3.4tdc forged pistons for boost?and anyone used a GT32 turbo

[dk05]

Sweet, thanks a ton!

[RebelGT]

I don't think i'd recomend the Hypereutectic pistons for boost, I've heard some bad things about those pistons.

[RacerX11]

What bad things have you heard? I know there is at least one Fiero guy pushing ~300whp with a turbo 3.4 DOHC running these hyper pistons.


Marty

[RebelGT]

I heard they are prone self destructing under high loads.

[SappySE107]

I thought they were good for moderate boost as long as you are tuned properly (as in, detonation and pre-ignition free).

[timg]

I thought they were good for moderate boost as long as you are tuned properly (as in, detonation and pre-ignition free).

Ditto.

IIRC Hypereutectic pistons were used in quite a few Syclones and Typhoons.

Personally, I wouldn't use them for 14+ psi, but for 7-14 psi I would have no problems with them.

I'll see if I can find out more about the process. I covered it a few years ago in a materials class, but can't remember exactly what it was.

Tim

[Kohburn]

they are better than cast not as good as forged

[SappySE107]

They are better than forged for a street driven daily driver that doesn't see lots of boost though. Tighter wall tolerance for less blowby (they don't expand as much as cast or forged). With forged, you really have to let it heat up and expand before you can get on it.

[RebelGT]

"TA Performance has noticed an increase in customer reported engine failures, due directly to the use of Hypereutectic Pistons. These newer pistons are very hard, thus brittle. These pistons have proven to be un-forgiving with spark detonation. The latest report received was analyzed and the results were as follows... at least one cylinder experienced spark detonation, resulting in one piston failing, then fragments of the exploded piston were introduced into the intake manifold and distributed to other cylinders resulting in an addition of 4 more pistons "exploding". This is not a recall on be half of TA Performance, because TA neither recommends nor sells these pistons, other parts warehouses push these pistons because of their flashy name, TA only recommends two types of pistons: cast for stock and mid performance street applications, and forged for high performance street and race applications. Over the last few months we have averaged approximately 3 calls per month regarding failed Hypereutectic pistons."

[TurboGTU]

Hyper. pistons are more for heat deflecting and less friction. Some cast pistons have "silocon" ..but not as much as Hyper do. I've heard mopar guys say thier stock hyper. pistons don't like to be raddled. Guess this is why.