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

[Edophus]

the st205 blocks were revised at some point due to wall thickness, later blocks will be similar to the beams blocks, seen plenty of early blocks split a cylinder wall as soon as the boost is increased.

for the blacktop exhaust controller simply removing the cam cover wont work, even in the st182 the clearence is minimal, pretty sure its impossible in a st20x without doing something with the engine mount, or dropping the exhaust vvti, i never tried it myself, i just had a look and thought no way..

vvti on the beams has nothing to do with manifold pressure, the vvti controller is driven by the ecu alone, and the beams dont even have a map sensor to read manifold pressure, it will alter the valve angle to whatever you set in the ecu tables.

I believe although i've never seen it done myself you can actually fit a beams head on a 3s-gte block and it'll work (not sure how true that is), but your compression ratio will be over 12:1 or something like that, the beams has a smaller combustion chamber than previous 3s engines.

you'd really need a programmable ecu for a boosted beams, if you were hybriding an earlier 3s-ge using 3s-gte parts you can use a 3s-gte ecu, but for a beams turbo your really going to need to either run very little boost something like 5psi at most or go aftermarket. Anyway redtop beams wiring is sooo easy, much easier to deal with than older 3s engines, blacktop beams however is a nightmare lol.

I dont think you can mix and match sump parts, i would think you need to use a complete sump be it in two parts or one, from the same engine along with the appropriate oil pump as they will match up.

I can check some of these things if you guys have questions as I have at the moment a rev 2 3s-gte, and a beams blacktop that i've converted to redtop in the garage at the moment, i dont have the blacktop sump or intake manifold anymore though, and i've got a rev 3 3s-gte in my st205 to compare. I also keep a bare blacktop head for measuring purposes.

This post has been edited by Edophus: Jul 23, 2011 - 6:43 AM

[delusionz]

the st205 blocks were revised at some point due to wall thickness, later blocks will be similar to the beams blocks, seen plenty of early blocks split a cylinder wall as soon as the boost is increased.

for the blacktop exhaust controller simply removing the cam cover wont work, even in the st182 the clearence is minimal, pretty sure its impossible in a st20x without doing something with the engine mount, or dropping the exhaust vvti, i never tried it myself, i just had a look and thought no way..

vvti on the beams has nothing to do with manifold pressure, the vvti controller is driven by the ecu alone, and the beams dont even have a map sensor to read manifold pressure, it will alter the valve angle to whatever you set in the ecu tables.

I believe although i've never seen it done myself you can actually fit a beams head on a 3s-gte block and it'll work (not sure how true that is), but your compression ratio will be over 12:1 or something like that, the beams has a smaller combustion chamber than previous 3s engines.

you'd really need a programmable ecu for a boosted beams, if you were hybriding an earlier 3s-ge using 3s-gte parts you can use a 3s-gte ecu, but for a beams turbo your really going to need to either run very little boost something like 5psi at most or go aftermarket. Anyway redtop beams wiring is sooo easy, much easier to deal with than older 3s engines, blacktop beams however is a nightmare lol.

I dont think you can mix and match sump parts, i would think you need to use a complete sump be it in two parts or one, from the same engine along with the appropriate oil pump as they will match up.

I can check some of these things if you guys have questions as I have at the moment a rev 2 3s-gte, and a beams blacktop that i've converted to redtop in the garage at the moment, i dont have the blacktop sump or intake manifold anymore though, and i've got a rev 3 3s-gte in my st205 to compare.

boost pressure could be a good way of continuous vvti triggering provided my understanding is correct that it's a one shot operation, small cam to big cam as opposed to a true continuously variable system that gradually increases profile

sump parts fit fine with some extra drilling and tapping...

[Edophus]

boost pressure could be a good way of continuous vvti triggering provided my understanding is correct that it's a one shot operation, small cam to big cam as opposed to a true continuously variable system that gradually increases profile

sump parts fit fine with some extra drilling and tapping...

yeah the sump parts can be modified to fit for sure with some metal work, i have seen a rev 3 sump modified to fit a rev 5 oil pump, wasnt pretty though lol but worked and probably better than using a blacktop sump because the oilpickup will be in the right place for transverse, personally i would just use the right sump for whatever i was doing though, so if using a beams oil pump use a redtop sump, its already the perfect fit for a 6th gen, and if using a 3s-gte oil pump use a rev 3 3s-gte sump.

the vvti on the beams isnt a one shot like the older vvt on the 4age engines, the ecu adjusts the cam phasing from 0rpm to the limiter depending on various things, i'm not sure what they all are cause you cant access the ecu, but from memory when i used the power-fc and the from the other ecu's i've looked at its i think by rpm and load, you just set a value which is the advance or retard of the cam relative to the crankshaft, so you just set it and the ecu controls the solenoid that feeds the oil pressure to the cam controller, so its whatever you set in the ecu, and unnaffected by things like boost pressure.