other internals for these things?

Hi Peter,

My 3.4 has a dry cone filter in front of a bigger MAF body and custom plumbing to the throttle body, TTP headers and cats, and re-mapped ECU (the dyno numbers came from the mapping session).

I really don't know what's inside any Porsche motors, haven't torn one apart yet, so I don't have any reason to say the stock 2.5 pistons won't be good for 300 HP other than that they are pretty high compression for a boosted motor.

I would go to Wiseco, Arias or Ross for custom pistons. You can usually get them for about $100 each, at least that's the ballpark for Audi parts. Rods can be had from Pauter or Carillo for about the same, if the Porsche parts turn out to be weak (the 2.5 is the odd man out with 72 mm stroke, I'm guessing that all the 78 mm stroke motors - 2.7, 3.2 and 3.4 - share their bottom end components for stocking and manufacturing efficiency).

Eric