Why can't we turbocharge a 3s-ge?, Compression ratio related Options

[dudeofchaos]

I know that the 3s-ge engine has a higher compression ratio than the 3s-gte (which I guess means that the pistons' head are thiner right?), but what does it change so that we can't (or shall not) turbocharge the 3s-ge?
Is it because it would (I don't know) be too much compressed exhaust gases for the turbo to hold?

BTW: what does the last number in the compression ratio mean? (Like in 10:3:1)

This post has been edited by dudeofchaos: Jun 26, 2011 - 10:51 PM

[Rusty]

found some info on an altezza forum

Other notes:
Retard Timing about 1 degree per PSI of boost.
2JZGTE Pistons will fit with slight machining to the piston skirt for oil squirters, factory 3SGE rings will fit the 2JZ Pistons. 3SGTE rods fit the 2JZ pistons with machining work.
3SGTE rods will bolt up to 3SGE pistons and 3SGE crank, they are stronger than factory 3SGE rods.
Compression with 2JZGTE pistons and stock headgasket is 9.6:1 which is perfect for good response SAAB boost.
Compression with 3SGTE 3rd Gen pistons is 11.2:1. Not the ideal setup.

Turbo Feeds:
Turbo oil feed can be tapped from one of the 3 bungs near the oil filter. This is direct oil pressure so use a 1mm restrictor if using a ball bearing based turbo. With journal bearing turbo's this is less of a problem.
Turbo oil return should be pressure free and as vertical as possible, the return from the turbo can be tapped into the rubber pipe running from the rear of the head on the passanger side down to the block. It will be hidden by a metal plate which can be removed.
Water feeds can be tapped from almost anywhere, a good choice would be the oil cooler on the side of the block under the manifold. Simply tap the outlet to the turbo and then back into the block.

looking at some dyno figures
275.9kW @ 18psi (though it was dyno in the wrong gear)
270.5KW @ 13.6psi
'could' be the most power you can get out of a blacktop/redtop(maybe?) BEAMS turbo with vvti and lack of aftermarket camshafts to suit situation.

[3WayStunna]

found some info on an altezza forum

Other notes:
Retard Timing about 1 degree per PSI of boost.
2JZGTE Pistons will fit with slight machining to the piston skirt for oil squirters, factory 3SGE rings will fit the 2JZ Pistons. 3SGTE rods fit the 2JZ pistons with machining work.
3SGTE rods will bolt up to 3SGE pistons and 3SGE crank, they are stronger than factory 3SGE rods.
Compression with 2JZGTE pistons and stock headgasket is 9.6:1 which is perfect for good response SAAB boost.
Compression with 3SGTE 3rd Gen pistons is 11.2:1. Not the ideal setup.

Turbo Feeds:
Turbo oil feed can be tapped from one of the 3 bungs near the oil filter. This is direct oil pressure so use a 1mm restrictor if using a ball bearing based turbo. With journal bearing turbo's this is less of a problem.
Turbo oil return should be pressure free and as vertical as possible, the return from the turbo can be tapped into the rubber pipe running from the rear of the head on the passanger side down to the block. It will be hidden by a metal plate which can be removed.
Water feeds can be tapped from almost anywhere, a good choice would be the oil cooler on the side of the block under the manifold. Simply tap the outlet to the turbo and then back into the block.

looking at some dyno figures
275.9kW @ 18psi (though it was dyno in the wrong gear)
270.5KW @ 13.6psi
'could' be the most power you can get out of a blacktop/redtop(maybe?) BEAMS turbo with vvti and lack of aftermarket camshafts to suit situation.

One thing i was curious about, is if all 3rd gens share the same blocks, shouldnt there already be "bungs" of some sort on the block itself that can be used? If not then i can completly see where tapping the new spots would be ncessary...

Amazing thing, i am reading through the same thread. Long as hell, but very imformative. Alot of talk about the use of 3sgte pistons and how (with certain headgasket thickneses) it would affect compression...will also say that this applied to the blacktop beams engine.

Some info about the redtop though, is that supposedly it shares the same rods and the st215 which would mean they are just as weak???

Also was also able to take out the TODA cams selection for the blacktop beams app.
http://www.toda-racing.co.jp/en/product/cam/3sgs-1.html

Also dumping bits of info for someone to possbily use...
general 3s information that applies to all 3sg cylinder heads

Capacity 1,998 cc (121.93 cu in)
Bore x Stroke 86 mm (3.39 in) x 86 mm (3.39 in)
Intake Valve Diameter 33.5 mm (1.32 in)
Exhaust Valve Diameter 29.0 mm (1.14 in)
Included Valve Angle 44.5 °