Do sti's have forged pistons as standard?
07 February 2008, 06:47 PM
#31
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I can buy some nice drop forged tools, doesnt make them as strong as other forged items, hence the word "forged" being quoted, ie forged does not mean its as strong as another forged item (because there are different methods of forging).
Tony
Tony
07 February 2008, 07:32 PM
#33
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forged an heres me thinking there not the real thing like forged pound notes doh lol only kidding
07 February 2008, 07:40 PM
#34
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bttt
07 February 2008, 08:02 PM
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Can you please clarify exactly how you believe the STI forged pistons are inferior to any other forged piston?
07 February 2008, 08:06 PM
#36
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bttt
i have no clue to the ins and outs but im interested in the whole topic of forged pistons etc
07 February 2008, 08:10 PM
#37
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Pretty much yes. The standard forged pistons are very good indeed. But when rebuilding a 60,000 mile engine (which we do a lot of) there is little point putting standard sized pistons in, when the bore is 4 thou oval. So you're faced with oversized pistons, and STI units are in the region of £800 for a set without rings. For that sort of money you can buy any number of alternative pistons, hence STI pistons in rebuilds are few and far between.
07 February 2008, 10:45 PM
#38
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Cheers for all the replies boys.
Not wanting to start a lancer vs impreza fight here, but one of the reasons i was asking about the sti (mainly v1-7) having forged pistons, is that a lancer of similar age WITHOUT forged pistons can be tuned to roughly 350-400 without too many problems, whereas the stis can also be tuned to roughly 350-400 but it already has forged pistons. Which is why Mr Burns may actually have a point. Pop some forged items into a lancer and your looking at 500..... I assume, pop some aftermarket forged items into a subaru and youre also looking at circa 500 bhp....
Btw, the stis dont have forged conrods do they????
mike
Not wanting to start a lancer vs impreza fight here, but one of the reasons i was asking about the sti (mainly v1-7) having forged pistons, is that a lancer of similar age WITHOUT forged pistons can be tuned to roughly 350-400 without too many problems, whereas the stis can also be tuned to roughly 350-400 but it already has forged pistons. Which is why Mr Burns may actually have a point. Pop some forged items into a lancer and your looking at 500..... I assume, pop some aftermarket forged items into a subaru and youre also looking at circa 500 bhp....
Btw, the stis dont have forged conrods do they????
mike
08 February 2008, 01:48 AM
#40
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i guess conrods seem to be the weak link in most high power engines. As long as an engine is running right (not rich or lean) then the pistons can take some big power, just a waiting game for the conrods to go snap 
kinda strange matching up 500hp pistons with 350 horsepower rods, but hey
cheers guys
08 February 2008, 06:51 AM
#41
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does not mean that the item made will be as strong as any other forged metal.
For instance, you can forge cast iron, you can forge mild steel, you can
forge alloy's, but which one is the best?
The material used denotes the strength of the item, not the fact that its
"forged", hence you get cast items that are stronger than the "forged"
pistons in STi's.
Tony
08 February 2008, 09:40 AM
#42
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Forging is only a method of manufacturing, you can forge any metal but that
does not mean that the item made will be as strong as any other forged metal.
For instance, you can forge cast iron, you can forge mild steel, you can
forge alloy's, but which one is the best?
The material used denotes the strength of the item, not the fact that its
"forged", hence you get cast items that are stronger than the "forged"
pistons in STi's.
Tony
does not mean that the item made will be as strong as any other forged metal.
For instance, you can forge cast iron, you can forge mild steel, you can
forge alloy's, but which one is the best?
The material used denotes the strength of the item, not the fact that its
"forged", hence you get cast items that are stronger than the "forged"
pistons in STi's.
Tony
If you have some real facts by all means share them.
08 February 2008, 10:23 AM
#44
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Well I'm just going to have to call BS on that one. While the alloy used in subaru's hyperspastic pistons may in fact be classed as stronger, we know it breaks much more easily. Toughness is not a strong suit of high silicone casting alloys. The whole point of forging is it allows you to use stronger alloys that are not inherently castable. You get finer grain structure, lower percentage of voids, and a flowing grain structure.
If you have some real facts by all means share them.
If you have some real facts by all means share them.
also can depend on if its hot forged or cold forged.
do you happene to know if theres a typical form of forging used for pistons or is it dependant on which company makes them?
08 February 2008, 04:41 PM
#46
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All this "moaning" !
They are only suppoesed to "cope" with 330 bhp...
The rest is a bonus....
Here comes 400 please.... (V7)
DunxC
They are only suppoesed to "cope" with 330 bhp...
The rest is a bonus....
Here comes 400 please.... (V7)
DunxC
10 February 2008, 02:03 PM
#47
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11 February 2008, 11:35 PM
#49
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otherwise we may have been able to push our 504hp(race fuel) record a little further
Last edited by GRD; 11 February 2008 at 11:37 PM.
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