Forged Pistons

[SilverSpear]

For some guys over here these questions may look a bit silly, but what is the exact difference between ordinary and forged pistons? are the SVX's pistons forged by nature? and what pistons can somehow fit the SVX (exactly fit or by customization) (for example the Impreza, legacy, or another brand car...). can the SVX's current internals handle a Turbo without forged pistons?

[svxfiles]

The svx's pistons are vacuum cast. Its the next best thing to forged.
The 2.2 litre Subarus have the same diameter, but I'm not certain that they do switch.
There are a couple of turbo svxi out there allready.
With the supercharging being done now, we will all know soon how well the 3.3 will hold up.

[SVXRide]

Danny,
The issue is going to be more one of compression ration versus lbs of boost. My guess is that the stock engine will handle 5-10 lbs of boost and still hold together.
-Bill

[SVXer95]

Casting: Molten material is poured into a mold, basic form is made, only finishing required.

Forging: Billet is forged (shaped) into form required by design. Finishing also needed.

Which is better? It is arguable and depends on the type of casting. Both methods have pluses and minuses. Some say that Hyper-eutectic cast pistons are better or just as strong as forged.

[SilverSpear]

Originally posted by svxfiles
The svx's pistons are vacuum cast. Its the next best thing to forged.
The 2.2 litre Subarus have the same diameter, but I'm not certain that they do switch.
There are a couple of turbo svxi out there allready.
With the supercharging being done now, we will all know soon how well the 3.3 will hold up.

aha, the 2.2 L subarus turbo are forged, right? why don't we switch them with the SVX's, find a way to lower the compression to 9.0:1 or 9.5:1 and plug a hardcore Garrett turbo ? doable ? pls comments

[UberRoo]

Since when were custom pistons expensive? Why not just go that route? Have you priced Subaru pistons?

Frankly, I think pushing the limits on a stock bottom end is foolish. The whole bottom end needs to be replaced with components that are known to be up to the job. There's no way to know what the stock guts are good for without testing them to yield. The only way to do this is to blow up an engine. Who wants to be first? ...actually, you'd have to murder several engines to get a good idea what the weakest link is, then you'd have to replace those parts and find out which link is next. Not cheap, and not fun.

To me, a couple grand spend on custom rods and pistons is money well spent. It's simply not worth screwing around with the questionable guesswork on factory parts, let alone the possible consequences of guessing wrong. Besides, a built bottom end should be good for a few hundred more horsepower. Why stop at 300 ponies?


...but more directly to the problem or question at hand, burning a piston usually isn't instant death. Throwing a rod is. I'd worry about the rods first, and the pistons last.

[SilverSpear]

Originally posted by UberRoo
Since when were custom pistons expensive? Why not just go that route? Have you priced Subaru pistons?

Frankly, I think pushing the limits on a stock bottom end is foolish. The whole bottom end needs to be replaced with components that are known to be up to the job. There's no way to know what the stock guts are good for without testing them to yield. The only way to do this is to blow up an engine. Who wants to be first? ...actually, you'd have to murder several engines to get a good idea what the weakest link is, then you'd have to replace those parts and find out which link is next. Not cheap, and not fun.

To me, a couple grand spend on custom rods and pistons is money well spent. It's simply not worth screwing around with the questionable guesswork on factory parts, let alone the possible consequences of guessing wrong. Besides, a built bottom end should be good for a few hundred more horsepower. Why stop at 300 ponies?


...but more directly to the problem or question at hand, burning a piston usually isn't instant death. Throwing a rod is. I'd worry about the rods first, and the pistons last.

I will stop at 300 ponies. the guys over here are talking about 350-450-2200 hp!!! I wanna be here when they realize those figures without finding a tranny able to handle them. tuning the SVX engine isn't a problem for me. over here the tuners are excellent, I am not worrying about them or tuning the engine, but I wanna know what turbo legacy/impreza parts do fit the SVX in order to tune it right. I wish I had a spare engine I can do research on, but USED SVX parts over here DO NOT EXIST... tuning this engine over here along with a new Garrett turbo will not cost me more than a couple of grands...

[SVXRide]

Danny,
300hp should be obtainable without having to touch the bottom end or - I might venture - the pistons. We can get there right now with NO2 - in limited duration - without breaking anything. We're talking roughly a 30% increase, which should be possible with a combination of better cams (higher lift - see current thread on the topic), larger injectors (LAN's Stage 3 effort), ram air (larger airbox), less restrictive exhaust (keep the stock exhaust manifolds, get rid of the primary cats, keep a single high flow cat if you have to pass emissions, and run a single 2.5 inch pipe all the way back with maybe (?) just a high flow resonator in the line - okay, this may be too loud ), and a Stage 1 + chip set from ECUTune (I'm hypothosizing here, that Michael would be will to further "tweak" the current v4 code). This would - hopefully - result in around 230hp at the wheels.
-Bill ("bench racing at its best" )

[SilverSpear]

Originally posted by SVXRide
Danny,
300hp should be obtainable without having to touch the bottom end or - I might venture - the pistons. We can get there right now with NO2 - in limited duration - without breaking anything. We're talking roughly a 30% increase, which should be possible with a combination of better cams (higher lift - see current thread on the topic), larger injectors (LAN's Stage 3 effort), ram air (larger airbox), less restrictive exhaust (keep the stock exhaust manifolds, get rid of the primary cats, keep a single high flow cat if you have to pass emissions, and run a single 2.5 inch pipe all the way back with maybe (?) just a high flow resonator in the line - okay, this may be too loud ), and a Stage 1 + chip set from ECUTune (I'm hypothosizing here, that Michael would be will to further "tweak" the current v4 code). This would - hopefully - result in around 230hp at the wheels.
-Bill ("bench racing at its best" )

Over here we don't have very large roads to be racing with NO2, I just wanna car with enough torque and Hp just to beat cars like the imprezas and 3000GT's. what i mean to say is that i don't want a system like opening bottles and pushing buttons to race cars. Our country is rocky in nature and 90% of it is made of mountains and curves. opening nitros on a curve could throw me against a wall or something...

