I can't figure out which is better for perf, like holding alot of turbo boost.
Forged vs Hyperereutectic pistons
chrome molly vs gapless rings

thx guys

and for those that were helping me w/ choosing an engine, thx! However, I thaught about it more and researched more, and It's just out of my range in several ways, mabie in a fiew years. I'm going to get a fiero V6 and perf rebuild it and eventually turbo and all, I'll post stuff when I get stuff done .

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'86 GT - 4speed RED!
Pioneer Radio

<>{RazorWing}<>
(I need a REAL sig, lol)

Well Forged would be better but alot more expensive. a good Hypereutectic piston will hold probably all the boost u want to shove in a fiero though.

Someone told me not to sue gapless rings when you boost but im not sure why

the reason why you don't want to run gapless rings when you boost is because of all the added heat that is introduced into the cylinder by forced induction can cause the gapless rings to shatter or break. you can use the standard moly rings they work just fine.

hyper pistons are ok for boost but don't push your luck with them. they can't handle the heat and detonation that well so as long as you are only going to be boosting on the conservative side, you should be ok. If you want to get serious about the amount of power you want then you will be better off going forged.

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1987 Fiero Coupe 3800 Series II Intercooled Turbo
1987 Trans Am GTA 5.7L Superram 4L60-E
1985 Fiero SE 2.8 (soon to have an L36)

Fiero-related Conversions Performed:
1985 SE 3800 Series 1 SC 4T60-E
1987 Coupe 3800 Series II Turbocharged 4T60-E
1987 SE 3.4 TDC 5-speed
1984 Coupe SBC V8 non-OD to 4T60 OD swap, electric power steering install
1985 SE 3800 Series II Supercharged 4T60-E

http://dtcc.cz28.com

Alot of people here mention forged pistons but no one mentions the only bad thing about them. Due to a forged piston expanding more than, say a cast piston, you have a lot of 'knock' when the motor is cold. Like running solid lifters over hydraulic, sure they are 'hi-performance' but who wants to listen to them 'tick-tick-tick'
So if you dont mind the noises you will hear then for sure run forged, its cheap insurance. please dont beat me up for abuse of the 'fingers in the air' LOL

Don't forget forged pistons also burn oil when the engine is cold.

I have heard of this issue but the new stuff that we find on the market today, you rarely have that problem. I have 3 friends running forged slugs in their turbo regals all have no noises on cold startup and running as you mentioned. but then again, they have all recently built their motors so they have the new technology pistons.

teflon coated skirts are our friends =)

A forged piston is better then a hypertected piston, and way better then a cast piston. I'm sure that the instructions that come with your rings will tell you to gap them more if your running nitrus or turbo. I have never heard of a forged piston expanding more then a cast piston, or burning oil when it's cold.

[This message has been edited by weldon (edited 08-15-2003).]

So just let the engine warm up before driving it much w/ forged pistons? lol. That's good! Does anyone know for shure if gapless rings can't run boost? I've seen gapless rings for STIs and EVOs, they run up to I think 12PSI. Can annyone confum this? How much boost do you think the 2.8 could hanlde with forged pistons and a fiero other streintheng engine parts? I know it can handle 5or6PSI bone stock without much problem... Thx guys!

I will also stick with the Forged ones, the hypers are ok but it may not hold up to detonation as well as the forged ones.Some people run them without any problems, spent a little more get the right stuff.

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"Turbo Cars are like hot women. A little edgy, every guy wants one, some guys can't handle them, and if you throw a little alchohol in the mix they'll rock your world"
1986 GT (waiting for Buick GN setup trasplant)
1984SE 5 Speed W/SBC V8
1987 Buick GN(10.70@124MPH)
1987 Trans Am SBC 355cid Twin Turbo(no track times yet)
1992 GMC Typhoon(13.20@ 99mph)
Other cars; JaguarXJ6 & Mercedes AMG 500SEC

Darth Fiero has covered this very well. I couldn't have said it better myself. Forged pistons have come a long way and they really are superior to any of the other choices especially as far as boost is concerned. Even in a mild boosted application you can have detenation. Hyper pistons tend to shatter where as forged tend to "dent" or give. A shattered piston = bye bye engine.
Now certainly it would take a good knock for that to happen but when you're putting together a boosted Fiero there's bound to be a lot of tuning and your A/F ratio is bound to be off at first until this tuning is complete so it would be a lot wiser to go with the protection and safety of the forged.
Just my .02 though.

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