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Lower Compression or Forged?

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Old 09-16-2009, 11:27 PM
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Default Lower Compression or Forged?

So I have a 95 LT1 Camaro. It's a stock engine but has a Vortech V1 running 5 lbs of boost. I want to raise it so I need to do some engine work, right? So in order to raise the boost do I need to get forged internals or can I just lower the compression and I will be fine? Would like to know. Thanks!
Old 09-16-2009, 11:46 PM
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How much would you like to raise the boost to? I'm thinking 8max if you keep the stock internals AND get a very solid tune AND run a good intercooler or Vortech Aftercooler. Those have hypereutectic pistons which are pretty strong but will SHATTER if you let the engine ping or detonate with a poor tune. Adding a meth injection system would be great insurance. If you want to go higher I would drop compression to aroun 9.5:1 and add forged pistons and great rod bolts.

Sounds nice!

Jim
Old 09-16-2009, 11:54 PM
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Originally Posted by DeltaT
How much would you like to raise the boost to? I'm thinking 8max if you keep the stock internals AND get a very solid tune AND run a good intercooler or Vortech Aftercooler. Those have hypereutectic pistons which are pretty strong but will SHATTER if you let the engine ping or detonate with a poor tune. Adding a meth injection system would be great insurance. If you want to go higher I would drop compression to aroun 9.5:1 and add forged pistons and great rod bolts.

Sounds nice!

Jim
Oh ya and I have meth injection too. However, I don't have an intercooler yet but we are working on that. I don't know how much more boost. Maybe 10 lbs. And I thought if you lower the compression then you are good. I found this stoker kit and I was wondering if I get the dish pistons will I be able to raise the boost up and if so how much? I can't afford forged pistons because they are very pricey so I need something cheap. I am on a SUPER tight budget. Thanks!
Old 09-17-2009, 12:48 AM
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If you lower the compression it gives you a bit more headroom for boost, but the 2 right ways to lower it are: a) Heads with bigger chambers or b) Dish pistons. Don't mess around with extra thick or double head gaskets because you ruind your quench (or squish) are between your piston and head and can end up with worse detonation than before.

And if you ping even once with a hyper piston, it can break into maybe 40 pieces. Not fun to recover from.

The stroker kit would be a fine option. With a Vortech S-trim on my 383 SBC, I put down 501rwhp and 469rwt at ~7.8# of boost after the intercooler and with 50 lb. injectors.

Now with the T-trim upgrade it is hitting 660rwhp...

Jim
Old 09-17-2009, 12:57 AM
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Originally Posted by DeltaT
If you lower the compression it gives you a bit more headroom for boost, but the 2 right ways to lower it are: a) Heads with bigger chambers or b) Dish pistons. Don't mess around with extra thick or double head gaskets because you ruind your quench (or squish) are between your piston and head and can end up with worse detonation than before.

And if you ping even once with a hyper piston, it can break into maybe 40 pieces. Not fun to recover from.

The stroker kit would be a fine option. With a Vortech S-trim on my 383 SBC, I put down 501rwhp and 469rwt at ~7.8# of boost after the intercooler and with 50 lb. injectors.

Now with the T-trim upgrade it is hitting 660rwhp...

Jim
So you are saying that with dish pistons I should be fine at like 8 lbs of boost? Thanks!
Old 09-17-2009, 05:28 AM
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Once the engine is apart and machine cost, etc, are accounted for, the cost difference between cheap and forged pistons becomes a mute point. I take it you are thinking of replacing the rings and pistons without doing any machine work, as you mentioned money is tight and you don't want to have to pay for forged pistons. I highly recommend leaving the short block the way it is, if money is tight.
I would add an intercooler to your car, and raise the boost up to 8-9 psi on the engine the way it is, and get a good tune. Check out my brother's '95 Formula at this link, which has had a ProCharger P-1SC on it since '02, on the stock bottom end.
http://www.exoticperformanceplus.com...tCar.php?car=7 Bob
Old 09-17-2009, 02:20 PM
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okay I am curious on the compression thing also. Say he does lower his compression with some heads would he be able to run higher boost levels safer than stock without breaking things?
Old 09-17-2009, 02:54 PM
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Originally Posted by The Fugitive
okay I am curious on the compression thing also. Say he does lower his compression with some heads would he be able to run higher boost levels safer than stock without breaking things?
in theory he will beable to run more psi, but lowering compression does not gurantee that it will not break. still on cast pistons and rings
Old 09-17-2009, 04:51 PM
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And if you lower it too much, a 350 will be a dog off-boost. A 383 would be better - the extra displacement will make it feel less soggy. I wouldn't go lower than 9:1 in a 350.

Jim
Old 09-17-2009, 07:20 PM
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Oh ok then. So lets say I wanted to go forged. What kind of pistons and what ever else I need. How much would it cost?
Old 09-18-2009, 01:48 AM
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That stroker kit you posted the link for had pistons included. If you only do pistons you will need pistons, rings, pins, retainers and rod bolts, plus perhaps a rebalance unless you can get pistons very similar in weight to the ones you are replacing. Ask the sponsors here or check one of the online supplier houses.

Jim



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