[SilverSpear]

anyway what other parts (engine) of the Legacy 2.2 L can fitour EG33 ? pls help me out, I can modify the engine over here to stand a turbo very easily if I knew what parts are interchangeable with the EG33.

[SVXRide]

Originally posted by SilverSpear


Over here we don't have very large roads to be racing with NO2, I just wanna car with enough torque and Hp just to beat cars like the imprezas and 3000GT's. what i mean to say is that i don't want a system like opening bottles and pushing buttons to race cars. Our country is rocky in nature and 90% of it is made of mountains and curves. opening nitros on a curve could throw me against a wall or something...

Danny,
Everything in my previous post should help out with bottom end torque - especially if you keep the exhaust pipe ID at 2.5 or less. We definitely don't want you - or your car - thrown up against a wall!
-Bill

[SilverSpear]

my point is that I want to find a DEFINITE way to deal with the engine, not stuff like NO2 and something... anyway thank you for everything and what was the threads name?

[SVXRide]

Originally posted by SilverSpear
my point is that I want to find a DEFINITE way to deal with the engine, not stuff like NO2 and something... anyway thank you for everything and what was the threads name?

Danny,
I think we might be having a language problem here
Let me try again...If you want to get to around 300hp at the engine, you could do the following "definite" things:

1. High flow "Green" drop in air filter
2. Remove the intake resonator in the passenger side front wheel well and run 3 to 4 inch ID flex line to a point below the front bumper to create a true "ram air" system.
3. Fabricate a larger air box and "Green" air filter to go with the ram air system
4. Remove the two main cat converters and replace the exhaust system behind the stock exhaust manifolds with a 2.5 inch ID system (connect the single pipe from each manifold at a "Y" connection and run a single pipe back to either a high flow resonator or a "cherry bomb" muffler - whatever works for you sound wise.
5. Install one of ECUTune's Stage 1 v4 chips in your ECU
6. Remove the belt from the AC compressor

Now for the more involved stuff

7. Add an MSD Stacker box to increase the efficiency of the combustion
8. Replace the injectors with NISMO pieces (see LAN's Stage 3 thread)
9. Replace the intake and exhaust cams with higher lift pieces (currently don't exist - several SVX owners have volunteered to figure out how much lift the engine can handle before we lose the "non-interference" nature of the engine.

Hope this is clearer.
-Bill

[Chiketkd]

Originally posted by SVXRide
Danny,
I think we might be having a language problem here
Let me try again...If you want to get to around 300hp at the engine, you could do the following "definite" things:

1. High flow "Green" drop in air filter
2. Remove the intake resonator in the passenger side front wheel well and run 3 to 4 inch ID flex line to a point below the front bumper to create a true "ram air" system.
3. Fabricate a larger air box and "Green" air filter to go with the ram air system
4. Remove the two main cat converters and replace the exhaust system behind the stock exhaust manifolds with a 2.5 inch ID system (connect the single pipe from each manifold at a "Y" connection and run a single pipe back to either a high flow resonator or a "cherry bomb" muffler - whatever works for you sound wise.
5. Install one of ECUTune's Stage 1 v4 chips in your ECU
6. Remove the belt from the AC compressor

Now for the more involved stuff

7. Add an MSD Stacker box to increase the efficiency of the combustion
8. Replace the injectors with NISMO pieces (see LAN's Stage 3 thread)
9. Replace the intake and exhaust cams with higher lift pieces (currently don't exist - several SVX owners have volunteered to figure out how much lift the engine can handle before we lose the "non-interference" nature of the engine.

Hope this is clearer.
-Bill

That's a good list of mods Bill. Only thing I'd add would be the 1/4" thick phenolic spacers.

-Chike

[SilverSpear]

Originally posted by SVXRide


Danny,
I think we might be having a language problem here
Let me try again...If you want to get to around 300hp at the engine, you could do the following "definite" things:

1. High flow "Green" drop in air filter
2. Remove the intake resonator in the passenger side front wheel well and run 3 to 4 inch ID flex line to a point below the front bumper to create a true "ram air" system.
3. Fabricate a larger air box and "Green" air filter to go with the ram air system
4. Remove the two main cat converters and replace the exhaust system behind the stock exhaust manifolds with a 2.5 inch ID system (connect the single pipe from each manifold at a "Y" connection and run a single pipe back to either a high flow resonator or a "cherry bomb" muffler - whatever works for you sound wise.
5. Install one of ECUTune's Stage 1 v4 chips in your ECU
6. Remove the belt from the AC compressor

Now for the more involved stuff

7. Add an MSD Stacker box to increase the efficiency of the combustion
8. Replace the injectors with NISMO pieces (see LAN's Stage 3 thread)
9. Replace the intake and exhaust cams with higher lift pieces (currently don't exist - several SVX owners have volunteered to figure out how much lift the engine can handle before we lose the "non-interference" nature of the engine.

Hope this is clearer.
-Bill

I have already done steps 1 to 4. step 5 is on its way. step 6 definitely currently not. step 7 did not UNDERSTAND (EXCUSE MY STUPIDITY). step 8 = very high fuel consumption !!! 555 cc injectors ? what about the thing with dual intake and dual green drops ??? If feasible I would do it ! and step 9 lets just wait and see if anyone will do it.

thank you again Ride !