Do our engines have forged pistons?

Been chatting to another petrol head and enquired about using NOS Octane Boost Racing Formula fuel additive which increases the octane rating about 7 points. He mentioned this really should only be used with forged pistons and then really only occassionally for track work. Has anyone used it? What was your experience?

right, i've had a quick scout about the www and it appears the pistons are cast not forged, so does anyone have experience of octane boosters?

I think everyone is scared to answer you in case the wife divorces you :lol: What do forged pistons do? Just extra strength?

? :?

last time we spoke you said she be mad if you bought and Xbox so i figure putting in forged pistons would mean more than a night on the couch :lol:

She doesn't know the half of it regarding my motor, bless her. Just arranged to stop off at Gert's to have the Rennesport motor mounts fitted on the way to the 'Ring. Was really enquiring about this octane booster, would not go to the lenghts of fitting forged piston's just to use the stuff.

Where my sig pic gone?

Your wife's removed it

looks like your image host has removed it or gone offline

Mark - unless your engine is remapped (ie, timing is advanced) to take advantage of the higher octane, you will not notice any significant performance improvement with high octance fuel.

To add to what Polar said (which is true)..... Did your "petrol head" acquaintance mention a reason for the piston upgrade? You are proposing to raise octane a few points, which in itself puts no extra load on pistons, unless accompanied with necessary tuning. Unless you raised cylinder pressure to the point of detonation, even an octane / tuning combination would not put a significant added load on the pistons. People put superchargers or turbochargers on these things without yanking the factory pistons out. Before switching pistons, I'd switch mentors. He's clueless.

have just checked mine and they are genuine :lol:

Bit late in on this thread. The long and the short of it, in answer to the question, is not unless you've got a Cup car.

Forged pistons are generally used in race engines or highly stressed turbo or supercharged engines. Their strength comes from the forging process - pressing the piston from a lump of quality alli versus a casting process that doesn't provide the same strength. Some Subaru STi models came with forged pistons from the factory. The downside to forged pistons is they used to require large cylinder wall clearances as they tended to expand far more than the cast variety. Recent developments in forging and alloy allow closer tolerances allowing a quieter running engine (less piston slap at startup until they're warm). There are pros and cons to both. In the majority of cases cast pistons are fine especially in normally aspirated cars. The heat produced by a turbocharged engine is far higher. Firstly the turbo blocks the exhaust retaining heat, then compressing air creates heat. Cast piston quality varies as well. Some are rubbish while others are much better quality. For example a Mitsubishi Evo cast piston is far better than a Subaru WRX piston. The normal reason a piston dies though after saying all this is due to detonation. Some cast pistons can handle it better however it shouldn't be there in the first place. Now down to octane boosters. If you put this in your fuel and then didn't advance the ignition to suit, you will LOSE power unless you were running a lower octane fuel than your car was tuned to run. By increase octane you are slowing the burn rate. You need to compensate the slower burn with earlier ignition. Lastly, when it says up to 7 points, its a perception and play on words. It is saying .7 (as in point 7) not 7 ie 97.7 not 97 + 7 Think about this. Elf racing fuel was costing us AU$4.50 / litre versus 98RON at $1. Elf racing was around 110RON octane. If we could have just added a bottle of octane booster to get to 105, it would have been a much cheaper alternative! Regards, Jeff