nitrous with hyper pistons??

100 shot is no problem. Make sure that there's enough fuel and keep the timing reasonable- it will work great.

Hyper pistons are a lot weaker and do not stand up to detonation as well as forged but they do a lot better than cast. I'm sure somebody else will chime in sooner or later. Anyway, a 100hp is safe.

i have a 93 notch with those great old lowsey hypers well anyway i have been spraying 150 shot into it all summer long. key is to make sure you use a wet kit keep fuel up and keep timing down. otherwise everything will be ok.

Why are they being difficult to put forged instead of hypers? Maby you should find someone else if you planning on running spray. Hypers will probally work just fine but they won't be as strong as forged.

hypers are just as good as forged in the right hands....its a bad tune that turns into a disaster...

bmorrisj said:

hypers are just as good as forged in the right hands....its a bad tune that turns into a disaster...

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Exactly. It doesnt matter if you run Hyper Pistons or Forged, if you run it really lean or run it with detonation its gonnna blow regardless. Now that being said, all forged does is offer you that lil extra security blanket if perhaps you do lean it out or it pings they'll hold out a bit longer. But Hypers will take a very good beating as long as the tune is safe. WITH a good tune the hyper pistons will outlast the block. The block would be the first thing to go.

nito88stang said:

Exactly. It doesnt matter if you run Hyper Pistons or Forged, if you run it really lean or run it with detonation its gonnna blow regardless. Now that being said, all forged does is offer you that lil extra security blanket if perhaps you do lean it out or it pings they'll hold out a bit longer. But Hypers will take a very good beating as long as the tune is safe. WITH a good tune the hyper pistons will outlast the block. The block would be the first thing to go.

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100% correct

I would also like to add that having too much fuel with N2O is just as bad as not enough, you can still pull the crown of the piston or burn holes when too RICH. The tune is most important, read your plugs they are your friend with N2O, but you have to read them right after you spray not after it idles for awhile which will destroy your readings.

To round out the discussion - it's not that the hypers are 'weaker' than forged pistons. In fact, if you do a google search, you can come up with all sorts of info -- I found tests which actually show higher tensile and fatigue strengths and greater stiffness with hypereutectics compared to forged. Both are aluminum alloys - the hypers have a bit more silicon content which, among other things, makes them more thermally stable. Clearances can be tighter and they are less noisy than forged slugs. Here's a blurb from KB about some of the advantages of hypers:

"The KB T6 hypereutectics are considerably different than the forgings. The KB pistons have shown improvement in power, fuel economy, cylinder sealing, service life, and cost effectiveness. The reduced thermal expansion rate allows the piston to be run with reduced clearance. A tight piston is less likely to rock, make noise, and burn oil. A rocking piston wears rings and increases blow-bye. The close fit of the KB piston allows the piston rings to truly seal, minimizing blow-by.

The design flexibility enjoyed by the KB series of pistons has an advantage over present day forging practices. The die for a forged piston must be designed so it can be easily removed. This limitation makes it difficult to make a light weight piston without sacrificing strength.

The KB pistons' utilization of the permanent mold with multiple die parts allows undercut areas above the pin hole and material distribution in the skirt area that stiffen the entire piston unit. The forged piston requires thick skirts to achieve comparable piston rigidity. A rigid piston rocks less in the cylinder and improves ring seal.

The forged pistons' thick skirts add weight. The design of KB pistons gives us the option to build the lightest pistons on the market. "

However, hypereutectic cast pistons are less ductile than forged pistons. A bit of an oversimplification - but you might say forged pistons have more bend before they break compared to hypers. The nature of a hypereutectic piston failure when put in a destructive detonation environment is usually more catastrophic than a forged slug. Consequently, you have companies like KB with things like this posted at their site: "Please Note: Our 40 yrs. experience has shown us that these pistons should NEVER be used with Nitrous, super charger or turbo's. They should also NOT be used with Stroker Applications because of increased piston speeds. A forged piston is recommended in these applications, remember hypereutectic pistons are still cast pistons."

However, many have used them with mild boost and nitrous. As others have said, tune seems to be the key. And if it were me, I wouldn't leave it to plug reading - I'd want some dyno data with wide-band a/f ratios. You might try a different titled post and ask those running safe nitrous tunes what kind of a/f ratios, compression ratios, and total timing are "safe" for a hyper set up.

i didnt read Mike's post but i can gurantee that hes right ...actually, if you ask some big HP n/a guys, a majority of them will say they run hypers over forged, due to lower cost and they weigh less